Open Collections

UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Geochemistry of a buried marine mine tailings deposit, Howe Sound, British Columbia Drysdale, Karen 1990

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Item Metadata

Download

Media
831-UBC_1990_A6_7 D79.pdf [ 16.93MB ]
Metadata
JSON: 831-1.0053297.json
JSON-LD: 831-1.0053297-ld.json
RDF/XML (Pretty): 831-1.0053297-rdf.xml
RDF/JSON: 831-1.0053297-rdf.json
Turtle: 831-1.0053297-turtle.txt
N-Triples: 831-1.0053297-rdf-ntriples.txt
Original Record: 831-1.0053297-source.json
Full Text
831-1.0053297-fulltext.txt
Citation
831-1.0053297.ris

Full Text

GEOCHEMISTRY OF A BURIED MARINE MINE TAILINGS DEPOS HOWE SOUND, BRITISH COLUMBIA by Karen Drysdale B.A. U n i v e r s i t y of Colorado, 1971 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE i n THE FACULTY OF GRADUATE STUDIES Oceanography We accept t h i s t h e s i s as conforming to the re q u i r e d standard THE UNIVERSITY OF BRITISH COLUMBIA September, 1990 © KAREN DRYSDALE, 1990 In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. The University of British Columbia Vancouver, Canada Department of DE-6 (2/88) ABSTRACT One hundred surface sediment samples and two 30 cm cores were c o l l e c t e d from Howe Sound, B r i t i s h Columbia, a deep (=280 m) f j o r d with a r e s t r i c t e d inner basin i n t o which mine t a i l i n g s had been dumped for 75 years. The abundances of major elements S i , A l , T i , Fe, Mg, Ca, Na, K, C, N, and P, and minor elements Ba, Co, Cr, Cu, Mn, Ni, Pb, Rb, Sr, V, Y, Zn, and Zr were determined as well as nutrient and trace metal concentrations i n porewater from the two cores. The solid-phase data suggest that the inner basin sediments are dominated by Squamish River-derived feldspars, while the outer basin i s characterized more by quartz and Fe and Mg minerals, which enter the southernmost portion of the f j o r d v i a estuarine c i r c u l a t i o n from Georgia S t r a i t . Although Fe, Cu, Pb, Zn, and Ba are s t i l l enriched i n sediments near the t a i l i n g s o u t f a l l , the lapse of 13 years since cessation of t a i l i n g s deposition has apparently resulted i n reduced metal l e v e l s throughout much of the rest of the i n l e t due to ongoing d i l u t i o n by natural sedimentation. P r o f i l e s of these metals with depth show that the t a i l i n g s deposit proper i s buried by =14 cm of natural sediment i n the deep c e n t r a l portion of the inner basin. Porewater analysis of the two cores revealed that active b a c t e r i a l remobilization of organic matter i s occurring at both locations; although the organic carbon content of the outer basin i s greater than that i n the inner basin, sulphate-reduction i s more intense i n the l a t t e r due to the higher sedimentation rate. Despite t h i s , dissolved sulphides were nearly absent i n porewaters, leading to the conclusion that authigenic p y r i t e p r e c i p i t a t i o n i s removing some of the dissolved Fe. Dissolved Cu and Zn are enriched i n s u r f i c i a l porewaters of both the outer and inner basins ( i . e . Cu = 215 and 132 nmol/L, respectively, and Zn = 32 pmol/L and 1.6 /jmol/L), but decrease r a p i d l y within the top 2-3 cm, suggestive of active removal by some mechanism. Dissolved Pb concentrations were low (<3 nmol/L) i n both cores, and d i d not show any surface enrichment. These data suggest that a strongly reducing environment such as i s found at depth i n natural sediments i n h i b i t s the release of some l a b i l e metals which may be contained within them. i i TABLE OF CONTENTS Page No. ABSTRACT i i LIST OF TABLES v LIST OF FIGURES v i ACKNOWLEDGMENTS X Chapter 1. INTRODUCTION 1.1 Out of Sight, Out of Mind 2 1.2 F l o r a , Fauna and Heavy Metals 12 1.3 The Physical Setting 19 1.4 C i r c u l a t i o n 27 1.5 Geology 1.5.1 The Squamish Drainage Basin 31 1.5.2 Britannia Creek Drainage Basin 34 1.5.3 Georgia S t r a i t Sediments 38 Chapter 2. MATERIALS AND METHODS 2.1 Core C o l l e c t i o n and Sampling Locations 41 2.2 Solid-phase Sediment Analyses 2.2.1 Major elements 44 2.2.2 Minor elements 45 2.2.3 X-Ray Fluorescence Spectrometry 4 6 2.2.4 Correction for Seasalt 55 2.2.5 C h l o r i n i t y Analysis 57 2.2.6 Total Carbon and Nitrogen Analysis 58 2.2.7 Inorganic Carbon 60 2.3 I n t e r s t i t i a l Water Analyses 2.3.1 Dissolved Phosphate 62 2.3.2 Dissoled Ammonia 63 2.3.3 Nit r a t e 65 2.3.4 Dissolved Sulphide 67 2.3.5 T i t r a t i o n A l k a l i n i t y 68 2.3.6 Sulphate 71 2.3.7 Dissolved Metals 2.3.7.1 Iron and Manganese 73 2.3.7.2 Copper, Zinc and Lead 7 5 Chapter 3. RESULTS AND DISCUSSION 3.1 Major Components 84 3.1.1 Seasalt 88 3.1.2 S i l i c o n and Aluminum 90 3.1.3 Titanium 97 3.1.4 Potassium, Sodium and Calcium 103 3.1.5 Iron and Magnesium 116 3.1.6 Organic Carbon and Nitrogen 125 3.1.7 Phosphorus 137 i i i TABLE OF CONTENTS (continued) Page No. 3.2 Geochemistry of Minor Elements 3.2.1 Introduction 149 3.2.2 Rubidium 152 3.2.3 Barium 159 3.2.4 Strontium 168 3.2.5 Cobalt, Chromium, Nickel & Vanadium 179 3.2.6 Yttrium 212 3.2.7 Manganese 218 3.2.8 Copper, Lead and Z i n c . 225 3.2.9 Zirconium 251 3.3 Porewater Chemistry 261 3.3.1 Dissolved Nutrients and A l k a l i n i t y 264 3.3.1.1 Ammonia and Phosphate 270 3.3.1.2 Sulphate 274 3.3.1.3 A l k a l i n i t y 275 3.3.2 Dissolved Metals 3.3.2.1 Manganese 278 3.3.2.2 Iron 281 3.3.2.3 Copper 284 3.3.2.4 Zinc 292 3.3.2.5 Lead 299 Chapter 4. SUMMARY AND CONCLUSIONS 304 BIBLIOGRAPHY 315 APPENDICES 332 iv LIST OF TABLES Page 1.1 Summary of r e d o x r e a c t i o n s w h i c h o c c u r w i t h d e p t h i n sediments 14 2.1 XRF i n s t r u m e n t c o n d i t i o n s f o r major elements 47 2.2 XRF i n s t r u m e n t c o n d i t i o n s f o r minor elements 48 2.3 XRF a n a l y t i c a l p r e c i s i o n f o r major e l e m e n t s 49 2.4 XRF a n a l y t i c a l p r e c i s i o n f o r minor e l e m e n t s 50 2.5 A c c u r a c y o f t h e m e a s u r i n g program f o r XRF a n a l y s i s o f major elements i n s u r f a c e sediment samples 51 2.6 A c c u r a c y o f t h e m e a s u r i n g program f o r XRF a n a l y s i s o f major elements i n c o r e samples 52 2.7 A c c u r a c y o f t h e m e a s u r i n g program f o r XRF a n a l y s i s o f minor e l e m e n t s i n s u r f a c e sediment samples 5 3 2.8 A c c u r a c y o f t h e m e a s u r i n g program f o r XRF a n a l y s i s o f minor elements i n c o r e samples 54 v LIST OF FIGURES Page Chapter 1 1.1 Study a r e a showing s u r f a c e sediment and c o r e l o c a t i o n s 7 1.2 D e t a i l o f t h e i n n e r b a s i n , Howe Sound 8 1.3 C r o s s - s e c t i o n o f Howe Sound 21 1.4 B a t h y m e t r i c map o f Howe sound 22 1.5 H y d r o l o g i c d a t a from s t a t i o n s HS 16-B and HS 64... 24 1.6 D i s s o l v e d oxygen l e v e l s i n upper b a s i n o v e r a 6-year p e r i o d 26 1.7 C u r r e n t regime i n Howe Sound 28 1.8 G e n e r a l s u r f a c e f l o w p a t t e r n f o r t h e i n n e r b a s i n 29 Chapter 2 2.1 S t a n d a r d c u r v e s f o r phosphate a n a l y s e s 64 2.2 S t a n d a r d c u r v e s f o r ammonia a n a l y s e s 66 2.3 S t a n d a r d c u r v e s f o r s u l p h i d e a n a l y s e s 69 Chapter 3 3.1 P e r c e n t s e a s a l t i n s u r f a c e sediments 89 3.2 Aluminum i n s u r f a c e sediments 91 3.3 S i l i c o n v s . aluminum i n s u r f a c e sediments 93 3.4 S i l i c o n : a l u m i n u m r a t i o i n s u r f a c e s e d i m e n t s 95 3.5 S i l i c o n : a l u m i n u m r a t i o v e r s u s o r g a n i c c a r b o n i n s u r f a c e sediments 96 3.6 Aluminum i n two sediment c o r e s 98 3.7 S i l i c o n t o aluminum r a t i o s i n sediment c o r e s 99 3.8 T i t a n i u m v s . aluminum i n s u r f a c e sediments 101 3.9 I r o n v s . t i t a n i u m i n s u r f a c e sediments 102 3.10 T i t a n i u m t o aluminum r a t i o s i n two Howe Sound sediment c o r e s 104 3.11 T i t a n i u m t o aluminum r a t i o s i n s u r f a c e s e d i m e n t s 105 3.12 P o t a s s i u m v e r s u s aluminum i n s u r f a c e s e d i m e n t s . . . 107 3.13 P o t a s s i u m t o aluminum r a t i o s i n Howe Sound s u r f a c e sediments 108 3.14 C a l c i u m t o aluminum r a t i o s i n s u r f a c e s e d i m e n t s 109 3.15 Sodium t o aluminum r a t i o s i n s u r f a c e s e d i m e n t s 110 3.16 Sodium t o p o t a s s i u m r a t i o s i n s u r f a c e s e d i m e n t s I l l 3.17 P o t a s s i u m t o aluminum r a t i o s i n sediment c o r e s . . . 113 3.18 Sodium t o aluminum r a t i o s i n two sediment c o r e s 114 3.19 C a l c i u m t o aluminum r a t i o s i n two sediment c o r e s 115 3.20 I r o n t o aluminum r a t i o s i n s u r f a c e s e d i m e n t s 118 3.21 Magnesium v s . i r o n i n s u r f a c e sediments 119 vi LIST OF FIGURES (cont'd! P a g e 3.22 Iron to magnesium r a t i o s i n surface sediments.... 120 3.23 Iron vs. potassium i n surface sediments 122 3.24 Magnesium to aluminum r a t i o s i n surface sediments . 123 3.25 Iron to aluminum r a t i o s i n two sediment cores.... 124 3.26 Magnesium to aluminum r a t i o s i n two sediment cores 126 3.27 Organic carbon i n surface sediments 127 3.28 Organic carbon to nitrogen r a t i o s i n surface sediments 131 3.29 Organic carbon i n two sediment cores 134 3.30 Organic carbon to nitrogen r a t i o s i n sediment cores 135 3.31 Phosphorus i n surface sediments 139 3.32 Phosphorus to aluminum r a t i o s i n surface sediments 140 3.33 Phosphorus vs. i r o n i n surface sediments 141 3.34 Phosphorus vs. silicon:aluminum r a t i o i n surface sediments 14 3 3.35 Phosphorus vs. magnesium i n surface sediments.... 144 3.36 Phosphorus vs. organic carbon i n surface sediments 145 3.37 Phosphorus i n two sediment cores 146 3.38 Organic carbon to phosphorus r a t i o s i n cores 147 3.39 Rubidium to aluminum r a t i o s i n surface sediments 153 3.4 0 Plot of rubidium vs. aluminum i n surface sediments 155 3.41 Rubidium vs. potassium i n surface sediments 156 3.42 Rubidium to aluminum i n sediment cores 158 3.4 3 Barium vs. aluminum i n surface sediments 160 3.44 Barium to aluminum r a t i o s i n surface sediments... 162 3.45 Barium vs. potassium i n surface sediments 163 3.46 Barium to potassium r a t i o s i n surface sediments 165 3.47 Barium i n sediment cores 166 3.48 Barium to aluminum r a t i o s i n sediment cores 167 3.49 Strontium vs. calcium i n surface sediments 169 3.50 Strontium vs. aluminum i n surface sediments 171 3.51 Carbonate carbon vs. strontium i n surface sediments 172 3.52 Strontium to aluminum r a t i o s i n surface sediments 173 3.53 Strontium to aluminum r a t i o s i n upper basin sediments 174 3.54 Strontium vs. rubidium i n surface sediments 176 3.55 Strontium:rubidium r a t i o vs. barium:rubidium r a t i o i n surface sediments 177 3.56 Strontium to aluminum r a t i o s i n sediment cores... 180 3.57 Strontium (ppm) i n sediment cores 181 v i i LIST OF FIGURES (cont'd) P a g e 3.58 C o b a l t t o aluminum r a t i o s i n s u r f a c e s e d i m e n t s . . . 183 3.59 C o b a l t v s . aluminum i n s u r f a c e s e d i m e n t s 185 3.60 C o b a l t t o aluminum r a t i o s i n sediment c o r e s 187 3.61 N i c k e l v s . chromium i n s u r f a c e s e d i m e n t s 188 3.62 Chromium t o aluminum d i s t r i b u t i o n i n s u r f a c e s e d i m e n t s 189 3.63 N i c k e l t o aluminum r a t i o s i n s u r f a c e s e d i m e n t s . . . 190 3.64 N i c k e l t o aluminum r a t i o s i n upper b a s i n s u r f a c e sediments 191 3.65 N i c k e l t o aluminum r a t i o s i n sediment c o r e s 192 3.66 Chromium v s . aluminum i n s u r f a c e s e d i m e n t s 194 3.67 N i c k e l v s . aluminum i n s u r f a c e s e d i m e n t s 195 3.68 Chromium v s . magnesium i n s u r f a c e s e d i m e n t s 196 3.69 Chromium v s . i r o n i n s u r f a c e s e d i m e n t s 197 3.70 N i c k e l v s . magnesium i n s u r f a c e s e d i m e n t s 198 3.71 N i c k e l v s . i r o n i n s u r f a c e s e d i m e n t s 199 3.72 Chromium t o magnesium r a t i o v s . o r g a n i c c a r b o n i n s u r f a c e sediments 201 3.73 Chromium:iron r a t i o s v s . o r g a n i c c a r b o n i n s u r f a c e sediments 202 3.74 N i c k e l : i r o n r a t i o v s . o r g a n i c c a r b o n i n s u r f a c e sediments 203 3.75 N i c k e l : m a g n e s i u m r a t i o v s . o r g a n i c c a r b o n i n s u r f a c e sediments 204 3.7 6 Chromium t o aluminum r a t i o i n sediment c o r e s 205 3.77 N i c k e l : a l u m i n u m r a t i o s i n sediment c o r e s 206 3.7 8 Vanadium t o aluminum r a t i o i n s u r f a c e s e d i m e n t s 208 3.7 9 Vanadium t o aluminum r a t i o s i n s u r f a c e s e diments o f i n n e r b a s i n , Howe Sound 209 3.80 Vanadium v s . aluminum i n s u r f a c e s e d i m e n t s 210 3.81 Vanadium v s . i r o n i n s u r f a c e s e d i m e n t s 211 3.82 Vanadium v s . n i c k e l i n s u r f a c e s e d i m e n t s 213 3.83 V a n a d i u m : i r o n r a t i o v s . o r g a n i c c a r b o n i n s u r f a c e s ediments 214 3.84 Vanadium t o aluminum r a t i o i n sediment c o r e s 215 3.85 Y t t r i u m t o aluminum r a t i o s i n s u r f a c e s e d i m e n t s 217 3.86 Y t t r i u m v s . c a l c i u m i n s u r f a c e s e d i m e n t s 219 3.87 Y t t r i u m v s . phosphorus i n s u r f a c e s ediments 220 3.88 Y t t r i u m t o aluminum r a t i o s i n sediment c o r e s 221 3.89 Manganese t o aluminum r a t i o s i n sediment c o r e s . . . 224 3.90 Copper (ppm) i n s u r f a c e s e d i m e n t s 229 3.91 Copper (ppm) i n s u r f a c e s e d i m e n t s o f i n n e r b a s i n 230 3.92 Copper t o aluminum r a t i o s i n sediment c o r e s 232 3.93 Z i n c v s . aluminum i n s u r f a c e s e d i m e n t s 233 3.94 Z i n c v s . i r o n i n s u r f a c e s e d i m e n t s 234 3.95 Z i n c (ppm) i n s u r f a c e s e d i m e n t s 236 3.96 Z i n c (ppm) i n s u r f a c e s e d i m e n t s o f i n n e r b a s i n . . . 237 vi i i LIST OF FIGURES (cont'd) Page 3.97 Zinc to aluminum r a t i o i n sediment cores 238 3.98 Lead vs. aluminum i n surface sediments 2 39 3.99 Lead vs. potassium i n surface sediments 240 3.100 Lead vs. copper i n surface sediments 242 3.101 Lead vs. zinc i n surface sediments 243 3.102 Lead to aluminum r a t i o s i n surface sediments.... 244 3.103 Lead to aluminum r a t i o s i n surace sediments of inner basin 245 3.104 Copper:magnesium r a t i o vs. organic carbon i n surface sediments 246 3.105 Zinc:iron r a t i o vs. organic carbon i n surface sediments 247 3.106 Lead:potassium r a t i o vs. organic carbon i n surface sediments 248 3.107 Lead to aluminum r a t i o i n sediment cores 250 3.108 Copper:zinc r a t i o s i n surface sediments 252 3.109 Copper:zinc r a t i o s i n surface sediments of inner basin 253 3.110 Copper: zinc r a t i o s i n sediment cores 110 3.111 Zirconium:aluminum r a t i o s i n surface sediments 256 3.112 Zirconium vs. rubidium i n surface sediments 258 3.113 Zirconium:rubidium r a t i o s i n surface sediments 259 3.114 Zirconium:aluminum r a t i o s i n sediment cores 260 3.115 Porewater nutrients and t i t r a t i o n alkavnity i n core HS 16-B, outer basin 268 3.116 Porewater nutrients and t i t r a t i o n alkavnity i n core HS 64, inner basin 269 3.117 Dissolved i r o n and manganese i n porewater from core HS 16-B, outer basin 279 3.118 Dissolved i r o n and manganese i n porewater from core HS 64, inner basin 280 3.119 Dissolved i r o n , copper and manganese i n porewater from core HS 16-B, outer basin 287 3.120 Dissolved copper, zinc and lead i n porewater from core HS 16-B, outer basin 288 3.121 Dissolved copper, i r o n and manganese i n porewater from core HS 64, inner basin 290 3.122 Dissolved zinc i n porewater from two Howe Sound sediment cores 295 3.123 Dissolved i r o n , zinc and manganese i n porewater from core HS 16-B, outer basin 297 3.124 Dissolved i r o n , zinc and manganese i n porewater from core HS 64, inner basin 298 3.125 Dissolved i r o n , lead and manganese i n porewater from core HS 16-B, outer basin 300 3.126 Dissolved i r o n , lead and manganese i n porewater from core HS 64, inner basin 302 3.127 Dissolved copper, lead and zinc i n porewater from core HS 64, inner basin 303 ix ACKNOWLEDGMENTS This p r o j e c t could not have been completed without a l o t of support, moral and otherwise. In p a r t i c u l a r , I am very g r a t e f u l t o the f o l l o w i n g agencies f o r f i n a n c i a l a s s i s t a n c e : NSERC, through a S t r a t e g i c Grant t o Drs. S.E. C a l v e r t and T.F. Pedersen, and through an Operating Grant t o Dr. T.F. Pedersen; the Department of F i s h e r i e s and Oceans, through a Science Subvention Grant t o Dr. T.F. Pedersen; and the M i n i s t r y of Energy, Mines and Petroleum Resources of the B.C. Government, through the B r i t i s h Columbia A c i d Mine Drainage Task Force. Thanks a l s o are due t o the c a p t a i n and crew of the C.S.S. Vect o r , and t o t e c h n i c i a n s A. Ramnarine, H. Maclean and M. Noyen, f o r t h e i r a s s i s t a n c e i n c o l l e c t i n g the sediment cores and h y d r o l o g i c a l data f o r the p r o j e c t ; t o Mo Soon f o r her i n v a l u a b l e , and always c h e e r f u l , help i n the l a b o r a t o r y ; t o f e l l o w lab-mates Jay McNee and Bert M u e l l e r f o r a l l the hours, weeks, months, years they spent p e r f e c t i n g the porewater e x t r a c t i o n method and AA a n a l y s i s , and f o r h e l p i n g t o n a i l the l i d on a l k a l i n i t y and charge imbalance once and f o r a l l ; and t o committee members Dr. A.G. Lewis and Dr. S.E. C a l v e r t f o r t h e i r encouragement and i n s p i r a t i o n , and my su p e r v i s o r Dr. T.F. Pedersen f o r h i s u n f a i l i n g good humour, c r i t i c a l a n a l y s i s , and high e x p e c t a t i o n s . On a personal note, I want t o express my e t e r n a l love and g r a t i t u d e t o my mother and f a t h e r Pamela and A l i s t a i r Drysdale, and t o my s i s t e r Alyson, f o r l o o k i n g a f t e r Cam a l l those long weekends and summers; t o Cam f o r p u t t i n g up w i t h only h a l f a mom f o r much of the l a s t s i x months; and f i n a l l y , t o my husband John f o r h i s i n t e r e s t , enthusiasm, and support f o r my goals (even when my own were wearing t h i n l ) , and f o r h i s i n f i n i t e p atience and energy i n keeping the house running smoothly i n my many absences. x Chapter 1 INTRODUCTION 1 Chapter 1. INTRODUCTION 1.1. Out of S i g h t , Out of Mind: The problem of t a i l i n g s  d i s p o s a l . In recent years a g r e a t e r a p p r e c i a t i o n of the v u l n e r a b i l i t y of the n a t u r a l environment has s t i m u l a t e d r e s e a r c h t h a t re-examines many t r a d i t i o n a l methods of waste d i s p o s a l . The world's oceans, long considered t o be an i n f i n i t e r e c e p t a c l e f o r our wastes, are now known t o be f i n i t e and f r a g i l e . As a r e s u l t , t h e r e i s i n c r e a s i n g pressure on i n d u s t r y and l e g i s l a t o r s t o assess thoroughly the procedures and consequences of d i f f e r e n t dumping p r a c t i c e s i n order t o minimize environmental damage. One such p r a c t i c e t h a t has come under increased p u b l i c s c r u t i n y of l a t e i s the d i s p o s a l of mine t a i l i n g s , the f i n e -g r a i n e d mixture of m e t a l - r i c h waste rock and p r o c e s s i n g chemicals produced from standard mining o p e r a t i o n s . Since t a i l i n g s - d i s p o s a l generates no revenue, the p r a c t i c e i n the past has been t o do i t as cheaply and as q u i c k l y as p o s s i b l e ( C a l d w e l l and Welsh, 1982). Two methods i n p a r t i c u l a r are more commonly used than others: 1) land-based d i s p o s a l i n a r t i f i c i a l l y - c o n s t r u c t e d impoundments on mountainsides or v a l l e y f l o o r s , and 2) r e l e a s e of the t a i l i n g s i n t o the waters of a nearby l a k e , r i v e r or marine b a s i n (Down and Stocks, 1977a). Although s t i l l used by a m a j o r i t y of mines, land-based d i s p o s a l presents many problems, i n c l u d i n g slumping, a c i d drainage and u n s i g h t l i n e s s , a l l of which may continue long a f t e r the mine has ceased t o operate. 2 Subaqueous d i s p o s a l has h i s t o r i c a l l y been used as a convenient and economic a l t e r n a t i v e when p o s s i b l e , without, however, much c o n s i d e r a t i o n as t o i t s environmental consequences. Recent experience has shown t h a t , f a r from g e t t i n g r i d of the problem, t h i s p r a c t i c e may present a host of new ones. However, there i s a growing consensus t h a t under c e r t a i n c o n d i t i o n s , d e p o s i t i o n of mine wastes i n t o a nearby l a k e or marine b a s i n may a c t u a l l y be p r e f e r r e d over d i s p o s a l on land (Waldichuk, 1978; Down and Stocks, 1977b). The c o n d i t i o n s under which t h i s may be an acceptable p r a c t i c e are found i n areas of heavy r a i n f a l l , h igh l o c a l r e l i e f , and hig h s e i s m i c i t y ; such c l i m a t i c , topographic and t e c t o n i c c o n d i t i o n s are found on the west coast of Canada, among other p l a c e s . The steep-walled f j o r d s of the B r i t i s h Columbia coast, w i t h t h e i r r e l a t i v e l y l i m i t e d p r o d u c t i v i t y and r e s t r i c t e d c i r c u l a t i o n , have long been considered by l o c a l mines t o be reasonable r e c e i v i n g environments f o r m e t a l - r i c h mine waste ( C a l d w e l l and Welsh, 1982). Problems r e s u l t i n g from t h i s p r a c t i c e , such as d e s t r u c t i o n of the b e n t h i c h a b i t a t and metal r e l e a s e from the t a i l i n g s themselves, were not addressed u n t i l r e s earchers, spurred by growing p u b l i c concern, began studying the ongoing chemical behavior of these a r t i f i c i a l sediments. As a r e s u l t , t h e r e i s a small but growing body of knowledge regarding the long-term consequences of t h i s 3 c e n t u r i e s - o l d mining p r a c t i c e . Recent work on t a i l i n g s d e p o s i t s i n c o a s t a l waters around the world i n d i c a t e s t h a t t a i l i n g s may behave very d i f f e r e n t l y than expected, both p h y s i c a l l y and c h e m i c a l l y , once deposited on a l a k e or fjord-bottom. For example, i n Rupert and Holberg I n l e t s on Vancouver I s l a n d , s i t e of the I s l a n d Copper Mine, t u r b u l e n t t i d a l f l o w r e g u l a r l y resuspends t a i l i n g m a t e r i a l from the i n l e t f l o o r , adding s u b s t a n t i a l l y t o the t u r b i d i t y of the water and re-exposing the metals contained w i t h i n them t o the o x i d i z i n g e f f e c t s of the upper water column (Johnson, 1974). In a d d i t i o n , porewater a n a l y s i s of the t a i l i n g s - r i c h sediments r e v e a l s small but measurable f l u x of copper and molybdenum t o the o v e r l y i n g waters of the i n l e t , although t h i s f l u x i s much s m a l l e r than t h a t from many n a t u r a l sediments (Pedersen, 1985). In A g f a r d l i k a v s a F j o r d i n Greenland, s i t e of the Greenex Black Angel Mine, extremely hig h l e v e l s of l e a d , z i n c and cadmium ( i . e . 248, 615, and 4 i g / L , r e s p e c t i v e l y ) , were observed i n the bottom waters (Asmund, 1980). High metal l e v e l s were a l s o recorded i n l o c a l b i o t a , d e s p i t e the presence of a shallow s i l l (21 m) which was meant t o c o n t a i n the t a i l i n g s and encourage d e n s i t y s t r a t i f i c a t i o n of the water column. On the coast of C h i l e , two mines have dumped c o p p e r - r i c h t a i l i n g s f o r many years d i r e c t l y onto the beach, r a d i c a l l y a l t e r i n g the geomorphology of the area and causing a severe negative impact on l o c a l b i o t a ; one r e g i o n was s t i l l l i f e l e s s e i g h t 4 years a f t e r c e s s a t i o n of t a i l i n g s d e p o s i t i o n ( C a s t i l l a , 1983) . I t i s obvious t h a t the problems encountered i n subaqueous t a i l i n g s d i s p o s a l are o f t e n s i t e - s p e c i f i c . However, the focus of c u r r e n t research i s t o t r y t o answer some general questions regarding the behavior of mine t a i l i n g s which w i l l add t o the l i m i t e d amount of s c i e n t i f i c data c u r r e n t l y a v a i l a b l e f o r s p e c i f i c cases. For example, do mine t a i l i n g s p h y s i c a l l y behave as n a t u r a l sediments? Do they r a d i c a l l y change the p r o d u c t i v i t y of the r e c e i v i n g environment, e i t h e r by o b l i t e r a t i n g the b e n t h i c h a b i t a t , adding s u b s t a n t i a l l y t o n a t u r a l t u r b i d i t y , or by a l t e r i n g the chemistry of the water, and i f so, are these changes permanent? Do t a i l i n g s r e l e a s e d i s s o l v e d metals t o the o v e r l y i n g water, or can we be s a t i s f i e d t h a t they w i l l remain i n e r t as they g r a d u a l l y become covered by n a t u r a l sedimentation? T h i s t h e s i s attempts t o broaden our understanding of t h i s s u b j e c t by examining a s i n g l e case, the submerged t a i l i n g s d e p o s i t from a mine t h a t has been abandoned f o r f i f t e e n years at the time of t h i s w r i t i n g . I f we can assume t h a t the t a i l i n g s have undergone some degree of b u r i a l by n a t u r a l sediments, t h i s s i t u a t i o n provides an i d e a l o p p o r t u n i t y t o examine the geochemical e f f e c t the t a i l i n g s have had on those sediments, and t o determine what we might expect over the long term i n s i m i l a r s i t u a t i o n s elsewhere. 5 The Anaconda mine, l o c a t e d at B r i t a n n i a Beach on the shores of Howe Sound, B r i t i s h Columbia (see F i g . 1.1), began op e r a t i o n s i n 1899 and f o r s e v e n t y - f i v e years dumped, on average, 1600 m3/d of t a i l i n g s s l u r r y e n r i c h e d i n go l d and the s u l p h i d e s of i r o n , copper, z i n c , l e a d , and s i l v e r i n t o the deep, r e s t r i c t e d upper b a s i n of nearby Howe Sound ( E l l i s and Popham, 1983). In the beginning the t a i l i n g s were discharged i n t o nearby B r i t a n n i a Creek, but i n ca. 1927 an o u t f a l l was co n s t r u c t e d which sent the t a i l i n g s d i r e c t l y i n t o Howe Sound a t a depth immediately below the low t i d e mark ( J . Lovering, pers. comm.). Between 1925 and 1929, t a i l i n g s were placed d i r e c t l y on the s h o r e l i n e i n a land r e c l a m a t i o n p r o j e c t ; some of t h i s subsequently became uns t a b l e and s l i d o f f i n t o the deeper waters of the sound. T h i s may have happened s e v e r a l times d u r i n g the h i s t o r y of the mine (Tenneco O i l and M i n e r a l s , 1966, unpubl. r e p . ) . Before t h i s i n t e r r u p t i o n , and s i n c e , the t a i l i n g s formed a plume which spread out from the e f f l u e n t source onto the f l o o r of the r e s t r i c t e d upper b a s i n , moving as f a r north as Watts P o i n t (see F i g . 2) , and southward t o the s i l l which separates the upper b a s i n from the r e s t of the sound (Thompson and McComas, 1974). In 1964, the coarse f r a c t i o n of the t a i l i n g s was w i t h h e l d and s o l d t o a l o c a l cement company f o r i t s s i l i c a content u n t i l the mine ceased o p e r a t i o n s ten years l a t e r (P. Brohman, pers. comm.). Since the c l o s u r e of the mine i n 1974, co n s i d e r a b l e 6 Fig. 1.1 Study area showing surface sediment and core locations, and the site of the Britannia Mine. Fig. 1.2 Detail of the inner basin, Howe Sound, British Columbia. a t t e n t i o n has been p a i d t o the ongoing e f f e c t s of t h i s massive t a i l i n g s d e p o s i t on l o c a l b i o t a and water chemistry. The beach i n the v i c i n i t y of the town and the sediments where t a i l i n g s are most i n evidence appear t o be q u i t e impoverished w i t h respect t o bottom-dwelling organisms (Harger, 1971; Levings and McDaniels, 1973; Thompson and McComas, 1974; P e t r i e and Holman, 1983; B r i g h t and E l l i s , 1989). Analyses of both have shown e l e v a t e d , though v a r i a b l e , l e v e l s of copper and z i n c i n l o c a l crabs, clams, o y s t e r s , mussels, and shrimp (Goyette, 1975; B r i g h t , 1984; van Aggelen and Moore, 1986); these l e v e l s g e n e r a l l y decrease w i t h d i s t a n c e from the mine o u t f a l l . O t t e r t r a w l s c a r r i e d out by the Environmental P r o t e c t i o n S e r v i c e of the f e d e r a l government i n the v i c i n i t y of Howe Sound (McDaniel e t a l , 1978; Levings and McDaniel, 1980) have revealed reduced numbers of most be n t h i c s p e c i e s , compared t o areas o u t s i d e the s i l l . A s e r i e s of P i s c e s submersible d i v e s (Levings and McDaniel, 1973; P e t r i e and Holman, 1983) r e p o r t e d a heavy t u r b i d i t y c l o u d , thought t o be suspended t a i l i n g s m a t e r i a l , extending 20 m upward from the bottom. They c o n s i d e r t h i s f i n e m a t e r i a l as being p a r t l y r e s p o n s i b l e f o r the depleted macrofaunal assemblages which they found i n the upper b a s i n , although p e r i o d i c a l l y low oxygen c o n c e n t r a t i o n s may a c t u a l l y be a more c r i t i c a l f a c t o r . These ob s e r v a t i o n s , although anecdotal, suggest t h a t there may have been c o n s i d e r a b l e impact on the b e n t h i c h a b i t a t by 9 the a d d i t i o n of the mine waste t o the f j o r d f l o o r . In a d d i t i o n , chemical analyses of the water column (van Aggelen and Moore, 1986) have shown d i s s o l v e d copper l e v e l s of up t o 2.36 IM i n B r i t a n n i a Bay s u r f a c e waters, a l e v e l t h a t i s t o x i c t o most marine organisms, and i s s i x times the "never t o be exceeded" l e v e l (361.9 nM) e s t a b l i s h e d by the EPA. Zinc l e v e l s i n su r f a c e waters were up t o nine times normal background l e v e l s of 16.8 nM. Deep waters showed a corresponding enrichment over background l e v e l s (Cu:. 2.5X background of 23.6 nM; Zn: 8X background of 19.9 nM) . While much of the d i s s o l v e d copper probably o r i g i n a t e s from a c i d drainage emanating i n t o B r i t a n n i a Creek from unused mine t u n n e l s (Harger, 1971; van Aggelen and Moore, 1986), l i t t l e i s known of the c o n t r i b u t i o n of metals from the t a i l i n g s d e p o s i t w i t h i n the f j o r d i t s e l f . Thompson and Paton (1978) found el e v a t e d l e v e l s of copper (avg. 18.9 nM) i n the deep waters of the i n n e r b a s i n versus 11.5 nM i n the outer b a s i n . They concluded t h a t metal r e l e a s e from t a i l i n g s was r e s p o n s i b l e , based on l i m i t e d porewater data from sediment samples throughout the b a s i n . In t h i s case, however, the h i g h e s t Cu values i n porewater were observed i n f r e s h Squamish D e l t a sediments and s i l l sediments, areas which the mine t a i l i n g s are not b e l i e v e d t o have reached. In a d d i t i o n , h i g h d i s s o l v e d metal l e v e l s i n e s t u a r i e s are themselves not unusual. Desorption from p a r t i c u l a t e s as sediments move from a f r e s h t o a s a l i n e environment has been 10 shown t o have a c o n s i d e r a b l e e f f e c t on d i s s o l v e d metal content of e s t u a r i n e deep waters (Thomas, 1975; O'Connor and K e s t e r , 1975; Gibbs, 1977), w h i l e l o c a l geology i s r e s p o n s i b l e f o r h i g h n a t u r a l l e v e l s of many metals i n B r i t i s h Columbia c o a s t a l waters and sediments (Harding and Goyette, 1989) . I t i s evident t h a t a c l o s e r examination of Howe Sound sediments i s r e q u i r e d i n order t o determine i f metals from the mine t a i l i n g s are indeed being r e m o b i l i z e d t h e r e . T h is study, t h e r e f o r e , attempts t o address two aspects of the B r i t a n n i a Beach t a i l i n g s d e p o s i t : 1) The a r e a l extent of the t a i l i n g s and the degree t o which they are being d i l u t e d and/or covered over by n a t u r a l sediments; and 2) the c o n t r i b u t i o n of t r a c e metals ( s p e c i f i c a l l y copper, z i n c , manganese, i r o n , and l e a d ) , from the o l d t a i l i n g s d e p o s i t t o the o v e r l y i n g waters of the f j o r d . A comprehensive a n a l y s i s of s u r f a c e sediments i n s o l i d phase throughout the sound, combined w i t h a knowledge of the sedimentation and c i r c u l a t i o n regimes, i s used t o shed l i g h t on the f i r s t problem. The second i s more complex. The f l u x of m a t e r i a l s i n t o or out of sediments i s c o n t r o l l e d by the chemical and p h y s i c a l environment of those sediments, and i n t e r s t i t i a l waters are a s e n s i t i v e i n d i c a t o r of d i a g e n e t i c ( i . e . post-d e p o s i t i o n a l ) changes i n these parameters. Therefore a study of the porewater chemistry, ( i n p a r t i c u l a r , redox-s e n s i t i v e elements such as Fe and Mn, and a s s o c i a t e d metals) 11 i n c oncert w i t h the composition of the s o l i d phase, should enable d e t e r m i n a t i o n of the extent of e a r l y d i a g e n e s i s w i t h i n the t a i l i n g s - s e d i m e n t mixture c u r r e n t l y c o v e r i n g the f j o r d f l o o r . To do t h i s , the c o n c e n t r a t i o n s of major and minor elements, t r a c e metals, o r g a n i c m a t e r i a l s and n u t r i e n t s , i n both s o l i d and d i s s o l v e d phase, have been analysed i n a number of sediment cores from both the upper and lower basins of Howe Sound. Zinc and copper are not d i r e c t l y i n v o l v e d i n o x i d a t i o n - r e d u c t i o n r e a c t i o n s w i t h i n sediments; however, t h e i r a s s o c i a t i o n w i t h i r o n and manganese oxides makes them s t r o n g l y a f f e c t e d by changes i n c o n c e n t r a t i o n of these elements. Although s o l u b i l i t y and b i o a v a i l a b i l i t y of t r a c e elements are s t r o n g l y c o n t r o l l e d by t h e i r s p e c i a t i o n w i t h i n marine systems, t h i s study w i l l not address t h i s aspect of t h e i r d i s t r i b u t i o n due t o time and a n a l y t i c a l c o n s t r a i n t s . 1 . 2 . F l o r a , Fauna and Heavy Metals. A b r i e f overview of  d i a g e n e s i s and other sediment processes. Sediments a c t as dynamic r e a c t o r s i n which v a r i o u s processes change the chemical and p h y s i c a l nature of the m a t e r i a l s t h a t are o r i g i n a l l y d e posited, i n a c o n t i n u i n g c y c l e of degradation and r e g e n e r a t i o n . The c o l l e c t i v e term f o r t h i s i s d i a g e n e s i s (Berner, 1976), and e a r l y d i a g e n e s i s r e f e r s t o those processes o p e r a t i n g i n recent sediments. The p r i n c i p a l agents of change are h e t e r o t r o p h i c and a u t o t r o p h i c b a c t e r i a which break down the organic matter 12 contained w i t h i n the sediment, u s i n g the energy r e l e a s e d as f u e l f o r t h e i r own metabolic processes. To c a t a l y s e the r e m i n e r a l i z a t i o n process, these b a c t e r i a u t i l i z e s p e c i f i c o x i d i z i n g agents present i n the environment as e l e c t r o n a c c e p t o r s . Table 1.1 shows a l i s t of oxidants a v a i l a b l e i n n a t u r a l sediments i n order of decreasing energy y i e l d per mole of org a n i c carbon o x i d i z e d (McKinney and Conway, 1957; Richards 1965, and o t h e r s ) . As one might expect, oxygen, being the most e f f i c i e n t o x i d i z i n g agent a v a i l a b l e , i s consumed f i r s t , f o l l o w e d by n i t r a t e and s o l i d phase manganese oxides, i r o n oxyhydroxides, and sulphate. Methanogenesis t y p i c a l l y occurs f o l l o w i n g the d e p l e t i o n of sulphate. Each oxidant i s u t i l i z e d by s p e c i f i c b a c t e r i a l communities, whose products o f t e n render the immediate environment poisonous t o other organisms. The net changes w i t h depth i n porewaters as a r e s u l t of these r e a c t i o n s are: 1. a decrease and eventual d e p l e t i o n of oxygen; 2. an i n i t i a l i n c r e a s e i n n i t r a t e (due t o o x i d a t i o n of organic N and NH 4 + d i f f u s i n g up from deeper i n the sediments), f o l l o w e d by i t s consumption as an oxidant, once oxygen i s depleted; 3. a r a p i d i n c r e a s e i n P 0 4 3 ~ t o a maximum i n the i r o n -o x i d e - r e d u c t i o n zone, f o l l o w e d by a more gradual r e l e a s e from decaying organic matter w i t h depth; 13 Table 1 .1 Summary of redox r e a c t i o n s which occur w i t h depth i n sediments. Oxidants are l i s t e d i n the order of decreasing energy a v a i l a b i l i t y . R eaction Oxidant Products Aerobic r e s p i r a t i o n N03_ > H 3P0 4 N i t r a t e r e d u c t i o n N03- NH 3, H 3P0 4 Mn r e d u c t i o n Mn02 NH3, H3PO4, Mn 2 + Fe r e d u c t i o n FeO(OH) NH 3, H 3P0 4, F e 2 + Sulphate r e d u c t i o n s o 4 2 " NH 3, H 3P0 4, HC03 Methanogenesis c o 2 NH 3, H 3P0 4 f CH 4 14 4. a steady i n c r e a s e i n t o t a l a l k a l i n i t y due t o proton consumption duri n g d i a g e n e s i s w i t h s l i g h t drops i n the Mn and Fe-reduction zones due t o CaC0 3 p r e c i p i t a t i o n ; 5. the v i r t u a l absence of d i s s o l v e d Mn 2 + and F e 2 + i n the upper o x i c l a y e r s , f o l l o w e d by a dramatic i n c r e a s e i n the u n d e r l y i n g Mn- and Fe-reduction zones and a decrease again i n the sulphate-reducing zone; 6. an i n c r e a s e i n oC0 2 produced from the decaying organic matter; 7. a gradual increase i n ammonia c o n c e n t r a t i o n below the o x i c l a y e r from breakdown of organic matter; 8. an i n i t i a l s t a b l e c o n c e n t r a t i o n of sulphate (h28 mM i n seawater) down t o the zone where a l l other a v a i l a b l e oxidants have been consumed, f o l l o w e d by i t d e p l e t i o n ; t h i s i s o f t e n accompanied by a concomitant r i s e i n d i s s o l v e d H 2S. As a r e s u l t , d i a g e n e s i s produces a s e r i e s of o v e r l a p p i n g zones w i t h i n the sediments, each c h a r a c t e r i z e d by a d i s t i n c t biogeochemical environment, between which d i s s o l v e d c o n s t i t u t e n t s d i f f u s e along c o n c e n t r a t i o n g r a d i e n t s . This v e r t i c a l l a y e r i n g has been c a l l e d " e l a s t i c " (Shimmield and Pedersen, 1990), because the t h i c k n e s s of each of the zones can vary c o n s i d e r a b l y from one l o c a t i o n t o 15 the next. Deep ocean sediments, f o r example, where the accumulation r a t e i s on the order of 1 cm per 1000 years, r e c e i v e very l i t t l e l a b i l e o r ganic matter and are a l s o exposed t o well-oxygenated water. As a r e s u l t , demand f o r o x i d i z i n g agents i s low, and oxygen penetrates t o a c o n s i d e r a b l e depth ( i . e . up t o s e v e r a l metres) i n the sediments before i t i s consumed ( F r o e l i c h e t a l , 1979). The t h i c k n e s s of the succeeding o x i d i z i n g zones are s i m i l a r l y " s t r e t c h e d " . A c o a s t a l sediment, however, w i t h a much higher sedimentation r a t e (^4-1000 cm per 1000 years) , w i l l use up the a v a i l a b l e oxidants f a i r l y q u i c k l y , and each l a y e r may be extremely t h i n , o f t e n only a few m i l l i m e t r e s . In the f j o r d s of B r i t i s h Columbia, where sedimentation averages hi cm/yr, the s i t u a t i o n i s o f t e n even f u r t h e r a f f e c t e d by the c y c l i c d e p l e t i o n of oxygen i n bottom waters behind s i l l s which separate one p o r t i o n of the i n l e t from another, or from the open ocean. The changing chemistry w i t h depth r e s u l t i n g from e a r l y d i a g e n e s i s of organic matter a l s o a f f e c t s the r e a c t i v i t y of many of the i n o r g a n i c c o n s t i t u e n t s of the sediments, i n c l u d i n g t r a c e metals. The d e p o s i t i o n of sediments w i t h a hi g h content of metal-sulphides on the f l o o r of an oxygenated b a s i n t h e o r e t i c a l l y may r e s u l t i n the o x i d a t i o n of those s u l p h i d e s , producing metal oxides and oxyhydroxides. Since these compounds are more s o l u b l e i n water than s u l p h i d e s , i n i t i a l l y a net r e l e a s e of metal ions 16 t o the o v e r l y i n g water could occur. The f l u x of d i s s o l v e d metals from sediments may be somewhat l i m i t e d by a high t a i l i n g s discharge r a t e , and/or a hi g h n a t u r a l sedimentation r a t e , which r e s t r i c t s the time t h a t the metals are exposed t o the o x i d i z i n g e f f e c t s of the water column. As w e l l , r a p i d b u r i a l would ensure t h a t d e t r i t a l s u l p h i d e s would more q u i c k l y be emplaced w i t h i n a zone of low or depleted oxygen, thus s e v e r e l y l i m i t i n g t h e i r c onversion t o more s o l u b l e forms. With f u r t h e r b u r i a l , they would e v e n t u a l l y l i e w i t h i n the sulphate-reducing zone, where the presence of HS~ i n the porewaters r a p i d l y p r e c i p i t a t e s d i s s o l v e d metals as i n s o l u b l e s u l p h i d e s . P r o v i d i n g such m i n e r a l s are not r e -exposed t o 0 2, they w i l l remain i n s o l i d phase. Superimposed on t h i s s i m p l i f i e d e x p l a n a t i o n of metal d i a g e n e s i s w i t h i n a s t e a d y - s t a t e , c l o s e d system are s e v e r a l processes which d i s t u r b the v e r t i c a l i n t e g r i t y of the model. B i o t u r b a t i o n , the movement of sediment p a r t i c l e s by b e n t h i c fauna, causes h o r i z o n t a l g r a d i e n t s of d i f f e r e n t redox p o t e n t i a l s s i m i l a r t o the dominant v e r t i c a l one t o e x i s t w i t h i n sediments, by p e r m i t t i n g otherwise-depleted oxidants t o be mixed deeper i n the sediment than would occur by molecular d i f f u s i o n alone (e.g. Berner, 1980; A l l e r and Rude, 1988). Thus i n m e t a l - r i c h sediments, worm burrows and v e n t i l a t i o n tubes of bottom-dwelling organisms might be the s i t e s of metal r e m o b i l i z a t i o n through o x i d a t i o n , although i t i s u n c l e a r t o what extent t h i s e f f e c t would be s i g n i f i c a n t . 17 E l d e r f i e l d et a l (1981) found s m a l l f l u x e s of metals a s s o c i a t e d w i t h b i o t u r b a t i o n i n a p o l l u t e d estuary, but concluded t h a t , o v e r a l l , sediments are more an important s i n k f o r t r a c e metals than a source, although l a r g e u n c e r t a i n t i e s i n the a v a i l a b l e data made t h i s c o n c l u s i o n " h i g h l y e q u i v o c a l " . Other f a c t o r s , a s s o c i a t e d w i t h the morphology of the r e c e i v i n g environment, may cause problems w i t h r e m o b i l i z a t i o n of metals contained w i t h i n sediments. As p r e v i o u s l y mentioned, t i d a l c u r r e n t s c o u r s i n g through narrow i n l e t s may cause continuous resuspension, and thus o x i d a t i o n , of t a i l i n g s f i n e s . Slumping or t u r b i d i t y c u r r e n t s along d e l t a f r o n t s and t a i l i n g s fans, which may be t r i g g e r e d by storms, e a r t h tremors, or increa s e d l o a d i n g s may a l s o re-expose b u r i e d t a i l i n g s t r a t a . In Howe Sound, f o r i n s t a n c e , observers on P i s c e s d i v e s i n 1972, 1976, and 1978 repo r t e d l a r g e r i d g e s of grey sediment up t o 10 m i n height running out p e r p e n d i c u l a r l y from the shore near the o l d mine o u t f a l l (D. Goyette, pers. comm.). These were thought t o be the r e s u l t of slumping of the unst a b l e t a i l i n g s m a t e r i a l down the steep w a l l s of the f j o r d . This area was p r a c t i c a l l y devoid of macrofauna, a t t e s t i n g at l e a s t t o i t s u n s u i t a b i l i t y as a be n t h i c h a b i t a t i f not t o i t s t o x i c i t y t o marine organisms ( P e t r i e and Holman, 1983; Levings and McDaniel, 1973). As w e l l , p e r i o d i c deep-water renewal events, common i n f j o r d s which are cut o f f from 18 f r e e l y - c i r c u l a t i n g bodies of water, r e - i n t r o d u c e h i g h l e v e l s of d i s s o l v e d oxygen whenever they occur, which i n the case of Howe Sound may be as o f t e n as once a month f o r mid-depths, o r as seldom as once every few years f o r bottom waters ( B e l l , 1973). This i n j e c t i o n of oxygen c o u l d t r i g g e r renewed o x i d a t i o n of m e t a l - r i c h s u r f a c e sediments which had been e s s e n t i a l l y i n s o l u b l e when o v e r l a i n by anoxic or hypoxic bottom water. 1.3. The P h y s i c a l S e t t i n g Howe Sound has been the focus of inte n s e environmental i n t e r e s t s i n c e the 1950's f o r s e v e r a l reasons: i t i s near a l a r g e m e t r o p o l i t a n area; i n d u s t r i a l a c t i v i t y i s c o n s i d e r -a b l e , i n the form of two pulp m i l l s , the FMC c h l o r - a l k a l i p l a n t a t Squamish, and the now-defunct B r i t a n n i a Mine; and the e x i s t e n c e of a r a i l w a y terminus a t Squamish renders Squamish a deep-sea p o r t . Howe Sound has t r a d i t i o n a l l y supported r e c r e a t i o n a l shrimp, crab, o y s t e r and clam f i s h e r i e s , and r e s i d e n t s boast of the re c o r d s i z e s of salmon and s t e e l h e a d caught o f f i t s shores. The p o s s i b i l i t y of human p o p u l a t i o n pressures and i n d u s t r i a l a c t i v i t i e s a d v e r s e l y a f f e c t i n g the water q u a l i t y are i s s u e s which are c u r r e n t l y a t t r a c t i n g a good dea l of a t t e n t i o n . The f o l l o w i n g p h y s i c a l and oceanographic data were taken, except where noted, from P i c k a r d (1961), Hoos and Void (1975) and S y v i t s k i and MacDonald (1982). 19 Howe Sound i s the f i r s t i n l e t north of Vancouver on the mainland of southwestern B.C. ( F i g s . 1.1 and 1.2). I t i s approximately 42 km long and has a mean width of 6 km. I t i s a c t u a l l y a sound-fjord combination, w i t h the upper one-t h i r d being narrow, deep, and w e l l - s t r a t i f i e d , and the remainder being a t r u e sound, broader, p a r t i a l l y - m i x e d , and w i t h s e v e r a l l a r g e i s l a n d s s c a t t e r e d over i t s s u r f a c e . The south end of Howe Sound connects w i t h the S t r a i t of Georgia from which Fraser R i v e r water i s able t o enter. At the northern end the Squamish R i v e r i s the f r e s h water source, d i s c h a r g i n g an average of 250 m 3 s e c - 1 i n t o the head of the i n l e t , w i t h l a r g e seasonal f l u c t u a t i o n s . Howe Sound i s a g l a c i a l l y - s c o u r e d U-shaped v a l l e y t h a t shows abundant evidence of i t s o r i g i n i n the form of g l a c i a l s t r i a t i o n s along the shore and s i l l - f o r m i n g t e r m i n a l moraines on the f j o r d f l o o r i t s e l f . The outer s i l l occurs a t the mouth, where the water depth decreases t o h70 m. Thi s s i l l i s cut by s e v e r a l deep channels; thus a f r e e exchange w i t h Georgia S t r a i t water i s not impeded. The inn e r s i l l separates the narrow northern p o r t i o n from the wider, more open body of the sound, r i s i n g from c l o s e t o 300 m depth t o w i t h i n 60 m of the su r f a c e (see F i g . 1.3a & b) . Both i n n e r and outer basins are c h a r a c t e r i z e d by steep w a l l s and f l a t bottoms (F i g . 1 . 4 ) . Howe Sound e x h i b i t s p o s i t i v e e s t u a r i n e c i r c u l a t i o n w i t h net water movement seaward a t the sur f a c e due t o heavy r i v e r 20 300^ ' •• '•• ' ' r -0 10 20 30 D i s t a n c e ( k m ) Fig. 1.3(a & b) Cross-section of Howe Sound from i t s northernmost point at the Squamish River to i t s connecting channel with the Strait of Georgia. Vertical scale on (b) is greatly exaggerated. 21 Fig. 1.4 Bathymetric map of Howe Sound showing 100, 200, and 280 m depth contours. 22 r u n - o f f from g l a c i e r s and s n o w f i e l d s , and s a l t water i n f l o w (landward) at depth. The maximum t i d a l range i s 4.8 m. There i s strong s t r a t i f i c a t i o n i n both temperature and s a l i n i t y p r o f i l e s i n the upper b a s i n , r e f l e c t i n g the r e l a t i v e l y f r e s h (S^7) surface l a y e r (\6 m t h i c k ) which o v e r l i e s denser s a l i n e water. The temperature s t r a t i f i c a t i o n i s enhanced i n summer due t o s o l a r h e a t i n g of the s t a b l e s u r f a c e l a y e r . Below the s u r f a c e , the h a l o c l i n e i s pronounced, such t h a t by 20 m the s a l i n i t y i s 90% t h a t observed a t g r e a t e r depths ( F i g . 1.5). The outer, or lower b a s i n , by c o n t r a s t , i s c o n s i d e r a b l y l e s s s t r a t i f i e d . By the time s u r f a c e water reaches t h i s r e g i o n , entrainment of s a l t water has increased i t s s a l i n i t y t o between 15 and 23, depending on the season. The northernmost s e c t i o n of Howe Sound, c a l l e d the B r i t a n n i a b a s i n (maximum depth 285 m) , i s bounded at the seaward end by the steep-sided s i l l and a t the head by the more g r a d u a l l y - s l o p e d Squamish R i v e r d e l t a ( F i g . 1.3). One e f f e c t of the s i l l i s t o prevent the continuous movement of deep water from ou t s i d e the s i l l , ( i . e . water w i t h p r o p e r t i e s s i m i l a r t o t h a t of Georgia S t r a i t water), i n t o the b a s i n . This i s o l a t i o n of the deep b a s i n i s not permanent, but i s s u b j e c t t o p e r i o d i c renewal at frequencies roughly i n v e r s e l y p r o p o r t i o n a l t o the depth reached by the incoming water. Mid-depth renewals might occur, f o r example, every few months, w i t h deep renewals once a year or 23 ro 0 0 ' j? 50 CD CO 100-— 150H SZ a CD Q 200 250 10 20 i • U 1 1 i. 1—L&j—i—_i—i 30 i A Station 16-B Outer Basin Oxygen Temp. (ml/L) fC) Sigma T Salinity 0 0 50-100-150-200-250-300 10 20 30 a. <» Station 64 0 Inner Basin i DD LT T Lt T CD • Oxygen Temp. (ml/L) Sigma T Salinity Fig. 1.5 Hydrographic data taken at stations 16-B and 64 in April, 1988. Note different depth scales at the two locations. even l e s s . These renewal events may be t r i g g e r e d by high down-channel ("Squamish") winds, heavy sur f a c e r u n - o f f , or d e n s i t y d i f f e r e n c e s induced by entrainment and d i f f u s i o n of b a s i n water i n t o the outflow l a y e r ( B e l l , 1973). U n t i l 1973 i t was assumed t h a t the s i l l was deep enough t o permit renewals s u f f i c i e n t l y f r e q u e n t l y so t h a t d i s s o l v e d oxygen l e v e l s i n the very deepest zones were never t o t a l l y absent. Recent evidence ( B r i g h t , pers. comm.; Levings and McDaniel, 1980) however, suggests t h a t i n c r e a s i n g anthropogenic a c t i v i t y w i t h i n and around the sound, and the r e s u l t i n g higher organic lo a d , may be i n d u c i n g o c c a s i o n a l anoxia before f l u s h i n g of the bottom water can prevent i t . F i g . 1.6 g i v e s the d i s s o l v e d oxygen l e v e l s f o r f i v e recent years i n the water column of the upper b a s i n . T h i s graph shows t h a t intermediate depth renewals occurred a t l e a s t t h r e e times over t h i s time p e r i o d , w h i l e the deep water was renewed only once (U.B.C. Oceanography Data Reports #50-56). The i n f l u e n c e of Fraser R i v e r sediments on those of Howe Sound can be detected throughout the lower b a s i n , but c h i e f l y w i t h i n the main channel east of Gambier I s l a n d . In a d d i t i o n , the numerous creeks which enter the i n l e t on a l l s i d e s c o n t r i b u t e l o c a l l y t o the composition of some nearshore sediments. This i s e s p e c i a l l y t r u e f o r the B r i t a n n i a Beach sediments, which are h e a v i l y contaminated w i t h the s u l p h i d e - r i c h waste rock d e r i v e d from the B r i t a n n i a S i l l s , the subsurface ore body mined f o r most of the 25 O 2 mL/L 300-1 1 Fig. 1.6 Dissolved oxygen levels In upper basin, Howe Sound, showing yearly changes in deep and intermediate water masses. 26 century. However, the dominant s e d i m e n t o l o g i c a l i n f l u e n c e on Howe Sound i s from the Squamish R i v e r , which d r a i n s an area of roughly 230,000 km2, and d e l i v e r s sediments d e r i v e d from the g r a n i t i c complexes and i n t e r l a y e r e d v o l c a n i c s and metasediments of the regio n . At the northern end, the sediment load from the Squamish has b u i l t a l a r g e bayhead d e l t a , which i s growing outward a t a r a t e of about 7 m per year (Hoos and Void, 1975) . The sedimentation r a t e f o r the whole of the sound i s thought t o be s i m i l a r t o other f j o r d s along the coast, i . e . ca. 1 cm y r - 1 . 1.4. C i r c u l a t i o n As noted e a r l i e r , the freshwater discharge from the Squamish R i v e r produces a net seaward flow i n Howe Sound. However, the dominant f o r c e a f f e c t i n g s u r f a c e flow v e l o c i t i e s i s wind (Buckley and Pond, 1976). F i g s . 1.7 and 1.8 show s i m p l i f i e d r e p r e s e n t a t i o n s of the su r f a c e flow p a t t e r n s i n the upper and lower b a s i n . Note the presence of cl o c k w i s e and counterclockwise eddies i n B r i t a n n i a Bay and northeast of Woodfibre. The su r f a c e l a y e r so a f f e c t e d i s about 2 m deep; below t h i s the seaward c u r r e n t reaches i t s maximum v e l o c i t y , d r i v e n predominantly by the r i v e r d i s c h a r g e and decreasing t o one-tenth the su r f a c e v e l o c i t y j u s t above the depth of the py c n o c l i n e at about 8 m (Buckley, 1977). Below t h i s depth there i s a t y p i c a l l y -e s t u a r i n e compensatory c u r r e n t which flows upstream t o re p l a c e s a l t water l o s t by entrainment, at v e l o c i t i e s which 27 Fig. 1.7 Current-regime of Howe Sound (from Syvitski and MacDonald, 1982) 28 Fig. 1.8 General surface flow pattern for the inner basin, Howe Sound. Arrow size is proportional to speed and persistence of current (from Buckley, 1977) 29 vary a c c o r d i n g t o season and the degree of s u r f a c e water outflow. V a r i a t i o n s i n winds, t i d a l f o r c e s , and r u n o f f r a t e s c r e a t e complex c i r c u l a t i o n p a t t e r n s , even i n the deeper l a y e r s , w i t h up t o s i x l a y e r s , from s u r f a c e t o bottom, moving i n opposing d i r e c t i o n s . S y v i t s k i and MacDonald (1982) have shown, however, t h a t f o r sedimentation purposes these c u r r e n t s mostly c a n c e l each other out. Thus p a r t i c u l a t e s (such as mine t a i l i n g s , f o r example) r e l e a s e d i n t o the s u r f a c e l a y e r appear t o f o l l o w a n e a r l y v e r t i c a l r e s i d u a l descent path once they have sunk below the s u r f a c e l a y e r , so t h a t r e s u l t i n g sedimentation p a t t e r n s c l o s e l y approximate the s u r f a c e c i r c u l a t i o n . However, p a r t i c l e s may t r a v e l long d i s t a n c e s up and down i n l e t before a c t u a l l y s e t t l i n g out. Once over the s i l l , s u r f a c e water dive r g e s around both s i d e s of A n v i l I s l a n d and southwest through Thornbrough Channel. The Squamish-driven c u r r e n t i s c o n s i d e r a b l y attenuated i n the lower b a s i n , and the c u r r e n t regime h e a v i l y i n f l u e n c e d by d a i l y wind and t i d a l f o r c e s as w e l l as seasonal changes i n freshwater i n p u t . In t h i s area of the sound incoming F r a s e r R i v e r water mixes w i t h and f u r t h e r m o d i f i e s the now-diluted Squamish R i v e r water, and these processes are r e f l e c t e d i n u n d e r l y i n g sediments ( S y v i t s k i and MacDonald, 1982). In the s p r i n g , the F r a s e r f r e s h e t commences about three weeks i n advance of the Squamish; t h e r e f o r e i t tends to dominate the c i r c u l a t i o n and 30 s e d i m e n t a t i o n p a t t e r n s i n t h e lower t h i r d o f Howe Sound d u r i n g t h i s t i m e , f o r c i n g the weaker Squamish s u r f a c e c u r r e n t southwestward t o e x i t t h r o u g h t h e c h a n n e l s on e i t h e r s i d e o f K e a t s I s l a n d ( T a b a t a , 1972) . As t h e Squamish f r e s h e t p e a k s , i t t a k e s o v e r and dominates the c i r c u l a t i o n o f t h e main e a s t e r n c h a n n e l as w e l l . Thus the e n t i r e sound i s i n f l u e n c e d by sediment i n p u t from t h e s e two s o u r c e s , i n p a t t e r n s complex and t o some e x t e n t u n p r e d i c t a b l e ( S y v i t s k i and M a c D o n a l d , 1982) . 1.5, Geology 1.5.1. The Squamish Drainage Basin The g e o l o g y o f t h e Squamish R i v e r d r a i n a g e a r e a has been d e s c r i b e d by Mathews (1958) i n d e t a i l , and summarized by Hoos and V o i d (1975) . The f o l l o w i n g b r i e f g e o l o g i c a l d e s c r i p t i o n o f t h e f o r m a t i o n s which o u t c r o p i n the a r e a has been t a k e n , except where n o t e d , from t h e l a t t e r . The Squamish R i v e r and i t s t r i b u t a r i e s , the Cheakamus and Mamquam R i v e r s , t o g e t h e r d r a i n an a r e a o f r o u g h l y 4,800 km , h i g h e r e l e v a t i o n s o f which a r e s t i l l c o v e r e d by g l a c i e r s and s n o w f i e l d s . The g r e a t e r p o r t i o n o f t h e a r e a ( i . e . Jj40%) i s composed o f p l u t o n i c M e s o z o i c r o c k s . Two segments o f t h e c o a s t a l b a t h o l i t h , named Squamish and C a s t l e Tower , c o v e r a f u r t h e r 11% o f t h e d r a i n a g e b a s i n , w i t h more r e c e n t v o l c a n i c r o c k s o f t h e G a r i b a l d i Group c o n t r i b u t i n g a p p r o x i m a t e l y 16%. M e t a v o l c a n i c s and metased imentary r o c k s 31 are exposed i n a few small areas; the remainder of the r e g i o n i s covered by l a k e s , g l a c i e r s , moraines, and g l a c i o f l u v i a l g r a v e l s from the e x t e n s i v e p e r i o d of orogeny, e r o s i o n , and g l a c i a t i o n which has dominated the west coast s i n c e the e a r l y Cenozoic. The Mesozoic p l u t o n i c rock, i n c l u d i n g the C a s t l e Tower b a t h o l i t h are composed p r i m a r i l y of quartz d i o r i t e s (plagioclase-dominated f e l d s p a r s ) , w h i l e quartz monzonite and g r a n o d i o r i t e s , w i t h t h e i r h i g h e r c o n c e n t r a t i o n s of o r t h o c l a s e , predominate i n the Squamish b a t h o l i t h . The metasediments and metavolcanics of the Mamquam R i v e r area comprise massive and bedded greenstone c h e r t , a r g i l l i t e , sandstones, conglomerates, and s c h i s t s . The v o l c a n i c rocks of the G a r i b a l d i group are dominated by l a r g e l y u n a l t e r e d l a v a s and p y r o c l a s t i c s , and moderately metamorphosed rocks such as g n e i s s , a m p h i b o l i t e , g r a n u l i t e , s c h i s t and q u a r t z i t e . The e v o l u t i o n of these formations i n g e o l o g i c h i s t o r y has been summarized by Armstrong, quoted i n Hoos and Void (1975) : "Eugeosynclinal sedimentation, vulcanism, meta-morphism, and s y n t e c t o n i c g r a n i t i z a t i o n , w i t h a s s o c i a t e d i n t r u s i o n , apparently covered an extended p e r i o d of time, from e a r l y Mesozoic or o l d e r t o , and perhaps i n c l u d i n g , the Upper Cretaceous. P r i o r t o Middle Eocene time, the southern Coast Mountains were u p l i f t e d and eroded, and p l u t o n i c and a s s o c i a t e d rocks were exposed. These p l u t o n i c rocks c o n t r i b u t e d n o t a b l y t o the Middle Eocene c o n t i n e n t a l sediments t h a t u n d e r l i e Vancouver, and which may reach t h i c k n e s s e s of as much as 12,000 f e e t [3650 m] . Since Middle Eocene time, the mountains have again been 32 u p l i f t e d ; remnants o f t h e sedi m e n t s now e x t e n d up t h e s o u t h e r n " f r o n t " o f t h e Coa s t M o u n t a i n s t o an a l t i t u t e o f 2,700 f e e t [800 m] . Though t h e s e d i m e n t s . . . have n o t been i n v o l v e d h e r e i n any major o r o g e n i c d i s t u r b a n c e , i n t e r m i t t e n t v o l c a n i s m has ex t e n d e d from M i d d l e Eocene t o Recent t i m e , and i s r e p r e s e n t e d b y . . . t h e l a v a s and p y r o c l a s t i c s o f t h e G a r i b a l d i a r e a . " The t o p o g r a p h y o f Howe Sound i t s e l f i s l a r g e l y t h e p r o d u c t o f P l e i s t o c e n e g l a c i a t i o n . D u r i n g t h e l a s t g l a c i a l p e r i o d , what i s now t h e Squamish v a l l e y was f i l l e d w i t h i c e t o a l m o s t 2000 m d e p t h . The o u t e r s i l l , w h i c h s e p a r a t e s Howe Sound from G e o r g i a S t r a i t , i s a g l a c i o m a r i n e d e p o s i t formed from t h e t i l l w h i c h a c c u m u l a t e d where t h e g l a c i e r met pack i c e from G e o r g i a S t r a i t . As t h e g l a c i e r r e t r e a t e d , r i v e r - b o r n e g r a v e l s and g l a c i a l d e b r i s were c a r r i e d t o t h e emerging f j o r d and a c c u m u l a t e d o v e r t h e v a l l e y f l o o r i n d e p o s i t s up t o 120 m t h i c k . The i n n e r s i l l i s composed o f a t h i c k , b o u l d e r - l a d e n moraine t h a t p e r h a p s marked t h e t e r m i n u s o f a p r e v i o u s g l a c i a t i o n (Mathews e t a l , 1966). The whole o f t h e Howe Sound b a s i n i s c o v e r e d by 50-150 m o f Ho l o c e n e s e d i m e n t w h i c h o v e r l i e s t h e P l e i s t o c e n e d e p o s i t s ( S y v i t s k i and MacDonald, 1982). The i s l a n d s w i t h i n t h e sound a r e composed o f m a i n l y m e t a v o l c a n i c s and metasediments o v e r l y i n g t h e o l d e r (Mesozoic) q u a r t z d i o r i t e s . On Gambier I s l a n d , a low-grade p o r p h y r y c o p p e r d e p o s i t t h a t e x i s t s w i t h i n t h e s e f o r m a t i o n s has been t a r g e t e d f o r p o s s i b l e f u t u r e e x p l o i t a t i o n . 33 1.5.2. Geology and History of Britannia Creek Drainage Basin The f o l l o w i n g g e o l o g i c a l i n f o r m a t i o n i s t a k e n from James (1929), a G.S.C. memoir w h i c h r e m a i n s t h e most comprehensive f i e l d a n a l y s i s o f t h i s a r e a t o d a t e . I n t r u s i o n o f p l u t o n i c r o c k s i n t h e Upper J u r a s s i c i n t o p r e - e x i s t i n g v o l c a n i c s produced a zone o f a l t e r a t i o n i n t h e B r i t a n n i a a r e a known as t h e B r i t a n n i a Shear Zone, w h i c h i s d e s c r i b e d i n d e t a i l below. S i n c e t h i s i n t r u s i o n , t h e main g e o l o g i c a l p r o c e s s e s have been u p l i f t and e r o s i o n . F o l l o w i n g t h e r e c e s s i o n o f t h e C o r d i l l e r a n i c e s h e e t i n t h e l a t e P l e i s t o c e n e , t h e c o a s t a l r e g i o n rebounded i s o s t a t i c a l l y up t o 250 m, w h i c h has f o s t e r e d c o n t i n u i n g e r o s i o n . A t p r e s e n t , s u r f i c i a l d e p o s i t s i n t h e a r e a c o n s i s t o f g l a c i o f l u v i a l and f l u v i a l g r a v e l s , w h i c h a r e u n d e r l a i n by g r a n o d i o r i t e and a n d e s i t i c t o r h y o d a c i t i c r o c k s , w i t h m i n o r s e d i m e n t a r y and metamorphic components. Thus e x p o s u r e a l o n g B r i t a n n i a Creek c o n s i s t s g e n e r a l l y o f g r a n o d i o r i t i c o r v o l c a n i c r o c k s o v e r l a i n by a v a r i a b l e , b u t t h i n , c o v e r i n g o f t i l l and c o l l u v i u m . A t t h e mouth, t h e c r e e k has i n c i s e d t h e s e g l a c i a l g r a v e l s . The B r i t a n n i a Creek w a t e r s h e d d r a i n s an a r e a r o u g h l y 2-3 km wide and 8-9 km l o n g , i n an e a s t - w e s t d i r e c t i o n . From i t s s o u r c e , h i g h i n t h e mountains s u r r o u n d i n g U t o p i a Lake, t h e c r e e k p r o p e r p a s s e s t h r o u g h t h e M i d d l e Goat M o u n t a i n f o r m a t i o n ( d e s c r i b e d below) and a s h o r t a r e a o f g r a n o -d i o r i t i c r o c k s b e f o r e e n t e r i n g t h e zone o f g l a c i a l a l l u v i u m 34 which covers the creek bed to i t s mouth at Howe Sound. However, a l l of the t r i b u t a r i e s on the south side of Britannia Creek are in c i s e d into several other formations, these being the Britannia Formation and the Britannia S i l l s . The oldest formation of i n t e r e s t on the south side of the creek i s the Lower T r i a s s i c Britannia Formation, which i s composed of medium-grained quartzites, black carbonaceous s l a t e s , dense cherts, and f i n e grey and green s i l i c e o u s s l a t e s . I n t e r s t r a t i f i e d i n the formation are fine-grained t u f f s and other c l a s t i c volcanic material. A l l the rocks have been highly metamorphosed by pressure and temperature changes associated with i n t r u s i o n of the ba t h o l i t h . The Upper T r i a s s i c Goat Mountain formation consists of three zones, two of which are well represented i n the Britannia area. The Middle Goat Mountain unit (approximately 2500 m thick) consists mainly of a serie s of massive s i l l s separated by narrow layers of "baked" carbonaceous shales; towards the top, basic t u f f s and flows are more predominant. The primary minerals are augite and labrad o r i t e , with c h l o r i t e , hornblende, and b i o t i t e conspicuous as replacement minerals. The Upper Goat Mountain u n i t i s a group of volcanic rocks whose p r i n c i p a l constituents are plagioclase feldspars, diopside and hornblende. Again, c h l o r i t e and b i o t i t e are common as secondary minerals, and occasionally c a l c i t e and k a o l i n i t e are observed as well. 35 The B r i t a n n i a and Goat M o u n t a i n f o r m a t i o n s c o l l e c t i v e l y c o m p r i s e t h e B r i t a n n i a Group, and may be summarized as a s e r i e s o f e x t e n s i v e l y a l t e r e d and metamorphosed v o l c a n i c and s e d i m e n t a r y r o c k s . The e a r l y J u r a s s i c B r i t a n n i a S i l l s i s t h e l a s t f o r m a t i o n formed b e f o r e t h e b a t h o l i t h i c i n t r u s i o n . I t c o n s i s t s o f number o f h y d r o t h e r m a l l y - a l t e r e d q u a r t z p o r p h y r i e s t h a t has been i n t r u d e d i n t o t h e B r i t a n n i a Group. By f a r t h e dominant r o c k i s a l b i t e d a c i t e w h i c h c o n s i s t s a l m o s t e n t i r e l y o f q u a r t z and s o d i c p l a g i o c l a s e w i t h m i n or c h l o r i t e o c c u r r i n g as f i n e f l a k e s o r a g g r e g a t e s . The B r i t a n n i a S i l l s h o s t s t h e B r i t a n n i a Shear Zone, w h i c h c o n t a i n s a l l t h e c o m m e r c i a l o r e d e p o s i t s t h a t have been mined s i n c e t h e e a r l y 1900's. A l t h o u g h t h e s h e a r zone does n o t have a s u r f a c e m a n i f e s t a t i o n , i t forms a wide band w i t h i n a c e n t r a l s e c t i o n o f t h e B r i t a n n i a S i l l s , and i s a l m o s t c o m p l e t e l y c o v e r e d by g l a c i a l g r a v e l s and t a l u s . The p r i n c i p a l l i t h o l o g i e s a s s o c i a t e d w i t h t h i s zone a r e g r e e n c h l o r i t i c s c h i s t s , v e r y f i s s i l e s o f t s l a t e s d e r i v e d from t h e t u f f s and f l o w s o f t h e B r i t a n n i a S i l l s , and s h e a r e d phases o f t h e "mine" p o r p h y r y . The o r e s c o n s i s t e d l a r g e l y o f c h a l c o p y r i t e , p y r i t e and q u a r t z , w i t h l o c a l d e p o s i t s o f s p h a l e r i t e (Zn,FeS), b a r i t e ( B a S 0 4 ) , g a l e n a ( P b S ) , and a n h y d r i t e ( C a S 0 4 ) . The b a t h o l i t h w h i c h i n t r u d e s i n t o t h e p r e v i o u s l y -d e s c r i b e d f o r m a t i o n s , c o n s i s t s o f o r d i n a r y , e v e n - g r a i n e d 36 granodiorites and quartz d i o r i t e s occurring through the c e n t r a l portion of the area, and a coarse-grained, s i l i c e o u s granodiorite that occurs i n the northwest region of the drainage basin. The Britannia Mine opened i n 1906, continued i n operation f o r nearly 70 years, and closed i n l a t e 1974. Copper, grading on average 1.26%, zinc, s i l v e r and gold were recovered from the massive sulphide ore. However, since the recovery of metals during the m i l l i n g process i s never 100% e f f i c i e n t , the t a i l i n g s which were discharged into the sound contained l e v e l s of Cu (0.2%), Zn (0.125%), and Fe (5.5%) ( E l l i s , 1984), appreciably higher than those of natural sediments within the sound, which average 60 ppm, 80 ppm, and 4.5%, res p e c t i v e l y . I t i s believed that sediments delivered to the sound by Britannia Creek are not notably d i f f e r e n t than those deposited by other creeks on the east side of the i n l e t . However, the addition of waste rock and mine t a i l i n g s to the Sound v i a the creek e a r l i e r i n the century, or l a t t e r l y v i a a point o u t f a l l , have rendered the area of the creek mouth a point source for introduction of high concentrations of s i l i c a , barium, copper, iron, lead, and zinc (and possibly gold and s i l v e r as w e l l ) . 37 1.5.3. Georgia S t r a i t Sediments I t has been suggested that the sediments of Georgia S t r a i t are dominated by inputs from the Fraser River (Pharo, 1972) . In turn, the lower reaches of Howe Sound are strongly influenced by S t r a i t sediments entering the i n l e t v i a estuarine c i r c u l a t i o n ( S yvitski and MacDonald, 1982). Accordingly, a b r i e f d escription of sediments found i n Georgia S t r a i t ( especially those i n the f i n e r grain sizes) i s required i n order to place the major and minor element composition of Howe Sound sediments into a s p a t i a l perspective. Pharo (1972) has examined the sediments of the entir e Georgia S t r a i t basin i n d e t a i l . The following summary i s taken from t h i s comprehensive study. The S t r a i t of Georgia i s a long, narrow, semi-enclosed basin which trends northwest-southeast. I t has a r e s t r i c t e d c i r c u l a t i o n with a single primary sediment source, the Fraser River, which d e l i v e r s most of i t s material during the spring freshet. (Other i n l e t s also empty into the s t r a i t , but compared to the Fraser River, t h e i r influence i s n e g l i g i b l e ) . The o v e r a l l general c i r c u l a t i o n within the s t r a i t , affected by the combined influences of t i d a l flow, C o r i o l i s e f f e c t , topography and the p r e v a i l i n g a n t i -clockwise wind patterns, i s an anti-clockwise "gyre" which d e f l e c t s fresh water northward along the east side of the s t r a i t , d i r e c t l y past the mouth of Howe Sound. Evidence for 38 t h i s net t r a n s p o r t of r i v e r water northward i s found i n he a v i e r s i l t i n g p a t t e r n s on the northern s i d e of the d e l t a than i n other areas (Mathews and Shepard, 1962). In Howe Sound, two s i l l s p r o v ide e f f e c t i v e sediment t r a p s f o r Squamish River-borne sediments, but o f f e r no b a r r i e r (at l e a s t i n the outer basin) t o Georgia S t r a i t -F r a s e r R i v e r m a t e r i a l s , which enter the sound i n the more s a l i n e waters t h a t r e p l a c e the f r e s h e r Squamish outflow. Sediments throughout the s t r a i t are c o m p o s i t i o n a l l y very s i m i l a r . Most of the sand-size m a t e r i a l found o f f the d e l t a i s w i t h i n the fine-san d g r a i n s i z e , and i s dominated by q u a r t z , f e l d s p a r , and ferromagnesian m i n e r a l s (mostly amphiboles). Mica i s a l s o found i n c o n s i s t e n t , though not abundant, q u a n t i t i e s . The coarse and medium s i l t f r a c t i o n s have s i m i l a r compositions t o the f i n e sands. Fine s i l t s are c h a r a c t e r i z e d by i n c r e a s i n g l y conspicuous p h y l l o s i l i c a t e m i n e r a l s , most not a b l y mica, m o n t m o r i l l o n i t e , and c h l o r i t e , which completely dominate i n the c l a y - s i z e f r a c t i o n s . Pharo found t h a t the degree of a l t e r a t i o n of c l a y m i n e r a l s by s u b s t i t u t i o n by exchangeable c a t i o n s decreases i n the order Mg + +>Na +>K +>Ca + +, but t h a t the i n f l u e n c e of t h i s process of di a g e n e s i s appears t o be minor i n the sediments of Georgia S t r a i t . 39 Chapter 2 . METHODS AND MATERIALS 40 Chapter 2. MATERIALS AND METHODS 2.1. Core C o l l e c t i o n and Sampling Locations The data f o r t h i s research were c o l l e c t e d d u r i n g two c r u i s e s on the f e d e r a l research v e s s e l C.S.S. Vector. The f i r s t , i n May of 1987, c o l l e c t e d 100 sediment cores throughout the sound f o r solid- p h a s e a n a l y s i s : f i f t y - f i v e i n the l a r g e r , outer b a s i n , and f o r t y - f i v e from a more concentrated coverage i n the upper (inner) b a s i n ( F i g s . 1.1 and 1.2). Core depths and geographic l o c a t i o n s are l i s t e d i n Appendix I . A l i g h t w e i g h t g r a v i t y c o r e r s u i t a b l e f o r sampling s o f t sediments (Pedersen et a l , 1985) was used t o c o l l e c t the cores, t h a t ranged from 4 cm t o over 60 cm i n l e n g t h ; the c o r e r does not have a core ca t c h e r attached, so damage t o the i n t e r f a c e was minimized. Each core was v i s u a l l y logged, extruded on deck, and s e c t i o n e d as f o l l o w s (with s e v e r a l exceptions as noted below): 2 cm s l i c e s f o r the f i r s t 10 cm, fo l l o w e d by two 5 cm s e c t i o n s ; the r e s t was di s c a r d e d . These s e c t i o n s were then packed i n l a b e l l e d p l a s t i c bags and s t o r e d i n the s h i p ' s f r e e z e r f o r l a t e r a n a l y s i s . The 0-5, 0-6 and 0-4 cm s e c t i o n s from s i t e 75, 91 and 93 r e s p e c t i v e l y , t h e 0-1 cm s l i c e s from cores 16-B, 64, 70, 80 and 82-B, and the 0-2 cm s l i c e from a l l the other cores were used as s u r f a c e sediment samples. As w e l l , f i v e f u l l -l e n g t h cores were sec t i o n e d and s t o r e d f o r a n a l y s i s , one from the outer b a s i n and four from the upper b a s i n . Three 41 of these cores were found t o be not s u i t a b l e f o r the purposes of t h i s study (although the data are i n c l u d e d ) : #70, which was below the s i t e of a gravel-washing o p e r a t i o n , c o n s i s t e d of extremely coarse, angular sand which s e v e r e l y contaminated the n a t u r a l sediment m a t r i x ; #80 was c o l l e c t e d from the center of a dumpsite used by v a r i o u s i n d u s t r i e s around the sound, and thus was h e a v i l y contaminated by bark, g r a v e l , sand, and wood-chips; i t a l s o s u f f e r e d a l a r g e degree of homogenization d u r i n g thawing and e x t r u s i o n due t o being thawed upside-down, and the r e l a t i v e element c o n c e n t r a t i o n s w i t h depth are thought t o be suspect f o r t h a t reason; core HS 82-B was l o c a t e d between the dump s i t e and the Woodfibre pulp m i l l , and l i k e a l l samples i n t h i s area (HS 82, 83, 84 and 86) was h e a v i l y contaminated by d e b r i s i n the form of wood c h i p s , g r a v e l , and f i b r o u s o rganic m a t e r i a l . F o r t u n a t e l y , the two remaining f u l l - l e n g t h cores (#16-B i n the outer b a s i n , and #64 i n the upper, or i n n e r , basin) were f r e e i f such contamination. These s i t e s were from the deepest, most c e n t r a l , f l a t area i n each of the two b a s i n s , where sedimentation should be e s s e n t i a l l y u n d i sturbed. These cores are t h e r e f o r e thought t o be a p p r o p r i a t e f o r the p a r t i c u l a r t h r u s t of t h i s study. The second c r u i s e , i n A p r i l 1988, c o l l e c t e d two cores f o r porewater a n a l y s i s , a t the same l o c a t i o n s as 16-B i n the lower b a s i n and 64 i n the upper. The f i r s t core taken on t h i s c r u i s e (HS 16-B) was a subsample of a K a s t e n l o t core. 42 T h i s c o r e r subsequently f a i l e d , and core HS 64 i n the i n n e r b a s i n was taken w i t h the l i g h t w e i g h t g r a v i t y c o r e r d e s c r i b e d e a r l i e r . The bottom few cm of HS 64 slumped downward s e v e r a l centimetres d u r i n g h a n d l i n g , r e s u l t i n g i n an a i r f i l l e d c o r i n g gap. This may have r e s u l t e d i n some o x i d a t i o n a t depth i n the core, as d i s c u s s e d i n Chapter 3. Both cores were extruded u s i n g a s p e c i a l l y - c o n s t r u c t e d e x t r u s i o n t a b l e , by pushing a p i s t o n w i t h a s c i s s o r s j a c k upwards through the core b a r r e l . The sediments were extruded d i r e c t l y i n t o a n i t r o g e n - f i l l e d glove bag, where s e c t i o n s were s l i c e d o f f w i t h a p l a s t i c s p a t u l a and p l a c e d i n acid-washed c e n t r i f u g e b o t t l e s . Each b o t t l e was capped, removed from the glove bag, and c e n t r i f u g e d at 1800 G (3000 rpm § r a d i u s 18 cm) f o r 20 minutes, a f t e r which i t was p l a c e d i n t o a separate N 2 - f i l l e d glove bag, and the supernatant poured o f f and f i l t e r e d through acid-washed 0.45 I f i l t e r s . The r e s u l t i n g f l u i d sample was d i v i d e d i n t o f o u r subsamples, not n e c e s s a r i l y equal i n volume, and p l a c e d i n 30 ml polypropylene sample b o t t l e s . Each sample b o t t l e had been acid-washed, l a b e l l e d , and t r e a t e d according t o the type of a n a l y s i s f o r which i t was d e s t i n e d , i . e . : A = A l k a l i n i t y and sulphate sample, acid-washed and pre-weighed. 4- T _ N = N u t r i e n t sample, f o r a n a l y s i s of NH 4 , P0 4 , and N0 3~, acid-washed on l y . 43 M = Trace metal sample, acid-washed and 50 ±1 u l t r a -pure concentrated HN0 3 added t o prevent subse-quent p r e c i p i t a t i o n or a d s o r p t i o n of d i s s o l v e d metals. S = Sulphide sample, acid-washed and 50 i l Zn acet a t e added t o p r e c i p i t a t e a l l d i s s o l v e d s u l p h i d e . Phosphate and ammonia analyses were c a r r i e d out on board s h i p immediately f o l l o w i n g c o l l e c t i o n ; the remaining porewater i n the "N" c o n t a i n e r s was f r o z e n f o r l a t e r n i t r a t e a n a l y s i s i n the l a b . A l l other sample b o t t l e s were kept r e f r i g e r a t e d f o r a n a l y s i s a t a l a t e r date. 2 . 2 . Solid-phase Sediment Analyses 2 . 2 . 1 . Major elements ( S i , A l , T i , Fe, Mg, Ca, K, Na, P) Fused g l a s s d i s c s were prepared f o r major element a n a l y s i s u s i n g a method based on the work of N o r r i s h and Hutton (1969): 0.4 g of d r i e d , ground sediment were added t o 3.6 g S p e c t r o f l u x 105 (47.03% L i 2 B 4 0 7 ; 36.63% L i C 0 3 ; 16.34% L a 2 0 3 ) . L i t h i u m t e t r a b o r a t e and l i t h i u m carbonate reduce the m e l t i n g temperature of the f l u x t o 700°C; lanthanum oxide i s used as a heavy absorber t o increase the mass ab s o r p t i o n of the samples, thus decreasing d i f f e r e n c e s i n the mass a b s o r p t i o n c o e f f i c i e n t s of the v a r i o u s sample m a t r i c e s . S p e c t r o f l u x 105 was k i l n d r i e d at 500°C f o r one hour and s t o r e d i n sealed c o n t a i n e r s before and between use. The sediment-flux mixture was fused i n a platinum c r u c i b l e 44 a t 1100°C f o r 20 minutes i n a m u f f l e furnace. A f t e r c o o l i n g , a small amount of S p e c t r o f l u x 100 was added t o make up the weight l o s s d u r i n g f u s i o n due t o the o x i d a t i o n of o r g a n i c matter and v o l a t i l i z a t i o n of H 20, CaC0 3 and other v o l a t i l e components. S p e c t r o f l u x 100 c o n t a i n s o n l y L i 2 B 4 0 7 ; thus i t s a d d i t i o n maintains the sample:lanthanum r a t i o . The sample was then remelted over a Meker burner i n a fume hood and poured i n t o an aluminum mold on a hot p l a t e s e t at ^400°C. The molten samples were pressed i n t o shape by a brass plunger, cooled, l a b e l l e d , and s t o r e d i n c l e a n , l a b e l l e d p l a s t i c bags f o r l a t e r a n a l y s i s . 2.2.2. Minor elements (Ba, Co, Cr , Cu, Mn, N i , Pb, Rb, Sr, V, Y, Zn and Zr) . Pressed powder p e l l e t s were made f o r minor element a n a l y s i s u s i n g the same d r i e d , ground sediment samples from which g l a s s d i s c s were made. Four grams of sediment were shaken w i t h 0.5 g of Chemplex Spectrographic X-ray mix powder i n a Spex m i x e r / m i l l f o r 10 minutes. The sample (minus the mixing b a l l ) was then placed i n a s t a i n l e s s s t e e l d i e and formed i n t o a r i g i d , borate-backed d i s c i n a h y d r a u l i c press a t 10 tons pressure f o r one minute. Each d i s k was l a b e l l e d and s t o r e d i n a t i s s u e - l i n e d box, sediment-side down (to prevent contamination by a i r b o r n e d u s t ) , u n t i l , a t a l a t e r date, they were loaded i n t o the XRF f o r a n a l y s i s . -> 45 2.2.3. X-Ray Fluorescence Spectrometry The analyses f o r major and minor elements were made on an automated P h i l i p s PW 1400 X-ray f l u o r e s c e n c e s p e c t r o -meter, u s i n g a Rh-target X-ray tube. The instrument was c o n t r o l l e d by a DEC PDT 11 microcomputer which was a l s o used to c a l c u l a t e elemental c o n c e n t r a t i o n s from the X-ray counts. The instrument s e t t i n g s are l i s t e d i n Table 2.1 and 2.2. A n a l y t i c a l p r e c i s i o n f o r the XRF was determined f o r both major and minor elements by d i v i d i n g two sediment samples (the 0-2 cm HS 64 sample f o r major elements, and the 0-5 cm HS 75 sample f o r minor elements) i n t o s i x subsamples each and pr e p a r i n g fused g l a s s and pressed powder d i s c s , r e s p e c t i v e l y , f o r each set of r e p l i c a t e s . The 21 r e l a t i v e standard d e v i a t i o n s f o r a l l elements are l i s t e d i n Tables 2.3 and 2.4. These values show s a t i s f a c t o r y agreement w i t h those obtained by Powys (1987), Losher (1985) and Fr a n c o i s (1987) u s i n g the same instrument s e t t i n g s and c a l i b r a t i o n standards. I n t e r n a t i o n a l geochemical r e f e r e n c e rock standards were used t o c a l i b r a t e the spectrometer and t o monitor i t f o r accuracy d u r i n g each run. Tables 2.5-2.8 l i s t the standards used and compare the measured va l u e s w i t h those recommended i n Abbey (1980) f o r each element. For minor elements w i t h KA wavelengths s h o r t e r than the Fe a b s o r p t i o n edge (elements w i t h atomic numbers g r e a t e r than 27), a ma t r i x c o r r e c t i o n was a p p l i e d u s i n g the Compton 46 Table 2.1 XRF Instrument Conditions for Major Elements. Element Tube Crystal Counter Peak Bkgrd Collimator * kv ma 28 ( ° ) 26 ( ° ) $ Si 60 40 T F 32.23 +2.3/-1.2 C Al 60 40 T F 37.88 + 1. 00 C Fe 60 40 L F 63.14 -1.60 C Ti 60 40 L F 86.35 +3.0/-1.0 c Ca 50 10 L F 113.34 + 1 . 40 C K 60 40 L F 136 .76 + 2 . 00 F Mn 50 20 L F 63.14 -0.86 C Mg 30 60 T F 45. 21 -1 . 20 C P 30 60 G F 141.12 -1 . 50 C S 60 40 G F 110.82 + 1 . 00 C *A11 elements measured on the Ka l ine, except Ba and Pb (LB) •Crystals: L = lithium fluoride (200); T = thallium acid phthalate; G = germanium •Counters: F = flow using 90% Ar & 10% CH«; S=scinti1lation *Coll imators : C = coarse (480 p.m); fine (160 um) 47 Table 2.2 XRF Instrument Conditions for Minor Elements. Element Tube Crys tal Counter Peak Bkgrd Collimator kv ma • V 26 («*) 26 ( ° ) * Ba 60 40 L F 87.19 + 1.20 F Co 60 40 L F 77 . 90 +.54/-.54 F Cr 60 40 L F 69.52 + 1. 00 C Cu 60 40 L F/S 45 . 00 -0. 62 F Ni 60 40 L F/S 48 . 66 +1.2/-0.6 F Pb 60 40 L F/S 28 .29 +0.5/-0.5 F Rb 60 40 L S 26.66 +0.4/-0.9 F Sr 60 40 L S 25.20 +0.6/-0.6 F V 60 40 L F 77.14 +4.0/-2.6 C Y 60 40 L S 23. 83 +0.6/-0.6 F Zn 60 40 L F/S 41.78 0.72 F Zr 60 40 L S 22. 56 +.74/-.74 F Na 30 60 T F 55 .25 + 3.4/-1.7 C *A11 elements measured on the Ka l ine, except Ba and Pb (LB) •Crystals ,: L = l ithium fluoride (200); T = thallium acid phthalate; G germanium •Counters ;: F = flow using 90% Ar & 10% CrU; S=scinti1lation *Collimators : C = coarse (480 pm); fine i (160 pm) 48 Table 2.3 XRF a n a l y t i c a l p r e c i s i o n for major elements, determined by a n a l y s i n g f i v e separate s p l i t s of a s i n g l e homogenized sample. A l l element concentrations presented on a s a l t - f r e e b a s i s . Element %Fe *Mn %ll %Ca %K %S1 U l *Mg *P %Na Repl.# RI 4.72 0.18 0. 42 3. 00 1 .31 26. 24 9 .01 1. 96 0.14 1. 52 R2 4.70 0.18 0. 42 3. 06 1 .35 26. 19 9 .02 1. 99 0.14 1. 51 R3 4.72 0.17 0. 41 2. 99 1 .31 26. 14 8 .97 1. 99 0.14 1. 46 R4 4.69 0.18 0. 42 3. 05 1 .33 26. 14 8 .94 2. 03 0.14 1. 51 R6 4.74 0.17 0. 42 3. 04 1 .31 26. 31 9 .00 2. 04 0.13 1. 49 MEAN 4.74 0.18 0. 42 3. 04 1 .34 26. 16 8 .94 1. 99 0.14 1. 51 1 0.06 0.01 0. 01 0. 04 0 .05 0. 11 0 .12 0. 04 0.00 0. 04 2 0.12 0.01 0. 01 0. 07 0 .10 0. 21 0 .24 0. 07 0.01 0. 07 *RSD(%) 2.61 6.02 3. 15 2. 43 7 .30 0. 82 2 .71 3. 58 4.41 4. 73 T o t a l p r e c i s i o n = % r e l a t i v e standard d e v i a t i o n (2 ) 49 Table 2.4 XRF a n a l y t i c a l p r e c i s i o n for minor elements, determined by a n a l y s i n g s i x separate s p l i t s of a s i n g l e homogenized sample. A l l element concentrations presented on a s a l t - f r e e b a s i s . Element Zr Y Sr Rb Pb Zn Cu NI Co Mn V Cr Ba Na Repl. # RI 83 16 448 40 22 142 192 15 19 946 146 40 827 5 R2 84 16 458 43 26 152 212 14 21 932 140 41 818 5 R3 84 16 461 45 27 149 217 18 27 938 141 46 819 5 R4 85 15 453 44 26 144 201 16 22 923 140 37 823 5 R5 82 14 451 42 20 143 202 14 19 922 136 44 826 5 R6 84 15 458 43 27 160 225 17 23 926 140 42 794 5 Mean 84 15 455 43 25 148 208 15 22 931 140 42 818 5 StdDev 1.1 0.7 4.5 1.6 2.6 6.3 10.8 1.5 2.6 8.7 3.1 2.8 10.9 0.0 2 2.2 1.5 9.0 3.2 5.3 12.7 21.7 3.0 5.3 17.4 6.3 5.5 21.9 0.0 *RSD(%) 2.6 9.7 2.0 7.5 21.5 8.5 10.4 19.7 24.4 1.9 4.5 13.3 2.7 0.7 * T o t a l p r e c i s i o n = % r e l a t i v e standard d e v i a t i o n (2 ) 50 Table 2.5 Accuracy of the measuring program for XRF a n a l y s i s of major elements i n surface sediment samples 1-93. Element concentrations expressed as wt. % oxides (m = measured values; r = recommended values) Element S i A l Ti Fe Ca Mg K Na Mn p Standard DR-N(m) 52.23 17.58 1.08 9.67 7. 05 4.36 1.71 3.36 0.21 0. 23 (m) 52.54 17.42 1.06 9.65 7. 12 4.44 1.78 3.36 0.22 0. 24 ( r ) 52.88 17.56 1.1 9.69 7. 09 4.47 1.73 3.01 0.21 0. 25 NIM-S(m) 62.91 16.93 0.02 1.43 0. 67 0.29 15.34 0.47 0 0. 12 ( r ) 63.63 17.34 0.04 1.4 0. 68 0.46 15.35 0.43 0.01 0. ,12 SY-2(m) 58.7 11.84 0.13 6.25 7. 89 2.65 4.59 4.25 0.33 0. ,43 ( r ) 60.1 12.12 0.14 6.28 7. 98 2.7 4.48 4.34 0.32 0. ,43 MRG-l(m) 38.75 8.23 3.67 17.85 14. 86 12.99 0.18 0.53 0.15 0, ,07 ( r ) 39.32 8.5 3.69 17.83 14. 77 13.49 0.18 0.71 0.17 0, .06 NIM-G(m) 75.23 12.26 0.08 1.98 0. 81 -0.09 5.01 2.83 0.02 0, .01 ( r ) 75.7 12.08 0.09 2.01 0. ,78 0.06 4.99 3.36 0.02 0 .01 BHVO-l(m) 49.67 13.45 2.72 12.37 11. ,57 7.49 0.52 2.3 0.17 0, .27 ( r ) 49.9 13.85 2.69 12.23 11. ,33 7.31 0.54 2.29 0.17 0 .28 GA(m) 68.14 14.48 0.36 2.7 2. ,45 0.82 4.11 3.64 0.07 0 .13 ( r ) 69.96 14.51 0.38 2.8 2. .45 0.95 4.03 3.55 0.09 0 .12 BCR-l(m) 53.75 13.41 2.22 13.48 6, .92 3.54 1.77 3.32 0.18 0 .37 ( r ) 54.53 13.72 2.26 13.42 6, .97 3.48 1.7 3.3 0.18 0 .36 AGV-l(m) 58.67 16.8 1.06 6.81 4 .97 1.61 2.96 4.37 0.11 0 .51 ( r ) 59.61 17.19 1.06 6.8 4 .94 1.52 2.92 4.32 0.1 0 .51 51 Table 2.6 Accuracy of the measuring program for XRF analysis of major elements in cores #16-B, 64, 70, 80 and 82-B. Element concentrations expressed as wt. % oxides (m= measured values; r= recommended values) Element SI Al Ti Fe Ca Mg K Na Mn P Standard GSP-l(m) 67.49 15.52 0.68 4. 36 2.02 1.07 5.5 3. 09 0.04 0. 29 (m) 67.82 15.85 0.68 4. 36 2.04 1.14 5 .43 3. 18 0.05 0. 31 (r) 67.32 15.28 0.66 4. 29 2.03 0.97 5 .51 2. 81 0.04 0. 28 MRG-l(m) 38.66 8.84 3.72 17. 91 14.93 13.2 0 .17 0. 83 0.18 0. 08 (r) 39.32 8.5 3.69 17. 83 14.77 13.49 0 .18 0. 71 0.17 0. 06 G-2(m) 67.94 15.32 0.53 2. 82 1.97 0.9 .45 3. 88 0.04 0. 14 (r) 69.22 15.4 0.48 2. 68 1.96 0.75 .46 4. 06 0.03 0. 13 SY-2(m) 59.62 12.3 0.14 6. 37 7.95 2.79 .48 4. 37 0.32 0. 45 (m) 59.95 12.35 0.15 6. 31 7.93 2.8 .51 4. 32 0.33 0. 45 (r) 60.1 12.12 0.14 6. 28 7.98 2.7 .48 4. 34 0.32 0. 43 DR-N(m) 52.56 17.54 1.08 9. 71 7.01 4.52 .72 3. 15 0.22 0. 23 (r) 52.88 17.56 1.1 9. 69 7.09 4.47 .73 3. 01 0.21 0. 25 NIM-G(m) 75.75 12.64 0.12 2. 03 0.8 0.07 .93 3 .2 0.02 0. 01 (r) 75.7 12.08 0.09 2. 01 0.78 0.06 .99 3. 36 0.02 0. 01 52 Table 2.7 Accuracy of the measuring program for XRF a n a l y s i s of minor elements i n surface sediment samples 1-93. A l l element con c e n t r a t i o n s expressed as ppm (ug/g); m = measured values, r = recommended values Element Ba Co Cr Cu Mn Ni Pb Rb Sr V Y Zn Zr Na Standard AGV-l(m) 1202 20 12 56 837 11 38 64 637 125 20 87 237 3.9 ( r ) 1200 16 10 59 728 15 33 67 660 125 19 86 230 4.3 G2(m) 1916 7 11 12 283 1 31 157 457 59 10 88 298 4.0 (m) 1871 6 3 14 280 0 33 163 474 59 7 86 300 3.9 ( r ) 1900 5 8 10 265 3 30 170 480 36 11 84 300 4.0 MRG-l(m) 32 76 490 115 1247 182 10 7 264 510 16 208 111 0.6 ( r ) 50 86 450 135 1320 195 10 8 260 520 16 190 105 0.7 DR-N(m) 390 40 39 39 1743 17 55 64 360 223 26 148 129 2.8 ( r ) 380 35 45 52 1703 22 65 75 400 220 30 150 125 3 GA(m) 896 14 14 19 781 3 35 167 302 47 19 74 143 3.3 (m) 874 10 12 25 736 5 34 163 300 51 19 80 147 3.4 ( r ) 850 5 12 16 700 7 30 175 310 38 21 80 150 3.5 GM(m) 374 7 14 8 414 3 37 235 125 15 21 34 130 3.8 ( r ) 330 3. 9.6 13 333 7 28 250 135 11 26 39 150 3.7 53 Table 2.8 Accuracy of the measuring program for XRF analysis of minor elements in cores 16-B, 64, 70, 80, and 82-B. A l l element concentrations presented as ppm (ug/g); m = measured values, r = recommended values Element Ba Co Cr Cu Mn Ni Pb Rb Sr Y Y Zn Zr Na Standard AGV-l(m) 1179 22 1 57 850 20 29 64 625 166 23 74 233 3.9 (r) 1200 16 10 59 728 15 33 67 660 125 19 86 230 4.3 DR-N(m) 387 36 33 38 1819 20 41 65 358 272 29 126 129 2.8 (r) 380 35 45 52 1703 22 65 75 400 220 30 150 125 3 GA(m) 850 19 11 18 794 10 23 159 281 74 23 64 143 3.4 (r) 850 5 12 16 700 7 30 175 310 38 21 80 150 3.5 GM(m) 357 2.7 16 4 435 8 28 232 117 37 24 27 129 3.8 (r) 330 3.8 9.6 13 333 7 28 250 135 11 26 39 150 3.7 GSP-l(m) 1335 1 4 19 316 14 43 235 219 84 28 91 511 2.9 (r) 1300 7 12 33 326 9 54 250 240 54 29 105 500 2.8 NIM-S(m) 2675 0.2 20 9 78 4 2 504 60 67 2 11 31 0.4 (r) 2400 4 12 19 80 7 5 530 62 10 3 10 33 0.4 54 r a t i o method outlined i n Reynolds (1963; 1967). The mass absorption c o e f f i c i e n t at a given wavelength (u) i s in v e r s e l y proportional to the i n t e n s i t y of the Compton scattered r a d i a t i o n of the primary X-ray beam. Therefore a mass absorption correction can be applied to the analyte l i n e s of elements within a sample based on the amplitude of the Compton-scattered part of the incident Rh Ka r a d i a t i o n . For elements with Ka wavelengths longer than the Fe absorption edge ( i . e . Mn, Cr, Co, with atomic numbers smaller than 27), and for Ba, which i s analysed using i t s L/3 l i n e , the Compton peak i s not proportional to u, since the emitted fluorescent Ka or L/3 x-rays from these elements are strongly absorbed by Fe i n the matrix. For these elements, matrix corrections are obtained by taking a r a t i o of t h e i r peak amplitude to the i n t e n s i t y of an adjacent background wavelength. Corrections are also needed for interferences where an analyte l i n e of one element overlaps that of another, i . e . Ba and V on Cr; Rb on Y; Ni and T i on V; and Sr on Zr. A l l s o l i d phase major and minor element r e s u l t s are l i s t e d i n Tables A-G, Appendix I I I . 2.2.4. Correction for Seasalt The presence of re s i d u a l sea s a l t i n dried marine sediment samples s i g n i f i c a n t l y a l t e r s the concentration of some elements. This e f f e c t i s most noticeable i n f i n e -grained surface samples with a high water content. Salt content of dried sediments can also serve as a rough 55 i n d i c a t o r of g r a i n - s i z e i n surface samples, as w e l l as the degree of compaction ( i . e . lower water content) w i t h depth i n a short core. To c o r r e c t f o r d i l u t i o n and s p e c i f i c element c o n t r i b u t i o n s from s e a s a l t each sample was analysed f o r c h l o r i n i t y ; the s a l i n i t y was c a l c u l a t e d from t h i s f i g u r e assuming a l l c h l o r i d e i n the sample came from sea s a l t , and the c o r r e c t i o n a p p l i e d t o each elemental c o n c e n t r a t i o n w i t h i n a given sample. Some elemental c o n c e n t r a t i o n s are in c r e a s e d by the presence of t h e i r d i s s o l v e d c h l o r i d e s ; f o r these elements, the c o r r e c t weight per cent i s obtained by ap p l y i n g the f o l l o w i n g c a l c u l a t i o n s (T.F. Pedersen, pers. comm.): % M 9 c o r r = t i n e a s " ( ° ' 0 6 7 X % C 1> % C a c o r r = C ameas - (0.021 X %C1) % K c o r r = Kmeas - (0.020 X %C1) ppm Sr = S r m e a s - (4.13 X %C1) The c o r r e c t i o n f o r d i l u t i o n a p p l i e d t o each element i n a sample was as f o l l o w s : [ E l e m e n t ] s a l t f r e e = [ E l e m e n t ] m e a S u r e d x ^ — 100-1.82(%C1) A l l values f o r major and minor elements have been so c o r r e c t e d and are presented i n graphs and t a b l e s on a s a l t -f r e e b a s i s . 56 2.2.5. Chlorinity Analysis C h l o r i n i t y of the sediment samples was determined v o l u m e t r i c a l l y by a method adapted from S t r i c k l a n d and Parsons (1968). For each surface sample or core i n t e r v a l , approximately 100 mg of d r i e d , ground sediment were weighed and placed i n a c l e a n p l a s t i c c e n t r i f u g e tube. F i v e ml of d i s t i l l e d water were added and the tube h e l d on a v o r t e x s t i r r e r f o r two minutes t o d i s s o l v e the s a l t s . The tubes were then c e n t r i f u g e d f o r t e n minutes at 3000 RPM and the supernatant poured o f f and s t o r e d i n covered p l a s t i c v i a l s . A l i q u o t s of one ml of the supernatant s o l u t i o n were pla c e d i n c l e a n g l a s s v i a l s w i t h a s m a l l t e f l o n - c o a t e d s t i r bar on a magnetic s t i r r e r . One hundred pi of potassium dichromate s o l u t i o n were added as an i n d i c a t o r , and the mixture t i t r a t e d w i t h AgN03 (=0.1484 M) t o the c h l o r i d e end p o i n t , i n d i c a t e d by a c o l o r change from y e l l o w t o red. The t i t r a t i o n s were c a r r i e d out i n t r i p l i c a t e u s i n g a Gilmont mic r o b u r e t t e reading t o t h r e e decimal p l a c e s . The AgNO-j was s t a n d a r d i z e d r e g u l a r l y a g a i n s t a known concen-t r a t i o n of NaCl. The c h l o r i d e content i n a given sediment sample was c a l c u l a t e d from the f o l l o w i n g : %C1~ = V o l . AgN0 3 X [AgN0 3] X 5 X At.Wt.Cl X 100 wt. sample i n g where V o l . AgN0 3 = volume i n ml of AgN0 3 s o l u t i o n used t o t i t r a t e e q u i v a l e n t u n i t s of C l ~ . [AgN0 3] = m o l a r i t y of AgN0 3. [ A g N 0 3 ] 5 m o l a r i t y of AgN0 3. no. of ml of d i s t i l l e d water used t o d i s s o l v e s a l t i n weighed sample. At.Wt. C l 35.45 X 10 3 mg/mole. 2.2.6. T o t a l Carbon and Nitrogen A n a l y s i s T o t a l carbon and n i t r o g e n were determined by gas chromatography on a Carlo-Erba CHN an a l y s e r (model 1106). An accurately-weighed 2 t o 5 mg sample i n a pure t i n co n t a i n e r i s dropped i n t o a v e r t i c a l quartz combustion tube heated t o 1030°C through which a constant flow of helium i s run. The He stream i s enriched w i t h pure oxygen as the sample i s introduced, and the sample i s flash-combusted, aided i n p a r t by o x i d a t i o n of the t i n c o n t a i n e r . The combustion gases which are r e l e a s e d are f u l l y o x i d i z e d , or q u a n t i t a t i v e l y combusted, by passing over a column of C r 0 2 • Excess oxygen i s removed, and n i t r o u s oxides reduced t o N 2, by p a s s i n g the gas over copper heated t o 650°C. The gas i s then passed through a chromatographic column heated t o 100°C, where the components are separated and e l u t e d as N 2, C0 2 and H 20, and measured by a thermal c o n d u c t i v i t y d e t e c t o r . The s i g n a l feeds a p o t e n t i o m e t r i c r e c order and an i n t e g r a t o r w i t h a d i g i t a l p r i n t o u t . The instrument i s c a l i b r a t e d by combusting a c e t a n i l i d e CH 3CONHC 6H 5 (71.09% C and 10.35% N by weight). Samples not run immediately were kept i n a d e s s i c a t o r u n t i l analysed. 58 A run c o n s i s t e d of two bl a n k s , f i v e standards, and 16 samples. Runs i n which the blanks were high were repeated. The mean of the two blanks was sub t r a c t e d from the t o t a l counts f o r each a n a l y s i s , then a constant (KQ f o r carbon, K N f o r n i t r o g e n ) , was c a l c u l a t e d by the f o l l o w i n g formula: Kc = % C i n standard  A r e a c of standard (counts) = 71.09 1 T o t a l counts (C) - blank The mean of the constants f o r the f i v e standards was taken t o be KQ f o r the run, and the t o t a l carbon of the sample was then c a l c u l a t e d by %C = K c — Area of sample (counts) ~ wt. of sample T o t a l n i t r o g e n was measured i n a s i m i l a r manner, using 10.35% N i n the standard t o c a l c u l a t e Kj*. A n a l y t i c a l p r e c i s i o n was determined by running four sediment samples each from two surf a c e l o c a t i o n s (HS 64 and HS 56). The r e l a t i v e standard d e v i a t i o n s (2a) f o r these r e s p e c t i v e set of analyses f o r carbon were: ±1.2% and ±2.4%; and f o r n i t r o g e n : ±7.1% and ±1.85%. Percent organic carbon f o r each sur f a c e and core sample was determined by s u b t r a c t i n g the i n o r g a n i c carbon (determined by coulometric a n a l y s i s ) from the t o t a l carbon measured by CHN a n a l y s i s . The t o t a l , o r g a n i c , and i n o r g a n i c carbon and t o t a l n i t r o g e n c o n c e n t r a t i o n s , and C/N r a t i o s f o r each sample are presented i n Tables H, I and J , Appendix I I I . 2 .2 .7 . Inorganic Carbon I n o r g a n i c , or carbonate, carbon was determined photo-m e t r i c a l l y i n a Coulometrics Inc. 5010 coulometer. Approx-i m a t e l y 25 mg of d r i e d sediment was placed i n a c l e a n g l a s s r e a c t i o n tube. The tube was attached t o the coulometer apparatus and f l u s h e d f o r two minutes w i t h a carbon d i o x i d e -f r e e stream of a i r t o remove a l l t r a c e s of atmospheric C0 2. Two ml of 10% HCL were then added t o the sample tube and the evolved C0 2 gas c a r r i e d t o a t i t r a t i o n c e l l f i l l e d w i t h a s o l u t i o n of ethanolamine and a c o l o u r i m e t r i c i n d i c a t o r . As the gas stream passes through the s o l u t i o n , the C0 2 i s q u a n t i t a t i v e l y absorbed, r e a c t i n g w i t h the ethanolamine t o form a str o n g , t i t r a t a b l e a c i d , i . e . C0 2 + HO-CH2-CH2-NH2 —> HO-CH2-CH2-NH-COOH This causes the blue i n d i c a t o r c o l o r t o fade, which i n t u r n causes the transmittance of a l i g h t beam through the s o l u t i o n t o in c r e a s e ; As the %T i n c r e a s e s , a t i t r a t i o n c u r r e n t switches on a u t o m a t i c a l l y and OH- ions are generated by reducing H 20 a t a s i l v e r e l e c t r o d e , i . e . Ag° —> A g + + e" H 20 + e~ —> "H2 + OH" The OH" n e u t r a l i z e s the a c i d , causing the s o l u t i o n t o r e t u r n t o i t s o r i g i n a l c o l o u r , a t which p o i n t the c u r r e n t i s a u t o m a t i c a l l y switched o f f : HO-CH2-CH2-NH-COOH + OH- —> HO-CH2-CH2-NOO- + H 20 60 The t o t a l amount of current used f o r the t i t r a t i o n i s integrated and the r e s u l t i s displayed as ug C. This figure i s then converted i n t o [ C ] c a r b by the following formula: % Ccarbonate = M CC02 " V<3 C b l a n k X 100 sample weight Each of the 147 surface and core samples was run at le a s t once, and r e p l i c a t e s done on 20 randomly chosen samples throughout the analyses. For these samples the mean was used as the value for the i n t e r v a l . Blanks were also run at regular i n t e r v a l s and showed a maximum value of 5.2 ug C, and a mean of 2.99 jig C. Corrections f o r these values were made within each group of analyses every time a blank was run. A standard of pure CaC03 (12.00% C) was run 19 times during the analysis, giving a mean value of 11.93 ±0.44 (2a) %C. Precision, as r e l a t i v e standard deviation, i s ±3.66% (2a). The r e s u l t s of these analyses were then corrected for d i l u t i o n by seasalt (see Section 2.2.4) and are presented i n Tables H, I and J, Appendix I I I . 6 1 2.3. I n t e r s t i t i a l Water Analyses 2.3.1. Dissolved Phosphate Phosphate i n i n t e r s t i t i a l water was determined c o l o u r i m e t r i c a l l y on board ship within s i x hours of core c o l l e c t i o n , following the method outlined i n Parsons, Maita and L a l l i (1984). Reaction between a mixed reagent and dissolved phosphate y i e l d s a blue solution, the o p t i c a l density of which i s measured at 885 nm. The reagent used consisted of 10 ml ammonium molybdate, 25 ml sulphuric acid, 10 ml ascorbic acid, and 5 ml potassium antimonyl-tartrate solutions mixed together on board ship and used immediately i n the analyses. Five hundred u l of reagent were added to a 5 ml porewater sample i n a clean glass t e s t tube, then measured i n a 1 cm o p t i c a l glass c e l l i n a Bausch and Lomb Spectronic 21 spectrophotometer for e x t i n c t i o n against d i s t i l l e d water. Parsons et a l ( 1984) recommend the use of 10 cm c e l l s , but experience has shown that 1 cm c e l l s are s u f f i c i e n t f o r porewater as i t t y p i c a l l y contains much higher nutrient concentrations than seawater. Indeed, many samples had to be d i l u t e d considerably to enable them to l i e within the range of maximum accuracy, i . e . <=0.5 absorbance u n i t s . A standard curve for each set of samples was determined by measuring the absorbances of a stock solution of KH^PO^ which had been d i l u t e d to concentrations of 60, 45, 30, 15, and 0 uM for core HS 16-B, and 60, 45, 30, 24, 15, 12, 6 and 62 0 /JM f o r core HS 6 4 . The r e s u l t a n t slopes ( F i g . 2 . 1 ) were used t o c a l c u l a t e the PO^ c o n c e n t r a t i o n i n the samples from t h e i r measured absorbance which had been c o r r e c t e d a g a i n s t the reagent blank. The f i n a l determinations of phosphate c o n c e n t r a t i o n s i n the porewater samples are presented i n Tables K and L, Appendix I I I . 2.3.2. Dissolved Ammonia Ammonia was measured i n porewater samples f o l l o w i n g the a l t e r n a t i v e method o u t l i n e d i n Parsons et a l ( 1 9 8 4 ) , s c a l e d t o f i t the small volumes of porewater samples. Ammonia r e a c t s w i t h phenol i n an a l k a l i n e c i t r a t e medium, w i t h sodium n i t r o p r u s s i d e added as a c a t a l y s e r , and the blue indophenol c o l o u r thus formed i s then measured s p e c t r o p h o t o m e t r i c a l l y . As w i t h phosphate, ammonia was measured on board s h i p immediately f o l l o w i n g e x t r u s i o n of the core. For the HS 1 6 -B samples, a 6 0 0 pi subsample of each i n t e r v a l was d i l u t e d w i t h d e i o n i z e d water t o 5.2 ml and placed i n a g l a s s t e s t tube. Then 1 ml phenol, 1 ml n i t r o p r u s s i d e , and 2.5 ml of an o x i d i s i n g agent ( c o n s i s t i n g of a mixture of sodium c i t r a t e , sodium hydroxide, and h y p o c h l o r i t e s o l u t i o n s ) were added. A f t e r one hour at room temperature, the s o l u t i o n was measured i n a one-cm g l a s s o p t i c a l c e l l a t a wavelength of 6 4 0 nm on a Bausch and Lomb Sp e c t r o n i c 2 1 spectrophotometer. For core HS 6 4 , the sample s i z e was reduced t o 2 0 0 ul t o al l o w the measurements t o f a l l w i t h i n the range of maximum 63 0 20 40 60 0 20 40 60 [P04], uM Fig.2.1 Standard curves for phosphate analyses of Howe Sound porewaters accuracy, i . e . <0.350 absorbance. A stock s o l u t i o n of 1.903 mM NH3 was prepared by d i s s o l v i n g 0.0509 g of NH 4C1 i n 500 ml H 20. This was then d i l u t e d t o v a r i o u s s t r e n g t h s and measured t o g i v e a standard curve f o r the sample c a l c u l a t i o n s . The standard curves are shown i n F i g . 2.2. The r e s u l t s of the ammonia analyses on the porewater samples are given i n Tables K and L, Appendix I I I . 2.3.3. Nitrate N i t r a t e s i n porewater were measured on a Technicon Autoanalyser I I f o l l o w i n g the method o u t l i n e d i n Parsons et a l (1984). The porewater sample i s passed through a column f i l l e d w i t h copper-coated cadmium f i l i n g s which reduces N03-t o N02-. This species then combines w i t h s u l f a n i l a m i d e and N-(1-naphthyl)-ethylenediamine t o form an azo dye which i s measured by a dedicated spectrophotometer at 543 nm. F o l l o w i n g phosphate and ammonia analyses on board s h i p , the remaining porewater samples i n the "N" b o t t l e s were placed i n the s h i p ' s f r e e z e r and kept f r o z e n u n t i l they were analysed a few months l a t e r . During the run, a set of standards ( c o n s i s t i n g of NaN0 3 i n 3% a r t i f i c i a l seawater at 4, 8, 12, 16, 20, and 24 uM) p l u s a blank was run at r e g u l a r i n t e r v a l s t o give a standard curve f o r the samples. U n f o r t u n a t e l y , n i t r a t e occurred i n h i g h l y v a r i a b l e amounts (from 7 uH t o over 600 /JM) i n the samples, r e f l e c t i n g s p o r a d i c , severe contamination, and i t was f e l t 65 8 Ammonia Standard Curve, Core HS 16-B Ammonia Standard Curve, Core HS 64 0 20 40 60 800 20 40 60 80 [NH3], UM Fig. 2.2 Standard curves for ammonia analyses in Howe Sound porewater t h a t the source of t h i s was most l i k e l y the n i t r i c a c i d wash which some of the sample b o t t l e s had undergone p r i o r t o the c r u i s e . For t h i s reason the data were deemed t o be u s e l e s s , and so are not i n c l u d e d here. 2.3.4. Dissolved Sulphide Hydrogen s u l p h i d e was determined c o l o u r i m e t r i c a l l y f o l l o w i n g the method o u t l i n e d by C l i n e (1969). The method i s i d e a l f o r porewater samples as i t i s s e n s i t i v e over the ranges t y p i c a l l y found i n c o a s t a l sediments (1-1000 uM) and i s u n a f f e c t e d by v a r y i n g s a l i n i t i e s or temperatures. This method i n v o l v e s the r e a c t i o n of H2S species i n the porewater w i t h N,N-dimethyl-p-phenylenediamine sulphate i n an a c i d i c medium w i t h f e r r i c c h l o r i d e as a c a t a l y s t , forming methylene blue which i s measured i n a spectrophotometer at 67 0 nm. The porewater samples d e s t i n e d f o r s u l p h i d e a n a l y s i s had been placed, f o l l o w i n g core e x t r u s i o n , i n 30-ml sample b o t t l e s which had been purged w i t h n i t r o g e n , and t o which 50 u l z i n c acetate had been added t o p r e c i p i t a t e the d i s s o l v e d s u l p h i d e s . These sample b o t t l e s were kept i n a p l a s t i c bag and r e f r i g e r a t e d u n t i l they were analysed about 60 days a f t e r the c r u i s e . A stock s o l u t i o n f o r determination of standard curves was prepared by d i s s o l v i n g a known amount of Na2S*9H20 i n oxygen-free water. This primary stock was s t a n d a r d i z e d w i t h a known c o n c e n t r a t i o n of t h i o s u l p h a t e , then d i l u t e d t o form secondary standards which corresponded t o the four 67 concentration ranges measured by the diamine reagents (1-3, 3-40, 40-250, and 250-1000 uM) . A series of solutions i n varying concentrations was then prepared by further d i l u t i n g t h i s secondary stock; each series was measured at 670 nm to give a standard curve for that concentration range. The standard curves are shown i n Figs. 2.3. Each porewater sample was treated with the diamine reagent corresponding to the expected concentration range and allowed to develop for = 20 minutes, then measured i n a 1-cm glass o p t i c a l c e l l on a Bausch and Lomb Spectronic 2000 spectrophotometer at 67 0 nm. The measurements obtained from the porewater samples are l i s t e d i n Tables K and L, Appendix I I I . 2.3.5. Titration Alkalinity The a l k a l i n i t y of the porewaters was determined by d i r e c t potentiometric t i t r a t i o n of the sample with HCl to the carbonate end point, following the p r i n c i p l e s outlined by Edmond (1970) and Gieskes and Rogers (1973). The porewater samples i n the "A" sample b o t t l e s were re f r i g e r a t e d following c o l l e c t i o n . Samples were t i t r a t e d i n the o r i g i n a l sample bottles to ensure that any CaCC>3 which might have p r e c i p i t a t e d on storage was included i n the anal y s i s . Varying amounts of d i s t i l l e d water were added to the samples to ensure that there was enough so l u t i o n to cover the pH electrode. (Although t h i s addition of d i s t i l l e d water had no apparent e f f e c t on the a l k a l i n i t y 68 [ H 2 S ] , uM I T 1 1 1 1 1 1 1 1 \J I I 1 1 I I I I 1 1 1 1 0 100 200 300 400 0 400 800 1200 [HaS], uM Fig.2.3 Standard curves for sulphide analyses in Howe Sound porewaters 69 measurements, i t was to prove problematic l a t e r when the same samples were used for sulphate analysis, causing small a n a l y t i c a l errors to be magnified up to 14X when the d i l u t i o n factor was applied.) The sol u t i o n was s t i r r e d with a small magnetic t e f l o n -coated s t i r r e r bar throughout the t i t r a t i o n , which was c a r r i e d out with 0.1 N HCl i n a 2 ml Gilmont microburette; the pH was measured i n mv by a Corning pH meter. The bicarbonate end point of the t i t r a t i o n was determined by extrapolating the l i n e a r portion (based on a minimum of 12 measurements) of a Gran function, as described by Gieskes and Rogers (1973). This method plots the volume of acid added (V^) versus F 2 , a factor which incorporates the measured voltage, the o r i g i n a l sample volume, the temperature, and a constant A. When graphed, the l i n e a r portion, which l i e s between the values of corresponding to pH 3.5-2.5, gives an x-intercept (V^) which represents the second end-point of the carbonic acid system. The a l k a l i n i t y i s then calculated by the formula TA = V 2'.N a)•lOOOmL/L  V o where TA = t i t r a t i o n a l k a l i n i t y i n meq/L V 2 = x-intercept of l i n e a r portion of Gran function N a = normality of acid V Q = o r i g i n a l sample volume. The accuracy of t h i s method was within 0.7-0.9%, 70 reasonably c l o s e t o the 0.5% recorded by Gieskes and Rogers (1973). The discrepancy might have been due t o small i n a c c u r a c i e s caused by d r i f t of the pH meter, which needed constant r e c a l i b r a t i o n a g a i n s t BDH (pH 4 and 7) b u f f e r s . The a l k a l i n i t y data are l i s t e d i n Tables K and L, Appendix I I I . 2.3.6. Sulphate Sulphate analyses were c a r r i e d out on the samples which had p r e v i o u s l y been used f o r a l k a l i n i t y t i t r a t i o n s . As p r e v i o u s l y noted, a . c e r t a i n amount of d i l u t i o n w i t h d e i o n i z e d water was necessary f o r the a l k a l i n i t y measurements i n order f o r the s o l u t i o n i n the sample c o n t a i n e r t o cover the pH e l e c t r o d e . This had l i t t l e or no e f f e c t on the a l k a l i n i t y measurements (once the sample volume had been c o r r e c t e d f o r the added w a t e r ) , but i t proved unfortunate f o r the accuracy of the sulphate analyses. Sulphate was measured according t o the method o u t l i n e d by Howarth (1977), which i n v o l v e s the a d d i t i o n of BaCl2 t o the porewater sample and c o l l e c t i n g the BaSO^ p r e c i p i t a t e on a f i l t e r , thus removing the e f f e c t of any i n t e r f e r i n g ions present i n the porewater. The p r e c i p i t a t e , e x t r a c t e d i n an EDTA s o l u t i o n at low pH, i s then r e d i s s o l v e d i n a known excess of EDTA at high pH. The excess EDTA i s then t i t r a t e d w i t h MgCl2 i n the presence of eriochrome black-T dye which t u r n s from a dark b l u i s h purple t o a p u r p l i s h red i n the 71 presence of free Mg ions. The end point i s somewhat subjective which makes pr e c i s i o n d i f f i c u l t . However, t h i s problem was a minor one compared with the d i f f i c u l t i e s experienced with having many handling steps, as well as the l i m i t e d accuracy associated with the p r i o r d i l u t i o n of the samples. In the end, analyses were c a r r i e d out i n t r i p l i c a t e to reduce the chance of error caused by loss of p r e c i p i t a t e during handling. If a l l three measurements were close ( i . e . within 2%), the mean was taken as the correct value; however, i f one of the three deviated from the mean by more than 2%, i t was discarded, and the mean of the other two was taken as the true measurement. One ml of porewater sample, 3 ml of 0.4 M HCl, and 4 ml of 0.01 M EDTA were placed i n a 25 ml erlenmeyer f l a s k and bo i l e d gently for ~2 min. Ten ml 0.05 M HCl were added, and a few minutes l a t e r 5 ml of 10% BaC^. The s o l u t i o n was allowed to s i t for 20 min., then pumped through a 0.45 u • R • • M i l l i p o r e f i l t e r , which c o l l e c t e d the BaSO^ p r e c i p i t a t e , allowing the other dissolved ions to pass through. The f i l t e r was then transferred back to the empty f l a s k , 4 ml of NH^OH and 5 ml 0.01 M EDTA added, and the s o l u t i o n placed again on a hot plate and heated to =90° f o r 15 minutes. After cooling, 0.5 ml of a pH 10 buffer s o l u t i o n was added to keep the pH high, and the solution was t i t r a t e d i n the f l a s k with 0.025 M MgCl2. The end point was reached when the solution turned from blue to a well-developed red/pink 72 c o l o r . Standards were prepared by d i l u t i n g IAPSO seawater ( 2 8 . 9 4 0 mM S 0 4 ) t o 1 4 . 4 7 0 , 1 1 . 5 7 6 , 5 . 7 8 8 , and 2 . 8 9 4 mM; these were run each day w i t h a reagent blank p r i o r t o the porewater samples f o r t h a t day. When new reagents were made up, a new set of standards was run. The sulphate content was then c a l c u l a t e d by ap p l y i n g the formula e s t a b l i s h e d by the standard curve f o r t h a t group of analyses, and c o r r e c t i n g f o r the d i l u t i o n f a c t o r . The data f o r the sulphate analyses are given i n Tables K and L, Appendix I I I . 2.3.7. Dissolved Metals 2.3.7.1. Iron and Manganese Porewater Mn and Fe were measured by fl a m e l e s s atomic a b s o r p t i o n spectrometry on a V a r i a n SpectrAA*300 w i t h a Zeeman g r a p h i t e tube atomizer. Pure or d i l u t e d samples were i n j e c t e d d i r e c t l y i n t o the furnace, along w i t h 5 ul of pal l a d i u m m o d i f i e r ( = 1 0 0 0 pmm Pd i n 1% H N O 3 ) f o r each measurement, i n order t o c o n t r o l the matrix e f f e c t s caused by d i s s o l v e d s e a s a l t i n the porewater. Standards were prepared by d i l u t i n g a primary stock s o l u t i o n of known co n c e n t r a t i o n s of the metals of i n t e r e s t w i t h d i s t i l l e d , d e i o n i z e d water t o l i e w i t h i n the ranges expected of the i n t e r s t i t i a l water v a l u e s . The instrument was c a l i b r a t e d r e g u l a r l y t o a l i n e a r curve based on these standards. The a c t u a l samples were d i l u t e d when necessary w i t h d i s t i l l e d , d e i o n i z e d water i n acid-washed sample cups, and a l l 73 manipulations were done i n a laminar c l e a n a i r flow hood. The programs f o r Fe and Mn were designed t o i n c l u d e a 52-second d r y i n g and ashing time, t o a l l o w the d i s s o l v e d s a l t s t o burn o f f completely before a t o m i z a t i o n of the t r a c e metal. The program measured three r e p l i c a t e s of each sample and computed the r e l a t i v e standard d e v i a t i o n , the mean absorbance, and the c o n c e n t r a t i o n i n ppb. The f i n a l c o n c e n t r a t i o n f o r each i n t e r v a l was determined by m u l t i p l y i n g t h i s r e s u l t w i t h the d i l u t i o n f a c t o r (determined l a r g e l y by t r i a l and e r r o r , e s p e c i a l l y f o r Fe, which v a r i e d w i d e l y from sample t o sample). The instrument was c a l i b r a t e d whenever a new g r a p h i t e tube was used, and the slope r e c a l c u l a t e d a f t e r every three or four samples i n order t o keep the R.S.D.'s w i t h i n reasonable l i m i t s . The l a r g e amount of s c a t t e r i n the d i s s o l v e d i r o n measurements being something of a concern, a second Fe run was performed on samples 127-183. For t h i s run, plat f o r m s were used i n the g r a p h i t e tubes. These have been shown t o help reduce the tube d e t e r i o r a t i o n and i n c r e a s e the accuracy and r e p r o d u c i b i l i t y of the measurement. The blanks and standards f o r t h i s run were made from seawater r a t h e r than DDW. As w e l l , the g r a p h i t e furnace parameters and the measuring program were s l i g h t l y d i f f e r e n t from the f i r s t run, i n c l u d i n g higher temperatures and longer times f o r d r y i n g and ashing, and a s l i g h t l y lower a t o m i z a t i o n 74 temperature (Tables 2.9 and 2.10). However, t h i s second run produced r e s u l t s s i m i l a r to the f i r s t ; therefore the data are included with those from the o r i g i n a l run, and are presented i n Tables M and N, Appendix I I I . 2.3.7.2. Copper, Zinc and Lead Samples were extracted using a method from Boyle and Edmond (1975) adapted to small sample sizes such as are obtained f o r porewaters (G. Klinkhammer, unpubl. rep.). A 1 ml porewater sample i s spiked with C 0 C I 2 and the dissolved trace metals co-precipitated with APDC (ammonium p y r r o l i d i n e dithiocarbamate) chelate. Afte r c e n t r i f u g a t i o n , the i n t e r f e r i n g s a l t matrix i s removed with the super natant, and the p r e c i p i t a t e redissolved i n n i t r i c a c i d . Trace metals were measured by graphite furnace atomic absorption spectrometry using a Varian SpectrAA*300 with a Zeeman background co r r e c t i o n . Klinkhammer (unpubl. rep.) found the accuracy of the method to be better than ±10%, even at concentrations of 0.1 ppb. A l l plasticware used for the analyses were acid-washed i n hot (40°C) 20% H N O 3 for 24 hours, followed by two 24-hour baths i n 0.1% H N O 3 , with deionized, d i s t i l l e d water rinses between each. Afte r drying, a l l materials were stored i n clean, l a b e l l e d p l a s t i c bags. The trace metal samples were those from which Fe and Mn had previously been measured, and had been a c i d i f i e d with 50 pi concentrated H N O 3 . One ml was removed from each sample 75 Table 2.9 Furnace parameters for dissolved Hn and Fe. Step No. T Time Gas Flow Gas Type Read ( O (sec) (L/min) Command Fe Mn Fe Mn 1 105 105 15.0 15.0 3.0 Normal No 2 150 150 20.0 20.0 3.0 Normal No 3 1400 1300 10.0 10.0 3.0 Alternate No 4 1400 1300 5.0 5.0 3.0 Alternate No 5 1400 1300 2.0 2.0 0.0 Normal No 6 2700 2700 0.8 0.7 0.0 Normal Yes 7 2700 2700 2.0 2.0 0.0 Normal Yes 8 2700 2700 2.0 2.0 3.0 Normal No Fe Run 12 Step No. T Time Gas Flow Gas Type Read ( O (sec) (L/min) Command 1 300 10.0 3.0 Alternate No 2 350 40.0 3.0 Alternate No 3 1500 10.0 3.0 Alternate No 4 1500 10.0 3.0 Alternate No 5 1500 2.0 0.0 Normal No 6 2650 0.6 0.0 Normal Yes 7 2650 2.0 0.0 Normal Yes 8 2650 2.0 3.0 Normal No 9 40 14.0 3.0 Normal No 76 Table 2.10 Graphite furnace settings for dissolved Fe and Hn. Fe Mn Instrument mode Calibration mode Measurement mode Lamp Position Lamp current (mA) S l i t width (nm) S l i t height Wavelength (nm) Sample Introduction Time Constant Measurement time (sec) Replicates Background correction Maximum absorbance Absorbance Concentration Peak height 1 5 0.2 Reduced 248.3 Sampler automixing 0.05 1.0 3 On 0.90 Absorbance Concentration Peak height 3 5 0.2 Normal 279.5 Sampler automixing 0.05 1.0 2 On 1.20 Fe (Run 2) Instrument mode Calibration mode Measurement mode Lamp Position Lamp current (mA) S l i t width (nm) S l i t height Wavelength (nm) Sample Introduction Time Constant Measurement time Replicates Background correction Maximum absorbance Absorbance Concentration Peak area 1 5 0.2 Reduced 248.3 Sampler automixing 0.05 1.0 2 On 0.90 77 b o t t l e and s a c r i f i c e d to determine, by colourimetric t i t r a t i o n (using 10 pi n i t r a z i n e yellow as an indic a t o r ) the quantity of NH4OH required to neutra l i z e the pH at 6.5 (the pH at which extraction e f f i c i e n c y was optimum). The amount of NH4OH added vari e d from sample to sample due to the d i f f e r e n t a c i d to porewater r a t i o s i n each sample. The procedure was as follows: 1) one ml of sample was removed from the sample b o t t l e and placed i n a 1.5 polypropylene centrifuge tube with a f i t t e d l i d . Twenty-five ul 4M C 0 C I 2 s o l u t i o n and the previously-recorded quantity of NH4OH were added. 2) 100 ul =2% APDC solution was added, and the solut i o n allowed to s i t f o r 15 minutes; the tube was then mixed on Vortex s t i r r e r f o r 10-20 seconds. 3) the tubes were placed i n the centrifuge and spun down fo r 20 minutes at 1500 g r a v i t i e s , a f t e r which the supernatant was taken o f f with an aspirator and f i n e pipette t i p . 4) one ml DDW was added, mixed on the Vortex s t i r r e r , and the centrifuge and a s p i r a t i o n procedure repeated. The p r e c i p i t a t e was then allowed to dry uncovered on a hot plate i n a laminar flow hood for 2-3 hours. 78 5) 200 u l 3M HN03 was added t o each tube and di g e s t e d on a hot p l a t e f o r 24 hours. Digested samples were a l l made up t o 1 ml by the a d d i t i o n of 800 ml of DDW. This r e s u l t e d i n a co n c e n t r a t i o n f a c t o r of 1. This s o l u t i o n was then run on the gr a p h i t e furnace. Standards were prepared by d i l u t i n g a primary stock s o l u t i o n of known co n c e n t r a t i o n s of the metals of i n t e r e s t w i t h d i s t i l l e d , d e i o n i z e d water t o l i e w i t h i n the ranges expected of the i n t e r s t i t i a l water v a l u e s . The instrument was c a l i b r a t e d r e g u l a r l y t o a l i n e a r curve based on these standards. The a c t u a l samples were d i l u t e d when necessary w i t h 0.6M HNO3 i n d i s t i l l e d , d e i o n i z e d water i n acid-washed sample cups, and a l l manipulations were done i n a laminar c l e a n a i r flow hood. The program measured two r e p l i c a t e s of each sample and computed the r e l a t i v e standard d e v i a t i o n , the mean absorbance, and the co n c e n t r a t i o n i n ppb. The f i n a l c o n c e n t r a t i o n f o r each i n t e r v a l was determined by a p p l y i n g the f o l l o w i n g equation: (V + C X)E + C 2 = M where V = Concentration of sample i n ppb C-i = contamination from C o C l 2 , NH4OH, APDC, p l a s t i c s , and handling a f t e r e x t r a c t i o n C 2 = contamination from 3M HNO3, p l a s t i c s , and handling a f t e r e x t r a c t i o n 79 E = extraction e f f i c i e n c y M = measured value, calcu l a t e d i n ppb was measured by running a DDW blank through the extraction process and subtracting C2. C2 was determined by performing the l a s t portion of the process only, i . e . placing 200 ul 3M HNO3 i n an empty clean centrifuge tube, d i l u t i n g i t to 800 ul with DDW, and measuring i t on the AA. E was measured by spiking d i s t i l l e d water, oxic porewater from Vancouver Harbour, and anoxic porewater from Saanich Inlet with standard additions of dissolved metals i n 100 pi 0.1% HN03. A DDW blank was also run, as well as an empty digestion blank (C2). E was the slope of the curve obtained from the pl o t of known concentration against recovered concentration of these standard additions. The concentrations i n ppb were converted to molar values using the following conversion f a c t o r s : Cu: 1 ppb = 1 ng/g = 15.7 nmol/L Zn: 1 ppb = 1 ng/g = 15.29 nmol/L Pb: 1 ppb = 1 ng/g = 4.83 nmol/L Two r e p l i c a t e extractions were performed on the inner basin core samples (HS 64). The furnace parameters and settings are l i s t e d i n Tables 2.11 and 2.12. The r e s u l t s of these runs are l i s t e d with the rest of the trace metals data, i n Tables M and N, Appendix I I I . 80 Table 2.11. Furnace parameters for dissolved Cu, Pb and Zn Copper and lead Step No. T ( C) Cu Pb 1 300 300 2 300 300 3 1000 600 4 1000 600 5 2700 600 6 2700 2300 7 2700 2300 8 40 2300 9 40 Zinc > No. T Time Gas Flow Gas Type Read ( C) (sec) (L/min) Command 1 300 3 3.0 Normal No 2 300 40 3.0 Normal No 3 700 5 3.0 Normal No 4 700 5 3.0 Normal No 5 700 1 0.0 Normal No 6 2000 0.7 0.0 Normal Yes 7 2000 2 0.0 Normal Yes 8 2000 1 3.0 Normal No 9 40 10 3.0 Normal No Time Gas Flow Gas Type Read (sec) (L/min) Command Cu Pb 10 10 3.0 Normal No 65 50 3.0 Normal No 5 5 3.0 Normal No 5 5 3.0 Normal No 0.9 1 0.0 Normal No 3.5 1 0.0 Alternate Yes 1 2 0.0 Alternate Yes 13.3 1 3.0 Normal No 11.8 3.0 Normal No 81 Table 2.12 Graphite furnace settings for dissolved Cu, Pb and Zn Cu Pb Instrument mode Absorbance Absorbance Calibration mode Concentration Concentration Measurement mode Peak area Peak area Lamp Position 1 1 Lamp current (mA) 4 5 S l i t width (nm) 0.5 0.5 S l i t height Reduced Reduced Wavelength (nm) 327.4 283.3 Sample Introduction Sampler automixing Sampler automixing Time Constant 0.05 0.05 Measurement time (sec) 1.0 1.0 Replicates 2 2 Background correction On On Maximum absorbance 1.6 1.4 Zn Absorbance Concentration Peak area 3 5 1.0 Reduced 213.9 Sampler automixing 0.05 1.0 2 On 0.90 Instrument mode Calibration mode Measurement mode Lamp Position Lamp current (mA) S l i t width (nm) S l i t height Wavelength (nm) Sample Introduction Time Constant Measurement time Replicates Background correction Maximum absorbance 82 Chapter 3. RESULTS AND DISCUSSION 83 Chapter 3. Re s u l t s and Di s c u s s i o n  3.1 Major Components The main c o n t r i b u t o r s t o ocean sediment are d e t r i t a l , a u t h i g e n i c and biogenous m a t e r i a l s ( C a l v e r t , 1976). The west coast of B r i t i s h Columbia, w i t h i t s high p r e c i p i t a t i o n , h igh r e l i e f , and r e l a t i v e l y young igneous and sedimentary t e r r a n e s , i s c h a r a c t e r i z e d by nearshore sediments which are dominated by the d e t r i t a l component. Since t h i s one f r a c t i o n overpowers the other sources, the chemical composition of sediments i n most f j o r d s should s t r o n g l y r e f l e c t the composition of the bedrock of the drainage basins which feed them. S y v i t s k i and MacDonald (1982) i d e n t i f i e d three sources of d e t r i t a l m a t e r i a l t o Howe Sound sediments: f i r s t , which dominates sediment d e l i v e r y t o the upper b a s i n , i s the Squamish R i v e r ; the second, a l s o i n the upper b a s i n , i s the B r i t a n n i a Mine ore body, from which t a i l i n g s were d e r i v e d ; and t h i r d i s the Fraser R i v e r plume, the i n f l u e n c e of which i s d i s c e r n i b l e t o v a r y i n g degrees i n sediments of the lower b a s i n . In t h i s study, the end members used t o represent these three sources are surface samples from core #93 (the san d i e s t of the Squamish D e l t a sediments, and probably the most p r i s t i n e of a l l the surface samples), core #1 (at the mouth of Howe Sound, where Fr a s e r R i v e r water enters the sound from Georgia S t r a i t ) , and core #75, a s i l t y / s a n d y 84 sample taken from c l o s e t o B r i t a n n i a Beach at a depth of 190 m. The surface sample from l o c a t i o n #54, which has the highest aluminum content of any sample, i s considered a reasonable end member f o r the c l a y f r a c t i o n . None of these l o c a t i o n s represent pure or " n a t u r a l " sediments, given the complexity of the c i r c u l a t i o n p a t t e r n s and the degree of anthropogenic a c t i v i t y i n and around the sound. However, f o r the purposes of t h i s study they are probably adequate. Other minor, or l o c a l sources of p o t e n t i a l l y v a r y i n g m i n e r a l compositions are the many creeks which enter the sound from a l l s i d e s . Most are sm a l l and t h e i r i n f l u e n c e may be considered t o be n e g l i g i b l e ; however, s e v e r a l creeks which i n c i s e i n t o formations r a d i c a l l y d i f f e r e n t from those nearby, such as Furry Creek on the east s i d e of the upper b a s i n , and P o t l a t c h Creek on the northwest s i d e of the lower b a s i n , serve as p o i n t sources f o r s p e c i f i c m i nerals not found elsewhere i n s i g n i f i c a n t c o n c e n t r a t i o n s . These w i l l be d i s c u s s e d l a t e r i n more d e t a i l . Two sources provide the bulk of the biogenous component of Howe Sound sediments. Plankton are the main source of organic m a t e r i a l i n p e l a g i c and hemipelagic marine sediments (Morris and C a l v e r t , 1977), and may c o n t r i b u t e a s i g n i f i c a n t organic f r a c t i o n t o nearshore d e p o s i t s as w e l l . However, i n semi-enclosed areas such as B.C. f j o r d s , the t e r r e s t r i a l o r g anic component i s f r e q u e n t l y s u b s t a n t i a l , as l e a v e s , s t i c k s , branches and other d e t r i t u s are washed i n t o the 85 sound f o l l o w i n g heavy r a i n s and du r i n g the f r e s h e t . In Howe Sound, the t e r r e s t r i a l organic load may a l s o be in c r e a s e d by the l a r g e amount of log-booming a c t i v i t y which occurs year-round i n the area, as w e l l as organic waste from two pulp m i l l s , one at the northern t i p of the upper b a s i n (Woodfibre), the other i n Thornbrough Channel, P o r t Mellon (see F i g s 1.1 and 1.2). Aut h i g e n i c c o n t r i b u t i o n s t o sediments are the r e s u l t of e a r l y d i a g e n e s i s and have been d i s c u s s e d i n S e c t i o n 1.2. Products of such r e a c t i o n s i n c l u d e i r o n and manganese oxi d e s , carbonates, i r o n sulphides such as p y r i t e and marc a s i t e , chamosite, and c l a y m i n e r a l s , which i n Howe Sound take the form p r i m a r i l y of b i o t i t e , i l l i t e , and c h l o r i t e ( S y v i t s k i and Macdonald, 1982). For t h i s study, Howe Sound sediments are broken i n t o f i v e u n i t s , based l a r g e l y on t h e i r l o c a t i o n i n the f j o r d : 1. Lower Basin - i n c l u d e s samples #1-40, 49-B, and 51, but excludes those l o c a t e d i n Thornbrough Channel. 2. Thornbrough Channel - samples #13, 17, 19, 22, 23, 26, and 29. 3. S i l l - samples #34, 37, 38, 41-47, 48, 50, 50B, 52, 53 and 58. (No major element analyses are a v a i l a b l e f o r sample #56, as the g l a s s d i s k repeatedly s h a t t e r e d on c o o l i n g ) . 4. Upper Basin - samples #51, 54, 55, 57, 59-82B (excluded i s sample #65 f o r the same reason as #56) . 5. D e l t a - samples #82-93. V a r i a t i o n s of elemental c o n c e n t r a t i o n s i n sediments do 86 not n e c e s s a r i l y r e f l e c t input by c e r t a i n m i n e r a l s , s i n c e v a r y i n g degrees of d i l u t i o n by other components may be o p e r a t i n g . To avoid m i s i n t e r p r e t a t i o n s caused by such e f f e c t s , r a t i o s of one element t o another are commonly used i n p l a c e of absolute abundance. Aluminum, an element e s s e n t i a l l y e x c l u s i v e t o s i l i c a t e m i n e r a l s , i s f r e q u e n t l y used t o normalize major element c o n c e n t r a t i o n s , and t o determine whether changes i n composition indeed r e v e a l v a r y i n g mineralogy of the source rocks or whether they are due simply t o d i l u t i o n by other m a t e r i a l s . Thus, element/Al r a t i o s w i l l be used f r e q u e n t l y i n t h i s work. G r a i n - s i z e v a r i a t i o n s f u r n i s h another c o n t r o l on the r e l a t i v e abundances of a number of elements i n sediments. This has t o do w i t h the mechanical w e a t h e r a b i l i t y of d i f f e r e n t m i n e r a l s ; thus c e r t a i n minerals are e nriched i n c o a r s e r ( i . e . sand, s i l t ) f r a c t i o n s w h i l e others are concentrated i n the f i n e r p o r t i o n s (mud, c l a y ) . This t e x t u r a l c o n t r o l i s so important t h a t any study of sediment composition must take i n t o account any d i s s i m i l a r i t i e s i n g r a i n s i z e e x i s t i n g between sediment samples ( C a l v e r t , 1976). For t h i s reason, two of the Howe Sound sur f a c e sediment subgroupings ( i . e . the s i l l and the d e l t a , which are both p r i m a r i l y l a g d e p o s i t s ) are expected t o be t e x t u r a l l y , and thus m i n e r a l o g i c a l l y , d i s t i n c t from the r e s t of the samples, which were mostly taken from the deep f l a t t e r p o r t i o n s of the i n l e t f l o o r . Exceptions are samples 87 taken from shallower locations near creek mouths, or from gently-sloping sections of the walls of the f j o r d . S y v i t s k i and Macdonald (1982) summarized the grain-size d i s t r i b u t i o n i n Howe Sound sediments as follows: the basins contain the f i n e s t grain sizes (<15 um) and consist of unimodal muds with clay patches. The s i l l s and shelves surrounding islands and shores host the coarsest, as well as the most poorly sorted, sediment. Sandy s i l t s and muds extend out from the Britannia mine source and from the de l t a , while s i l l s , platforms, and i s l a n d bays are la r g e l y covered with gravelly mud, muddy sand, and sandy mud. Although no grain size analysis was done i n t h i s study, the l i k e l i h o o d of a strong t e x t u r a l influence must constrain our i n t e r p r e t a t i o n of the chemical composition of these sediments. 3.1.1 Seasalt S a l t content analyses were c a r r i e d out pri m a r i l y to correct the solid-phase data for bulk d i l u t i o n by seasalt i n dri e d samples, as well as for addition to the sediments of c e r t a i n elements ( s p e c i f i c a l l y Na, Mg, Ca, K, and Sr) which are major components i n seasalt. A l l major and minor element, and carbon and nitrogen data have been thus corrected, and a l l concentrations i n t h i s t h e s i s are presented on a s a l t - f r e e basis. F i g . 3.1 shows a plot of % seasalt i n dried surface sediments from a l l sample locations. Only the samples from 88 Fig, 3.1 Percent seasalt in Howe Sound surface sediments. 89 cores extruded i n the laboratory (#16-B, 64, 70, 80 & 82-B) are omitted, since a good deal of the water drained from the surface of these cores during storage, creating a sampling a r t i f a c t which had nothing to do with the o r i g i n a l water content of the mud. Since s a l t content i s d i r e c t l y related to the amount of water contained within i t , and that i n turn i s a function of grain s i z e , i t follows that a higher s a l t concentration i n a dried sample probably indicates a f i n e r grain s i z e . In Howe Sound, areas with the higher seasalt content are the c e n t r a l and deepest parts of both basins (>10% s e a s a l t ) , while nearshore areas, shallow platforms and the Squamish delta have markedly lower values ( i . e . <4%). In addition the upper basin has o v e r a l l lower concentrations than the lower, or outer basin, although hydrologic data (Fig. 1.5) taken from both basins show s i m i l a r bottom water s a l i n i t i e s . These findings support the grain-size analysis of S y v i t s k i and MacDonald (1982), who found that while the sediments as a whole were poorly sorted, the deep basins contained f i n e r sediments, coarser sizes appearing along the shores and on the d e l t a of the upper basin. 3.1.2 Silicon and aluminum The d i s t r i b u t i o n of A l i s shown i n F i g . 3.2. A l ranges from 6.5% to 9.26% by weight, the highest concentrations i n clays of the inner and outer basins, the lowest i n Thornbrough Channel, where d e t r i t a l components are d i l u t e d 90 Fig. 3.2 Aluminum (_wt, %) in Howe Sound surface sediments. 91 by the organic material from pulp m i l l waste. Moderately high values occur i n the s i l l and upper basin, the areas where the influence from Squamish River-borne A l - r i c h p lagioclase feldspars i s most l i k e l y to be dominant. The S i content i n Howe Sound sediments varies from 21.79% to 28.17% throughout the sound, with the highest values occurring at the mouth of the sound and the three locations nearest to Squamish on the del t a , and the lowest i n Thornbrough Channel, which i s heavily influenced by pulp m i l l waste from Port Mellon. The S i d i s t r i b u t i o n probably r e f l e c t s l a r g e l y the d i s t r i b u t i o n of quartz, a ref r a c t o r y mineral which dominates larger ( i . e . sand and s i l t ) grain sizes and i s therefore expected i n the coarser material of the d e l t a , mine t a i l i n g s and Fraser River sediment entering the sound from the south. A p l o t of S i vs. A l (Fig. 3.3) shows a reasonably good c o r r e l a t i o n i n the Thornbrough Channel, s i l l and de l t a sediments (r = 0.63, 0.73, and 0.69, r e s p e c t i v e l y ) . The r e l a t i o n s h i p between the two elements i n the muds and clays of the deep basins i s more v a r i a b l e . This plo t also i l l u s t r a t e s the greater influence of quartz i n the lower basin samples compared to the aluminum-rich sediments of the s i l l and upper basin. The exception to t h i s i s the high s i l i c a content ( c i r c l e d ) i n the one very sandy sample from the d e l t a , #93. The S i / A l r a t i o i s independent of d i l u t i o n by other 92 30 25 20 Si vs. Al • • • D r 5 i n r = 0 . 6 9 Lower Thornbrough Sill Upper Delta basin Channel basin • • * o • I . I . I . 7 8 9 10 %AI Fig.3.3 Silicon vs. aluminum in Howe Sound surface sediments 93 components and therefore provides a more accurate means of detecting mineralogical changes within sediments than does absolute abundance. The areal d i s t r i b u t i o n of the S i / A l r a t i o s i n Howe Sound (Fig. 3.4) varies from 2.87 to 3.62, the higher values (>3.3) occurring i n the southernmost half of the outer basin, including Thornbrough Channel, and the lower values (<3.1) ch a r a c t e r i z i n g the upper basin (excluding sediments near the Britan n i a Mine o u t f a l l (Si/Al=3.2) and the one very sandy sample of the upper d e l t a , #93 (Si/Al=3.21)). These r a t i o s are s i m i l a r to those reported for shales (3.33) by Clarke and Washington (1924). The presence of clay minerals such as i l l i t e and c h l o r i t e , with S i / A l r a t i o s of 1.5 (Mackenzie et a l , 1949) and 0.93 (McMurchy, 1934), respectively, are l i k e l y responsible for d i l u t i n g the g r a n o d i o r i t i c (Si/Al=3.6, Daly, 1933) sediments to various degrees and generally decreasing the S i / A l values to the ranges observed i n Howe Sound. Coarser d e l t a i c sediments and mine t a i l i n g s contribute to v a r i a b i l i t y within the sound, while the higher A l content of feldspars from the Squamish River accounts for the low S i / A l values for that area. The S i / A l : C o r g r a t i o has been used elsewhere to define the diatomaceous s i l i c a content i n sediments (e.g. Francois, 1987), and i s shown i n F i g . 3.5. The regression l i n e for Saanich Inlet diatomaceous oozes (Francois, 1987) i s included i n the fi g u r e . I t i s c l e a r that i n Howe Sound any 94 Fig.3.4 S i l i c o n to aluminum r a t i o i n Howe Sound surface sediments. 95 Si/Al vs. C Q r g Saanich Inlet, r— . 6 8 Lower Thornbrough Sill Upper Delta • • * Basin Channel Basin I . I . I . 2 4 6 % Corg 8 F i g . 3.5 Si l icon:aluminum ra t i o versus organic carbon in Howe Sound surface sediments. Regression l i ne from Saanich In let sediments included for reference, 96 c o v a r i a t i o n between the two parameters i s completely masked by the high content of terrigenous organic matter, and that the contribution of diatomaceous opal to the s i l i c a content of the sediments i s n e g l i g i b l e . F i g . 3.6 shows that the concentration with depth of aluminum varies l i t t l e i n the two basins. The inner basin sediments have s l i g h t l y higher A l concentrations (=8.5%-9%) than the outer basin (=8-8.5%), r e f l e c t i n g the greater influence i n t h i s region of plagioclase feldspar sediments from the Squamish River. S i / A l r a t i o p r o f i l e s for the two cores are shown i n F i g . 3.7. The inner basin core shows highly variable S i / A l r a t i o s with depth ( i . e . 2.9—3.2), r e f l e c t i n g the poorly sorted nature of the sediments there. Slumps or t u r b i d i t y flows o r i g i n a t i n g on the d e l t a or the f j o r d walls w i l l increase the grain size and thus the r e l a t i v e S i content of the b a s i n - f l o o r deposits considerably. The outer basin sediments show much less v a r i a b i l i t y (though the o v e r a l l values are higher) r e f l e c t i n g a more uniform grain s i z e , and the greater influence of deposition of q u a r t z - r i c h Fraser River plume s i l t s . 3.1.3 Titanium Titanium i n marine sediments may occur e i t h e r as r e f r a c t o r y oxides such as ilmenite, r u t i l e , anatase and brookite, which are concentrated i n the sand f r a c t i o n (Calvert, 1976), or as finely-disseminated c r y p t o c r y s t a l l i n e 97 Al, wt. % o 10 E o C L CD Q 2 0 30 8 Aluminum natural sediments tailings HS 16-B e <D i i Inner basin Outer basin HS 64 ©i 10 Fig. 3,6 Aluminum (wt.%) in two Howe Sound sediment cores, Nay, 1987, 98 2.5 Si/AI Ratio 3 10 E o CD Q 20 30 ~i 1 1 r Si/AI natural sediments tailings Inner basin HS 16-B HS64 O - - • 3.5 Q i i i i 0 I t i i O Outer basin Fig, 3.7 Silicon to aluminum ratios in two Howe Sound sediment cores, May 1987. 99 r u t i l e "needles" which are a weathering product and adsorb to clay minerals i n the f i n e r f r a c t i o n s (Degens, 1965). In Howe Sound, the concentration of T i ranges from 0.37% to 0.48%, with values increasing with distance from the head of the i n l e t . Such concentrations bracket the T i content reported f o r average shale (0.46%; Krauskopf, 1979). To c l a r i f y the p a r t i t i o n i n g of T i i n Howe Sound, pl o t s of the element versus aluminum and i r o n (Figs. 3.8 and 3.9) show that i n Squamish delta, upper basin, and Thornbrough Channel sediments, T i correlates well with A l (r=0.79, 0.70, and 0.73, r e s p e c t i v e l y ) , whereas i n the outer basin, i t associates more c l o s e l y with Fe. The seasalt d i s t r i b u t i o n (Fig. 3.1) indicates that the coarser grain-size f r a c t i o n s i n the sound occur i n the delta and nearshore sediments, e s p e c i a l l y i n the upper basin, a l l areas where T i i s low. Therefore the T i i n the sediments i s l i k e l y of the f i n e -c r y s t a l l i n e type which adsorbs to clay minerals. Since feldspars are generally low i n T i , the o v e r a l l concentration i n Squamish River-dominated sediments i s also low, r e l a t i v e to the sediments i n the outer basin. This i s p a r t i c u l a r l y evident i n the T i / A l d i s t r i b u t i o n p l o t shown i n F i g . 3.8. In the outer basin sediments, the reasonable c o r r e l a t i o n of T i with Fe (r=0.60) implies that the titanium enrichment i n t h i s basin i s due to an iron-bearing clay mineral phase, possibly c h l o r i t e , which i s a s i g n i f i c a n t component of Fraser River sediments. 100 0.5 0.4 0.3 Ti vs. Al • • • • • > • • • .CP- ' 0 > r - 0.79 > Lower Thornbrough Sill Upper Delta basin Channel basin • • * > • 7 8 9 Al, W t . % 10 Fig. 3.8 Titanium vs. aluminum in Howe Sound surface sediments 101 Lower Thornbrough Sill Upper Delta basin Channel basin — B — • -* 1> • 0.3 0.4 0.5 0.6 Ti , wt. % Fig. 3.9 Iron vs. titanium in Howe Sound surface sediments 102 F i g . 3.10 shows the Ti/AI r a t i o s with depth i n cores 16-B and 64. In the upper basin, small reductions and increases i n T i r e l a t i v e to A l c o r r e l a t e c l o s e l y , but a n t i -p a t h e t i c a l l y , with the Si/AI r a t i o . This i s confirmation of the t e x t u r a l and associated mineralogical control on the abundance of titanium i n these sediments. T i i s s l i g h t l y enriched (avg. 0.047) i n the sediments contaminated by mine t a i l i n g s , i . e . those below 14 cm i n the upper basin. The Ti/AI r a t i o i n the outer basin core i s more uniform with depth, as well as being s l i g h t l y higher o v e r a l l (=0.057 compared to =0.045), as i s also indicated by the areal d i s t r i b u t i o n i n the sound (Fig. 3.11). This supports the conclusion that Fraser River sediments are the primary source of fine-grained T i i n Howe Sound; the mine t a i l i n g s + are a minor source only. 3.1.4 Potassium, Sodium and Calcium These elements are important constituents of feldspars, the most abundant rock-forming mineral i n the earth's crust. K i s enriched i n orthoclase feldspars, while Na and Ca form a s o l u t i o n series i n plagioclase feldspars. They are also, with Mg, abundant constituents i n clay minerals both as s t r u c t u r a l and exchangeable cations. Potassium i n sediments occurs p r i m a r i l y i n the orthoclase v a r i e t y microcline, and i n the mica group as muscovite and b i o t i t e , while Na and Ca substitute for each other i n a continuous series from a l b i t e 103 Ti/AI 0 0.025 0 , I I I I I I 0.05 10 E o CD Q 20-30 J L Ti/AI natural sediments tailings s Inner basln-HS 16-B -o HS 64 9 i t i <i> \ l <D i i (D l i i i r 6 t <P 0.075 Outer basin Fig. 3,10 Titanium to aluminum ratios in two Howe Sound sediment cores, May 1987, 104 Fig. 3.11 Titanium to aluminum ratios in Howe Sound surface sediments, May, 1987. 105 ( N a - p l a g i o c l a s e ) t o a n o r t h i t e ( C a - p l a g i o c l a s e ) . M u s c o v i t e and b i o t i t e appear i n Howe Sound i n t h e f i n e r g r a i n s i z e s , w h i l e t h e t h r e e f e l d s p a r s o f i m p o r t a n c e i n t h e b a s i n a r e b y t o w n i t e , a l b i t e and o r t h o c l a s e ( S y v i t s k i and MacDonald, 1982) . The mean p o t a s s i u m c o n c e n t r a t i o n i n Howe Sound s e d i m e n t s ranges from a low o f 1.35% i n Thornbrough C h a n n e l , where t h e r e i s c o n s i d e r a b l e d i l u t i o n by o r g a n i c m a t t e r , t o a h i g h o f 1.67% on t h e s i l l . H i g h e s t and l o w e s t K / A l r a t i o s o c c u r r e s p e c t i v e l y i n t h e l o w e r b a s i n (0.210) and on t h e d e l t a ( 0 . 1 5 5 ) ; i n t e r m e d i a t e r a t i o s c h a r a c t e r i z e t h e s i l l a r e a . The K c o n c e n t r a t i o n c o r r e l a t e s v e r y p o o r l y w i t h A l i n s u r f a c e s e d i m e n t s , w i t h t h e s o l e e x c e p t i o n o f l o w e r b a s i n d e p o s i t s , where a weak p o s i t i v e a s s o c i a t i o n i s o b s e r v e d (r=0.49; F i g . 3.12). The r e l a t i v e l y low K / A l r a t i o i n Squamish D e l t a s e d i m e n t s s u g g e s t s t h a t o r t h o c l a s e i s n o t a s i g n i f i c a n t component of t h e s e d e p o s i t s . H i g h e r K / A l r a t i o s o b s e r v e d i n t h e f i n e r - g r a i n e d d e p o s i t s i n much of t h e l o w e r b a s i n c a n be a t t r i b u t e d t o t h e p r e s e n c e of p o t a s s i u m - r i c h i l l i t e / m u s c o v i t e (K/A1=0.1-0.3, F r a n c o i s 1987), w h i c h p r e s u m a b l y i s d e r i v e d l a r g e l y from t h e F r a s e r R i v e r . The a r e a l K / A l d i s t r i b u t i o n i n t h e sound ( F i g . 3.13) i m p l i e s t h a t c r e e k s on t h e n o r t h w e s t s h o r e o f t h e l o w e r b a s i n , p a r t i c u l a r l y P o t l a t c h and McNab, a l s o c o n t r i b u t e K - r i c h m i n e r a l s t o t h e i n l e t . F i g s . 3.14, 3.15 and 3.16 show t h e C a / A l ( c o r r e c t e d f o r 106 2.5 K vs . A l • • • Lower Thornbrough Sill Upper Delta basin Channel basin — B — • * > • 6 7 8 9 10 Al, wt. % Fig, 3,12 Potassium versus aluminum in Howe Sound surface sediments, May 1987, 107 Fig.3.13 Potassium to aluminum ratios in Howe Sound surface sediments, May 1987. 108 Fig,3.14 Calcium to aluminum ratios in Howe Sound surface sediments, May 1987. 109 Fig. 3.15 Sodium to aluminum ratios in Howe Sound surface sediments, May 1987. 110 Fig. 3.16 Sodium to potassium ratios in Howe Sound surface sediments May 1987. I l l CaC0 3 content), Na/Al and Na/K d i s t r i b u t i o n s , and indicate that Georgia S t r a i t - F r a s e r River sediments (Samples 1 and 2, see Table B, Appendix III) are considerably depleted i n Na r e l a t i v e to A l , as are sediments along much of the eastern edge of the sound. The higher Ca/Al, Na/Al and Na/K values i n the upper basin and along the northern and western reaches of the lower basin show the predominance of plagioclase feldspars over orthoclase i n these sediments. In the c e n t r a l basins, lower Na/Al, Ca/Al, and Na/K values suggest a higher proportion of Na- and Ca-deplete but K-rich clay minerals, which i s consistent with the potassium d i s t r i b u t i o n discussed e a r l i e r . Potassium to aluminum r a t i o p r o f i l e s for inner and outer basin cores are shown i n F i g . 3.17. In sediments contaminated by mine t a i l i n g s , the K/Al r a t i o i s generally higher (=0.2) than i n the "natural" sediments which o v e r l i e them (K/A1=0.15). Since cessation of t a i l i n g s deposition, the K/Al r a t i o has increased s t e a d i l y with time. This i s p a r a l l e l e d by a corresponding decrease i n Na and Ca abundances (Figs. 3.18 and 3.19), suggesting that the proportion of K-feldpspars r e l a t i v e to plagioclase may have progressively increased i n the sediments accumulating i n the c e n t r a l part of the upper basin over the l a s t 15 years. A l t e r n a t i v e l y , a s h i f t i n the r e l a t i v e proportions of clay minerals present i n these fine-grained, deep-basin deposits could also account for t h i s change, such as a recent 112 113 Na/AI Ratio 0 0.2 0.4 3 0 _i Fig.3.18 Sodium to aluminum ratios in two Howe Sound sediment cores, May 1987. 114 Ca/AI Ratio 0 0.2 0.4 Q i i 6 i 0 i (D i \ <D i i natural \ \ sediments j tailings / i <D t i T HS 64 i I Inner basin HS16-B -^ | Outer basin i i * i 6 Fig. 3.19 Calcium to aluminum ratios in two Howe Sound sediment cores, May 1987. 115 i n c r e a s e i n i l l i t e / m u s c o v i t e abundance. The d a t a do not p e r m i t d i s c r i m i n a t i o n of t h e s e a l t e r n a t i v e s . 3.1.5 Iron and Magnesium F e - b e a r i n g o x i d e and o x y h y d r o x i d e phases such as h e m a t i t e , g o e t h i t e , and l e p i d o c r o c i t e a r e common i n o x i c d e p o s i t s w h i l e i n s o l u b l e s u l p h i d e s such as p y r i t e a r e t y p i c a l c o n s t i t u e n t s o f r e d u c i n g marine sediments (Degens, 1965). H e m a t i t e i s t h e most s t a b l e F e - o x i d e m i n e r a l i n o x i d i z i n g e n v i r o n m e n t s , w h i l e p y r i t e and s i d e r i t e (Fe2CC"3), a r e s t a b l e i n a n o x i c sediments ( K r a u s k o p f , 1979). Fe o c c u r s i n d e t r i t a l s e diments i n i l l i t e , m i c a , m a f i c m i n e r a l s such as a m p h i b o l e s , and t o a minor e x t e n t , K - f e l d s p a r s , as w e l l as i n a u t h i g e n i c m i n e r a l s such as g l a u c o n i t e . D i s s o l v e d Fe e x h i b i t s n o n - c o n s e r v a t i v e b e h a v i o u r i n e s t u a r i e s as i t p a s s e s from f r e s h i n t o s a l i n e w a t e r s , b e i n g removed from s o l u t i o n and i n c o r p o r a t e d i n t o o x i d e o r h y d r o x i d e c o a t i n g s on m i n e r a l p a r t i c l e s . T h i s p r o c e s s i s v i r t u a l l y c o m p l e t e by t h e t i m e a s a l i n i t y o f 1 5 ° / 0 0 i s r e a c h e d ( B u r t o n and L i s s , 1976) . Magnesium o c c u r s w i t h i r o n i n many s e d i m e n t a r y r o c k s . I t i s a l s o one o f t h e most abundant i o n s i n seawater and i s i n v o l v e d i n exchange r e a c t i o n s d u r i n g t h e w e a t h e r i n g o f c l a y s . However, because w e a t h e r i n g i s a r e l a t i v e l y s l o w p r o c e s s , and d e p o s i t i o n i n f j o r d s i n g e n e r a l l y r a p i d , t h e a u t h i g e n i c e n r i c h m e n t o f Mg (and o t h e r e x c h a n g e a b l e c a t i o n s ) does n ot s i g n i f i c a n t l y a f f e c t t h e o v e r w h e l m i n g l y d e t r i t a l 116 nature of f j o r d surface sediments (Skei, 1983; Calvert, 1976) . In the surface sediments of Howe Sound, ir o n increases down-inlet, both i n absolute abundance and when ratioe d to A l , from =4.3% (Fe/Al=0.51) i n the de l t a to 4.9% (Fe/Al = 0.64) i n the lower basin (Fig. 3.20). This trend i s consistent with the view that plagioclase feldspars (which are low i n Fe) dominate the Squamish Delta sediments. In Thornbrough Channel and the upper basin, and on the del t a , Fe correlates well with Mg (r=0.97, 0.73 and 0.57, respec t i v e l y ; F i g . 3.21), which suggests that i n the f i r s t two areas at l e a s t , both elements occur i n the same mineral, or i n minerals with s i m i l a r Fe/Mg r a t i o s . Candidate phases include b i o t i t e - v e r m i c u l i t e , hornblende, or Mg-chamosite, a l l of which e x i s t i n s i g n i f i c a n t quantities i n Howe Sound sediments ( S y v i t s k i and MacDonald, 1982). High Fe/Mg r a t i o s (>2.5) occur i n Georgia Strait-dominated sediments and those near the Britannia mine o u t f a l l (Fig. 3.22), i n d i c a t i n g that some of the iro n here i s c a r r i e d i n a r e l a t i v e l y Mg-depleted phase i n sediments from these two sources. This mineral i s l i k e l y F e - r i c h c h l o r i t e , which i s common i n Fraser River and Britann i a Creek sediments but which i s depleted i n Squamish River sediments (Pharo, 1972, James, 1929, S y v i t s k i and MacDonald, 1982). P y r i t e i n mine t a i l i n g s almost c e r t a i n l y contributes to the iro n enrichment i n sediments near Brita n n i a Beach. In addition, i r o n i s added to nearshore 117 Fe/AI ) <50 .50 -.60 >.60 Fig. 3.20 Iron to aluminum ratios in Howe Sound surface sediments, May 1987, 118 6 CD Mg vs. Fe • • • • • fl r = 0.97 Lower Thornbrough Sill Upper Delta basin Channel basin • * > • i l l i i i i l l i 1.2 1.6 2 2.4 Mg, wt. % Fig. 3.21 Magnesium vs. iron in Howe Sound surface sediments 119 Fig. 3,22 Iron to magnesium ratios in Howe Sound surface sediments, May 1987. 120 sediments i n t h i s area as a r e s u l t of p r e c i p i t a t i o n of dissolved i r o n from acid drainage flowing into Britannia Creek. Fe and K (Fig. 3.23) co r r e l a t e reasonably well i n a l l sediments (r>0.50) except those on the s i l l , i n d i c a t i n g that the same mineral (probably b i o t i t e ) i s p a r t l y responsible for the presence of these elements. The higher Fe i n the lower basin and several upper basin stations supports the idea than addi t i o n a l iron-bearing minerals are present i n these areas. The Mg/Al d i s t r i b u t i o n i n Howe Sound (Fig. 3.24) i s s i m i l a r to that of Fe/Al. Generally higher Mg/Al values are found i n the lower basin, s i l l , and Thornbrough Channel sediments (=0.24) than i n the upper basin and d e l t a areas (0.22 and 0.21, r e s p e c t i v e l y ) . S u r p r i s i n g l y , areas of highest r e l a t i v e Mg enrichment are adjacent to Gambier and Keats Islands. Presumably, t h i s l o c a l enrichment r e f l e c t s the s l i g h t l y d i f f e r e n t geology of Gambier Island (the presence of a roof pendant intruding into the b a t h o l i t h , which i s the source of a low-grade porphyry copper deposit), and the enhanced presence of Mg-bearing phases such as amphibole or o l i v i n e . The Fe/Al p r o f i l e s i n the upper and lower basin cores (Fig. 3.25) r e f l e c t the influence of the three primary sediment inputs: the high-Fe Fraser River source, the r e l a t i v e l y low-Fe, plagioclase-dominated Squamish Delta 121 Lower Thornbrough Sill Upper Delta basin Channel basin — B — • * I> • 1 2 K, wt. % Fig. 3.23 Iron versus potassium in Howe Sound surface sediments, May 1987. 122 Fig. 3.24 Magnesium to aluminum ratios in Howe Sound surface sediments, May 1987, 123 Fe/AI Ratio Inner basin HS 16-1 o- ••• HS 64 Outer basin 0 Fig. 3.25 Iron to aluminum ratios in two sediments cores from Howe Sound, May 1987. 124 sediments, and the p y r i t e - r i c h Britannia Beach mine t a i l i n g s . The Mg/Al r a t i o s (Fig. 3.26) show a s i m i l a r , though le s s dramatic, d i s t r i b u t i o n . In t h i s case, however, the Mg content of the t a i l i n g s i s greater than i n the Fraser River sediments, l i k e l y due to the strong presence of magnesian minerals i n the ore body. 3.1.6 Organic Carbon and Nitrogen Organic material i n estuarine sediments consists of an autochthonous contribution r e s u l t i n g from primary production within the estuary and allocthonous contributions from adjacent ecosystems, s p e c i f i c a l l y t e r r e s t r i a l drainage basins and contiguous marine areas (Head, 1976). Added to these i n the Howe Sound case are contributions from anthropogenic a c t i v i t i e s i n and around the estuary. The d i s t r i b u t i o n of organic C (wt. %) i n Howe Sound surface sediments i s shown i n F i g . 3.27. High C o r g (>5%) values are found i n Thornbrough Channel and the northwest portion of the upper basin, with a strong l o c a l enrichment offshore from Potlatch Creek, west of the s i l l . In the rest of the upper basin and the main channel of the lower basin, the organic carbon content i s t y p i c a l l y <2%. These values are f a i r l y t y p i c a l of many nearshore and estuarine environments (see, for example, Calvert, 1976; Krom and Sholkovitz, 1977; Rosenfeld, 1979; Francois, 1987; and McNichol et a l , 1988, among others), which have high marine 125 Mg/Al 0.1 0.2 0.3 J I L J I L Inner basin natural sediments tailings Fig, 3,26 Magnesium to aluminum ratios in two Howe Sound sediment cores, May 1987. 126 Fig. 3.27 Organic carbon (% dry weight) in Howe Sound surface sediments, May 1987. 127 p r o d u c t i v i t y and/or high t e r r i g e n o u s i n p u t s . I t was shown e a r l i e r t h a t l i t t l e of the s i l i c o n i n Howe Sound surf a c e sediments can be c o r r e l a t e d w i t h the organic carbon content, suggesting t h a t diatoms are not a major c o n t r i b u t o r t o the organic component of Howe Sound sediments. The carbonate content of the sediments a l s o i s very low (see Table H, Appendix I I I ) , averaging <0.1% throughout the sound (excepting only t h r e e surface l o c a t i o n s near Woodfibre pulp m i l l ; see S e c t i o n 3.1.4, Calcium). Opaline s i l i c a d i s s o l v e s e a s i l y ; t h e r e f o r e i t i s imp o s s i b l e t o determine t o what degree primary production by diatoms w i t h i n the sound c o n t r i b u t e s t o the organic carbon content of the u n d e r l y i n g sediments. However, the extremely high organic carbon content of c e r t a i n regions w i t h no corresponding changes i n S i or CaCOg content s t r o n g l y suggests t h a t , r e l a t i v e l y speaking, the autochthonous c o n t r i b u t i o n i s a minor one. The c o n c l u s i o n , t h e r e f o r e , supported by v i s u a l o b s e r v a t i o n of the f r e s h sediment samples, and by high C o rg/N r a t i o s (>15) i n nearshore zones and i n areas u n d e r l y i n g heavy log-booming a c t i v i t y (Hoos and Voi d , 1975) and pulp m i l l dumpsites, i s t h a t the primary c o n t r i b u t o r t o the organic f r a c t i o n i s t e r r i g e n o u s m a t e r i a l , and t h a t i t overshadows any input by l o c a l p r o d u c t i v i t y . The C o rg/N r a t i o i s o f t e n used as an index of the r e l a t i v e c o n t r i b u t i o n s of marine and t e r r e s t r i a l m a t e r i a l t o the organic load of sediments because t e r r i g e n o u s p l a n t 128 materials such as leaves, bark, and wood contain a good deal less nitrogen than marine plankton; thus, terrigenous organic detritus exhibits C Q r g / N molar ratios of >15 compared to =6 for marine phytoplankton (Borodowskiy, 1965; Muller, 1977). However, other factors affect the C Q r g content and C/N ratios within sediments. Organic material i s often associated with the finer fractions ( i . e . clays) because of the adsorptive a f f in i ty of the la t ter for certain organic compounds during deposition and early buria l (Premuzic et a l , 1982). In addition, organic detritus i s often comminuted and of low density; i t therefore behaves in a hydraulical ly equivalent fashion to clay or fine s i l t - s i z e d inorganic part ic les . As a result , organic matter and fine-grained detritus tend to be deposited together in low energy environments (Kuinen, 1965; Calvert, 1987). However, the seasalt content (Fig.3.1) and the S i / A l d is tr ibut ion (Fig. 3.4) within Howe Sound indicate that the coarsest grain sizes occur in the delta, s i l l and nearshore areas, while the finer sediments are in the deep central basins. With the exception of the delta area, those zones of assumed larger grain sizes generally contain more organic carbon, leaving the deep basins re la t ive ly depleted. Thus, the expected preferential accumulation in fine sediments in not seen in Howe Sound. The reason for this i s c lear. Comparison of the %CQ rg and C/N distributions (Figs. 3.27 129 and 3.28) indicates that the organic matter i n carbon-rich sediments i s l a r g e l y t e r r e s t r i a l . Note for example the coincidence of high C/N r a t i o s and high C Q r g values i n Thornbrough Channel sediments, the area off Potlatch Creek, and elsewhere. Because these d i s t r i b u t i o n s are independent of grain size v a r i a t i o n s , i t must be concluded that hydraulic sorting of the sediments plays a minor r o l e i n determining organic carbon content; l o c a l i n j e c t i o n s of t e r r e s t r i a l organic matter of widely-ranging grain size provide the p r i n c i p a l control on the carbon d i s t r i b u t i o n . Another factor a f f e c t i n g the C o rg/N r a t i o of a sediment i s the r e s u l t of b a c t e r i a l degradation and early diagenesis of organic material within the water column and at the sediment/water i n t e r f a c e . The protein ( i . e . nitrogen-bearing) portion of organic d e t r i t u s i s generally 'believed to be remineralized more r a p i d l y than other components, r e s u l t i n g i n an increase i n the C Q rg/N r a t i o s with time (e.g Degens and Mopper, 1976; Rosenfeld, 1979; Jorgensen, 1983), although t h i s i s a s i m p l i f i c a t i o n , since biodegradability of an organic p a r t i c l e depends on many factors, including pH, s a l i n i t y , temperature, and redox p o t e n t i a l of the environment as well as the biochemical make-up of the p a r t i c l e i t s e l f . This decrease may be f u l l y or p a r t i a l l y o f f s e t by an increase i n N within the degrading material over time r e l a t i v e to C, caused by ei t h e r the presence of a high biomass of p r o t e i n - r i c h microbes within the d e t r i t u s 130 Fig. 3.28 Organic carbon to nitrogen ratios (weight ratio) in Howe Sound surface sediments, May 1987. 131 ( H a r r i s o n and Mann, 1975; Rice and Tenore, 1981), or by ammonium (e.g. Stevenson and T i l o , 1969) and other n i t r o g e n compounds (Stevenson and Cheng, 1970; M u l l e r , 1977) which, when r e l e a s e d from decaying d e t r i t u s , become f i x e d i n t o the l a t t i c e s of a l u m i n o s i l i c a t e s w i t h i n the sediments. Thus, d i a g e n e s i s obscures the d i v i d i n g l i n e between t e r r e s t r i a l and marine m a t e r i a l , r e s u l t i n g i n a s i t u a t i o n i n which the r e l a t i v e amounts of the two d i s t i n c t sources may be i m p o s s i b l e t o determine q u a n t i t a t i v e l y . However, t h i s c o n s i d e r a t i o n a p p l i e s more t o longer-term v a r i a b i l i t y i n the C/N r a t i o as a f u n c t i o n of depth (and t h e r e f o r e time) and not t o surface sediments, which are assumed here t o represent r e l a t i v e l y f r e s h l y - d e p o s i t e d m a t e r i a l . Two of the three areas of extremely high (>30) C o rg/N r a t i o s (samples #22 i n Thornbrough Channel, and #82 i n the upper basin) are dumpsites f o r pulp m i l l waste; the t h i r d (#'s 56 and 58) i s a shallow p l a t f o r m covered w i t h t e r r e s t r i a l d e t r i t u s i n the form of le a v e s , t w i g s , and grasses, a l l of which were c l e a r l y v i s i b l e i n the samples at the time of c o l l e c t i o n (see Appendix I I , Core d e s c r i p t i o n s ) . C/N r a t i o s g e n e r a l l y decrease w i t h d i s t a n c e from these three p o i n t sources ( F i g . 3.28). C l e a r l y , the Squamish R i v e r r e presents a f o u r t h source; although sediments on the d e l t a c o n t a i n very l i t t l e organic carbon, the C/N r a t i o (>20) of the m a t e r i a l designates i t as d e c i d e d l y t e r r e s t r i a l . P u b l i s h e d C Q rg/N weight r a t i o s of much r i v e r - b o r n e p l a n t 1 3 2 debris r a r e l y exceed 20 (De Groot, 1973; Malcolm and Price, 1984), but c e l l u l o s e - r i c h material such as bark and wood frequently exh i b i t C/N r a t i o s considerably higher, ranging as high as 200 (Emerson and Hedges, 1988). The high r a t i o s observed i n some samples i n t h i s study probably r e f l e c t a s i g n i f i c a n t proportion of woody matter. In addition, the p r e f e r e n t i a l loss of N during early diagenesis fosters higher C/N r a t i o s ; such r e a c t i v i t y may contribute to the high values observed i n t h i s study, but t h i s i s d i f f i c u l t to determine. F i g . 3.29 shows the organic carbon content versus depth i n the two cores examined i n d e t a i l . The outer basin contains =1.75% C 0 r g a*" ^ n e surface, which decreases l i n e a r l y to =1.15% at a depth of 25-30 cm. This d i s t r i b u t i o n may represent steady loss of t o t a l organic carbon from the sediment during early diagenesis. In the upper basin, the i n f l u x of organic material to the sediments appears to have o s c i l l a t e d considerably over the i n t e r v a l studied; i n addition, the o v e r a l l C o r g content i s lower (range=0.5-1.1%) i n core HS 64 than i n the outer basin core (HS 16B). The lower concentrations here presumably r e f l e c t d i l u t i o n by inorganic constituents from the Squamish River suspended load. Seasonal and/or annual changes i n the input of organic debris in t o the sound probably account for the wide range of concentrations found at d i f f e r e n t depths. The C Q rg/N p r o f i l e s (Fig. 3.30) suggest that t h i s i s indeed the 133 0 0 1<H E o O Q 20 30 % C org I O r g a n i c / C a r b o n / / 4 J natural £ sediments / tailings «v » > Q> ' i <? 1 / ( 1 I » i J - * — HS 16-B I Outer basin ^ j HS64 • inner basin © Fig. 3.29. Organic carbon (% dry weight) in two Howe Sound sediment cores, May 1987. 134 C org /N (molar ratio) 0 10 20 30 30 _ i Fig. 3.30 Organic carbon to nitrogen ratios in two Howe Sound sediment cores, May 1987. 135 case: the outer b a s i n , w i t h a lower C o rg/N r a t i o o v e r a l l (=12-15), must r e c e i v e a higher p r o p o r t i o n of i t s organic matter from p l a n k t o n i c sources; i n these sediments, d i a g e n e t i c breakdown and r e m o b i l i z a t i o n of both C and N are more or l e s s i n balance, r e s u l t i n g i n very l i t t l e change of the COT.a/N r a t i o w i t h depth. In the upper b a s i n , l a r g e f l u c t u a t i o n s of the C o rg/N r a t i o , as w e l l as much higher values ( i . e . 16-28) support the ide a t h a t t h i s r e g i o n i s sub j e c t t o l a r g e seasonal or annual changes i n the input t o the sediments, and t h a t the major organic matter sources are t e r r e s t r i a l . The s p r i n g f r e s h e t of the Squamish R i v e r i s one such i n f l u e n c e t h a t would enhance the t e r r i g e n o u s s i g n a l on a seasonal b a s i s , at the same time damping marine primary p r o d u c t i v i t y by i n c r e a s i n g the t u r b i d i t y i n the f r e s h s u r f a c e l a y e r . There appears t o be no d e t e c t a b l e d i f f e r e n c e between the o r g a n i c carbon and n i t r o g e n content of sediments de p o s i t e d d u r i n g the p e r i o d of mine t a i l i n g s discharge and those l a i d down s i n c e the mine c l o s e d , at l e a s t as f a r as the t o t a l input and type of organic matter i s concerned. This might r e f l e c t slow r e c o l o n i z a t i o n of the benthic community on and i n the sediments of the upper b a s i n i n the years s i n c e the shutdown of the mine, assuming t h a t such r e c o l o n i z a t i o n would be r e f l e c t e d by a change i n the net organic composition of the sediments. A l t e r n a t i v e l y , i t may suggest t h a t other c o n d i t i o n s , not a s s o c i a t e d w i t h the 136 presence of m e t a l - r i c h t a i l i n g s (such as p e r i o d i c anoxia events, or a high n a t u r a l sedimentation r a t e l e a d i n g t o s u b s t r a t e i n s t a b i l i t y ) , are i n f a c t r e s p o n s i b l e f o r the sparseness or absence of a l a r g e - s c a l e benthic community. 3.1.7 Phosphorus Phosphorus d i s t r i b u t i o n i n sediments i s c o n t r o l l e d by f o u r f a c t o r s : the P content of the m i n e r a l matter i n the d e t r i t a l f r a c t i o n , the c o n c e n t r a t i o n of Mn and Fe compounds at the sediment s u r f a c e , the organic matter content, and r e d i s t r i b u t i o n s of P v i a d i a g e n e t i c r e c y c l i n g (Chester, 1965). In the d e t r i t a l f r a c t i o n P occurs i n a p a t i t e phases (Ca-phosphates), as adsorbed c o a t i n g s on Mn and Fe hydroxides (Mason and Moore, 1982), and as s i g n i f i c a n t c o n s t i t u e n t s of c l a y minerals (Fuchtbauer and M i i l l e r , 1977). In the biogenous f r a c t i o n P i s an e s s e n t i a l component of organic matter, being found i n ATP, n u c l e i c a c i d s and s k e l e t a l m a t e r i a l (Bowen, 1979). During e a r l y d i a g e n e s i s P i s r e l e a s e d both from decaying organic matter and from the r e d u c t i o n of Fe oxides i n the suboxic zone. This\ d i s s o l v e d PO4 migrates along a c o n c e n t r a t i o n g r a d i e n t and may be p r e c i p i t a t e d w i t h d i s s o l v e d i r o n on contact w i t h oxygen near the sediment/seawater i n t e r f a c e , or i t may be i n c o r p o r a t e d i n t o m i c r o b i a l biomass and form p a r t of the organic component again. In Howe Sound the c o n c e n t r a t i o n of P ranges from an 137 average low of 0.14% i n Thornbrough Channel to a high of 0.16% on the s i l l (Table A, Appendix I I I ) ; when ratioed to A l , the v a r i a t i o n s throughout the sound are very small, with minor enrichments i n the outer basin and Thornbrough Channel, and a gradual decrease as one approaches the head of the i n l e t . These values are higher than the average for marine sediments (0.09%; E l Wakeel and Riley, 1961) and for c r u s t a l rocks (0.11%; Krauskopf, 1979); thus, there must be an a d d i t i o n a l contribution from e i t h e r organic matter or an enrichment of P i n the l o c a l source rocks. The average N:P molar r a t i o i n marine organic matter i s 16:1, and since there i s l i t t l e d i f f e r e n t i a t i o n i n the remineralization of N and P during early diagenesis, t h i s r a t i o i s f a i r l y stable (Jorgensen, 1983). The N:P molar r a t i o i n Howe Sound averages around 2.2:1, thus providing a d d i t i o n a l evidence for a source of P i n the inorganic f r a c t i o n . Although carbonates are v i r t u a l l y absent i n these sediments, i t i s f e l t that the p r i n c i p a l P-bearing inorganic phase i s apatite. That the P d i s t r i b u t i o n does not covary s i g n i f i c a n t l y with Ca (r<20) i s not c r i t i c a l , since Ca i s present i n many other phases. F i g . 3.31 shows the d i s t r i b u t i o n of P i n Howe Sound, and F i g . 3.32 the P content normalized to A l . These d i s t r i b u t i o n s , coupled with a good c o r r e l a t i o n of P with Fe (Fig. 3.33), suggest that i n the s i l l and the d e l t a (r=0.49 and 0.73, r e s p e c t i v e l y ) , Fe 138 Fig. 3.31 Phosphorus (wt,%) in Howe Sound surface sediments, May 1987. 139 Fig. 3.32 Phosphorus to aluminum ratios in Howe Sound surface sediments, May 1987. 140 6 5H CD 3 H P vs. Fe • • Lower Thornbrough Sill Upper Delta basin Channel basin • • * > — • — 1—i—i—i—i—i—i—i—i—i—i—i—i—i—i—i—i—i—i—i—i—i—i—r 0 0.5 1 1.5 2 2.5 P, ppt Fig. 3.33 Phosphorus vs. iron in Howe Sound surface sediments 141 minerals host at l e a s t part of the observed phosphorus. The negative c o r r e l a t i o n of P with the Si/AI r a t i o (r = 0.72) i n the same sediments (Fig. 3.34) suggests that these minerals are concentrated i n the f i n e r grain s i z e s , e i t h e r as constituent elements i n Fe-bearing aluminosilicate minerals or as coatings on amorphous ir o n oxides. In Thornbrough Channel the strong negative c o r r e l a t i o n of P with Fe (r=0.66) and Mg (r=0.64; see F i g s . 3.33 and 3.35), coupled with the corresponding covariance of P and organic carbon (r=0.74; see F i g . 3.36) and of P and N (r=0.64) suggests that organic material i s l a r g e l y responsible for i t s enrichment, both there and i n the carbon-rich sediments near Potlatch Creek. The %P p r o f i l e s of the two cores (Fig. 3.37) show a gradual decrease with depth i n both basins, which can be a t t r i b u t e d i n part to diagenetic remobilization of P from both organic matter and from the reduction of Fe oxides below the oxic zone. The surface enrichment, therefore, probably r e f l e c t s a combination of the r e l a t i v e freshness of the organic matter and the presence of adsorbed phosphate on solid-phase hydrous ir o n and Mn oxides i n the surface layer. The molar r a t i o s of C o r g to P i n the cores are shown i n F i g . 3.38. The low values (3-8) i n the upper basin r e f l e c t d i l u t i o n of the organic component by inorganic P-bearing minerals i n the source rocks of t h i s area. Fluctuations i n the C/P r a t i o with depth i n the upper basin p a r a l l e l those 142 2.5 "i—i—i—i—|—i—i—i—i—|—i—i—i—i—|—i—i—i—i—|—i—i—i—r O 0.5 1 1.5 2 2.5 P, ppt Fig.3.34 Phosphorus vs. silicon:aluminum ratio in Howe Sound surface sediments 143 2.4 2.2 H 2 J 1.8 1.6 H 1.4-4 1.2 P vs. Mg • • CD Lower Thornbrough Sill Upper Delta basin Channel basin • • -* t> • 1 1 j 1 , . , . 1 1 1 1 j r 0.8 1 1.2 1.4 1.6 1.8 2 2.2 P, ppt Fig. 3.35 Phosphorus vs. magnesium in Howe Sound surface sediments 144 % Co Fig. 3.36 Phosphorus vs. organic carbon in Howe Sound surface sediments 145 P, wt. % 0 0.1 0.2 0 1 1 1 ' * 1 1 1 1 I I I I I I I I L 10 -E o Q_ CD Q 20 -30 Phosphorus a> natural sediments HS 64 Inner basin HS 16-B Outer basin Fig. 3,37 Phosphorus (wt,%) in two Howe Sound sediment cores, May 1987. 146 C/P 10-4 E o Q_ CD Q 20 30 HS 64 Inner basin HS 16-B Outer basin Fig. 3,38 Organic carbon to phosphorus ratios in two Howe Sound sediment cores, May 1987, 147 seen i n the C/N r a t i o ( F i g . 3.30), and are thought t o be caused by v a r i a t i o n s i n the r e l a t i v e p r o p o r t i o n s of marine t o t e r r i g e n o u s organic m a t e r i a l d e l i v e r e d t o the sediments over time. The average P content of the t a i l i n g s (0.125%) i s the same as t h a t of t h a t of the o v e r l y i n g sediments; t h e r e f o r e the t a i l i n g s are not p a r t i c u l a r l y enriched i n P-bearing m i n e r a l s compared t o the source rocks of the r e g i o n . 148 3.2 Geochemistry of Minor Elements  3.2.1 Introduction Minor elements i n sediments and rocks are those that occur i n concentrations of a few tenths of a percent or less by weight (Richardson and McSween, 1989). While t h e i r d i s t r i b u t i o n i n nearshore sediments may be c o n t r o l l e d by t h e i r occurrence i n the l a t t i c e s of the major minerals, they also p a r t i c i p a t e i n a v a r i e t y of biogeochemical reactions within estuarine waters and sediments (Troup and Bricker, 1974), i n marked contrast to the nearly conservative behavior of most major elements. E l d e r f i e l d (1976) suggests that weathering, which influences surface properties, i s more i n f l u e n t i a l i n defining minor element d i s t r i b u t i o n than i s the c r y s t a l l i n e structure of p a r t i c l e s themselves. In sediments dominated by terrigenous d e t r i t u s , minor elements w i l l t y p i c a l l y c o r r e l a t e with one or more of the major rock-forming elements (e.g. S i , A l , or Fe; Calvert, 1976; Krauskopf, 1979). However, other associations may also be present to varying degrees. Non-detrital f r a c t i o n s such as carbonate phases, organic material, dispersed oxides, and authigenic minerals may s i g n i f i c a n t l y influence the d i s t r i b u t i o n of c e r t a i n trace elements i n sediments over t h e i r natural occurrences i n c r u s t a l rocks. Minor element geochemistry i s strongly affected by changes i n s a l i n i t y , temperature, pH and redox p o t e n t i a l of the surrounding waters (Troup and Bricker, 1974). 149 Adsorption and desorption of trace metals to or from p a r t i c l e surfaces during estuarine mixing are important processes regulating the p a r t i t i o n i n g of these elements between dissolved and s o l i d phases. Cations adsorbed from r i v e r water onto suspended p a r t i c l e s and i n hydrous Fe and Mn oxides may be released on contact with estuarine water by ion exchange and/or desorption processes which operate at higher s a l i n i t i e s , during which p a r t i c l e s adsorb seawater cations and release trace elements. Oxide coatings on sediment p a r t i c l e s , which are stable i n oxic surface waters, may dis s o l v e r e a d i l y i n anoxic conditions, thereby releasing c o p r e c i p i t a t e d metals to the surrounding waters. Trace elements which are incorporated into clay minerals at low temperature and pressure may be released upon changes i n pH and pressure. Most minor elements show a marked preference for f i n e -grained sediments (Krauskopf, 1979). This i s because the ion-exchange reactions which are responsible for many minor-element enrichments are important processes i n the weathering of c l a y minerals. As well, trace metals are often associated with organic matter, which, l i k e the clays, tends to be concentrated i n f i n e r grain s i z e s . Organic material i s often associated with s p e c i f i c minor element enrichments due e i t h e r to metal content of the o r i g i n a l planktonic material or to adsorption from seawater during s e t t l i n g and early diagenesis. Trace metals bound 150 within organic p a r t i c u l a t e s may be released i n dissolved form during decomposition. The degree to which t h i s occurs depends on the o r i g i n a l composition of the organic matter and the i n t e n s i t y of b a c t e r i a l a c t i v i t y , which i n sediments i s strongly dependent on depth (Troup and Bricker, 1974). There i s evidence that changes i n the p a r t i t i o n i n g of trace metals between s o l i d and dissolved phases occur seasonally, with lower r e l a t i v e concentrations occurring i n the sediment f r a c t i o n i n winter due to ongoing decay of organic matter and subsequent release of trace metals i n dissolved form (Carpenter et a l , 1975). Authigenic minerals such as phosphorites, glauconite, p y r i t e , and Fe and Mn oxides may also incorporate trace elements into l a t t i c e positions or onto mineral surfaces (Calvert, 1976); a l t e r n a t i v e l y , minor elements may form d i s c r e t e mineral phases of t h e i r own, such as Mn carbonates or ( t h e o r e t i c a l l y at least) insoluble metal sulphides i n anoxic sediments (Krauskopf, 1979; Suess, 1980). Minor elements occur within d e t r i t a l mineral grains i n quantities that are related c h i e f l y to t h e i r a b i l i t y to substitute for major ions i n the c r y s t a l l a t t i c e s of the p r i n c i p a l rock-forming minerals (Krauskopf, 1979). Thus Ba, Rb and Pb, with i o n i c r a d i i s i m i l a r to that of K, substitute f o r K i n late-forming minerals such as K-feldspar and mica. Sr, with a radius intermediate between Ca and K, substitutes f o r both, and thus appears throughout the feldspar s e r i e s . 151 Cr, N i , and Co substitute f o r Mg i n ultramafic rocks, and Mn and V f o r Fe. Most of the t r a n s i t i o n metals (Cu, Zn, Pb) , however, do not r e a d i l y substitute for other ions but instead form sulphide ores from r e s i d u a l solutions r i c h i n sulphur. Likewise Zr, which because of i t s small size does not f i t into common s i l i c a t e structures, forms the independent mineral zircon. Many minor elements exh i b i t s i m i l a r geochemical behavior, due to s i m i l a r i t i e s i n i o n i c r a d i i , charge, and/or binding capacity. In the following pages, the d i s t r i b u t i o n of the minor elements i n Howe Sound w i l l be discussed i n the context of t h e i r common associations. 3.2.2 Rubidium Rb increases from a low of 25 ppm on the Squamish d e l t a to a high of 71 ppm at the mouth of Howe Sound, with the greatest v a r i a b i l i t y occurring i n the upper basin and delta sediments (Table B, Appendix I I I ) . The highest Rb/Al values (i.e.>8 X 10 -^) occur i n the lower t h i r d of the sound (Fig. 3.39), excluding Thornbrough Channel. This area i s the zone most strongly affected by landward transport of Georgia S t r a i t sediments ( S y v i t s k i and MacDonald, 1982) and approximates the d i s t r i b u t i o n of K/Al (see Section 3.1.4 and F i g . 3.12). These Rb values are low compared to values of Rb i n granites (150 ppm), shales (140 ppm) and average crust (90 152 Fig, 3,39 Rubidium to aluminum ratios in Howe Sound surface sediments, May 1987. 153 ppm) as reported by Krauskopf (1979). However, they agree c l o s e l y with those reported by Francois (1987) for Saanich I n l e t , another f j o r d whose sediment i s p a r t i a l l y derived from the coastal range g r a n o d i o r i t i c b a t h o l i t h . Rb appears to be negatively c o r r e l a t e d with A l i n Howe sound surface sediments (Fig. 3.40); however, i t i s c l e a r that t h i s trend i s a c t u a l l y a mixing l i n e between two sediment sources: the Squamish River with high A l and low Rb, and the Georgia S t r a i t - F r a s e r River with intermediate A l and high Rb. A p l o t of Rb vs. K (Fig. 3.41) shows some scatter, e s p e c i a l l y i n the lower basin, where the sediments represent a mixture of several d i f f e r e n t Rb-bearing minerals. In the d e l t a the c o r r e l a t i o n i s reasonably good (r=0.64), suggesting that i n t h i s f a c i e s Rb and K occur i n the same mineral phases, though i n low concentrations. Higher Rb/K values i n the outer basin (mean=38 x 10"^) r e l a t i v e to the inner basin (mean=28 x 10"^) probably r e f l e c t a greater o v e r a l l mica:feldspar r a t i o i n the former, since the Rb/K r a t i o of mica i s higher than that of feldspar (Rankama and Sahama, 1950). Although S y v i t s k i and MacDonald (1982) report that greater than 50% of the clay f r a c t i o n (<2 um) i n the upper basin consists of mica, the f a c t that Rb and K values are low i n t h i s region i s a d d i t i o n a l evidence f o r the small contribution of c l a y - s i z e d p a r t i c l e s to the t o t a l sediment fac i e s i n the upper basin. Indeed, i n the upper 154 80 60 CC 40 20 Rb vs. Al • • 13 • "86 > 84 • > > • 82 Lower Thornbrough Sill Upper Delta basin Channel basin • • * > • 7 8 9 Al, wt. % 10 Fig. 3.40 Plot of rubidium versus aluminum in Howe Sound surface sediments. 155 80 60 cr 40 20 Rb vs. K • • • • EL OD • • o • • * a r = 0.63 L o w e r T h o r n b r o u g h Sill U p p e r D e l t a basin Channel basin • • it- > — • — 1.5 K, wt.% Fig. 3.41 Plot of rubidium versus potassium in Howe Sound surface sediments. 156 b a s i n m u s c o v i t e i s t h e dominant K - b e a r i n g m i c a . O r t h o c l a s e o c c u r s i n t h e d e l t a sands i n q u a n t i t i e s l e s s t h a n 5%, and m i c r o c l i n e , t h e o t h e r predominant K - b e a r i n g f e l d s p a r , e x i s t s o n l y i n t r a c e amounts (Hoos and V o i d , 1975), a l t h o u g h b o t h may be r e s i d u a l l y e n r i c h e d t o some degree i n c o a r s e r f r a c t i o n s and i n l a g d e p o s i t s on t h e s i l l . F i g . 3.42 shows t h e R b / A l and Rb (ppm) v a l u e s w i t h d e p t h i n t h e two c o r e s . I n t h e o u t e r b a s i n (HS 16-B), Rb v a r i e s f rom 64-71 ppm (mean=68, la=±2, n=12), w h i l e t h e R b / A l r a t i o shows l i t t l e change w i t h d e p t h , a v e r a g i n g 8.25 x 10"^ (±0.17) o v e r t h e i n t e r v a l 0-30 cm. I n t h e upper b a s i n , Rb i s l o w e r and ranges from 26 t o 45 ppm (mean=35 ±6, n=8) i n t h e n a t u r a l s ediments and from 45-49 ppm (mean=47 ±1, n=5) i n t h e mine t a i l i n g s T a b l e D, A p p e n d i x I I I ) . The R b / A l r a t i o shows a s i m i l a r p r o f i l e , a v e r a g i n g 5.4 x 10"^ (±0.14, n=4) i n t h e mine t a i l i n g s v e r s u s 3.95 x 1 0 - ^ (±0.68, n=7) i n t h e n a t u r a l s e d i m e n t s . These p r o f i l e s r e f l e c t t h e homogeneity o f t h e o u t e r b a s i n s e d i m e n t s o v e r t i m e , as w e l l as t h e g r e a t e r c o n t e n t o f R b - b e a r i n g m i n e r a l s i n t h a t a r e a . The r e l a t i v e e n r i c h m e n t o f Rb i n mine t a i l i n g s s u g g e s t s t h a t t h e K - f e l d s p a r c o n t e n t o f t h e o r e body i s h i g h e r t h a n Squamish R i v e r - b o r n e d e t r i t u s , a l t h o u g h s t i l l not as h i g h as i n G e o r g i a S t r a i t s ediment. 157 0 Rb/AI (x 1 0 5 10 -E o QL CD Q 20 -30 10 Q Rb/AI i i <J i © f <? i natural ^ sediments i i 6 i tailings r "f <»> i \ I \ • 0 7 » / i / I / 1 / i HS 64 — • Inner basin I I [ I i 4 I t \ I \ i \ ^\ • HS 16-B ° Outer basin Fig. 3.42 Rubidium to aluminum ratios in two Howe Sound sediment cores, May 1987. 158 3.2.3 Barium Barium, l i k e rubidium, also substitutes f o r K infe l d s p a r s and mica. However, because of i t s smaller size and double charge, i t tends to enter early-forming K minerals, and i s not as well represented i n f e l s i c rocks as i s Rb (Krauskopf, 1979). Thus, mafic rocks have a higher Ba/K r a t i o than late-forming rocks such as feldspars and muscovite. Ba also substitutes i n c e r t a i n Mn(IV) oxides (Burns and Burns, 1977). In Howe Sound, an additi o n a l source i s l i k e l y to be the mine t a i l i n g s , as b a r i t e i s a common gangue mineral i n the ore (James, 1929), where i t occurs as intrusions i n the ore porphyry at various loc a l e s (Schofield, 1918). In Howe Sound surface sediments, Ba ranges from an average low of 650 ppm (la=±28, n=6) i n Thornbrough Channel to a mean of 825 ppm (±86, n=29) i n the upper basin, with the greatest v a r i a b i l i t y i n the upper basin (See Table C, Appendix I I I . The Ba/Al r a t i o , however, i s lowest i n the outer basin, averaging 89 x 10"^ ( l a = ± 5 , n=39), while both s i l l and upper basin sediments have the highest values at 96.5 x 10~ 4 (la=±5 and 10, n=15 and 29, res p e c t i v e l y . In general, Ba corre l a t e s with A l i n the f i v e regions (Fig. 3.43), with the exceptions of the two samples (#67 and 71) nearest the eastern shore i n the upper basin (which have concentrations of over 1000 ppm) , and the two samples from the northernmost portion of the de l t a (#91 and 93), which 159 0.12 0.10 co C O 0.08 0.06 Ba vs. Al 71 67 > * > tt> • • • r> — LTD mSaP I 9 1 93 Lower Thornbrough Sill Upper Delta basin Channel basin • * > • 7 8 9 10 Al, wt. % Fig. 3.43 Barium versus aluminum in Howe Sound surface sediments, May 1987. 160 p l o t below the common Ba/Al trend. The data f a l l i n t o two c l e a r l y defined f i e l d s : seaward of the s i l l the sediments are characterized by r e l a t i v e l y low Ba content, while north of the s i l l the d e l t a , s i l l and upper basin sediments host higher Ba concentrations (Fig. 3.44). I t i s c l e a r that the upper basin i s a trap for Ba-containing sediments. F i g . 3.44 shows t h i s enrichment of Ba along the whole eastern shore of the upper basin, l i k e l y the r e s u l t of b a r i t e occuring i n rocks i n several drainage basins which i n c i s e the ridge on the east side of the sound. The higher Ba/Al on the crest of the s i l l may be the r e s u l t of t i d a l winnowing which enriches lag deposits such as these with heavier minerals. B i o t i t e i s a source of Ba which occurs i n the f i n e r grain sizes (Mason and Moore, 1982); the reasonably high Ba/Al values throughout most of the sound are probably due to t h i s mineral which occurs i n Squamish sediments (Hoos and Void, 1975) as well as Britannia Creek sediments (James, 1929). In the area most affected by incoming Georgia S t r a i t suspended sediments, Ba i s lower, i n d i c a t i n g the l e s s e r , though s t i l l s i g n i f i c a n t , contribution of K feldspars and micas from that source. Ba versus K r e l a t i o n s h i p s are shown i n F i g . 3.45. Only i n the d e l t a and some upper basin and s i l l sediments i s there a reasonable c o r r e l a t i o n (delta: r= 0.64), i n d i c a t i n g that part of the Ba contribution here i s from a single Squamish-derived mineral, b i o t i t e and/or plagioclase. The 161 Fig.3.44 Barium to aluminum ratios in Howe Sound surface sediments, May 1987. 162 0.12 0.1 H DQ 0.08 H 0.06 B a v s . K r = 0.64 V • m • "t> Lower basin • Thornbrough Channel • Sill * Upper basin 0 Delta 1 . 5 2 K, wt. % 2 . 5 Fig. 3.45 Barium vs. potassium in Howe Sound surface sediments 163 lower Ba/K values i n most of the other samples indicates the decreasing presence of plagioclase and/or the increasing presence of orthoclase down-inlet. The large degree of scatter i n the lower basin indicates once again that these sediments are poorly sorted and r e f l e c t several d i f f e r e n t and only partially-determined sources. The Ba/K r a t i o d i s t r i b u t i o n i n the f j o r d (Fig. 3.46) shows c l e a r l y that the de l t a and the Britannia mine t a i l i n g s are sources of the element. The Ba/Rb r a t i o i s often used to delineate areas of feldspar enrichment i n sediments (Wright, 1972; Calvert, 1976). In Howe Sound the Ba/Rb decreases down-inlet, from an average of 22 i n the d e l t a to 11 i n the lower basin. Since feldspars occur i n a l l si z e f r a c t i o n s ( S y v i t s k i and MacDonald, 1982), t h i s suggests that the primary source f o r feldspars i n Howe Sound i s the Squamish River rather than Georgia S t r a i t . The concentration of Ba with depth and the Ba/Al r a t i o vs. depth p r o f i l e s are shown i n Figs. 3.47 and 3.48. Both show the r e l a t i v e constancy of the Ba content (mean = 718 ug/g, la=±41, n=12) i n the outer basin. In contrast, the natural sediments i n the upper basin show considerably more v a r i a b i l i t y (mean = 750 ug/g ±63, n=8) that i s not due to d i l u t i o n by other factors but i s l i k e l y a grain-size e f f e c t . The t a i l i n g s signature i s unmistakable i n the upper basin core, as Ba increases from 653 ug/g at 11 cm to over 1000 164 Fig. 3.46 Barium to potassium ratios in Howe Sound surface sediments, May 1987. 165 Ba, ug/g 800 1,000 1,200 •Q I ' l *m\ ' I ' I 1 I • 9 f ;o natural sediments 0'' ^ " " ^ • - ^ ^ ^ tailings o ^ ^ ^ ^ \ o HS 16-B / Outer basin T HS64 \ b Inner basin • Fig. 3,47 Barium (ppm) in two Howe Sound cores, May 1987. 166 Ba/AI (x 1 0 4 ) 50 100 150 Fig. 3.48 Barium to aluminum ratios in two Howe Sound sediment cores, May 1987. 167 ug/g at 17 cm, and remains high (even increases) to the bottom of the core. Thus Ba may be used to i d e n t i f y areas of t a i l i n g s influence, at lea s t to a l i m i t e d degree. 3.2.4 Strontium Sr has an i o n i c radius intermediate between Ca and K and therefore substitutes for both major elements i n c r y s t a l l a t t i c e s (Krauskopf 1979). However, due to i t s small size i t i s not able to f i t into the structure of micaceous minerals (Taylor, 1965). Thus i t i s enriched i n a l l feldspars (even though Ca and K abundances are inversely r e l a t e d i n these minerals), but depleted i n micas. It i s also present i n carbonates and amphiboles (Bowen, 1979), and forms i t s own minerals c e l e s t i t e and s t r o n t i a n i t e . Of the l a t t e r , c e l e s t i t e i s a common, though minor, constituent of evaporites, and s t r o n t i a n i t e occurs occasionally i n carbonates (Krauskopf, 1979). Since carbonates are v i r t u a l l y absent i n Howe Sound sediments, and c e l e s t i t e i s f a i r l y soluble, i t i s assumed that any contribution to the Sr content from these sources i s n e g l i g i b l e . In Howe Sound Sr ranges from an average low of 292 ppm (la=±48, n=39) i n the lower basin to 575 ppm (la=±42, n=9) i n the d e l t a sediments. The Sr/Al r a t i o follows the same trend, from 38 x 10~ 4 i n the lower basin (±6) to 68 (±4) on the d e l t a (see Table F, Appendix I I I ) . F i g . 3.49 shows a strong c o r r e l a t i o n of Sr with non-carbonate Ca i n a l l 168 6 0 0 -4 0 0 C D CO 2 0 0 -C a v s . S r r - 0 .96 / Lower Thornbrough Sill Upper Delta basin Channel basin B • * 0 • 2 3 4 Ca, wt. % Fig. 3.49 Strontium vs. calcium in Howe Sound surface sediments. Calcium is presented on a carbonate-free basis 169 sediments (r=0.96); an intercept near zero indicates that the two elements are occurring i n the same mineral phase throughout the sound, although the scatter i n Thornbrough Channel and the upper basin, and the s l i g h t l y d i f f e r e n t slope i n the d e l t a sediments suggest that a d d i t i o n a l Sr-bearing minerals are also occurring i n these areas. F i g . 3.50 supports t h i s conclusion, as the f i e l d s f o r the f i v e regions are quite d i s t i n c t : the areas between the low-Sr lower basin and the high-Sr d e l t a sediments r e f l e c t a mixing l i n e along which Sr concentrations are roughly proportional to the distance between the two sources. (The anomalous points to the l e f t of the main f i e l d s represent sample stations thought to be strongly affected by d i l u t i o n by organic matter; those to the r i g h t are quiet c e n t r a l areas with high-Al, and presumably high clay, content). A comparison of Sr vs. carbonate carbon i n the f i v e regions (Fig. 3.51) reveals that i n Thornbrough Channel and the s i l l area (r = 0.00) v i r t u a l l y a l l the Sr has to be i n c a l c i c feldspars. In the upper basin some covariance of inorganic carbon and strontium indicates that i n several samples offshore from Woodfibre Creek there i s an a d d i t i o n a l source of CaC03, and hence, Sr. Figs 3.52 and 3.53 p l o t the d i s t r i b u t i o n of Sr/Al i n Howe Sound. These maps show that the Squamish River i s the primary source f o r Sr (and thus for Ca), with a d d i t i o n a l inputs from Woodfibre Creek and the west side of Thornbrough 170 600 400 ZJ CO 200 Sr vs. Al > 86 82 54 52 6 Lower Thornbrough SHI Upper Delta basin Channel basin • • * > • I . I . 1 7 8 9 10 Al, W t . % Fig. 3.50 Strontium versus aluminum in Howe Sound surface sediments, May 1987. 171 600 H -5? ZJ CO 400 A 200 u Carbonate C vs. Sr Delta r = 0.65 ^ * * 0 Upper Basin r = 0.17 * • C D • Lower Basin r = 0.25 i r r 0.1 0.2 C(inorg), wt. % 0.3 Fig. 3,51 Inorganic (carbonate) carbon versus strontium in Howe Sound sediments, May 1987, 172 Fig. 3.52 Strontium to aluminum ratios in Howe Sound surface sediments, May 1987. 173 Fig. 3.53 Strontium to aluminum ratios in upper basin of Howe Sound, May 1987, 174 Channel (see Section 3.1.4). Since Sr does not occur i n micas, and Rb i s depleted i n feldspars (except K-feldspars), i t follows that Sr and Rb should be inversely proportional to each other i n sediments dominated by one or the other of these mineral types. F i g 3.54 i s a p l o t of Sr versus Rb and indicates that the d e l t a , with the highest Sr values, i s probably dominated by feldspars over micas. However, Rb concentrations of =40 ppm in d i c a t e that micas and/or K-feldspars are also constituents. Likewise the lower basin, with higher Rb concentrations, but low Sr, has a greater proportion of micaceous minerals than do sediments i n the other areas. The presence of =200 ppm Sr (close to 250 ppm for average s o i l s , as reported by Bowen, 1979) suggests that feldspars are present, i f not as abundant. To c l a r i f y the dominant mineralogies here, the combined behaviours of Ba, Rb, and Sr may be taken i n t o account. Since Sr does not occur i n micas, i t s presence suggests feldspars; Ba i s present i n b i o t i t e and plagioclase feldspars, but depleted i n l a t e -forming K-minerals; and Rb occurs i n micas and K-feldspars. Therefore a high Sr/Rb r a t i o suggests a f e l d s p a r - r i c h sediment, while a low Sr/Rb r a t i o indicates mica-rich sediment. Taken i n concert with the p r e v a i l i n g Ba/Rb r a t i o s , which d i s t i n g u i s h between l i g h t and dark micas, and between K-feldspars and plagioclase, one can show how these assemblages are r e l a t e d i n Howe Sound (Fig. 3.55). The 175 100 20 -0 L 0 Lower basin — B — Thornbrough Channel • Sill -* Upper basin t> Delta • i i . , i i i 200 I 400 i i i 1 1 600 Sr, ug/g Fig. 3.54 Strontium vs rubidium in Howe Sound surface sediments 176 O 10 20 30 Ba/Rb Fig. 3.55 Strontium-.rubidium ratio vs. barium .rubidium ratio in Howe Sound surface sediments 177 following conclusions can be drawn from t h i s p l o t : 1) the de l t a sediments contain a high proportion of plagioclase feldspars (high Sr/Rb, high Ba/Rb); 2) the upper basin sediments and those on the s i l l contain a mixture of feldspars and micas, of which b i o t i t e i s a notable constituent close to the t a i l i n g s o u t f a l l (#'s 67, 71 and 75); 3) the lower basin and Thornbrough Channel, with r e l a t i v e l y low Sr/Rb and Ba/Rb r a t i o s , contain a higher proportion of micas than occur i n the upper basin (from which b i o t i t e i s la r g e l y absent); the dominant micaceous minerals, by default, are muscovite or a m u s c o v i t e / i l l i t e mixture; and 4) that the s i l l provides a reasonable b a r r i e r to the exchange of sediments from the two d i f f e r e n t sources, but tends to be influenced more by the saltwater inflow at depth than the Squamish-driven outflow at the surface. These d i s t r i b u t i o n s may also be a r e f l e c t i o n to some degree of natural sorting of Squamish sediments, although S y v i t s k i and MacDonald (1982) argue against such a conclusion, as they found that grain s i z e does not decrease i n a l i n e a r fashion either down-inlet or a c r o s s - i n l e t , but i s influenced more by l o c a l topography and the strength of bottom water c i r c u l a t i o n . The present data suggest that there i s detectable sorting of Squamish-derived sediments, and that the Sr/Rb plot i s therefore, to some extent, a gra i n - s i z e proxy. In Core HS 16-B from the outer basin, Sr averages 246 178 ug/g (la=±6, n=12) and Sr/Al = 30 ±0.53 over the whole core. In the upper basin core the mean Sr i n the natural sediments i s 556 ug/g (±29, n=8) versus 436 ug/g (±18, n=5) i n the t a i l i n g s , while Sr/Al = 61.9 (±3.99, n=7) versus 49.9 (±1.55, n=4) i n the t a i l i n g s . The Sr/Al r a t i o versus depth i s shown i n F i g . 3.56, and absolute Sr abundances are p r o f i l e d i n F i g . 3.57. The top of, the mine t a i l i n g s i s c l e a r l y v i s i b l e i n the Sr p r o f i l e from the upper basin core, and suggests e i t h e r that the plagioclase content of the t a i l i n g s i s lower than the sediment curren t l y being deposited, or that the presence of b i o t i t e (which i s low i n Sr) i s d i l u t i n g the Sr content of the tailings-sediment mixture. The lower (and more constant) Sr concentrations i n the outer basin supports the conclusion that micaceous minerals play a larger part i n the geochemical make-up of these sediments. 3.2.5 Cobalt, Chromium, Nickel and Vanadium These four t r a n s i t i o n metals a l l have intermediate r a d i i s i m i l a r to that of i r o n ( F e 3 + = 0.73A) and Mg (0.80A), and therefore substitute for these major ions i n ultramafic rocks and some basalts. They also form minerals i n which they are often, though not always, associated with i r o n , e.g. F e C r 2 0 4 , CoS 2, CoAs 2, MgCr 20 4, NiS, VS 4 and CaV 20 4 (Bowen, 1979). A l l are found i n the early-forming Fe and Mg minerals of the o l i v i n e and pyroxene groups, and i n 179 S r / A I (x 1 0 4 ) 100 Outer basin Fig, 3,56 Strontium to aluminum ratios in two Howe Sound sediment cores, May 1987, 180 Sr, ug/g 200 300 400 500 600 Fig. 3.57 Strontium (ppm) in two Howe Sound sediment cores, May 1987. 181 addition, V i s found i n apatite, b i o t i t e and amphiboles (Mason and Moore, 1982). In sedimentary rocks they are enriched i n shales over sandstones and limestones, and i n marine sediments i n clays over sands and carbonates (Bowen, 1979) . L a t t i c e p ositions i n the major minerals are not the only sources f o r trace metals. As previously described, many trace metals are pa r t i t i o n e d between several d i f f e r e n t sediment phases, both hydrogenous and biogenous. They are often coprecipitated with Mn and Fe oxides as coatings on d e t r i t a l and biogenous p a r t i c l e s ; they are involved i n ion-exchange processes during the weathering of clay minerals; and they are often c l o s e l y associated with organic matter, both as integrated compounds and as adsorbed coatings (Troup and Bricker, 1975). Carpenter et a l (1975) concluded that organic matter i s a s i g n i f i c a n t source for Co, Cr, Cu, Mn, Ni, Pb, and Zn, since the concentrations of these metals i n estuarine waters r i s e s considerably during the winter months when organic material i s decaying. The d i s t r i b u t i o n s of Cu, Pb and Zn i n Howe Sound are complicated by t h e i r high concentrations i n the mine t a i l i n g s , and they w i l l be examined separately i n another section. In Howe Sound, Co concentrations do not show a d i s t i n c t north-south trend, but rather reveal only l o c a l i z e d enrichments (Fig. 3.58). In absolute abundances Co averages 27 ug/g (la=±5, n=39), 34 ±10 (n=7) i n Thornbrough Channel, 182 26 ±3 on the s i l l , 31 ±9 i n the upper basin and 29 ±4 on the d e l t a . The greatest v a r i a b i l i t y occurs i n the upper basin, where Co ranges from 15 ug/g to 53 ug/g over a r e l a t i v e l y short distance (see Table E, Appendix I I I ) . The Co/Al r a t i o s f o r the lower basin, upper basin and d e l t a sediments are a l l =3.5 x 10~ 4; Thornbrough Channel i s s l i g h t l y enriched (4.9 x 10~ 4) i n Co, and the s i l l sediments are s l i g h t l y depleted (3.1 x 10~ 4). Local enhancements occur near Port Mellon i n Thornbrough Channel, i n the shallow s t r a i t separating Bowen and Gambier Islands, and i n sediments near the Watts Point dumpsite i n the upper basin. Surface sediments close to the Britannia Beach o u t f a l l have Co/Al r a t i o s <2.0, suggesting that Co i s not associated with the sulphides that form the mine ore. The Co versus A l plot for the f i v e regions (Fig. 3.59) shows no d i s t i n c t c o r r e l a t i o n between Co and the terrigenous component. However, t h i s p l o t does i l l u s t r a t e that the highest Co concentrations are i n two stations i n Thornbrough Channel and i n several samples i n the northern part of the upper basin (excluding the NE-trending arm). Both these regions are close to pulp m i l l dumpsites, although i t i s unclear why Co should be enriched i n solid-phase pulp m i l l waste. There i s scant c o r r e l a t i o n of Co with Mg (r = 0.05), Fe (r = 0.09) or with C (r = 0.00), i n d i c a t i n g that there y i s l i t t l e a ssociation of Co with s p e c i f i c mafic mineral 184 C o vs. Al 51 82l> D11 • 46 > 72 68|> 80 76 > 077 82-bD> > B • IX 93 • a\3r ft _ D _ D _ > > * £ > > Lower Thornbrough Sill Upper Delta basin Channel basin • • * > • 6 8 10 Al, wt. % Fig. 3.59 Cobalt vs. aluminum in Howe Sound surface sediments 185 phases or organic matter i n Howe Sound surface sediments. Presumably, cobalt i s par t i t i o n e d among several d i f f e r e n t sediment phases, without any p a r t i c u l a r phase being the dominant host. Co/Al r a t i o p r o f i l e s f or the two cores are shown i n F i g . 3.60. There appears l i t t l e d i fference i n Co concentrations between the two areas, eit h e r s p a t i a l l y or with depth, and no re l a t i o n s h i p between the Co d i s t r i b u t i o n and the presence or absence of t a i l i n g s . Chromium and n i c k e l d i s t r i b u t i o n s appear to be c l o s e l y linked i n Howe Sound (Fig. 3.61), thus they are probably hosted by the same mineral phase. The abundances of both elements increase down-inlet, with increasing distance from the Squamish River (Figs. 3.62, 3.63 and 3.64). Since they tend to be enriched i n mafic minerals, these d i s t r i b u t i o n s suggest that the source for t h e i r common host phases i s the Fraser River, rather than the fi n e f r a c t i o n of Squamish sediments. Indeed, S y v i t s k i and MacDonald (1982) concluded that Ni provides a sen s i t i v e tracer f or Fraser River sediment. I t i s c l e a r that Cr may also serve t h i s function. Both metals are depleted i n the deep upper basin sediments, although s l i g h t l y higher values are found i n the shallow areas and nearshore zones which might consist of coarser material. Ni also shows a r e l a t i v e enrichment near the t a i l i n g s o u t f a l l , but the Ni/Al p r o f i l e of the upper basin core (Fig. 3.65) indicates that Ni must be a very minor 186 Co/AI ( x 1 0 4 ) o 8 10 0 10-20-30 Co/AI Outer basin HS 64 Inner basin Fig. 3.60 Cobalt to aluminum ratios in two Howe Sound sediment cores, May 1987. 187 Ni, ug/g Fig. 3.61 Nickel versus chromium in Howe Sound surface sediments, May 1987. 188 Fig. 3.62 Chromium to aluminum distribution in Howe Sound surface sediments, May 1987. 189 Fig, 3.63 Nickel to aluminum ratios in Howe Sound surface sediments, May 1987. 19Q Fig. 3.64 Nickel to aluminum ratios in surface sediments of upper basin, Howe Sound, May 1987. 191 Ni/AI (x 10 4 ) Inner basin Fig, 3,65 Nickel to aluminum ratios in two Howe Sound sediment cores, May 1987. 192 component of the sulphide ore body from which the t a i l i n g s were derived. The d i s t r i b u t i o n s of Cr and Ni versus A l (Figs. 3.66 and 3.67) are s t r i k i n g l y s i m i l a r . Except for Thornbrough Channel, the d i s t r i b u t i o n s p l o t along a mixing l i n e l i n k i n g high trace metals with low A l abundance (in the lower basin), and lower metal values with high A l i n the upper basin, further evidence that the metals are not l a r g e l y contained within the clay minerals which make up part of the fi n e f r a c t i o n . Plots of Cr and Ni versus Mg and Fe are shown i n Figs. 3.68, 3.69, 3.70 and 3.71. These graphs suggest, unexpectedly, that Fe and not Mg minerals are hosts for these metals, at lea s t i n the enriched outer basin sediments. I t i s uncertain whether Cr and Ni form part of the c r y s t a l l i n e l a t t i c e of these minerals or are present as pr e c i p i t a t e d coatings on sediment p a r t i c l e s . The considerable scatter i n the data on a l l the graphs indicates that Cr and Ni concentrations are probably p a r t i t i o n e d among several d i f f e r e n t phases by a v a r i e t y of processes - surface adsorption, c o p r e c i p i t a t i o n , and ion exchange reactions, and as constituents i n c r y s t a l l a t t i c e s and organic material. This m u l t i p l i c i t y of po t e n t i a l host phases has been noted i n sediments from many d i f f e r e n t estuaries (e.g. Troup and Bricker, 1975; Gibbs, 1973; Carpenter et a l , 1975). Francois (1987) found that both Cr and Ni are enriched i n 193 150 100 O 50 Cr vs. Al • • • u • * " c P asm _ •XX" > Lower Thornbrough Sill Upper Delta basin Channel basin • • * > • I . I . I . 7 8 9 10 Al, wt. % Fig. 3,66 Chromium versus aluminum in Howe Sound surface sediments, May 1987. 194 60 40 20 Ni vs. Al • O • -* • • Lower Thornbrough Sill Upper Delta basin Channel basin • • * > • 8 10 Al, wt. % Fig. 3.67 Nickel versus aluminum in Howe Sound surface sediments, May 1987, 195 20- Lower Thornbrough Sill Upper Delta basin Channel basin —B— • * 0 ' — i — i — i — i — i — i — i — i — \ — i — i — i — i — i — 1 1.5 2 2.5 Mg, wt. % Fig. 3,68 Chromium versus magnesium in Howe Sound surface sediments, May 1987. 196 Lower Thornbrough Sill Upper Delta basin Channel basin —B— • * |> • 3 4 5 6 Fe, wt. % Fig. 3.69 Chromium versus iron in Howe Sound surface sediments, May 1987, 197 50 40 30 20 1(H NI v s . M g o a D cP D D D B > ft. • * L f f t * * • ^ > Lower Thornbrough Sill Upper Delta basin Channel basin • • •* > • 1 T 1 1 I 1.5 i — i — r T i—i—r 2.5 Mg, wt. % Fig. 3,70 Plot of Nickel versus magnesium in Howe Sound surface sediments, May 1987. 198 60 Lower Thornbrough SHI Upper Delta basin Channel basin —a— • * > • I 1 . 1 1 3 4 5 6 Fe, w t % Fig, 3,71 Plot of nickel versus iron in Howe Sound surface sediments, May 1987. 199 organic-rich Saanich Inlet sediments, and suggested that e i t h e r organic material i s hosting the Cr and Ni, or that conditions which favor high organic C also favor deposition of Cr and Ni. Accordingly, the Cr/Mg and Cr/Fe r a t i o s , when plo t t e d against the organic carbon content of Howe Sound sediments (Fig. 3.72 and 3.73) show that, although the sediments with the highest Corg content ( i . e . Thornbrough Channel) do not have the highest metal l e v e l s , there i s a strong c o r r e l a t i o n between the r a t i o s and the carbon content i n t h i s region (r = 0.89). The d e l t a region, with considerable contamination by pulp m i l l waste near Woodfibre Creek, also show a strong association (r = 0.87 and 0.80 for Cr/Mg and Cr/Fe vs. C o rg/ r e s p e c t i v e l y ) . These r e s u l t s provide a d d i t i o n a l evidence that Cr i s associated with the organic-rich f r a c t i o n . The high-Cr concentrations i n the outer basin show no such association. The graphs of Ni/Fe and Ni/Mg vs. C o r g (Figs. 3.74 and 3.75) i l l u s t r a t e s i m i l a r associations, with the exception that the poor c o r r e l a t i o n of Ni/Fe and Ni/Mg with organic C i n areas affected by pulp m i l l a c t i v i t y ( i . e . i n Thornbrough Channel and the westernmost portions of the delta) indicates that the t e r r e s t r i a l l y - d e r i v e d debris which dominates the organic f r a c t i o n i n these sediments i s not a s i g n i f i c a n t host for N i . The Cr/Al and Ni/Al vs. depth p r o f i l e s (Figs. 3.7 6 and 3.77) show l i t t l e v a r i a t i o n . Neither metal shows any 200 Lower Thornbrough Sill Upper Delta basin Channel basin • » * t> • 0 1 2 3 4 5 6 7 8 9 10 Corg, W t . % Fig. 3.72 Chromium imagnesium ratio vs. organic carbon in Howe Sound surface sediments 2Q1 C o r g , wt. % Fig. 3.73 Chromium:lron ratio vs. organic carbon in Howe Sound surface sediments 202 10 8 -6 ->< CD 4 -2 -• • • 0 > 0 Ni/Fe vs. C org Lower Thornbrough Sill Upper Delta basin Channel basin • • * 0 , 1 , 1 , 1 , 1 R 0 2 4 6 8 10 C 0rg i W t . % Fig. 3.74 Plot of nickel:iron ratio versus organic carbon in Howe Sound surface sediments, May 1987, 203 Lower Thornbrough Sill Upper Delta basin Channel basin • • * > — • — 0 1 2 3 4 5 6 7 8 9 10 Corg, W t . % Fig. 3.75 Nickel imagnesium ratio vs. organic carbon In Howe Sound surface sediments 204 Cr/AI (x 10 4 ) 10 20 0 j i i i J I L J I I I I I I I I I I 1 1 1 1 L 1<M 20 H 30 Cr/AI i u> natural sediments i tailings ^ 9 I f HS 16-B Outer basin HS 16-B « Inner basin Fig. 3,76 Chromium to aluminum ratio in two Howe Sound sediment cores, May 1987, 205 Ni/AI (x 10 4 ) Fig. 3.77 Nickel:aluminum ratios in two Howe Sound sediment cores, May, 1987. 206 association with the t a i l i n g s . Vanadium i s hosted p r i m a r i l y by Fe minerals, generally those formed at a l a t e r stage of c r y s t a l l i z a t i o n than those containing Cr, Co and Ni. V i s depleted i n very ea r l y -forming dunite and later-forming granites, but enriched i n basalts (Bowen, 1979), occurring i n magnetite, pyroxenes, amphiboles and b i o t i t e (Mason and Moore, 1982). V may also be bound i n small quantities to organic matter, which fix e s the vanadyl cation (V0)^ + from seawater (Brumsack and Gieskes, 1983). V increases down-inlet i n Howe Sound, averaging 144 ug/g (lo=±6.5, n=9) on the de l t a and increasing s t e a d i l y to 180 ±12 ug/g (n=46) i n the lower basin Table E, Appendix I I I ) . Local enrichments appear i n the upper part of Thornbrough Channel (Fig. 3.78), and i n some ce n t r a l basin sediments both north and south of the s i l l . A c l o s e r look at the inner basin (Fig. 3.79) suggests that V i s i n some way connected with the Fe-rich mine t a i l i n g s (possibly with b i o t i t e , which i s common i n the Britannia S i l l s ) . The V versus A l r e l a t i o n s h i p approximates those of Cr and Ni with A l , ( Fig. 3.80), the only difference being that Thornbrough Channel i s enriched i n V, though not p a r t i c u l a r l y so i n Cr or N i . A plot of V vs. Fe (Fig. 3.81) shows a stronger c o r r e l a t i o n , and demonstrates that vanadium i n d e l t a and lower basin sediments, while covarying with Fe, i s contained i n d i f f e r e n t Fe minerals. Squamish d e l t a sediments contain 207 Fig. 3.78 Vanadium to aluminum ratios in Howe Sound surface sediments, May 1987. 208 Fig, 3.79 Vanadium to aluminum ratios in surface sediments of inner basin, Howe Sound, May 1987, 209 200 CT) CT) 150 100 V vs . A l • • n n > > > • • Lower Thornbrough Sill Upper Delta basin Channel basin • • * > • 7 8 Al, W t . % 10 Fig. 3,80 Plot of vanadium versus aluminum in Howe Sound surface sediments, May 1987. 210 250 200 -CD Z3 150 -100 V vs. Fe L !>...••• Lower Thornbrough Sili Upper Delta basin Channel basin — B • * > • -• 3 4 5 F e , wt. % Fig. 3.81 Plot of vanadium versus iron in Howe Sound surface sediments, May 1987. 211 s i g n i f i c a n t amounts o f b o t h b i o t i t e and amphiboles (Hoos and V o i d , 1975), so e i t h e r o r b o t h o f t h e s e may be c o n t r i b u t i n g t o V i n t h i s a r e a . A s l i g h t c o v a r i a n c e o f V w i t h N i i n o u t e r b a s i n s ediments ( F i g . 3.82) i s e v i d e n c e t h a t some m i n e r a l o t h e r t h a n an i r o n - b e a r i n g phase ( s i n c e N i i s not w e l l c o r r e l a t e d w i t h Fe) may be a h o s t f o r b o t h e l e m e n t s i n t h i s r e g i o n . F i g . 3.83 shows t h e V/Fe r a t i o p l o t t e d a g a i n s t o r g a n i c C; t h e h i g h V/Fe r a t i o s i n Thornbrough Channel c o u p l e d w i t h h i g h C o r g ( r = 0.44) s u g g e s t s t h a t a t l e a s t p a r t o f t h e V e n r i c h m e n t i s r e l a t e d t o t h e h i g h e r o r g a n i c c o n t e n t o f t h e Channel s e d i m e n t s . T h i s o b s e r v a t i o n i s c o n s i s t e n t w i t h h i g h V measured i n o r g a n i c - r i c h s e d i m e n t s e l s e w h e r e ( C a l v e r t and M o r r i s , 1977; Brumsack, 1980). The V / A l d i s t r i b u t i o n w i t h d e p t h i n t h e two c o r e s ( F i g . 3.84) shows a v e r y s l i g h t e n r i c h m e n t o f V i n t h e t a i l i n g s p o r t i o n o f t h e i n n e r b a s i n c o r e , l i k e l y due t o s m a l l amounts o f b i o t i t e . No a d d i t i o n a l i n c r e a s e w i t h d e p t h can be n o t e d i n e i t h e r c o r e ; t h u s , any e n r i c h m e n t w h i c h might be due t o d i a g e n e t i c f i x a t i o n o f d i s s o l v e d V by o r g a n i c m a t t e r i n t h e a n o x i c p o r t i o n s i s not d e t e c t a b l e a t t h e s e l o c a t i o n s . 3.2.6 Yttrium A l t h o u g h n o t i t s e l f a r a r e e a r t h , y t t r i u m i s o f t e n used as a r a r e e a r t h i n d i c a t o r as i t s b e h a v i o r mimics t h a t o f t h e l e s s abundant elements i n t h e s e r i e s ( C a l v e r t , p e r s . comm.). 212 250 > 100 50 Lower Thornbrough Sill Upper Delta — B — • * > • basin Channel basin 20 40 60 Ni, ug/g Fig, 3,82 Plot of vanadium versus nickel in Howe Sound surface sediments, May 1987, 213 50 3 0 -Lower Thornbrough Sill Upper Delta basin Channel basin • • * t> • C o r g , wt. % Fig. 3.83 Vanadium:iron ratio vs. organic carbon in Howe Sound surface sediments 214 V/AI (x 10 4 ) 0 20 30 40 50 30 1  Fig, 3.84 Vanadium to aluminum ratios in two Howe Sound sediment cores, May 1987. 215 Its i o n i c radius i s 0.98 A, and therefore occasionally substitutes for Ca (Krauskopf, 1979). In igneous rocks i t i s notable i n the heavy mineral f r a c t i o n i n some pegmatites, where i t mostly forms i n d i v i d u a l minerals rather than s u b s t i t u t i n g f o r major elements (Mason and Moore, 1982). In sediments, i t i s high i n phosphatic ca l c a r e n i t e s of some upwelling areas, where i t substitutes for Ca i n authigenic carbonate f l u o r a p a t i t e (Calvert, 1983). Bowen (1979) reports l i t t l e d i f f e r e n t i a t i o n of Y between the major s o i l and rock types, c i t i n g 33 ug/g for granite, 27 ug/g for basalt, 40 ug/g for s o i l , 41 ug/g for shale, 23 ug/g for limestone and 54 ug/g for sandstone. In marine clays Y averages 32 ug/g, and 42 u/g i n carbonates. Calvert (1983) found concentrations of over 80 ug/g i n a p a t i t e - r i c h sediments of the Namibian Shelf o f f west A f r i c a . The Y l e v e l s i n Howe Sound are much lower than any of these. The highest value recorded i s 24 ug/g (at l o c a t i o n #7) o f f Horseshoe Bay i n the lower basin, and the lowest (15 ug/g) at lo c a t i o n #67 i n the upper basin, although the l a t t e r i s somewhat anomalous since the east side of the upper basin appears to have a l o c a l enrichment of Y over the generally low l e v e l s i n the region (Fig. 3.85). In general, Y increases down-inlet, which i s the opposite trend to that of Ca, suggesting that i t i s probably hosted by low l e v e l s of heavy minerals which are entering 216 Fig. 3.85 Yttrium to aluminum ratios in Howe Sound surface sediments, May 1987, 217 Howe Sound from Georgia S t r a i t , rather than being associated with c a l c i c minerals from the Squamish source. The Y:Ca trend i n F i g . 3.86 supports t h i s conclusion, i n d i c a t i n g that only i n the high-Ca delta area i s there even a small c o r r e l a t i o n of Ca with Y. A further attempt to c l a r i f y the d i s t r i b u t i o n i n Howe Sound i s shown i n F i g . 3.87, which pl o t s Y against the phosphorus content of the sediments. I t can thus be concluded that authigenic phosphate i s not a s i g n i f i c a n t part of the sediments i n t h i s i n l e t . F i g . 3.88 shows the Y/Al r a t i o s versus depth i n the two cores. Considerable fluctuations i n both basins are att r i b u t e d to grain-size e f f e c t s . There appears to be no di s c e r n i b l e Y enrichment or depletion i n the mine t a i l i n g s . 3.2.7 Manganese Due to the s i m i l a r i t i e s i n t h e i r i o n i c r a d i i , Mn substitutes f or Fe i n early-formed mafic minerals (Krauskopf, 1979). I t i s poorly represented i n feldspars, micas, and apatite, but enriched i n b i o t i t e and hornblende (Mason and Moore, 1982). Mn i s also s i m i l a r i n s i z e to the Ca ion and therefore proxies for Ca i n mineral l a t t i c e p o s i tions i n which the l a t t e r might t h e o r e t i c a l l y f i t ; however, as i t i s more electronegative than Ca i t seldom i s found a c t u a l l y replacing Ca (Mason and Moore, 1982). Mn also forms s i l i c a t e s , sulphides, carbonates and 2 1 8 Y vs . C a • Lower Thornbrough Sill Upper Delta basin Channel basin • • * > • Ca, wt. % Fig. 3.86 Yttrium vs. calcium in Howe Sound surface sediments. Calcium is presented on a carbonate-free basis. 219 30 Y v s . P • Lower Thornbrough Sill Upper Delta basin Channel basin • • * — f r — • 10 1 1 1 1 1 1 1 1 1 1 1 1 1 — i — I 0.5 1 1.5 2 P. ppt Fig.3.87 Plot of y t t r ium versus phosphorus in Howe Sound surface sediments, May 1987. 220 Y/AI (x 1 0 ^ ) 3 Y / A I I .0 <3^ natura l s e d i m e n t s a t a i l i ngs or 0 H S 6 4 Inner b a s i n - H S 1 6 - B O u t e r b a s i n 6 Fig. 3.88 Yttrium to aluminum ratios in two Howe Sound sediment cores, May 1987. 221 o x i d e s , many of which are s t r o n g l y a f f e c t e d by s m a l l changes i n pH and redox p o t e n t i a l . T h i s complex g e o c h e m i c a l b e h a v i o r o f Mn makes i t s d i s t r i b u t i o n i n sediments d i f f i c u l t t o i n t e r p r e t , s i n c e the element may be p a r t i t i o n e d between s e v e r a l hydrogenous , b iogenous and t e r r i g e n o u s p h a s e s . Mn(IV) o x i d e s a r e u b i q u i t o u s phases t h a t range from r e f r a c t o r y anhydrous compounds t o h y d r a t e d m i n e r a l s t h a t are s t a b l e a t low t empera tures (Burns and B u r n s , 1979) . They a r e formed by p r e c i p i t a t i o n o f d i s s o l v e d Mn from seawater under h i g h Eh c o n d i t i o n s , e i t h e r i n o r g a n i c a l l y o r c a t a l y s e d by b a c t e r i a . They p r e c i p i t a t e f i r s t as c o l l o i d s w i t h a n e g a t i v e s u r f a c e charge and thus adsorb l a r g e numbers of c a t i o n s from seawater ( s p e c i f i c a l l y Ba , Co , Cu , K , 9 + 9 + N i and Pb^ ; K r a u s k o p f , 1979) . Upon b u r i a l i n sediments below the oxygen- and n i t r a t e - r e d u c t i o n zones , Mn 9 + • • o x y h y d r o x i d e s a r e commonly reduced t o Mn by b a c t e r i a which use t h e energy l i b e r a t e d t o o x i d i z e o r g a n i c m a t t e r (see S e c t i o n 1 . 2 ) . The d i s s o l v e d Mn, which i s s t a b l e i n s l i g h t l y a c i d c o n d i t i o n s t h a t a r e d y s a e r o b i c o r a n o x i c , may t h e n form MnC03, MnSiC^ o r MnS i f the a p p r o p r i a t e porewater a n i o n i s p r e s e n t a n d , i n the case o f the l a t t e r two, abundant . (A c a v e a t here i s t h a t MnC03 i s h i g h l y f a v o r e d , even w i t h low d i s s o l v e d C C ^ - , so t h a t the o t h e r two phases w i l l o n l y form 9 • — 2-when low i s combined w i t h h i g h S1O3 o r S^ ( K r a u s k o p f , 1979); i n a d d i t i o n , MnS i s c o m p a r a t i v e l y v e r y s o l u b l e and i s r a r e i n marine sediments ( e . g . S u e s s , 1978) ) . 222 This d i a g e n e t i c behavior of Mn makes a s s e s s i n g the Mn d i s t r i b u t i o n i n Howe Sound surface sediments somewhat d i f f i c u l t . Mn oxides are reduced j u s t below the o x i c zone i n sediments, and the d i s s o l v e d Mn which i s l i b e r a t e d migrates upward along a c o n c e n t r a t i o n g r a d i e n t u n t i l i t comes i n contact w i t h oxygen d i f f u s i n g downward from above, whereupon i t r e p r e c i p i t a t e s as amorphous Mn oxid e s . Thus a high-Mn l a y e r i s concentrated at or near the base of the o x i c zone which, as des c r i b e d e a r l i e r , may be w i t h i n a few mm of the sediment/seawater i n t e r f a c e . The surfa c e samples i n Howe Sound discussed here c o n s i s t of the top two cm. I t i s c l e a r from the Mn co n c e n t r a t i o n s l i s t e d i n Table E, Appendix I I I t h a t many of the samples i n c l u d e d p a r t or a l l of t h i s high-Mn l a y e r ; thus much of the v a r i a t i o n between contiguous s t a t i o n s can be a t t r i b u t e d t o a sampling a r t i f a c t . The d i a g e n e t i c enrichment of Mn i n near-surface sediments i s c l e a r l y demonstrated i n F i g . 3.89. In the outer b a s i n , high Mn/Al values (Mn/Al=450; Mn, ug/g = 3666) i n the surfa c e l a y e r decrease r a p i d l y w i t h i n the top four cm t o a constant value of =150 (=1200 ug/g Mn ) throughout the r e s t of the core. In the upper b a s i n , s u r f a c e c o n c e n t r a t i o n s are l e s s o v e r a l l over the top decimetre, probably r e f l e c t i n g a s l i g h t m i n e r a l o g i c d i s p a r i t y between these and outer b a s i n sediments. (The upper b a s i n i s higher i n f e l d s p a r s and lower i n i r o n m i n e r a l s , and s i n c e Mn i s 223 Mn/AI ( x 1 0 4 ) 600 Outer basin Fig, 3,89 Manganese to aluminum ratios in two Howe Sound sediment cores, May 1987. 224 depleted i n the former and enriched i n the l a t t e r , t h i s i s r e f l e c t e d i n t h e i r Mn/Al ra t i o s . ) An unexpected feature i n the upper basin core i s an enrichment i n Mn from just above the top of the t a i l i n g s ( = 12 cm depth) to near the bottom of the core (@ 24 cm). This i s most l i k e l y the r e s u l t of a change i n the mineralogy of the ore body which was mined i n the l a s t few years of the Brit a n n i a Beach operation. 3.2.8. Copper, Lead and Zinc Copper, lead and zinc are t r a n s i t i o n metals, and l i k e others i n the group tend to be p r e f e r e n t i a l l y enriched i n fine-grained sediments (Krauskopf, 1979). However, t h e i r disparate occurrences i n igneous rocks r e f l e c t t h e i r s l i g h t l y d i f f e r i n g geochemistries. They are grouped together here because of t h e i r known abundance i n the sulphide minerals of the Britannia Beach ore body. Pb has a large radius (1.26 A) and therefore can substitute for K + i n f e l s i c rocks (Krauskopf, 1979). However, because i t i s much more electronegative than K, such s u b s t i t u t i o n i s l i m i t e d (Mason and Moore, 1982). The p r i n c i p a l d i s c r e t e lead minerals are PbS, PbCOg and PbSO^, and the element i s often c o - c r y s t a l l i z e d i n apatite and i n the heavy mineral t i t a n i t e (Bowen, 1979). Zinc i s also concentrated i n f e l s i c rocks, but only because i t i s enriched i n r e s i d u a l solutions (Krauskopf, 1979). Because i t s i o n i c s i z e (0.83 A) i s s i m i l a r to those 225 o f Fe and Mg, i t s u b s t i t u t e s f o r t h o s e elements i n s i l i c a t e l a t t i c e s . I n we a t h e r e d c l a y s i t appears e n r i c h e d because o f i t s r e s i s t a n c e t o l e a c h i n g (Bowen, 1979). W r i g h t (1972) o b s e r v e d abundant Zn (and Cu) i n c l a y s o f t h e B a r e n t s Sea, where he c o n c l u d e d t h a t t h e y were h e l d i n l a t t i c e p o s i t i o n s o f m i c a and c h l o r i t e . Zn a l s o e x i s t s i n d e p e n d e n t l y as ZnS, t h e p r i n c i p a l o r e o f Zn, and one o f t h e t a r g e t o r e s o f t h e B r i t a n n i a Mine. Cu i s n o t c a p a b l e o f f o r m i n g i t s own h i g h t e m p e r a t u r e m i n e r a l s , n or o f s u b s t i t u t i n g f o r common i o n s i n s i l i c a t e r o c k s , and t h e r e f o r e a l s o t e n d s t o be c o n c e n t r a t e d i n r e s i d u a l s o l u t i o n s ( K r a u s k o p f , 1979). I t s r a d i u s (0.96 A) i s s i m i l a r t o t h a t o f Na b u t i t i s not found i n Na m i n e r a l s because i t forms much weaker i o n i c bonds t h a n Na. Cu i s fo u n d i n many common m i n e r a l s , however, n o t a b l y Cu s u l p h i d e s , CuO, Cu2C03(OH)2, and w i t h Fe i n c h a l c o p y r i t e (Bowen, 1979), t h e l a t t e r b e i n g t h e c h i e f s o u r c e o f Cu i n t h e mine o r e body (James, 1929). K r a u s k o p f (1979) and Troup and B r i c k e r (1975) s u g g e s t t h a t t h e c h i e f p r o c e s s w h i c h c o n t r o l s m i n or element abundance i n sedi m e n t s i s a d s o r p t i o n o n t o t h e f i n e m i n e r a l and b i o g e n o u s f r a c t i o n s o f a sed i m e n t . However, t h e r e a r e many e x c e p t i o n s t o t h i s , e s p e c i a l l y i n a r e a s o f l a r g e d e t r i t a l i n p u t ( C a l v e r t , 1976). F o r example, Schmidt (1978) c o n c l u d e d t h a t o v e r 60% o f t h e Cu i n San F r a n c i s c o Bay se d i m e n t s i s h e l d i n t h e l a t t i c e p o s i t i o n s o f c l a y m i n e r a l s , 226 the remainder a s s o c i a t e d w i t h hydrous Fe and Mn ox i d e s , w i t h a minor f r a c t i o n (<5%) i n organic matter and s u l p h i d e s . Because of the overwhelmingly d e t r i t a l nature of Howe Sound sediments, i t i s expected t h a t the d i s t r i b u t i o n of these metals can be mostly explained by t h e i r presence i n the mine r a l s which o r i g i n a t e i n the surrounding drainage b a s i n s . The i n p u t of Cu-, Pb- and Z n - r i c h t a i l i n g s t o the upper b a s i n , however, obviates c l e a r d etermination of n a t u r a l background l e v e l s of these three elements. Highest Cu l e v e l s i n Howe Sound sediments are found i n the four nearshore samples c l o s e s t t o the mine o u t f a l l (#67, 71, 75 and 78), which c o n t a i n 245, 299, 316, and 180 ug/g Cu, r e s p e c t i v e l y (See Table E, Appendix I I I ) . In the r e s t of the sound, Cu averages 77 (la=±15) ug/g i n the lower b a s i n , 88 ±6 ug/g i n Thornbrough Channel, 118 ±16 ug/g on the s i l l , 109 ±21 ug/g i n the upper b a s i n , and 91 ±27 ug/g on the d e l t a . These values are c l o s e t o the 80 ug/g which Thompson and Paton (1976) regard as background l e v e l s f o r Howe Sound, although they are high compared t o recent analyses on sediments from uncontaminated i n l e t s on the west coast of B r i t i s h Columbia, which range from 4-37 ug/g (Harding and Goyette, 1989). Schmidt (1978) concluded t h a t Cu may range from 2-7 8 ug/g i n n a t u r a l sediments, but up t o 3000 ug/g i n contaminated sediments near i n d u s t r i a l s i t e s . (The g e n e r a l l y low Cu i n n a t u r a l lithogenous sediments i s due t o o x i d a t i v e weathering and r e l e a s e of Cu i n t o 227 solution.) In Howe Sound, the Cu content of sample #93 from the most northerly, shallow end of the de l t a i s 53 uq/q; t h i s i s considered to be a reasonable end member for Cu i n the s i l t / s a n d f r a c t i o n of Squamish-borne sediments. In sample #1, at the mouth of the sound, Cu i s 64 uq/q, which i s marginally higher than values observed i n fine-grained sediments i n other well-mixed B.C. Fjords (C.J. Jones, pers. comm.). A comparison of the r e s u l t s obtained here with those reported by Thompson and Paton (1976) indicates that i n sediments near the o u t f a l l , Cu has decreased dramatically i n the l a s t 14 years, from over 1400 uq/q i n the mid-1970's to a maximum of 316 uq/q i n the l a t e 1980's. I t i s c l e a r that t h i s decline r e f l e c t s progressive and continuing d i l u t i o n by natural sedimentation. However, slumping of nearshore material and homogenization by burrowing fauna w i l l no doubt continue to sustain excess Cu concentrations i n surface sediments i n the o u t f a l l area for some time. F i g . 3.90 shows the areal d i s t r i b u t i o n of Cu i n the Sound. I t i s c l e a r that the majority of the mine t a i l i n g s , as represented by Cu, i s e f f e c t i v e l y trapped by the s i l l , and that the f l a t c e n t r a l bottom of the basin r e f l e c t s the greatest degree of d i l u t i o n by low-Cu sediments derived from the Squamish River (Fig. 3.91). Some fine-grained, Cu-rich suspended material has escaped to the lower basin, however, and has elevated the Cu content i n those sediments to some 228 Fig. 3.90 Copper (ppm) in Howe Sound surface sediments, May 1987. 229 Fig. 3f91 Copper distribution (ppm) in surface sediments of inner basin, Howe Sound, May 1987. 230 degree. In the main channel east of Gambier Island and north of Bowen Island, low-Cu Georgia S t r a i t sediments further d i l u t e the copper i n the t a i l i n g s f i n e s . Cu/Al p r o f i l e s for the two cores (Fig. 3.92) show s i m i l a r surface r a t i o s , but below 14 cm i n the upper basin Cu increases sharply, marking the top of the t a i l i n g s . A gradual r e l a t i v e decrease i n Cu i n the outer basin core from depth toward the surface suggests that the Cu content of the fin e suspended p a r t i c u l a t e s that reach the lower basin i s also decreasing with time. The zinc d i s t r i b u t i o n i n Howe Sound i s more complex than that of Cu. Zn varies much less than Cu (the regional averages for Zn range from 111 ±13 ug/g on the de l t a to 161 ±10 ug/g on the s i l l ; see Table E, Appendix I I I ) ; the highest c o l l e c t i v e zinc to aluminum r a t i o s also occur on the s i l l and i n the lower basin. The highest single Zn/Al values, however, occur i n three samples near the mine o u t f a l l . The large scatter i n the Zn vs. A l pl o t (Fig. 3.93), suggests that aluminosilicates account for only part of the Zn i n Howe Sound, and that the rest i s associated with other phases. F i g . 3.94 suggests a p o s i t i v e c o r r e l a t i o n for Zn and Fe i n the upper basin and delta sediments, but a c l e a r l y negative one i n the lower basin. Therefore, Zn i s l i k e l y p a r t i t i o n e d among Mn oxides, Fe- and Mg-sil i c a t e s , Zn sulphide from the t a i l i n g s , and/or organic material. As well, there may be contamination from 231 Cu/AI (x 10 4 ) 30 Fig. 3.92 Copper to aluminum ratios in two Howe Sound sediment cores, May 1987. 232 300 Zn vs. Al > > Lower Thornbrough Sill Upper Delta basin Channel basin • • * > • I i I i I i l i I 6 7 8 9 10 Al, wt. % Fig. 3.93 Plot of zinc versus aluminum in Howe Sound surface sediments, May 1987, 233 300 200 CJ) 100 Zn vs. Fe Lower Thornbrough Sill Upper Delta basin Channel basin — B — • * o • 3 4 5 6 Fe, wt. % Fig. 3.94 Plot of zinc versus iron in Howe Sound surface sediments, May 1987. 234 a n t h r o p o g e n i c s o u r c e s such as p u l p m i l l e f f l u e n t (Hoos and V o i d , 1975). F i g . 3.95 and 3.96 i l l u s t r a t e t h e d i s t r i b u t i o n o f Zn i n s u r f a c e s e d i m e n t s . Zn ranges from <125 ug/g on t h e d e l t a t o o v e r 225 ug/g n e a r B r i t a n n i a Beach, and i s e n r i c h e d i n se d i m e n t s s u r r o u n d i n g Gambier I s l a n d , s i t e o f a p o t e n t i a l l y e x p l o i t a b l e c o p p e r / z i n c d e p o s i t (James, 1929). The Z n / A l p r o f i l e s i n t h e two c o r e s a r e a l m o s t r e p l i c a t e s o f t h e C u / A l r a t i o p r o f i l e s ( F i g . 3.97). The t o p o f t h e t a i l i n g s i s c l e a r l y v i s i b l e a t 14 cm d e p t h , and a g r a d u a l r e l a t i v e d e c r e a s e i n l o w e r b a s i n z i n c s i n c e c e s s a t i o n o f t a i l i n g s d e p o s i t i o n can be n o t e d . Pb has many o f t h e same a s s o c i a t i o n s as Cu and Zn. I t i s f o u n d i n h i g h e r c o n c e n t r a t i o n s i n c l a y s t h a n i n sands o r c a r b o n a t e s , and i s o f t e n a s s o c i a t e d w i t h o r g a n i c C and hydrous Mn o x i d e s . I n a d d i t i o n , as n o t e d e a r l i e r , i t i s found i n o r t h o c l a s e f e l d s p a r s where i t s u b s t i t u t e s f o r K. A l s o , i t s p r e s e n c e as a g a s o l i n e a d d i t i v e c a u s e s i t t o be i n t r o d u c e d t o t h e marine system v i a t h e atmosphere, and s u b s e q u e n t l y d e l i v e r e d t o t h e s e d i m e n t s . I n Howe Sound, Pb ranges from <10 ug/g on t h e d e l t a t o o v e r 40 ug/g i n t h e l o w e r b a s i n ( T a b l e E, App e n d i x I I I ) . A g e n e r a l t r e n d o f i n c r e a s i n g Pb w i t h d e c r e a s i n g A l i n a s o u t h e r l y d i r e c t i o n ( d o w n - i n l e t ) i s o b s e r v e d ( F i g . 3.98), and t h e r e i s a c l e a r l a c k o f c o r r e l a t i o n o f Pb w i t h K ( F i g . 3.99), i n d i c a t i n g t h a t K - f e l d s p a r s a r e c o n t r i b u t i n g l i t t l e 235 Fig. 3.95 Distribution of zinc in Howe Sound surface sediments, May 1987. 236 Fig. 3.96 Distribution of zinc in surface sediments of inner basin, Howe Sound, May 1987. 237 Zn/AI (x 1 0 4 ) 10 20 30 40 50 Fig, 3,97 Zinc to aluminum ratios in two Howe Souns sediment cores, May 1987. 238 60 40 O p 20 0 Pb vs. Al • • o • T i n • o > •X-3d ^ T * • • ^ * • !> -X-* • < > Lower Thornbrough SHI Upper Delta basin Channel basin • • > • 6 8 10 Al, wt. % Fig. 3,98 Plot of lead versus aluminum in surface sediments of Howe Sound, May 1987. 239 6 0 5 0 4 0 CT) CT) 3 0 H 2 0 H 1 0 Pb vs. K > • • • O -r-,D> C P -x-• •X-> • > Lower Thornbrough Sill Upper Delta basin Channel basin • • * |> • ~ i — i — i — i — | — i — i — i — i — | — i — i — i — i — | — i — i — i — r 1 1 . 2 5 1 . 5 1 . 7 5 K, wt. % Fig, 3.99 Plot of lead versus potassium in surface sediments of Howe Sound, May 1987. 240 t o the o v e r a l l Pb content of these sediments. P l o t s of Pb vs. Cu and Pb vs. Zn ( F i g . 3.100 and 3.101) are more r e v e a l i n g . I t i s c l e a r t h a t l e a d i s p r i m a r i l y a s s o c i a t e d w i t h the copper and z i n c - h o s t e d minerals i n both b a s i n s , and t h a t the s i l l i s an area of mixing of the minerals from the two d i s t i n c t sources. The Pb/Al d i s t r i b u t i o n ( F i g s . 3.102 and 3.103) shows s e v e r a l areas of r e l a t i v e enrichment: the B r i t a n n i a Beach area, where high Pb i s a s s o c i a t e d w i t h the t a i l i n g s , the l a r g e bay south of Gambier I s l a n d , and p a r t of Thornbrough Channel west of Gambier I s l a n d . Pulp m i l l waste i s discharged t o the l a t t e r area, and F i g s . 3.104, 3.105 and 3.106 a l l suggest t h a t the high organic C contents i n the sediments i n t h i s area, and i n those near Woodfibre on the Squamish d e l t a , are a s s o c i a t e d w i t h i n c r e a s e d l o a d i n g s f o r Cu, Zn and Pb above those accounted f o r by the major element mineralogy. These areas, where t e r r e s t r i a l wood d e b r i s i s abundant, may concentrate metals e i t h e r by ads o r p t i o n from seawater or by ind u c i n g p r e c i p i t a t i o n of au t h i g e n i c s u l p h i d e s i n the a s s o c i a t e d H^S-bearing d e p o s i t s . I t i s not c l e a r whether or not there i s a d i r e c t a d d i t i o n of metals t o the Sound i n the pulp m i l l e f f l u e n t s . In the r e s t of the sound, the Pb/Al d i s t r i b u t i o n i m p l i e s t h a t the Pb i s present mainly i n s u l p h i d e minerals a s s o c i a t e d w i t h the two main ore bodies of Howe Sound ( B r i t a n n i a Beach and Gambier I s l a n d ) , w i t h an a d d i t i o n a l , a l b e i t minor, source being the Georgia 241 300 200 O 100 H ,-l> Pb vs. Cu > / t> Lower Thornbrough Sill Upper Delta basin Channel basin • — • — * > • 0 •i" 20 I ' 40 6 Pb, ug/g Fig. 3.100 Plot of lead versus copper in surface sediments of Howe Sound, May 1987. 242 300 200 CT) CZ N 100 0 Pb vs. Zn Lower Thornbrough Sill Upper Delta basin Channel basin • • * > • 0 20 40 60 Pb, ug/g 80 Fig. 3.101 Plot of lead versus zinc in surface sediments of Howe Sound, May 1987. 243 Fig, 3.102 Lead to aluminum ratios in Howe Sound surface sediments, May 1987. 244-150 100 H 0> 13 o 50 H Cu/Mg vs. C(org) > Lower Thornbrough Sill Upper Delta basin Channel basin • • * > • n —i— 1 —r 2 4 1 ' 1 r 6 8 10 C(org), wt. % Fig. 3.104 Copperimagnesium ratio vs. organic carbon in Howe Sound surface sediments 246 60 P Zn/Fe vs. C(org) Fig. 3.105 Znc:iron ratio vs. organic carbon in Howe Sound surface sediments 247 P b / K v s . C(org) t> t> Lower Thornbrough Sill Upper Delta basin Channel basin • • * r> a 0 2 4 6 8 10 C(org), wt. % Fig. 3.106 Lead:potassium ratio vs organic carbon in Howe Sound surface sediments 248 S t r a i t sediments. Generally, Pb i s higher i n Howe Sound than i n other west coast i n l e t s , which average =10 uq/q (Harding and Goyette, 1989). Proximal anthropogenic sources almost c e r t a i n l y contribute to the high l e v e l s observed; such sources include i n d u s t r i a l a c t i v i t i e s i n nearby Vancouver Harbour and Burrard Inl e t , as well as the pulp m i l l e f f l u e n t s , acid mine drainage, sewage and i n d u s t r i a l waste which flow into the sound i t s e l f , and deposition of Pb-enriched aerosols derived from combustion of gasoline. Indeed, such a c t i v i t i e s are thought to play a part i n the high "background" l e v e l s of a l l three metals i n sediments of the sound. F i g . 3.107 c l e a r l y i l l u s t r a t e s the presence of the three sediment sources for Pb i n the two cores: the high-Pb outer basin sediments, i n which Pb increases from depth toward the surface, doubtless r e f l e c t i n g an increasing anthropogenic component; the low-Pb sediments deposited i n the upper basin, derived from the Squamish River; and the mine t a i l i n g s below 14 cm i n the upper basin, which have a higher Pb:Al signature than eith e r of the other two l i t h o l o g i e s . Copper correlates c l o s e l y with Zn i n surface sediments, which f o r the upper basin r e f l e c t s t h e i r j o i n t enrichment i n the t a i l i n g s , and i n the lower basin, t h e i r s i m i l a r association with the c l a y - s i z e d f r a c t i o n . Thompson and 249 Pb/AI (x 1 0 4 ) 2 4 I . I . 6 8 I . I . 10 • Q • I I ' / ^ 1 \ 1 \ T Pb/AI i / j_ / • © r ^ \ * natural sediments X / •k ® tailings 1 \ 1 \ <? \ HS 64 i X t \ Inner basin ^ - H S 16-B ^ Outer basin Fig. 3.107 Lead to aluminum ratios in two Howe Sound sediment cores, May 1987. 250 Paton (1976) suggested that the Cu:Zn r a t i o i s a useful parameter for determining the extent of the t a i l i n g s influence i n Howe Sound sediments, as Zn varies much less than Cu. Accordingly, Figs. 3.108 and 3.109 show that the primary source of Cu enrichment i s the B r i t a n n i a Beach source, with minor input from Furry Creek and Daisy Creek on the east side of the upper basin. The r e s t of the d i s t r i b u t i o n i s s i m i l a r to that of Cu/Al and shows eithe r that the currents which carry the Squamish suspended p a r t i c u l a t e s are mainly diverted westward in t o Thornbrough Channel a f t e r crossing the s i l l , or that the Squamish signal i s considerably attenuated i n the main channel by landward-moving undercurrents from Georgia S t r a i t which enter through Queen Charlotte Channel. This agrees well with previous studies by S y v i t s k i and MacDonald (1982), and with current meter data of Tabata et a l (1970), B e l l (1975), and Buckley (1977). The o v e r a l l Cu:Zn r a t i o s , as p r o f i l e d i n the two cores (Fig. 3.110) are higher i n the upper basin, r e f l e c t i n g the continuing influence of t a i l i n g s copper i n surface sediments there, despite considerable overlying natural sedimentation. 3.2.9. Zirconium Zirconium i s l a r g e l y found i n the r e s i s t a t e mineral, zircon. Unlike yttrium, however, i t s i o n i c radius (0.80 A) i s too small, and i t s i o n i c charge too high (+4), to permit f a c i l e s u b s t i t u t i o n i n most s i l i c a t e l a t t i c e p o s i t i o n s . 251 i.7 Fig. 3.108 Copperrzinc ratios in surface sediments of Howe Sound, May 1987. 252 Fig. 3.109 Copper:zinc ratios in surface sediments of inner basin, Howe Sound, May 1987. 253 Cu/Zn Ratio 0 0.5 1.0 1.5 2.0 Fig. 3.110 Copper:zinc ratios in two Howe Sound sediment cores, May 1987. 254 Thus Zr tends to accumulate i n the f e l s i c end of a rock se r i e s only because d i f f e r e n t i a t i o n leaves i t concentrated i n r e s i d u a l solutions (Krauskopf, 1979). In Howe Sound Zr values are highest i n the delta samples (average 118 uq/q, la=±15, n=9) and lowest i n Thornbrough Channel (mean=93 ±7.4 uq/q, n=6). When plot t e d as the areal Zr/Al r a t i o , three d i s t i n c t zones can be delineated (Fig. 3.111): the d e l t a , with an average Zr/Al=14 (x 10"^); the s i l l and upper basin, with Zr/Al = 11.4 (x 10" ^ ) ; and the lower basin, including Thornbrough Channel, at = 13 (x 10 -^). The r e l a t i v e l y high Zr values seen i n the northernmost and southernmost extremes of the i n l e t , and i n some nearshore sediments ( p a r t i c u l a r l y those near the mine o u t f a l l ) are thought to r e f l e c t the grain s i z e d i s t r i b u t i o n rather than contributions from d i s t i n c t sources. The areas of Zr enrichment are also areas where the Si/AI r a t i o i s high, which l e d to the e a r l i e r conclusion that these sediments are somewhat coarser (see Section 3.1.2, Fig.3.4). Thus, i t appears that Zr i s pr i m a r i l y concentrated i n the s i l t and sand fr a c t i o n s of the sediment. This i s borne out by many researchers who have found Zr much more abundant i n sands than i n eithe r shales, muds, clays, or carbonates (e.g. Bowen, 1979; Krauskopf, 1979; Wright, 1972; Calvert, 1983, among others). Calvert (1983) concluded that on the Namibian shelf, Zr/Rb r a t i o s >3.0 indicate a f a i r l y sandy sediment, while 255 Fig. 3.111 Zirconium to aluminum ratios in surface sediments of Howe, Sound, May 1987. 256 those <3.0 are found i n muds w i t h a good p r o p o r t i o n of c l a y s . In Howe Sound, a l l sediments except those on t h e d e l t a have very low Zr/Rb r a t i o s ( F i g . 3.112). The one ex c e p t i o n , #80, has a Zr/Rb r a t i o of 5, which r e f l e c t s i t s l o c a t i o n as a dumpsite. The high r a t i o i s due t o the high abundance of coarse sand and g r a v e l at the s i t e . The d e l t a sediments average Zr/Rb=3.7, but range from 2.8 (at l o c a t i o n s 85 and 86) t o 5.9 i n sample #93, the one very d i s t i n c t l y u nconsolidated sandy sediment encountered (see Core D e s c r i p t i o n s , Appendix I I ) . The upper b a s i n sediments average 2.3 (la=±0.6) at the northernmost p o i n t and near the shores ( i n c l u d i n g the mine o u t f a l l ) , and decrease down-inlet ( F i g . 3.113). On the s i l l and i n the lower b a s i n , average Zr/Rb r a t i o s range from 1.5 - 1.9, i n d i c a t i n g the gre a t e r p r o p o r t i o n of f i n e a l u m i n o s i l i c a t e s i n these sediments. In the cores, the Z r / A l r a t i o s at both l o c a t i o n s p a r a l l e l the S i / A l p r o f i l e s ( F i g s . 3.114 and 3.7), and the t a i l i n g s do not appear t o d i f f e r s i g n i f i c a n t l y i n Zr abundance from the n a t u r a l sediments above. 257 120 H a* N 100 H 80 r = 0.91 \l> >*\ Lower Thornbrough Sill Upper Delta basin Channel basin • * — — • — 0 20 40 60 80 100 Rb, ug/g Fig. 3.112 Zirconium vs. rubidium In Howe Sound surface sediments 258 Fig. 3,113 Zirconiumtrubidium ratios in surface sediments of Howe, Sound, May 1987. 259 Zr/AI (x 10 4 ) 10 15 20 j i i i I i i i i I i i i i HS 64 Inner basin Zr/AI HS 16-B Outer basin Fig, 3.114 Zirconium:aluminum ratios in two Howe Sound sediment cores, May 1987, 260 3.3 Porewater Chemistry One objective of t h i s study was to determine whether the metal-rich t a i l i n g s , which are currently being covered by natural sediments, are releasing dissolved metals to the waters of Howe Sound. C l e a r l y , the best way to approach t h i s problem i s to study the solid-phase composition and porewater chemistry i n concert. Degradation of organic material i s the primary d r i v i n g force f o r many of the reactions within sediments which a f f e c t the accumulation or release of c e r t a i n components. While a general diagenetic reaction sequence with depth may be predicted (see Chapter 1.2, Diagenesis), many s p e c i f i c reactions are dependent on the depositional environment at a given l o c a t i o n . The most c r u c i a l of these environmentally-mediated factors i s the redox condition within the sediment, which i s dependent i n turn upon the o v e r a l l sedimentation rate, the quantity and q u a l i t y of organic matter, the presence or absence of bottom-dwelling fauna, and the oxygen content of the overlying water (Sholkovitz, 1973). During diagenesis many components are remobilized from the s o l i d phase and released as solutes to the surrounding water. When t h i s occurs at the sediment/seawater i n t e r f a c e , the oxidation products are released d i r e c t l y to the overlying water. If i t occurs a f t e r b u r i a l , they accumulate i n porewater and may migrate upward or downward along concentration gradients u n t i l they encounter conditions 261 w h i c h c a u s e them t o p a r t i c i p a t e i n o t h e r p r e c i p i t a t i o n a nd/or d i s s o l u t i o n r e a c t i o n s . Thus, t h e s t u d y o f p o r e w a t e r c h e m i s t r y can g i v e c l u e s as t o w h i c h of t h e s e e a r l y d i a g e n e t i c r e a c t i o n s a r e o c c u r r i n g . I t has been de m o n s t r a t e d i n Howe Sound t h a t t h e d e p o s i t i o n a l e n v i r o n m e n t s w i t h i n t h e two b a s i n s a r e q u i t e d i f f e r e n t , and i t i s e x p e c t e d t h a t t h i s w i l l be r e f l e c t e d i n t h e c h e m i s t r y o f t h e p o r e w a t e r s . The upper b a s i n i s c o n s i d e r e d t o have a h i g h e r n a t u r a l s e d i m e n t a t i o n r a t e (=1 cm/yr, based on t h e d e p t h t o t h e b u r i e d t a i l i n g s ) t h a n t h e o u t e r b a s i n , s i n c e a l a r g e p r o p o r t i o n o f t h e Squamish s e d i m e n t s i s e f f e c t i v e l y t r a p p e d b e h i n d t h e s h a l l o w s i l l . A s i m p l e method f o r e s t i m a t i n g s e d i m e n t a t i o n r a t e , u s i n g s u l p h a t e c o n c e n t r a t i o n s i n p o r e w a t e r ( B e r n e r , 1978), s u g g e s t s t h a t t h e sediment d e p o s i t i o n r a t e i n t h e upper b a s i n (=0.5 cm/yr) i s a p p r o x i m a t e l y two and one h a l f t i m e s t h a t o f t h e l o w e r (0.2 c m / y r ) . The o r g a n i c c o n t e n t o f t h e o u t e r b a s i n i s h i g h e r t h a n t h a t o f t h e i n n e r b a s i n , due p r i m a r i l y t o d i l u t i o n by t h e l a r g e i n f l u x o f d e t r i t a l s i l i c a t e s t o t h e l a t t e r . As n o t e d e a r l i e r , t h e o r g a n i c component i n o u t e r b a s i n s ediments i s g e n e r a l l y more marine i n c h a r a c t e r ( a t l e a s t i n t h e open p a r t o f t h e b a s i n ) , whereas t h e main c o n t r i b u t o r t o t h e o r g a n i c l o a d i n t h e upper b a s i n i s t e r r e s t r i a l m a t e r i a l , a s i g n i f i c a n t p r o p o r t i o n o f w h i c h i s d e r i v e d f rom a n t h r o p o g e n i c a c t i v i t i e s s uch as log-booming and p u l p p r o d u c t i o n . The marine 262 component i n t h e upper b a s i n i s c o n s i d e r e d t o be n e g l i g i b l e , i n p a r t due t o h i g h t u r b i d i t y a s s o c i a t e d w i t h t h e s p r i n g f r e s h e t , w h i c h l i m i t s t h e l i g h t a v a i l a b l e f o r p h y t o p l a n k t o n p h o t o s y n t h e s i s . The most i m p o r t a n t d i f f e r e n c e between t h e two b a s i n s , i n a d i a g e n e t i c s e n s e , i s t h e p e r i o d i c a l l y - l o w oxygen c o n t e n t o f t h e bottom w a t e r o f t h e upper b a s i n , and i t s e f f e c t on b e n t h i c o r ganisms and on r e d o x c o n d i t i o n s w i t h i n t h e s e d i m e n t s . ( F i g . 1.6 shows oxygen p r o f i l e s o v e r a s e v e n - y e a r p e r i o d w h i c h s u g g e s t t h a t deep-water r e n e w a l s a r e r e g u l a r , though i n f r e q u e n t , e v e n t s . ) D i m i n i s h e d a v a i l -a b i l i t y o f oxygen t o t h e s e d i m e n t s w i l l produce a c o n t r a c t i o n o f t h e " b i o g e o c h e m i c a l r u b b e r band" ( S h i m m i e l d and P e d e r s e n , 1990) w h i c h r e p r e s e n t s t h e sequence of o x i d a t i o n zones i n t h e s e d i m e n t , and w i l l e n s u r e t h a t r e d u c i n g c o n d i t i o n s w i l l be e s t a b l i s h e d much more c l o s e l y t o t h e s e d i m e n t / s e a w a t e r i n t e r f a c e t h a n d u r i n g p e r i o d s when t h e bottom w a t e r i s o x y g e n - r e p l e t e . The a p p l i c a t i o n o f p o r e w a t e r a n a l y s i s t o t h e s t u d y of m e t a l m o b i l i t y i n b u r i e d mine t a i l i n g s d e p o s i t s i s a r e c e n t development. F o r example, P e d e r s e n (1983, 1985) was a b l e t o c a l c u l a t e t h e degree o f m e t a l f l u x f r om t a i l i n g s d e p o s i t s i n b o t h marine and f r e s h w a t e r s y s t e m s , e s t a b l i s h i n g i n one c a s e t h a t t h e f l u x was s m a l l e r t h a n has been measured i n n a t u r a l s e d i m e n t s e l s e w h e r e , and i n a n o t h e r c a s e t h a t t h e d e p o s i t e d t a i l i n g s were a c t u a l l y a s i n k f o r m e t a l s r a t h e r t h a n a s o u r c e . L o s h e r (1985) d e t e r m i n e d t h a t p o r e w a t e r Mo l e v e l s 263 were up to 300 times higher than those measured i n the overlying water; t h i s enrichment supported a fl u x which could account f o r up to =4% of the t o t a l Mo inventory of the i n l e t i n which the t a i l i n g s were deposited. A s i m i l a r approach to the analysis of the Howe Sound t a i l i n g s deposit i s therefore expected to give a much cl e a r e r i n t e r p r e t a t i o n than would be obtained by studying the solid-phase portion of the sediment i n i s o l a t i o n . 3.3.1 Dissolved Nutrients and Alkalinity The d i s t r i b u t i o n s of the dissolved constituents NH 4 +, P0 4 3~, NO3-, S0 4 2~, and HS~ e s s e n t i a l l y define the state of organic matter diagenesis i n sediments. Ammonia and phosphate are d i r e c t products of organic matter decay; n i t r a t e and sulphate are used by heterotrophic bacteria as ox i d i z i n g agents i n the breakdown of organic matter; and sulphide i s a product of sulphate-reduction whose presence, with NH 4 +, c l e a r l y indicates anoxia. NH 4 + accumulates i n porewaters during early diagenesis, and w i l l migrate upward along a concentration gradient u n t i l i t i s oxidized to n i t r a t e on contact with oxygen, t y p i c a l l y i n near-surface sediments. I t may also be removed from porewater by ion-exchange reactions with sediment p a r t i c l e s , p a r t i c u l a r l y the clays i l l i t e and montmorillonite (Muller. 1977; von Breymann and Suess, 1988) and by reactions with, or adsorption onto, organic matter (Rosenfeld, 1979; Boatman and Murray, 1982; Reeburgh, 1983). These exchange reactions 264 are e a s i l y r e v e r s i b l e and are se n s i t i v e to temporal changes i n the concentration of organic matter (Berner, 1974, 1980; A l l e r , 1980) and other porewater cations (Suess and Muller, 1981). Coarse-grained sediments and those with s i g n i f i c a n t carbonate content tend to be poor agents of removal f o r NH^"*" (Mackin and A l l e r , 1984). Porewater NH 4 + may also be assimilated by sediment bacteria as a more favorable source of N than n i t r a t e (Jorgensen, 1983). T y p i c a l l y accompanying the buildup of ammonia i n porewaters i s a concomitant r i s e i n a l k a l i n i t y as HC03~ i s added by the reaction of N H 3 with CO2 released from the decaying organic matter. Phosphate i s not involved i n redox reactions d i r e c t l y as i t i s stable i n the marine environment i n i t s +5 oxidation state. PO4 ~ does not usually b u i l d up to high concentrations because i t i s almost immediately bound to surfaces of hydrous f e r r i c oxyhydroxides under o x i d i z i n g conditions or clay minerals (Krauskopf, 1979; Berner, 1980) or p r e c i p i t a t e d as calcium phosphate (ap a t i t e ) . The former are themselves reduced below the oxic zone by bac t e r i a which use the oxygen contained within them as energy to f u e l d i s s i m i l a t o r y metabolic processes, releasing Fe and the o _ adsorbed PO4 to porewaters at a depth i n sediments that s l i g h t l y overlaps the NC^" and Mn-reduction zones (see, e.g. Pric e , 1973; F r o e l i c h et a l , 1979; Krom and Berner, 1981). PO4 w i l l migrate along concentration gradients both upwards and downwards from t h i s subsurface maximum, and w i l l 265 e i t h e r be released at the sediment/seawater i n t e r f a c e , or be re p r e c i p i t a t e d with dissolved Fe i n the presence of oxygen 3-as dispersed oxide phases within the sediments. PO^ may also be removed by authigenic apatite formation i n the presence of fine-grained calcium carbonate (Stumm and • 9+ 9+ . Leckie, 1970); a low Ca" :Mg" r a t i o , however, appears to i n h i b i t t h i s process (Gulbrandsen, 1969; Martens and Harris, 1970; Burnett, 1977). Af t e r oxygen, dissolved n i t r a t e i s the most e f f i c i e n t oxidant a v a i l a b l e to sedimentary bacteria (Stumm and Morgan, 1970), and i s thus r a p i d l y depleted below the oxic zone. Most of the NC^- i n porewaters i s derived from the oxidation of NH 4 + d i f f u s i n g up from greater depths i n the sediments, and therefore i t s concentration reaches a peak i n the lower part of the oxic zone (Jorgensen, 1983). During n i t r a t e reduction a series of obligate intermediates (NC>2~, NO, N 20) are formed as transients, u n t i l eventually N i s removed from the sediment diagenetic cycle as N 2 ( L i s s , 1983). The primary dissolved sulphur species SO4 and HS - are heavily involved i n , and affected by, changing redox . 9_ conditions i n sediment porewaters. SO4 predominates i n ox i d i z i n g conditions while H2S and HS~ ex i s t i n reducing environments. During b a c t e r i a l diagenesis, the availa b l e oxidants ( 0 2, Mn02, NO3"", F e 2 0 3 , and SO4 "") are used i n order of t h e i r decreasing free energy (Stumm and Morgan, 1970). When the f i r s t four are exhausted, the abundant 266 seawater ion SO^ i s reduced by anaerobic bacteria to HS~ and at ph >7 and <7, respe c t i v e l y . Hydrogen sulphide species are poisonous to most l i f e forms and therefore sediments i n which they are found are l a r g e l y undisturbed. Dissolved sulphide, l i k e other porewater constituents, d i f f u s e s along a gradient u n t i l i t i s removed from solu t i o n by reactions with metal cations ( p a r t i c u l a r l y Fe ; Howarth, 1979; Berner, 1984), or i s oxidized to sulphate on contact with 0*2 d i f f u s i n g into sediments from overlying water. A l k a l i n i t y i s also produced as a consequence of sulphate reduction, p r i m a r i l y as HCO3 -. The core p r o f i l e s for dissolved ammonia, phosphate, sulphate and t i t r a t i o n a l k a l i n i t y are shown i n Figs. 3.115 and 3.116. The top of the t a i l i n g s deposit, as i n f e r r e d from the solid-phase Cu, Zn and Pb p r o f i l e s i s indicated at = 14 cm depth i n the p r o f i l e s for HS 64. Ni t r a t e i s not shown, as the HNO3 acid wash for the sample bottles rendered the r e s u l t s suspect. No dissolved sulphide data are shown because measured values were below the detection l i m i t (<lumol/L) i n a l l samples except for maxima of =2 umol/L at 7-11 cm i n the outer basin core and at 6-9 cm i n the inner basin. 267 ro CTl oo 400 800 0 20 40 0 10 20 30 10 e o a <D 30 Q 40 50 , 1 . 1 . 1 . _ l — 1 — 1 — "a \ NH3,uM/L b. 'B. 'B. 'a. 'to 1— H T J 1 1 1 1 1 • a . . • • - a ; P0 4 , uM/L V \ ' S0 4,mM/L ] \ * - • to i rf" 4 b. "b k A "tj A >? k b • A O i a a 0 o A i a <J A O q a A O a 6 • • : i \ T.Alk, meq/L Fig. 3.115 Porewater nutrients and titration alkalinity in core HS 16-B, April 1988. Fig. 3.116 Porewater nutrients and titration akalinity in core HS 64, Howe Sound, B.C. Alkalinity values in parentheses (} are thought to be the result of oxidation. 3 . 3 . J . J . Ammonia and Phosphate I n t h e o u t e r b a s i n c o r e (HS 16-B, F i g . 3.115), N H 4 + i n c r e a s e s s t e a d i l y f r om a s u r f a c e minimum o f 72 umol/L t o 939 umol/L a t t h e bottom o f t h e c o r e . Phosphate i s low a t t h e s u r f a c e (6.6 umol/L) and i n c r e a s e s d r a m a t i c a l l y t o a mid-depth maximum o f 57 umol/L between 5-15 cm, t h e r e a f t e r d e c r e a s i n g w i t h d e p t h t o =28 umol/L a t t h e base o f t h e c o r e . I n t h e i n n e r b a s i n c o r e (HS 64) N H 4 + i s l o w e r i n t h e s u r f a c e l a y e r (=28 umol/L) compared t o t h e o u t e r b a s i n , but i n c r e a s e s t o r o u g h l y t h e same a t d e p t h (1013 um o l / L ) . Phosphate i n c r e a s e s t o o v e r 130 umol/L i n t h i s c o r e between 3 and 15 cm d e p t h . Below 15 cm, where t a i l i n g s a r e f i r s t c l e a r l y i n e v i d e n c e , P 0 4 3 ~ d e c r e a s e s s h a r p l y t o =30 umol/L and r e m a i n s a p p r o x i m a t e l y c o n s t a n t a t t h a t l e v e l . The N H 4 + d i s t r i b u t i o n i n HS 16-B i s c l e a r l y i n d i c a t i v e o f a c t i v e b a c t e r i a l d e c o m p o s i t i o n o f o r g a n i c m a t t e r t h r o u g h o u t t h e sampled i n t e r v a l . The concave-upward shape o f t h e N H 4 + p r o f i l e i n t h e i n n e r b a s i n , i n c o n t r a s t , s u g g e s t s s l i g h t r e m o v a l by a d s o r p t i o n o r io n - e x c h a n g e w i t h c l a y m i n e r a l s , w h i c h a r e more abundant h e r e t h a n i n t h e o u t e r b a s i n (see S e c t i o n 3.1.2.). S t o i c h i o m e t r i c c a l c u l a t i o n s based on S h o l k o v i t z (1973) i n d i c a t e t h a t t h e 9— 2 — amount o f S 0 4 r e d u c e d o v e r t h e c o r e d i n t e r v a l ( SO4 =10 mmol/L) would g e n e r a t e =3 mmol/L N H 4 + i n t h e p o r e w a t e r a t t h a t d e p t h ; however, o n l y o n e - t h i r d o f t h a t amount i s p r e s e n t ; t h i s d i f f e r e n c e p r o b a b l y r e f l e c t s a s t o i c h i o m e t r y 270 f o r the degrading organic matter d i f f e r e n t than that used by Sholkovitz (1973). The phosphate p r o f i l e f or HS 16-B i s consistent with that predicted by a steady-state model (Berner, 1980) which assumes organic matter breakdown and authigenic mineral p r e c i p i t a t i o n below a subsurface maximum. The model also assumes that adsorption of PO4 by ir o n oxides i s absent or n e g l i g i b l e i n reducing sediments. Jahnke et a l (1983) have proposed that v a r i a t i o n s i n the flux of p a r t i c u l a t e matter might cause episodic inputs of excess P to porewater, r e s u l t i n g i n subsurface maxima such as are observed here. This i s u n l i k e l y to be happening i n t h i s case since the C o r g and C/N p r o f i l e s suggest a consistency through time i n the quantity and qu a l i t y of the organic material at t h i s l o c a t i o n . Sholkovitz (1973) demonstrated the necessity of knowing the C:N:P r a t i o of the degrading organic matter i n order to pred i c t the ammonia and phosphate concentrations which are observed i n porewaters. If one assumes an N:P r a t i o of 16:1 for the organic matter being decomposed (Redfield, 1958; Richards, 1965), i t i s cl e a r that NH 4 + i s being produced f a r i n excess of P 0 4 3 " at depth (N:P=34:1) i n Core HS 16-B, whereas i n the top half of the core NH 4 + i s depleted with respect to PG4 ~ (N:P=5-10:1). It should be noted, however, that the standard Redfield r a t i o of 16:1 for marine organic matter does not hold for terrigenous plant material i n which 271 P i s considerably lower (N:P=(23-1200):1; Bowen, 1979). Also, N and P are usually l o s t p r e f e r e n t i a l l y with respect to C during s e t t l i n g and early diagenesis (e.g. G r i l l and Richards, 1964), although t h i s process may be i n h i b i t e d i n coas t a l regions which undergo rapid sedimentation and, therefore, have less bioturbated sediments (Martens et a l , 1978) and often quantitative oxidant consumption from i n t e r s t i t i a l waters. The solid-phase C/N r a t i o of 11-13 i n core HS 16-B (see Section 3.1.6.) suggests e i t h e r a considerable t e r r e s t r i a l component, or some p r e f e r e n t i a l s t r i p p i n g of N before and during b u r i a l , or both. If the model holds true, and no F e - p r e c i p i t a t i o n i s occurring i n the upper portion of the core, an N:P r a t i o of 10:1 may be safel y assumed, based on the r e l a t i v e amounts of NH4+ and PO4 which are observed. Thus, any PO4 below 15 cm that i s being regenerated from decaying organic matter i s being r a p i d l y consumed. Apatite formation i n sediments i s thought to be favored under conditions of high CaC03 content (Stumm and Leckie, 1970), low sedimentation rate and a strong regenerative mechanism for P, i . e . high P input and high sediment porosity (Suess, 1981). Both solid-phase Ca and carbonate C contents are low i n HS 16-B, and the sedimentation rate r e l a t i v e l y high. However, other phosphate minerals such as v i v i a n i t e and s t r u v i t e have also been formed i n anoxic 2+ 2 + sediments through reactions with the cations Fe^ , Mg and 272 NH4 under conditions s i m i l a r to those observed here (Nriagu, 1972; Malone and Towe, 1970). An a l t e r n a t i v e explanation i s that the roughly l i n e a r decrease of PO4 - below 15 cm does not r e f l e c t removal of PO4 but i s merely a concentration gradient between stable 3 — low-P concentrations at depth and high PO4 values i n the Fe-reduction zone. Standard stoichiometric considerations would argue against such a p o s s i b i l i t y , but i n the absence of a r e l i a b l e end-member for the N:P r a t i o of the buried organic matter, i t cannot be ruled out. As noted e a r l i e r , NH4+ may be removed to some extent by adsorption onto mineral grains, although t h i s process i s not a dominant one owing to the low clay content of the sediments. Assuming an N:P r a t i o for the decaying organic matter of 10:1, the regeneration of =1 mmol/L NH4+ i n core HS 64 should be accompanied by an increase of =100 umol/L of PO4 over the same i n t e r v a l . However, over 130 umol/L PO4 are noted i n t h i s core between 3 and 16 cm depth; the excess i s almost c e r t a i n l y the r e s u l t of desorption of PO4 from Fe oxides as the l a t t e r are reduced below the bioturbated zone (Section 1.2). That t h i s i s a q u a n t i t a t i v e l y s i g n i f i c a n t process i s displayed i n the solid-phase Fe p r o f i l e (Fig. 3.25) which shows a surface enrichment of more than 160 mmol/kg Fe above the minimum observed just above the 3 — t a i l i n g s . The coincidence of the rapid decrease i n PO4 below 15 cm with the appearance of t a i l i n g s suggests a 273 causative r e l a t i o n s h i p . Pedersen (1984) noted that lime (CaO) i s often added to t a i l i n g s s l u r r i e s to increase the pH and encourage f l o c c u l a t i o n of t a i l i n g s f i n e s , and concluded that t h i s added Ca w i l l promote p r e c i p i t a t i o n of authigenic f l u o r a p a t i t e . I t i s conceivable that t h i s i s occurring here also, although the coincident removal of NH 4 + and a l k a l i n i t y over the same i n t e r v a l suggests that authigenic s t r u v i t e -formation (MgNH4P04.6H2O) i s an ad d i t i o n a l p o s s i b i l i t y (Malone and Towe, 1970; Hallberg, 1972; Handschuh and Orgel, 1973). The increase i n solid-phase P over the i n t e r v a l 15-30 cm (Fig. 3.37) may be further evidence f o r p r e c i p i t a t i o n of phosphate minerals. 3.3.1.2. Sulphate Sulphate decreases very l i t t l e over the length of the outer basin core, from =27.6 mmol/L i n the surface to 24.6 mmol/L at the bottom. In HS 64, sulphate decreases from a surface concentration of =26 mmol/L to =16 mmol/L at depth. The SO4 of =3 mmol/L between top and bottom samples of the outer basin agrees well with that expected from the production of 939 pmol/L NH 4 + at depth (3.1 mmol/L S0 4 2", 2 — based on a stoichiometric r e l a t i o n s h i p of 3.3 moles of S0 4 reduced per mole of NH 4 + released; Richards, 1965; F r o e l i c h , 1979). A subsurface S0 4^~ minimum of =22 mmol/L was observed between 5-13 cm depth, which i s unexplainable i n terms of the ammonia, a l k a l i n i t y and sulphides measured i n that i n t e r v a l , although the l a t t e r two of these parameters 274 show s m a l l i n c r e a s e s t h a t a r e w e l l w i t h i n t h e a n a l y t i c a l e r r o r . However, as e x p l a i n e d e a r l i e r ( S e c t i o n 2.3.6), t h e SO^ d a t a may be i n a c c u r a t e , e s p e c i a l l y t h o s e v a l u e s i n t h e upper p o r t i o n s o f t h e c o r e s where sample volumes were v e r y s m a l l . G e n e r a l l y , a r a p i d d e l i v e r y o f sedi m e n t s w i l l have t h e same e f f e c t on p o r e w a t e r c h e m i s t r y as an abundance o f o r g a n i c m a t t e r , i . e . i t w i l l i n d u c e a n o x i c i t y a t a f a i r l y s h a l l o w d e p t h . T h i s happens because a sediment h o r i z o n w i l l be q u i c k l y removed from d i f f u s i v e c o n t a c t w i t h o x y g e n a t e d b o t t o m w a t e r , and t h e i n d i g e n o u s b a c t e r i a w i l l t h e n have t o use a l t e r n a t e e l e c t r o n a c c e p t o r s ( e . g . SO4 ) d u r i n g t h e breakdown o f o r g a n i c m a t t e r . A l t h o u g h t h e o v e r a l l C Q r g c o n t e n t i n t h e i n n e r b a s i n c o r e (mean = 0.73%) i s about h a l f t h a t i n t h e o u t e r b a s i n (mean = 1.5%), t h e g r e a t e r degree of SO4 r e d u c t i o n h e r e s u g g e s t s t h a t t h e s e d i m e n t a t i o n r a t e i s h i g h e r . A l s o , t h e low oxygen c o n t e n t o f t h e upper b a s i n b ottom w a t e r r e s u l t s i n a t h i n n i n g o f t h e d i a g e n e t i c zones: t h u s s e d i m e n t s a t t h e s u r f a c e a r e a l r e a d y i n a s u b o x i c s t a t e and s u l p h a t e i s r a p i d l y r e d u c e d a t s h a l l o w d e p t h s . 3.3.1.2 Alkalinity A l k a l i n i t y i n c r e a s e s o n l y s l i g h t l y o v e r t h e l e n g t h of t h e o u t e r b a s i n c o r e , from 3.41 meq/L a t t h e s u r f a c e t o 4.9 meq/L a t d e p t h , due t o p r o d u c t i o n o f d i s s o l v e d c a r b o n a t e 2 • • s p e c i e s d u r i n g SO4 r e d u c t i o n . I n t h e i n n e r b a s i n , a l k a l i n i t y i n c r e a s e s f rom 2.74 meq/L t o 17.4 meq/L o v e r t h e 275 same i n t e r v a l , a TA of 14.66 meq/L. The observed values for the outer basin core are about one-fourth the expected 9 2 — increase based on the observed SO^ decrease (1 mole SO4 reduced produces 2 meq. of a l k a l i n i t y ) . Likewise, the 9 — s o 4 ( = 10 mmol/L) over the length of the inner basin core should produce 20 meq/L of t i t r a t i o n a l k a l i n i t y . That observation, coupled with the shape of the TA curve suggests 2-removal by some mechanism. I t i s c l e a r that i f the SO4 data are accurate, a l k a l i n i t y i s being removed i n both cores by p r e c i p i t a t i o n of some carbonate species. According to the model developed by Sholkovitz (1973) i t i s possible to predict the a l k a l i n i t y at any point i n a + 9— 9 + core from observed NH4 , SO4 , and Ca concentrations, given an i n i t i a l a l k a l i n i t y of overlying bottom water. 2 + Conversely, i t i s possible to ca l c u l a t e the amount of Ca which i s consumed by CaCC>3 p r e c i p i t a t i o n . The a p p l i c a t i o n of Sholkovitz's equation to the data here y i e l d s a value of 9 + 2.7 mmol/L Ca consumed by carbonate p r e c i p i t a t i o n i n the outer basin core. This must be regarded as only a tentat i v e figure due to the uncertainty i n the measured SO4 values. Applying the same ca l c u l a t i o n s as i n the outer basin core, the expected decrease i n dissolved carbonate species i n HS 64 i s 2.68 meq/L. According to Sholkovitz (1973), most of the a l k a l i n i t y d e f i c i t i n Santa Barbara basin 2 + sediments i s explicable by the observed decrease i n Ca , 276 although dissolved Mg may also be playing a part. Suess (1979) suggests that a mixed carbonate phase co n s i s t i n g of varying amounts of Mn, Ca and Mg may be formed under s i m i l a r conditions. Without porewater measurements of the l a s t two constituents, however, i t i s d i f f i c u l t to e s t a b l i s h whether such a process has occurred here. In summary, the porewater analyses discussed here show that reducing conditions p r e v a i l c l o s e r to the sediment surface i n the inner basin than i n the outer basin, due p r i m a r i l y to the diminished oxygen content of the bottom water. Active diagenesis of organic matter i s shown by the production of =1 mmol/L NH44" i n both cores, although some removal by clay mineral p r e c i p i t a t i o n may be occurring i n the inner basin. The phosphate maximum i n HS 64 i s more than double that observed i n the outer basin, and i s a t t r i b u t e d to release from d i s s o l v i n g Fe oxides i n the more strongly reducing sediments of the inner basin. Sulphate-reduction i s much more pronounced i n HS 64, as i s the corresponding increase i n carbonate a l k a l i n i t y . The values of the l a t t e r i n both cores suggest removal by some authigenic phase, possibly a calcium or mixed Ca-Mn carbonate. 277 3.3.2. Dissolved Metals 3.3.2.1. Manganese Dissolved Mn p r o f i l e s from the inner and outer basin cores are plotted i n Figs. 3.117 and 3.118. Each p r o f i l e w i l l be discussed i n turn. In the outer basin core Mn increases from 129 umol/L i n the surface layer to 469 umol/L at 6.5 cm depth, decreasing exponentially thereafter to 75 umol/L at the base of the core. The Mn maximum coincides 2-with the appearance of a subsurface decrease i n SO4 . Manganese and iro n oxides are, a f t e r oxygen and n i t r a t e , the n e x t - u t i l i z e d o x i d i z i n g agents of organic matter (Stumm and Morgan, 1970). Mn i s reduced at a higher oxidation p o t e n t i a l than Fe, and therefore Mn generally appears at shallower depths than does dissolved i r o n . The d i s t r i b u t i o n s i n the outer basin core indicate that oxygen and n i t r a t e have v i r t u a l l y disappeared by =5 cm depth. (Fig. 3.89 demonstrates the e f f e c t of t h i s process on the d i s t r i b u t i o n of solid-phase Mn i n the core c o l l e c t e d at the same l o c a t i o n the previous year, i n which Mn i s reduced to less than half i t s surface value within the top 3 cm.) The dissolved Mn p r o f i l e here i s consistent with a model proposed by Calvert and Price (1972), whereby the decrease i n dissolved manganese with depth i s caused by a combination of two processes: 1) the removal of dissolved Mn by p r e c i p i t a t i o n as carbonate, and 2) the downward, exponentially-decreasing production rate of Mn" due to 278 ro 10 0 10i O 2(H 0 30 Q 40 [Fe], umol/L 10 20 30 i • i • i . i . i «... 0 (°) Fe [Mn], umol/L 200 i i ' I L 400 i Mn Fig. 3.117 Dissolved iron and manganese in porewater from core HS 16-B, outer basin, Howe Sound, April 1988. Data point in parentheses is thought to be due to contamination. 0 0 10 20 30 40 [Fe], umol/L [Mn], umol/L 100 200 o 200 400 1 1 1 1 1 1 1 i i natural \ sediments t°) 7 A°] / / tailings / Mn • ^ (799) ( Fig. 3.118 Dissolved iron and manganese in porewater from core HS 64, inner basin, Howe Sound, April 1988. Values in parentheses are thought to be due to oxidation during extrusion. r a p i d r e d u c t i o n o f o x i d e s near t h e s u r f a c e . Because Mn s u l p h i d e i s r e l a t i v e l y s o l u b l e ( J a c o b s and Emerson, 1982), and d i s s o l v e d s u l p h i d e l e v e l s a r e e x t r e m e l y low, MnS p r e c i p i t a t i o n i s not l i k e t o be c o n t r i b u t i n g t o d i s s o l v e d manganese remo v a l a t d e p t h . The p r o b a b l e a u t h i g e n i c c a n d i d a t e w h i c h c a n a c c o u n t f o r t h e Mn d e p l e t i o n a t depth i s a mixed Mn-Ca-Mg c a r b o n a t e m i n e r a l ; such phases a r e known t o p r e c i p i t a t e i n a n o x i c s e d i m e n t s ( e . g . C a l v e r t and P r i c e , 1972; S u e s s , 1979; Pe d e r s e n and P r i c e , 1982). I n t h e i n n e r b a s i n c o r e (HS 64) d i s s o l v e d Mn r e a c h e s a maximum o f 336 jjmol/L a t 3.2 cm d e p t h and d e c r e a s e s , i n a s i m i l a r f a s h i o n t o HS 16-B, t o =60 pmol/L a t t h e base o f t h e c o r e . A l t h o u g h o r g a n i c c a r b o n i n t h i s c o r e i s l o w e r t h a n i n HS 16-B, t h e low oxygen c o n t e n t o f t h e bottom w a t e r i s t h o u g h t t o be r e s p o n s i b l e f o r t h e s h a l l o w e r M n - r e d u c t i o n zone h e r e . T h i s e f f e c t i s d i s c e r n i b l e as w e l l i n t h e c o r e a n a l y s e d f o r s o l i d phase, where t h e Mn c o n c e n t r a t i o n d e c r e a s e s m a r k e d l y w i t h i n t h e t o p c e n t i m e t r e o f t h e c o r e ( F i g . 3.89). 3.3.2.2. Dissolved Iron D i s s o l v e d i r o n i n s e d i m e n t s i s t h e r e s u l t o f b o t h a b i o t i c and m i c r o b i a l l y - m e d i a t e d r e d u c t i o n o f l a b i l e i r o n o x i d e s d u r i n g o x i d a t i o n o f o r g a n i c m a t t e r . I n t h i s p r o c e s s , 9 + s o l i d phase F e ( I I I ) i s r e d u c e d t o Fe* , w h i c h b u i l d s up i n i n t e r s t i t i a l w a t e r s t o l e v e l s w h i c h a r e l i m i t e d by t h e s o l u b i l i t y p r o d u c t o f such a u t h i g e n i c p r e c i p i t a t e s as p y r i t e 281 ( i n a n o x i c e n v i r o n m e n t s ) o r , i n t h e p r e s e n c e o f oxygen, p o o r l y - s t r u c t u r e d o x i d e s . F e - r e d u c t i o n o c c u r s a t a l o w e r 2+ o x i d a t x o n p o t e n t i a l t h a n does Mn and t h e r e f o r e Fe i s n o t e x p e c t e d t o appear i n p o r e w a t e r s u n t i l r e d u c t i o n o f a l l a v a i l a b l e Mn i s co m p l e t e (Myers and N e a l s o n , 1988). Thus an i d e a l i z e d s e d i m e n t a r y p r o f i l e would show d i s s o l v e d i r o n v i r t u a l l y a b s e n t from t h e sediment s u r f a c e down t o t h e base o f t h e M n - r e d u c t i o n zone, f o l l o w e d by a r a p i d i n c r e a s e as Fe* i s r e l e a s e d t o i n t e r s t i t i a l w a t e r , and a g r a d u a l d e c r e a s e t h e r e a f t e r as Fe i s p r e c i p i t a t e d as a u t h i g e n i c p y r i t e . I n p r a c t i c e , k i n e t i c e f f e c t s and d i f f u s i o n promote t h e o v e r l a p o f t h e Mn- and F e - o x i d e r e d u c t i o n zones. I n t h e o u t e r b a s i n c o r e (HS 16-B) , t h e d i s s o l v e d i r o n d i s t r i b u t i o n more o r l e s s f o l l o w s t h i s g e n e r a l i z e d 2+ d i a g e n e t i c z o n a t i o n scheme ( F i g . 3.117). The Fe c o n c e n t r a t i o n i s low i n t h e s u r f a c e l a y e r (=2 /jmol/L) , and does n o t i n c r e a s e u n t i l a d e p t h o f ~1 cm i s r e a c h e d . A maximum v a l u e o f 30 /Jmol/L i s a t t a i n e d a t ~9 cm d e p t h , and t h e c o n c e n t r a t i o n remains g e n e r a l l y a t o r s l i g h t l y below t h i s l e v e l t o 28 cm, a f t e r w h i c h i t d e c r e a s e s a g a i n t o n e a r -z e r o c o n c e n t r a t i o n s t o t h e base o f t h e c o r e . T h i s d e c r e a s e must be due t o p y r i t e p r e c i p i t a t i o n , s i n c e , as n o t e d above, no s u l p h i d e was d e t e c t a b l e e i t h e r d u r i n g c o r e e x t r u s i o n o r fr o m p o r e w a t e r a n a l y s i s , d e s p i t e l i m i t e d b u t measurable s u l p h a t e r e d u c t i o n and a subsequent i n c r e a s e i n a l k a l i n i t y o v e r t h e t o t a l l e n g t h o f t h e c o r e . 282 In the inner basin core ( F ig. 3.118), where the dissolved Mn d i s t r i b u t i o n indicates a much shallower • 9 + redoxcline, Fe also shows an increase at a shallower depth (5 cm) than i n the outer basin core. Unlike the outer basin core, however, the increase (from 3 umol/L to 12 umol/L) at t h i s depth i s not as rapid, owing possibly to the lower Fe oxide content i n the natural sediments of the upper basin (see F i g . 3.24). Rather than decreasing thereafter, the concentration of dissolved i r o n continues to increase with depth (with some s c a t t e r ) , to a maximum r e l i a b l e value of =200 umol/L at =36 cm depth. The large amount of scatter i n the lower part of the p r o f i l e i s almost c e r t a i n l y the r e s u l t of varying degrees of oxidation which must have occurred during extrusion, as a consequence of the upward migration of the a i r bubble which was trapped at the base of the core upon i n i t i a l core recovery. 9 + The o v e r a l l Fe concentrations are much higher i n the inner basin core than i n the outer core. The natural sediments appear to have l i t t l e d i s s o l vable Fe oxides, since despite obvious d i s s o l u t i o n of Mn oxide, the expected rapid 2+ Fe increase i n pore water i s not seen at the appropriate depth (=5 cm). Sulphate reduction i s notable at depth i n t h i s core (see Section 3.3.1), but I^S was l a r g e l y absent; thus, despite the low Fe oxide content of the upper basin sediments, there must be s u f f i c i e n t d i s s o l v a b l e Fe at depth to q u a n t i t a t i v e l y p r e c i p i t a t e a l l H^S produced by sulphate-283 reduction. The source of t h i s "excess" Fe must be the t a i l i n g s . The porewater p r o f i l e i n t h i s core suggests, therefore, that upward d i f f u s i o n from the t a i l i n g s , and p r e c i p i t a t i o n of Fe oxides at =3-4 cm, i s responsible f o r the observed Fe concentrations. 3.3.2.3. Dissolved Copper Copper exhibits a very complex biogeochemistry i n marine systems. The f r a c t i o n contained within d e t r i t a l s i l i c a t e s i s l a r g e l y unreactive and generally not involved i n sediment transformations (Price, 1973; Gambrell et a l , 1976; Davies-Colley et a l , 1984). Dissolved copper within the water column i s , however, e a s i l y scavenged by suspended material and i s subsequently delivered to the sediments i n p a r t i c u l a t e form. There i s general agreement that of a l l sedimentary components, organic material has the greatest a f f i n i t y for trace metals (Khalid et a l , 1978; Klinkhammer, 1980; Oakley et a l , 1981; and others). However, i n carbon-poor or rapidly-accumulating sediments a range of other sediments components are thought to sequester Cu ions from the surrounding water. Boyle et a l (1977), Klinkhammer (1980) and Sawlan and Murray (1983) suggest that an a d d i t i o n a l c a r r i e r phase i s Mn oxides, but more recent work (Davies-Colley et a l , 1984; Pedersen, 1985; Tipping et a l , 1986) indicates that Fe oxides may also play a r o l e . At any rate, t h i s adsorbed copper i s much more l a b i l e than that held i n c r y s t a l l a t t i c e s , and may undergo several cycles of 284 remobilization and removal within porewaters before being e i t h e r released to bottom waters or permanently buried i n insoluble constituents within the sediment. The rates at which these processes occur are strongly dependent on porewater pH (Tipping et a l , 1986), redox p o t e n t i a l (Khalid et a l , 1978), and sediment accumulation rate (Duchart et a l , 1973), as well as on the r e l a t i v e proportions of various sedimentary components such as organic material, reducible oxides, clays, and dissolved sulphide (Oakley et a l , 1981; Davies-Colley et a l , 1985). Most Cu* released at the sediment surface enters the bottom water (Sawlan and Murray, 1983; Heggie, 1983), but a f r a c t i o n may d i f f u s e downward to be r e p r e c i p i t a t e d on hydrous Mn and/or Fe oxides which form an enriched layer below the sediment surface. When these materials are themselved reduced, Cu may once again be released to porewater, to be subsequently removed as insoluble sulphides or, i n the presence of extremely high ' sulphide concentrations, to form soluble c h l o r i d e , bisulphide and/or polysulphide complexes (Davies-Colley et a l , 1985; Shea and Helz, 1988). I t has long been assumed that a f t e r b u r i a l i n sediments, trace metals are permanently removed as insoluble sulphides. However, recent work (Shea and Helz, 1988) suggests that bisulphide and polysulphide complexes of Cu are extremely stable and may e x i s t i n high concentrations i n equilibrium with CuS ( c o v e l l i t e ) . In sediments with c l e a r l y 285 defined oxic, and n i t r a t e - , Mn-, and Fe-reducing zones, scavenging by freshly-forming c o l l o i d a l oxides of Fe and Mn i n surface sediments may e f f e c t i v e l y seal o f f the underlying pool of dissolved trace metals from the overlying waters. In highly-reducing sediments, however, where sulphate-reduction begins very close to the sediment/seawater i n t e r f a c e , these dissolved or complexed metals may be released into the bottom water before they can be sequestered by Fe and/or Mn oxides. Bioturbation can s u b s t a n t i a l l y a f f e c t porewater concentrations of Cu and other trace metals by introducing dissolved oxygen more deeply into sediments than could enter by d i f f u s i v e processes alone. The oxidation to sulphate of dissolved sulphide which has b u i l t up i n the porewaters may subsequently lower the trace metal removal capacity of reducing sediments (Emerson et a l , 1984). In the outer basin of Howe Sound dissolved Cu i s highest (215 nmol/L) i n the top 0.5 cm, decreasing r a p i d l y to <20 nmol/L at a depth of 1.5 cm and becoming nearly undetectable near the bottom of the core (see Table M, Appendix I I I ) . A secondary peak of =50 nmol/L occurs between 2.5 and 3.5 cm and appears to correspond to the onset of Mn-reduction below the oxic layer (Fig. 3.119). A t h i r d peak at 22.5 cm coincides with a concomitant increase 9 + 9 + i n Pb"6 and Zn" (Fig. 3.120) and i s almost c e r t a i n l y due to contamination. The very low dissolved Cu l e v e l s (i.e.<5 286 [Fe], umol/L [Cu], nmol/L [Mn], umol/L 0 10 20 30 0 200 400 0 200 400 0 10 20-30-40 50 ^ 1 . I . 1 . 1 . I , I . , 1 , 1 , 1 , 1 , «. '«. •••• •"• • • *' Cu • • • * 0 • * • > / Mn • Fe • • • • k * Fig. 3.119 Dissolved iron, copper and manganese in porewater from core HS 16-B, outer basin, Howe Sound, April 1988. Values in parentheses are thought to be due to contamination. [Cu], nmol/L [Zn], umol/L [Pb], nmol/L 0 1 0 0 2 0 0 0 10 20 30 0 5 10 15 I ' 1 — 1 )..m 1 I I i i I i l i i I • • i i Ii i i i l l l l l I l l l ll i I I I i i i i I i i l l I Fig, 3.120 Dissolved copper, zinc and lead in porewater from core HS 16-B, outer basin, Howe Sound, April 1988. Values in parentheses ( ) are thought to be the result of contamination. nmol/L) i n the bottom t h i r d of the core are accompanied by low Fe (but not low Mn) concentrations (Fig. 3.119). In the inner basin core (HS 64), the s u r f i c i a l Cu concentration (=132 nmol/L) i s considerably lower than i n the outer basin, and decreases within the top centimetre to <20 nmol/L (Table N, Appendix I I I ) . A subsurface spike of 298 nmol/L at 4.1 cm coincides with a Fe peak at the same horizon (Fig. 3.121), and i s also thought to r e f l e c t contamination. In the lower half of the core, where t a i l i n g s are c l e a r l y present i n the s o l i d phase, dissolved Cu values are low (4-39 nmol/L) but v a r i a b l e , and generally p a r a l l e l the scatter i n the dissolved Fe data. The dissolved Cu concentrations i n the surface pore water samples of both cores are higher than those reported for inshore anoxic sediments (4-77 nmol/L; Shaw et a l , 1990; Presley et a l , 1972; Sawlan and Murray, 1983; Heggie et a l , 1987), but lower than those from organic-rich, oxic sediments i n such areas as the Bering Sea continental shelf (337 nmol/L; Heggie et a l , 1987). The d i s t r i b u t i o n s i n the Howe Sound cores suggest that i n these sediments Cu behavior i s c o n t r o l l e d by several processes: 1) release of adsorbed Cu from l a b i l e organics i n the presence of oxygen at the sediment/seawater i n t e r f a c e , 2) release from oxides i n the Fe and/or Mn reduction zones, and 3) removal at depth by p r e c i p i t a t i o n as CuS, c o p r e c i p i t a t i o n with authigenic Fe sulphides, adsorption onto p a r t i c l e surfaces, or sequestra-289 ro o [Fe], umol/L [Cu], nmol/L [Mn], umol/L 0 100 200 0 100 200 0 10 E o a Q 30 40 200 400 1 I 1 1 1 I 1 I \ (°) • i i • | Cu (' \ natural sediments , 1 , 1 , 1 , 1 , : ^ M n (•) 7 •<*C(799) -1 tailings ( / Fig. 3.121 Dissolved iron, copper and manganese in porewater from core HS 64, inner basin, Howe Sound. Values in parentheses are thought to be due to oxidation (Fe) and contamination (Cu). t i o n by b u r i e d o r g a n i c m a t e r i a l . A f o u r t h f a c t o r t o be c o n s i d e r e d i n Howe Sound se d i m e n t s i s r e l e a s e o f d i s s o l v e d Cu from t h e t a i l i n g s . H o f f e t a l (1982) and P e d e r s e n (1985) n o t e d r a p i d r e l e a s e o f Cu and o t h e r m e t a l s from t a i l i n g s exposed t o a e r a t e d 2+ s e a w a t e r f o r a p e r i o d o f s e v e r a l h o u r s . The s u r f i c i a l Cu v a l u e s r e p o r t e d h e r e a r e much h i g h e r t h a n t h o s e o b s e r v e d i n t a i l i n g s - c o n t a m i n a t e d s u r f a c e s e d i m e n t s i n R u p e r t I n l e t , B.C. (25 nmol/L; P e d e r s e n , 1985). However, t h e h i g h e r v a l u e s i n t h i s i n l e t may be r e l a t e d t o l o c a l p r o d u c t i v i t y r a t h e r t h a n t h e p r e s e n c e o f t a i l i n g s . I t i s c l e a r t h a t t h e d i s s o l v e d Cu d i s t r i b u t i o n s o b s e r v e d i n b o t h i n n e r and o u t e r b a s i n s e d i m e n t s a r e s i m i l a r t o t h o s e i n a number o f o t h e r c o a s t a l and open ocean s e t t i n g s ( e . g . Klinkhammer, 1980; Emerson e t a l , 1984; Heggie e t a l , 1986; and Heggie e t a l , 1987), and t h u s t h a t Howe Sound sed i m e n t s s u p p o r t a b e n t h i c e f f l u x o f copper t o t h e o v e r l y i n g w a t e r column w h i c h i s s i m i l a r i n magnitude t o f l u x e s seen e l s e w h e r e . There i s no i n d i c a t i o n t h a t t h e t a i l i n g s o r c o p p e r - e n r i c h e d n a t u r a l s e d i m e n t s i n t h e upper b a s i n o f Howe Sound a r e r e l e a s i n g Cu t o t h e w a t e r column a t a l e v e l i n e x c e s s o f t h a t o b s e r v e d i n p r i s t i n e c o a s t a l , h e m i p e l a g i c o r p e l a g i c s e d i m e n t s . I n d e e d , assuming t h a t t h e p r o f i l e s p r e s e n t e d h e r e a r e r e p r e s e n t a t i v e , t h e b e n t h i c c o p p e r e f f l u x i n t h e upper b a s i n o f Howe sound, where t a i l i n g s were d e p o s i t e d i n t h e p a s t , i s about h a l f t h a t i n t h e t a i l i n g s - f r e e l o w e r b a s i n . 291 In s t r o n g l y reducing sediments measured elsewhere i n t e r f a c i a l porewaters e x h i b i t l i t t l e or no enrichment (e.g. P r e s l e y e t a l , 1972; Sawlan and Murray, 1983; Westerlund et a l , 1986; Heggie e t a l , 1987). L i k e w i s e , the low oxygen val u e s i n the bottom water of the upper b a s i n , which render the sediments anoxic very c l o s e t o the i n t e r f a c e , appear t o i n h i b i t the r e l e a s e of Cu from the surface of core HS 64. This s i t u a t i o n c o u l d change r a p i d l y a f t e r a deep water renewal, when the i n f l u x of well-oxygenated seawater could d r i v e the o x i c zone deeper i n t o the sediment, thereby supp o r t i n g a f l u x t o the o v e r l y i n g water of l a r g e q u a n t i t i e s of metals which had been adsorbed onto e a s i l y - r e d u c i b l e f r a c t i o n s w i t h i n the sediments. I t i s not c o n c l u s i v e whether Fe or Mn oxides are an a d d i t i o n a l source f o r Cu i n Howe Sound. The very t h i n zone of Cu enrichment a t the surface of the sediments c l e a r l y i m p l i c a t e s organic matter as the primary adsorbent; however, the subsurface peaks i n both cores ( i f r e a l ) p o i n t t o a p o s s i b l e secondary a s s o c i a t i o n w i t h Fe r a t h e r than Mn. 3.3.2.4. Dissolved Zinc The behavior of z i n c i n aq u a t i c sediments i s , l i k e t h a t of Cu, i n t i m a t e l y l i n k e d w i t h major b i o l o g i c a l and geochemical c y c l e s . D i s s o l v e d Zn i s scavenged from the water column onto p a r t i c l e s u r f a c e s , notably the o p a l i n e f r u s t u l e s of diatoms (Bruland, 1979). When the s i l i c a 9 + d i s s o l v e s at the sediment s u r f a c e , the Zn which i s 2 9 2 released may enter the overlying water or be incorporated i n t o a number of sedimentary components, of which c o l l o i d a l Mn oxides are l i k e l y the primary phase (Spear, 1981; B a l i s t r i e r i and Murray, 1986). Upon d i s s o l u t i o n of the l a t t e r i n suboxic sediments, Zn ions may d i f f u s e upwards (to be r e p r e c i p i t a t e d on freshly-forming Mn oxides on contact with oxygen near the sediment/seawater i n t e r f a c e ) , or downwards, where t h e i r concentrations are c o n t r o l l e d by p r e c i p i t a t i o n of sulphides or by complexation with dissolved organic or inorganic ligands. Thus the dissolved Zn d i s t r i b u t i o n i n sediment porewaters often p a r a l l e l s those changes i n Mn and S i concentrations which are due to diagenetic r e c y c l i n g (Adams, 1986). The adsorbed f r a c t i o n , which may make up to 4 0% of the t o t a l Zn i n organic-rich estuarine sediments (Presley et a l , 1972; Khalid et a l , 1978), i s highly l a b i l e and e a s i l y released upon minor changes i n such physicochemical p r o p e r i t i e s of the sediment as pH and redox p o t e n t i a l . This causes Zn to be p o t e n t i a l l y very b i o a v a i l a b l e , which may be s i g n i f i c a n t i n areas where large quantities of Zn are added to the sediments by anthropogenic a c t i v i t y . For example, Grieve and Fletcher (1976) found high concentrations of exchangeable trace metals (including zinc, lead and copper) i n sediments and biota near a metal-rich sewage o u t f a l l . The existence of t a i l i n g s on the sloping walls of Howe Sound well above the zone which i s subject to periodic hypoxia 293 ( i . e . near the o r i g i n a l t a i l i n g s o u t f a l l ) , and the p r o b a b i l i t y that some of the very f i n e suspended f r a c t i o n of the t a i l i n g s s l u r r y has been transported to the outer basin, has made t h i s p a r t i c u l a r mobility of Zn a cause of some concern. 2 + In both Howe Sound cores examined m t h i s study, Zn i s enriched i n the surface porewaters (Fig. 3 . 1 2 2 ) . Concentrations i n the top half centimetre of HS 16-B are over 32 pmol/L but decrease by three orders of magnitude by a depth of 4 cm. In HS 64, surface concentrations are much lower, being =1.6 jjmol/L and decreasing to =29 nmol/L within the top 2 cm. The fact that surface enrichments occur i n both cores, and are defined by at lea s t two samples, suggests that they may be r e a l . This suggestion must be tempered by the r e a l i z a t i o n that the concentration measured i n the upper f i v e millimetres of HS 16-B ( 3 2 uM i s ex t r a o r d i n a r i l y high. Porewater zinc measurements are rare i n the l i t e r a t u r e . Enhanced Zn l e v e l s up to 1.5 uM were measured i n s u r f i c i a l sediments of a c i d i c (pH<0.5) lakes (Tessier et a l , 1989), but i n lake sediments with higher pH, and i n reducing marine sediments, the few ava i l a b l e data suggest that Zn occurs i n very low quantities ( i . e . <40 nM) i n i n t e r f a c i a l porewaters ( E l d e r f i e l d et a l , 1981; Pedersen, 1983; Westerlund et a l , 1986; Tessier et a l , 1989) . The subsurface portions of the cores reveal very 294 [Zn], umol/L Fig. 3.122 Dissolved zinc in porewater from two Howe Sound cores. Note different scales on depth axes. Values in parentheses () are thought to be due to contamination. 2 + d i f f e r e n t p r o f i l e s . Below 4 cm i n HS 16-B, [Zn] averages 48 nmol/L (two maxima - 95 nmol/L at 16 cm and 2.5 umol/L at 25 cm - correspond to Fe increases at the same horizons and 2 + may r e f l e c t contamination; see F i g . 3.123). In HS 64 [Zn]" i s moderately high but variable (99-321 nmol/L) i n the natural sediments above the mine t a i l i n g s (Fig. 3.124). Subsurface single-point peaks of 1.6 umol/L at 5 cm and at 2.2 umol/L at 12 cm are at t r i b u t e d to contamination. Below 14 cm the values are generally lower (4-85 nmol/L) and less v a r i a b l e . 2+ • Like the Cu p r o f i l e s , the Zn d i s t r i b u t i o n s suggest 2 + release at the surface of Zn from d i s s o l u t i o n of some phase ( l i k e l y opal or organic matter) and subsequent removal at depth by adsorption by oxyhydroxides or onto p a r t i c l e surfaces, p r e c i p i t a t i o n of zinc sulphide or c o p r e c i p i t a t i o n with i r o n sulphide. The subsurface bulge i n the outer basin core between 2 and =10 cm suggests secondary release through d i s s o l u t i o n of Mn oxide, but t h i s i s not conclusive. As with dissolved Cu, the data here suggest that although Zn i s released from sediments to the overlying waters i n quantities heretofore unreported i n the l i t e r a t u r e , the t a i l i n g s i n the upper basin (presently buried well below the oxic zone) do not appear to be the source of t h i s l a b i l e zinc. 296 [Fe], umol/L [Zn], umol/L [Mn], umol/L 10 20 o 10 20 30 o " 1 1 1 1 1 1 1 1 1 1 111 n i 11 I I i ' 11111} f ij i Fig. 3.123 Dissolved iron, zinc and manganese in porewater from core HS 16-B, outer basin Howe Sound, April 1988. Values in parentheses are thought to be due to contamination during extrusion and/or extraction." 0 10 20 30 40 [Fe], umol/L 100 200 o [Zn], nmol/L 1.0 20 o [Mn], umol/L 200 400 , I , I , I , I \ (•) , 1 , 1 , 1 , 1 , • > (D) , 1 , 1 , 1 , 1 , 1 , 1 , 1 , : \ Fe - \ natural > I / sediments J D J 1°) J I tailings II > ( Mn (•) 7 f Zn i i j i (D) ( Fig. 3.124 Dissolved iron, zinc and manganese in porewater from core HS 64, inner basin Howe Sound, April 1988. Values in parentheses are thought to be due to oxidation (Fe) and contamination (Zn). 3.3.2.5. Dissolved Lead L i k e o t h e r t r a c e m e t a l s , Pb i s known t o be s e q u e s t e r e d f r o m t h e w a t e r column and d e l i v e r e d t o se d i m e n t s w i t h i n f a l l i n g p a r t i c u l a t e s ( P r i c e , 1973; B o y l e e t a l , 1977). The c o m p l e x i n g a f f i n i t y o f t h e element f o r humic m a t e r i a l i s g r e a t e r t h a n t h a t o f Zn b u t l e s s t h a n t h a t o f Cu ( L u t h e r e t a l , 1986); t h u s i t i s p a r t i a l l y c o n t a i n e d w i t h i n o r g a n i c compounds w h i c h a r e s u b j e c t t o breakdown a t t h e se d i m e n t / s e a w a t e r i n t e r f a c e . Recent work a l s o s u g g e s t s t h a t a s e c o n d a r y a s s o c i a t i o n w i t h a u t h i g e n i c Fe compounds c o n t r i b u t e s t o a p a s s i v e i n v o l v e m e n t i n r e d o x - m e d i a t e d r e c y c l i n g w i t h i n s ediments ( G o b e i l and S i l v e r b e r g , 1989). I n Howe Sound t h e r e i s l i t t l e e v i d e n c e o f an en r i c h m e n t a t t h e sediment s u r f a c e s i m i l a r t o t h a t shown f o r Cu and Zn. 2+ I n HS 16-B Pb c o n c e n t r a t i o n s a r e low t h r o u g h o u t t h e c o r e , r a n g i n g from 0.57 nmol/L a t t h e s u r f a c e t o u n d e t e c t a b l e l e v e l s below 31 cm (See T a b l e M, Ap p e n d i x I I I ) . S i n g l e -p o i n t maxima o f 1.7 nmol/L a t 0.75 cm, and 15 nmol/L a t 6.5 cm a r e t h o u g h t t o r e f l e c t c o n t a m i n a t i o n ( F i g . 3.120). However, t h e s e p o i n t s a r e not s u p p o r t e d by t r e n d s i n t h e Pb p r o f i l e o r i n t h o s e o f Cu and Zn. A s e c o n d a r y e n r i c h m e n t l o w e r i n t h e c o r e between 14-30 cm c o r r e s p o n d s g e n e r a l l y t o t h e zone i n w h i c h e l e v a t e d Fe v a l u e s a r e o b s e r v e d ( F i g . 3.125). I n t h e i n n e r b a s i n c o r e Pb c o n c e n t r a t i o n s a r e low t h r o u g h o u t , r a n g i n g from u n d e t e c t a b l e l e v e l s t o =3 nmol/L 299 CO o o [Fe], umol/L [Pb], nmol/L [Mn], umol/L o 10 20 30 o Q j 1 1 1 1 1 1 1 1 1 1 1 10-E O 20H § " 3 0 Q 40 50 Fe 5 10 15 0 • • L_i i i < I i i i i L 200 400 Pb (°) -1 I 1_ Mn Fig. 3.125 Dissolved iron, lead and manganese in porewater from core HS 16-B. outer basin Howe Sound, April 1988. Values in parentheses are thought to be due to contamination. (Table N, Appendix I I I ) . The high concentration measured i n the deepest sample i n the core i s matched by s i m i l a r enrichments of other metals, and i s thought to indicate contamination (Fig. 3.126 and 3.127). The surface sample contains 1.45 nmol/L, and that immediately underlying, 0.2 nmol/L. Although t h i s could r e f l e c t release of Pb at the i n t e r f a c e , the concentrations are aso low that t h i s suggestion cannot be promoted with any degree of c e r t a i n t y . Thus i n Howe Sound the association of Pb with organic matter i s not as clear-cut as are those of Cu and Zn, or a l t e r n a t i v e l y , that Pb i s adsorbed more strongly or i s bound to more refra c t o r y portions of the p a r t i c l e s . Gobeil and Silverberg (1989) present porewater data from Laurentian Trough sediments which strongly implicate Fe oxides as an a d d i t i o n a l c a r r i e r for adsorbed Pb. In both cores, there at l e a s t appears to be more of a connection between Pb and Fe than with any other phase, e s p e c i a l l y i n the subsurface horizons. There i s no evidence to i n d i c a t e that the Pb associated with the mine t a i l i n g s i s being released to the overlying water, as there i s l i t t l e v a r i a t i o n with depth i n the generally low dissolved Pb concentrations i n the inner basin core. 301 o ro E o a Q [Fe], umol/L [Pb], nmol/L [Mn], umol/L 2000 10 15 o 200 400 J , I I I I I I I I I I 1 I I I I I I I I I I I I 1 I 1 I I . f natural \ sediments • tailings 7 / Mn ( Fig. 3.126 Dissolved iron, lead and manganese in porewater from core HS 64, inner basin, Howe Sound, April 1988. Values in parentheses are thought to be due to oxidation during extrusion (Fe) and contamination (Pb). [Cu], nmol/L [Pb], nmol/L [Zn], umol/L 0 100 200 0 5 10 15 0 10 20 30 co O oo Fig. 3.127 Dissolved copper, lead and zinc in porewater from core HS 64, inner basin, Howe Sound, April 1988. Values in parentheses are thought to be the result of contamination. C h a p t e r 4 . SUMMARY AND CONCLUSIONS 304 Chapter 4. Summary and Conclusions The major element d i s t r i b u t i o n s within Howe Sound surface sediments c l e a r l y r e f l e c t the predominant mineral associations of the three main sources of sediment to the i n l e t i . e . the Squamish River at the head of the inner basin, Georgia S t r a i t , which i s primarily influenced by sedimentation from the Fraser River, and the Anaconda mine at B r i t a n n i a Beach, which released t a i l i n g s into the inner basin from ca. 1899 to 1974. Ca l c i c and sodic feldspars dominate Squamish River-borne sediments, while quartz, K-feldspar, and such Fe and Mg minerals as c h l o r i t e , and possibly hornblende, chamosite, and/or o l i v i n e characterize the lower basin sediments, which are thought to enter Howe Sound v i a estuarine c i r c u l a t i o n from Georgia S t r a i t . The greater influence of feldspars i n the inner basin i s also r e f l e c t e d i n the higher A l content there, while quartz appears to be more prevalent i n the outer basin (excepting only the sandier portions of the Squamish d e l t a ) . The sediments close to the Britannia mine o u t f a l l are, l i k e those of the outer basin, enriched i n S i , Fe and Mg and depleted i n Ca and Na feldspars. Titanium appears to be most c l o s e l y associated with a fin e sediment f r a c t i o n whose source i s the Georgia S t r a i t , while the phosphorus concentrations suggest input from both organic and d e t r i t a l sources i n both basins. The organic carbon d i s t r i b u t i o n and high C/N r a t i o s 305 throughout most of the sound i n d i c a t e t h a t t e r r e s t r i a l d e b r i s , r a t h e r than marine p l a n k t o n i c m a t e r i a l , dominates the organic f r a c t i o n . O v e r a l l the C o r g content of the i n n e r b a s i n i s lower than t h a t of the outer, r e f l e c t i n g d i l u t i o n by i n o r g a n i c d e t r i t u s . Both the % C o r g and C/N core p r o f i l e s show more v a r i a b i l i t y i n the upper b a s i n than i n the lower, i m p l y i n g t h a t strong seasonal i n p u t s or e p i s o d i c anthropogenic a c t i v i t i e s are the dominant c o n t r o l on the organic matter content of sediments north of the s i l l . P r o f i l e s of the two sediment cores which were examined i n d e t a i l r e v e a l t h a t the t a i l i n g s b u r i e d beneath recent Squamish-borne sediments are high i n Fe, Mg, and K ( i n d i c a t i v e of a higher p r o p o r t i o n of K - f e l d s p a r s , p y r i t e and/or b i o t i t e , i n the ore body). Titanium i s only s l i g h t l y e n r i c h e d i n t a i l i n g s over n a t u r a l sediments, w h i l e Ca and Na are s i g n i f i c a n t l y depleted. The c o n c e n t r a t i o n s of phosphorus, s i l i c o n , and aluminum show no i d e n t i f i a b l e d i f f e r e n c e s between t a i l i n g s and o v e r l y i n g sediments. The minor elements (with the exception of Co, Y and Zr) a l l c o r r e l a t e w i t h one or more of the major components i n Howe Sound sediments. The d i s t r i b u t i o n of rubidium, f o r example, c l o s e l y f o l l o w s t h a t of potassium, and t h e r e f o r e the element i s more enriched i n the micas and K - f e l d s p a r s which c h a r a c t e r i z e outer b a s i n sediments and mine t a i l i n g s than i n the plagioclase-dominated i n n e r b a s i n sediments. Barium, on the other hand, c o r r e l a t e s w e l l w i t h aluminum, 3 0 6 and i s concentrated i n the upper b a s i n , both i n Squamish sediments and w i t h i n the mine t a i l i n g s as b a r i t e . Strontium shows a n e a r l y complete a s s o c i a t i o n w i t h c a l c i u m (r=0.96), and i s t h e r e f o r e b e l i e v e d t o be r e p l a c i n g the l a t t e r almost t o t a l l y i n c a l c i c f e l d s p a r s , w i t h only minor i n p u t s from some carbonate minerals i n the upper b a s i n . The Rb, Ba and Sr data i n concert show t h a t the p r o p o r t i o n of p l a g i o c l a s e s and b i o t i t e decreases and t h a t of l i g h t micas i n c r e a s e s i n sediments i n a down-inlet d i r e c t i o n from the Squamish D e l t a . Chromium, n i c k e l and vanadium appear t o be a s s o c i a t e d w i t h non-sulphide Fe minerals and are t h e r e f o r e r e l a t i v e l y e n r i c h e d i n the outer b a s i n . A f u r t h e r a s s o c i a t i o n of the metals w i t h the organic carbon content suggests an a d d i t i o n a l enrichment i n p l a n k t o n i c and/or t e r r e s t r i a l p l a n t m a t e r i a l i n some areas. Although vanadium i s s l i g h t l y e n r i c h e d i n the t a i l i n g s , n e i t h e r Cr nor N i shows a s i g n i f i c a n t a s s o c i a t i o n w i t h t h i s phase. The y t t r i u m content i s low everywhere i n Howe Sound, and appears t o be more c l o s e l y a s s o c i a t e d w i t h s m a l l q u a n t i t i e s of heavy minerals from Georgia S t r a i t than w i t h Ca-feldspars from the Squamish b a s i n . Manganese does not hold a primary a s s o c i a t i o n w i t h any p a r t i c u l a r element, due t o i t s u b i q u i t o u s occurrence i n many d i f f e r e n t d e t r i t a l , biogenous, and a u t h i g e n i c f r a c t i o n s . However, the r a p i d decrease below the s u r f a c e l a y e r i n both cores suggests t h a t a s i z a b l e p o r t i o n of sedimentary Mn i n Howe Sound i s contained w i t h i n 307 reducible oxides, which are u t i l i z e d i n suboxic decomposition of organic matter. An enrichment at the top of the buried t a i l i n g s deposit i s believed to r e f l e c t mineralogical differences i n the most recently mined portions of the Britannia ore body. Copper, lead, and zinc c o r r e l a t e well with Fe and with each other, e s p e c i a l l y i n the upper basin i n sediments near the t a i l i n g s o u t f a l l , r e f l e c t i n g the strong influence of metal sulphides within the t a i l i n g s . ..All show s i m i l a r and d i s t i n c t depth p r o f i l e s i n the upper basin core, i n d i c a t i n g that at t h i s l o c a t i o n , the t a i l i n g s deposit was buried by =14 cm of natural sediment i n 1987, 13 years a f t e r the mine ceased operations. The surface d i s t r i b u t i o n s also show that, although some di s p e r s a l of metal-rich t a i l i n g s has occurred beyond the s i l l i n t o the lower basin, the concentrations near the mine o u t f a l l are now less than one quarter those measured shortly a f t e r closure of the mine, and approach background l e v e l s i n much of the outer basin and the d e l t a . Zirconium has l i t t l e a ssociation with any major or minor element due to i t s i n a b i l i t y to substitute for other ions i n most c r y s t a l l a t t i c e s . I t s occurrence i n the independent and re f r a c t o r y mineral zircon means that i t tends to be concentrated i n s i l t and sand grain s i z e s , and i n Howe Sound these are found i n the northernmost and southernmost portions of the i n l e t . 308 Of a l l the minor elements, only Sr i s depleted i n mine t a i l i n g s , f o l l o w i n g the t r e n d e s t a b l i s h e d by Ca and Na. Chromium, n i c k e l , y t t r i u m and zirconium a l l show no d i s c e r n i b l e d i f f e r e n c e i n the t a i l i n g s compared w i t h o v e r l y i n g sediments. Of the remainder, barium, copper, lead and z i n c are s t r o n g l y enriched i n the t a i l i n g s , w h i l e rubidium, vanadium and manganese are s l i g h t l y l e s s so. A n a l y s i s of porewater c o n s t i t u e n t s i n the two cores which were c o l l e c t e d from the deep c e n t r a l p o r t i o n s of both basins o f f e r some c l u e s t o the d i a g e n e t i c c o n d i t i o n s which p r e v a i l below the sediment s u r f a c e . The ammonia and phosphate p r o f i l e s i n d i c a t e t h a t a c t i v e b a c t e r i a l breakdown of organic matter i s o c c u r r i n g i n both areas, although the sur f a c e o x i c l a y e r i s s l i g h t l y t h i n n e r i n the i n n e r b a s i n . A concave-upward ammonia p r o f i l e i n the in n e r b a s i n core i n d i c a t e s some removal of t h i s n u t r i e n t , p o s s i b l y by ad s o r p t i o n onto c l a y minerals which are more abundant i n upper b a s i n sediments. Phosphate appears t o be r e l e a s e d t o i n t e r s t i t i a l waters both by breakdown of organic matter and by d e s o r p t i o n from i r o n oxides as the l a t t e r are reduced below the b i o t u r b a t e d zone. Although NH^ "1" co n c e n t r a t i o n s i n both cores are s i m i l a r ( i . e . =1 mmol/L a t depth), the PO4 maximum ( = 130 umol/L) i n the i n n e r b a s i n core i s more than t w i c e t h a t recorded i n the outer c o r e , l i k e l y due t o r e l e a s e from d i s s o l v i n g Fe oxides i n the s t r o n g l y reducing sediments of the i n n e r b a s i n . However, below 15 cm i n both cores, 309 removal by a u t h i g e n i c minerals such as carbonate 3_ f l u o r a p a t i t e or s t r u v i t e xs b e l i e v e d t o c o n t r o l the PO4 c o n c e n t r a t i o n s . D i s s o l v e d sulphides (EH^S) were v i r t u a l l y absent i n porewaters from both cores, d e s p i t e s u l p h a t e - r e d u c t i o n which i s pronounced i n the inner b a s i n and l e s s so i n the outer b a s i n . I t i s b e l i e v e d t h a t a u t h i g e n i c p y r i t e p r e c i p i t a t i o n i s removing a l l a v a i l a b l e s u l p h i d e . The higher sedimentation r a t e i n the upper b a s i n (which causes d e p o s i t i n g sediments t o be q u i c k l y removed from d i f f u s i v e c ontact w i t h o v e r l y i n g seawater) plus the lower oxygen content of the bottom water, i s l i k e l y r e s p o n s i b l e f o r the more in t e n s e sulphate r e d u c t i o n t h e r e . The i n c r e a s e i n t i t r a t i o n a l k a l i n i t y l i k e w i s e i s more notable i n the i n n e r b a s i n core and i s a l s o c o n s i s t e n t w i t h the g r e a t e r degree of s u l p h a t e - r e d u c t i o n observed t h e r e . However, i n both c o r e s , some removal of a l k a l i n i t y by p r e c i p i t a t i o n of a mixed carbonate phase may a l s o be o c c u r r i n g . D i s s o l v e d Fe, Mn, Cu, Zn and Pb were a l s o measured i n porewater. Reducible i r o n and manganese oxides i n sediments are e f f i c i e n t oxidants i n the absence of oxygen; d u r i n g t h i s process Fe and Mn* are r e l e a s e d t o porewaters and the shape of t h e i r p r o f i l e s o f f e r c l u e s t o the s t a t e of suboxic 2+ dxagenesxs xn sediments. In the Howe Sound cores Mn reach maxima at 6 cm and 3 cm depth i n , r e s p e c t i v e l y , the outer and i n n e r b a s i n s . This i s the c l e a r e s t evidence, i n the 310 absence of n i t r a t e data, t h a t oxygen i s depleted at a shallower depth i n the in n e r b a s i n than i n the outer. Below 2 + < • the peaks i n both cores, the decreasing Mn values i n d i c a t e removal by p r e c i p i t a t i o n of an a u t h i g e n i c phase such as Mn-Ca-Mg carbonate. D i s s o l v e d i r o n reaches a maximum (=30 umol/L) i n the outer b a s i n core at =10 cm, c o n s i s t e n t w i t h i t s s t a b i l i t y at 2+ lower redox p o t e n t i a l s than Mn. L i k e d i s s o l v e d Mn, Fe decreases w i t h depth, presumably because of p y r i t e 2+ • p r e c i p i t a t i o n . In the in n e r b a s i n core Fe values s i m i l a r t o those observed i n the outer b a s i n (<100 umol/L) c h a r a c t e r i z e the n a t u r a l sediments which o v e r l i e the t a i l i n g s , but are c o n s i d e r a b l y enriched (up t o 2 00 umol/L) i n porewaters below 15 cm, and do not decrease w i t h depth but appear t o i n c r e a s e l i n e a r l y t o the bottom of the core. Because there i s some u n c e r t a i n t y as t o the degree of o x i d a t i o n which may have occurred d u r i n g e x t r u s i o n of t h i s c o r e , the co n c e n t r a t i o n s r e p o r t e d must be regarded as minimum v a l u e s . This unusual p r o f i l e suggests t h a t the t a i l i n g s are an abundant source of r e d u c i b l e i r o n o x i d e s , producing an excess of d i s s o l v e d Fe r e l a t i v e t o a v a i l a b l e HS~ (which i s undetectable i n porewaters; the i r o n d i f f u s e s upward along a c o n c e n t r a t i o n g r a d i e n t u n t i l i t i s p r e c i p i t a t e d at =3 cm depth. The t r a c e metals Cu, Zn and Pb were measured t o determine i f any r e l a t i o n e x i s t s between high metal l e v e l s 311 i n the t a i l i n g s s o l i d s and release of dissolved metals from the sediment/water i n t e r f a c e . Copper decreases from maxima of =215 and 130 nmol/L, respectively, i n the outer and inner basin cores, to <20 nmol/L within the top 2 cm. Such a p r o f i l e suggests release from decomposing organic material at the sediment surface (in magnitudes s i m i l a r to those measured i n other coastal sediments) and consumption at depth. There may be some minor release from d i s s o l v i n g Fe and/or Mn oxides below the oxic zone, but t h i s i s not conclusive. The l i k e l y candidate for Cu removal at depth i s p r e c i p i t a t i o n with dissolved sulphide as CuS. There i s no evidence that t a i l i n g s are involved i n the release of copper to the overlying water i n the upper basin core. Indeed, based on these data, the Cu e f f l u x from the t a i l i n g s - f r e e outer basin sediments appears to be greater than from the inner basin sediments, and t h i s difference may be re l a t e d to the low oxygen l e v e l s i n the bottom watter (and hence thinner oxidizng zone i n the underlying sediments) i n the l a t t e r . The dissolved zinc p r o f i l e s are s i m i l a r i n many ways to those of Cu. Extremely high concentrations (=32 uxaol/L) were recorded i n the surface layer of the outer basin core, but these dropped o f f r a p i d l y to <100 nmol/L by 2.5 cm depth. The surface concentrations i n the inner basin core were much less ( = 1.5 umol/1,), but remained moderately high (=200-300 nmol/L) within the top 14 cm. Only i n the 312 t a i l i n g s - r i c h stratum ( i . e . below 14 cm) do Zn^ concentrations f a l l below 100 nmol/L. These data suggest that dissolved zinc, l i k e Cu, i s released at or near the sediment surface by decomposing organics, and i s consumed at depth by p r e c i p i t a t i o n within some sulphide phase. The s u r f i c i a l concentrations noted here are much higher than those reported for s i m i l a r sediments elsewhere, though such data are l i m i t e d . As with Cu, release appears to be much greater from sediments i n the outer basin than from those i n the inner basin, suggesting that the source of the l a b i l e zinc does not appear to be the buried mine t a i l i n g s . Dissolved lead concentrations are low (<3 nmol/L) throughout both cores, and there appears to be l i t t l e or no release ei t h e r from organic material at the sediment surface or from the t a i l i n g s at depth. The porewater data presented here imply that b u r i a l by natural sediments may strongly i n h i b i t the release of some trace metals from metal-rich sediments such as mine t a i l i n g s . I t must be noted, however, that t h i s conclusion may not be j u s t i f i e d f or sediments i n which the t a i l i n g s are exposed or l i e within the upper oxic layer, such as might e x i s t at shallower depths or i n unstable deposits on the f j o r d walls. The two cores analysed i n t h i s study were taken from the deep c e n t r a l basins, areas which are less l i k e l y to be disturbed by slumping or t i d a l currents. In addition, metal release i n the upper basin i s l i k e l y 313 i n h i b i t e d by low oxygen l e v e l s i n the bottom water, and t h i s i s a d i r e c t consequence of a very shallow s i l l which r e s t r i c t s deep water c i r c u l a t i o n . The much higher c o n c e n t r a t i o n s i n the outer b a s i n surface sediment may be r e p r e s e n t a t i v e of s e t t i n g s which are subject t o anthropogenic disturbance but have no a p p r o p r i a t e n a t u r a l b u f f e r s . 314 BIBLIOGRAPHY 315 BIBLIOGRAPHY Abbey, S. 1983. Studies i n "standard samples" of s i l i c a t e rocks and minerals, 1969-1982. G.S.C. Paper 83-15, 114 p. Adams, H.E. 1988. Trace element d i s t r i b u t i o n s i n near-surface calcareous sediments of the East and Central Equatorial P a c i f i c Ocean. Unpubl. B.Sc. Thesis, Dept. of Oceanography, Univ. of B r i t i s h Columbia. A l l e r , R.C. 1980. Diagenetic processes near the sediment-water inte r f a c e of Long Island Sound, I. Decomposition and nutrient element geochemistry (S,N,P). In Estuarine Physics  and Chemistry: Studies i n Long Island Sound (B. Saltzman, ed.), Advances i n Geophysics, v.22. Academic Press. A l l e r , R.C. & P.D. Rude, 1988. Complete oxidation of s o l i d phase s u l f i d e s by manganese and bacteria i n anoxic sediments. Geochim. Cosmochim. Acta 52:751-765. Asmund, G., 1980. Water movements traced by metals dissolved from mine t a i l i n g s deposited i n a f j o r d i n Northwest Greenland. In Fiord Oceanography, H.J. Freeland, D.M. Farmer & CD. Levings (eds.). NATO Conference Series IV, Plenum Press, N.Y. B a l i s t r i e r i , L.S. and Murray, J.W. 1986. The surface chemistry of sediments from the Panama Basin: The influence of Mn oxides on metal adsorption. Geochim. Cosmochim. Acta 50:2235-2243. Barbeau, C , R. Bougie and J.-E. Cote, 1981. Temporal and s p a t i a l v a r i a t i o n s of mercury, lead, zinc, and copper i n sediments of the Saguenay f j o r d . Can J . Earth S c i . 18(6) :1065-1074. B e l l , W.H., 1973. The exchange of deep water i n Howe Sound Basin. Marine Science Directorate, P a c i f i c Region. Pac. Mar. S c i . Rep. 73-13. 109 p. B e l l , W.H. 1975. The Howe Sound current metering program. 3. Data report Stn. HS-5. Pac. Mar. S c i . Rep., 75-7, A:426 p; B:440 p. Berner, R.A. 1974. K i n e t i c models for the early diagenesis of nitrogen, sulfue, phosphorus, and s i l i c o n i n anoxic marine sediments. In The Sea, v.5 (E.D. Goldberg, ed.), Wiley, N.Y., pp. 427-450. Berner, R.A. 197 6. Inclusion of adsorption i n the modelling of early diagenesis. Earth Planet. S c i . L e t t . 29:333-340. 316 Berner, R.A. 1978. Sulfate reduction and the rate of deposition of marine sediments. Earth Planet. S c i . L e t t . 37:492-498. Berner, R.A. 1980. Early Diagenesis. a Theoretical Approach. Princeton Univ. Press, Princeton, N.J. 241 p. Berner, R.A. 1984. Sedimentary p y r i t e formation: An update. Geochim. Cosmochim. Acta 48:605-616. Boatman, CD. and J.D. Murray, 1982. Modelling exchangeable NH4+ adsorption i n marine sediments: processes and controls of adsoption. Limnol. Oceanogr. 27(1):99-110. Borodowskiy, O.K., 1965. Accumulation of organic matter i n bottom sediments. Mar. Geol. 3:33-82. Bowen, H.J.M. 1979. Environmental Chemistry of the Elements. Academic Press, London. 333 p. Boyle, E.A. and J.M. Edmond, 1975. Determination of trace metals i n aqueous solution by APDC chelate co-p r e c i p i t a t i o n . Adv. In Chem. Ser. No. 147, A n a l y t i c a l Methods i n Oceanography, Am. Chem. Soc. Boyle, E.A., F.R. Sclater, and J.M. Edmond, 1977. The d i s t r i b u t i o n of dissolved copper i n the P a c i f i c . Earth Planet. S c i . Lett . 37:38-54. Bright, D.A. and D.V. E l l i s , 1989. Aspects of histology i n Macoma c a r l o t t e n s i s ( B i v a l v i a : T e l l i n i d a e ) and in s i t u histopathology related to mine-tailings discharge. J . Mar. B i o l . Assn. U.K. 69:447-464. Bruland, K.W. 1979. Oceanographic d i s t r i b u t i o n s of cadmium, zinc, n i c k e l and copper i n the north P a c i f i c . Earth Planet. S c i . L e t t . 47:176-198. Brumsack, H.J. & J.M. Gieskes, 1983. I n t e r s t i t i a l trace-metal chemistry of laminated sediments from the Gulf of C a l i f o r n i a . Mar. Chem. 14:89-106. Buckley, J.R. 1977. The currents, winds and t i d e s of northern Howe Sound. Ph.D. Thesis, Univ. of B r i t i s h Columbia. 228 p. Buckley, J.R. and Pond, S., 1976. Wind and the surface c i r c u l a t i o n of a f j o r d . J . F i s h . Res. Bd. Can. 33(10) .-2265-2271. Burnett, W.C. 1977. Geochemistry and o r i g i n of phosphorite deposits from o f f Peru and C h i l e . Geol. Soc. Amer. B u l l . 88:813-823. 317 Burns, R.G. and V.M. Burns, 1977. Mineralogy of manganese nodules. In Marine Manganese Deposits (G.P. Glasby, ed.), p. 185-248. E l s e v i e r , Amsterdam. Burns, R.G. and V.M. Burns, 1979. Manganese oxides. Ch. 1 in Marine Minerals (R.G. Burns, ed.). Min. Soc. Amer. Reviews i n Mineralogy, V.6. Burton, J.D. and P.S. L i s s (eds.), 1976. Estuarine Chemistry. Academic Press, London, 229 p. Caldwell, J.A. & J.D. Welsh, 1982. T a i l i n g s disposal i n rugged, high p r e c i p i t a t i o n environments: an overview and comparative assessment. In D.V. E l l i s (ed.) Marine T a i l i n g s  Disposal p. 5-62. Ann Arbor Press, Ann Arbor, Mich. Calvert, S.E., 1976. The mineralogy and geochemistry of near-shore sediments. Ch. 33 i n : Chemical Oceanography, v.6, 2nd e d i t i o n , J.P. Riley & R. Chester (eds.), Academic Press, London, pp 187-280. Calvert, S.E. & N.B. Price, 1972. D i f f u s i o n and reaction p r o f i l e s of dissolved manganese i n the pore-waters of marine sediments. Earth Planet. S c i . Lett. 16:245-249. Calvert, S.E. & N.B. Price, 1983. Geochemistry of Namibian Shelf sediments. In Coastal Upwelling (Suess, E., & J. Thiede, eds.), Plenum Press, N.Y., London, pp 337-375. Carpenter, J.H., W.L. Bradford and V.E. Grant, 1975. Processes a f f e c t i n g the composition of estuarine waters. In Estuarine Research (L.E. Cronin, ed.) v . l . New York, Academic Press, p. 188-214. C a s t i l l a , J . C , 1983. Environmental impact on sandy beaches of copper mine t a i l i n g s at Chanaral, C h i l e . Mar. P o l l ; . B u l l . 14:459-464. Chester, R. 1965. Elemental geochemistry of marine sediments. In Chemical Oceanography (J.P. Riley and G. Skirrow, eds.), v.2, p.23-80, Academic Press. Church, T.M. (ed.), 1975. Marine Chemistry i n the Coastal  Environment. ACS Symposium Series 18, Washington, D.C, 710 p. Clarke, F.W. and H.S. Washington, 1924. The composition of the earth's crust. U.S. Geol. Survey Prof. Paper 127, 117 p. C l i n e , J.D. 1969. Spectrophotometric determinatin of hydrogen s u l f i d e i n natural waters. Limnol. Oceanogr. 14: 454-458. 318 Daly, R.A., 1933. Igneous Rocks and the Depth of the Earth. McGraw-Hill, London. Davies-Colley, R.J., P.O. Nelson and K.J. Williamson, 1984. Copper and cadmium uptake by estuarine sedimentary phases. Environ. S c i . Technol. 18(7):491-499. Davies-Colley, R.J., P.O. Nelson and K.J. Williamson, 1985. Sul f i d e control of cadmium and copper concentrations i n anaerobic estuarine sediments. Mar. Chem. 16:173-186. Degens, E.T. 1965. Geochemistry of sediments, a b r i e f survey. Prentice-Hall, Englewood C l i f f s , N.J., 342 p. Degens, E.T. and K. Mopper, 1976. Factors c o n t r o l l i n g the d i s t r i b u t i o n and early diagenesis of organic material i n marine sediments, p. 59-113. In Chemical Oceanography (J.P. Riley and R. Chester, eds.), v.6. Academic Press. Down, C G . and J . Stocks, 1977a. Methods of t a i l i n g s d i s p o s a l . Mining Magazine 136:345-359. Down, C G . and J . Stocks, 1977b. Environmental problems of t a i l i n g s d i sposal. Mining Magazine 137:25-33. Duchart, P., W.E. Calvert and N.B. Price, 1973. D i s t r i b u t i o n of trace metals i n the porewaters of shallow water marine sediments. Limnol. Oceanogr. 18(4)605-610. Edmond, J.M. 1970. High pr e c i s i o n determination of t i t r a t i o n a l k a l i n i t y and t o t a l carbon dioxide content of seawater by potentiometric t i t r a t i o n . Deep-Sea Res. 17:737-750. E l d e r f i e l d , H. 1976. Hydrogenous material i n marine sediments; excluding manganese nodules. In Chemical  Oceanography (J.P. Riley and R. Chester, eds.), p.137-215. E l d e r f i e l d , H. & A. Hepworth, 1975. Diagenesis, metals and p o l l u t i o n i n estuaries. Mar. P o l l . B u l l . 6:85-87. E l d e r f i e l d , H., N. Luedke, R.J. McCaffrey, & M. Bender, 1981. Benthic flux studies i n Narragansett Bay. Am. J . S c i . 281:768-787. E l l i s , D.V. (ed.), 1982. Marine T a i l i n g s Disposal. Ann Arbor S c i . Publ., Ann Arbor Press, Ann Arbor, Mich. 319 E l l i s , D.V. & J.D. Popham, 1983. Accidental formation and subsequent disappearance of a contaminated beach: a case h i s t o r y of environmental management. In: McLachlan, A. & T . Erasmus (eds.) Sandy Beaches as Ecosystems. The Hague: Dr. W. Junk Publ. pp 719-726. El-Wakeel, S.K., and J.P. Riley, 1961. Chemical and mineralogical studies of deep-sea sediments. Geochim. Cosmochim. Acta:25:110-146. Emerson, S. and J . I . Hedges, 1988. Processes c o n t r o l l i n g the organic carbon content of open ocean sediments. Paleoceanogr. 1(5):621-634. Emerson, S., R. Jahnke and D. Heggie, 1984. Sediment-water exchange i n shallow water estuarine sediments. J. Mar. Res. 42:709-730. Francois, R., 1987a. Some aspects of the geochemistry of sulphur and iodine i n marine humic substances and t r a n s i t i o n metal enrichment i n anoxic sediments. Ph.D. Thesis, University of B r i t i s h Columbia, 462 p. F r o e l i c h , P.N., G.P. Klinkhammer, M.L. Bender, N.A. Luedke, G.R. Heath, D. Cullen, P. Dauphin, D. Hammond, B. Hartman and V. Maynard, 1979. Early oxidation of organic matter i n pelagic sediments of the eastern equatorial A t l a n t i c : suboxic diagenesis. Geochim. Cosmochim. Acta 43:1075-1090. Fiichtbauer, H. and G. Muller, 1977. Sediment-Petrologie, T e i l I I : Sedimente und Sedimentgesteine, 3. Auflage, Stuttgart, 784 p. Gambrell, R.P., Rk.A. Khalid and W.H. Patrick, J r . Physicochemical parameters that regulate mobilization and immobilization of toxic heavy metals. In Krenkel, P.A., Harrison, J . Burdick I I I , J.C. (eds.) Proceedings of the  Specialty Conference oh Sredging and i t s Environmental  E f f e c t s . Mobile, Alabama, Jan. 26-29, 1976. Gardner, J.V., W.E. Dean and T.L. V a l l i e r , 1980. Sedimentology and geochemistry of surface sediments, outer continental shelf, southern Bering Sea. Mar. Geol.35:299-329. Gibbs, R.J., 1973. Mechanisms of trace metal transport i n r i v e r s . Science 180:71-73 Gibbs, R.J., 1977. Transport phases of t r a n s i t i o n metals i n the Amazon & Yukon Rivers. Geol. Soc. Am. B u l l . , 88:829-843. 320 Gieskes, J.M. and W.C. Rogers, 1973. A l k a l i n i t y determination i n i n t e r s t i t i a l waters of marine sediments. J. Sediment. P e t r o l . 43:272-277. Gobeil, C. and N. Silverberg, 1989. Early diagenesis of lead i n Laurentian Trough sediments. Geochim. Cosmochim. Acta 53:1889-1895. Goyette, D.E., 1975. Marine t a i l i n g s disposal - case studies. Paper presented at Mine E f f l u e n t Regulations/Guidelines and E f f l u e n t Treatment Seminar, Banff, Alberta. Dec. 9-10, 1975. Unpubl. 19 p. Grieve, D.A. and W.K. Fletcher, 1976. Heavy metals i n d e l t a i c sediments of the Fraser River, B r i t i s h Columbia. Can. J . Earth S c i . 13:1683-1693. G r i l l , E.V, and F.A. Richards, 1964. Nutrient regeneration from phytoplankton decomposing i n seawater. J. Mar. Res. 22:51-59. Gulbrandsen, R.A. 1969. Physical and chemical factors i n the formation of marine apatite. Econ. Geol. 64:365-382. Hallberg, R.O. 1972. Iron and zinc s u l f i d e s formed i n a continuous culture of sulfate-reducing b a c t e r i a . Neues Jahrb. Mineral. Monatsh. 11:481-500. Handschuh, G.J. and L.E. Orgel, 1973. Struvite and p r e b i o t i c phosphorylation. Science 179:483-485. Harding, L., 1983. Use of fjords for disposal of mine t a i l i n g . From: Proceedings of the Third Symposium on  Coastal and Ocean Management ASCE/San Diego, CA. June 1-4, 1983. Harding, Lee and D. Goyette, 1989. Metals i n northeast P a c i f i c coastal sediments and f i s h , shrimp, and prawn t i s s u e s . Mar. P o l l . B u l l . 20(4):187-189. Harger, J.R.E., 1971. Environmental impact of the Anaconda mine at Britannia Beach, p.55-86 In Whom the Gods Would  Destroy: the mining industry and environmental control i n  B.C. Published by the Environmental Systems Community Assoc. On f i l e with B.C. P o l l u t i o n Control Branch. Harrison, P.G. and K.H. Mann, 1975. Detritus formation from eelgrass (Zostera marina L . ) : The r e l a t i v e e f f e c t s of fragmentation, leaching, and decay. Limnol. Oceanogr. 20:924-934. 321 Heggie, D.T., 1983. Copper i n the Resurrection Fjord, Alaska. Est. Coast. Shelf S c i . 17:613-635. Heggie, D., D. Kahn and K. Fischer, 1986. Trace metals i n metalliferous sediments, MANOP Sit e M: i n t e r f a c i a l porewater p r o f i l e s . Earth Planet. S c i . L e t t . 80:106-116. Heggie, D., G. Klinkhammer and D. Cullen, 1987. Manganese and copper fluxes from continental margin sediments. Geochim. Cosmochim. Acta 51:1059-1070. H i r s t , D.M. 1962. The geochemistry of modern sediments from the Gulf of Paria - I. The r e l a t i o n s h i p between the mineralogy and the d i s t r i b u t i o n of major elements. Geochim. Cosmochim. Acta 26:309. Hoff, J.T., J.A.J. Thompson & C.S. Wong, 1982. Heavy metal release from mine t a i l i n g s into seawater - a laboratory study. Mar. P o l l . B u l l . 13:283-286. Hoos, L.M. and Void, C.L., 1975. The Squamish River estuary status of environmental knowledge to 1974. Estuary Working Group, Dept. of Environment, P a c i f i c Region, Special Estuary Series, Report 2, 361 p. Howarth, R.W. 1978. A rapid and precise method for determining s u l f a t e i n seawater, estuarine waters, and sediment pore waters. Limnol. Oceanogr. 23:1066-1069. Howarth, R.W. 1979. P y r i t e : i t s rapid formation i n s a l t marsh and i t simportance i n ecosystem metabolism. Science 203:49. Island Copper Mine, 1984. 1983 Annual Environmental Assessment Report (2 v o l s ) . Utah Mines Ltd. Jacobs, L., and S. Emerson, 1982. Trace metal s o l u b i l i t y i n an anoxic f j o r d . Earth Planet. S c i . L e t t . 60:237-252. Jahnke, R.A., S.R. Emerson, K.K. Roe and W.C. Burnett, 1983. The present day formation of apatite i n Mexican continental margin sediments. Geochim. Cosmochim. Acta 47:259-266. James, H.T. 1929. Britannia Beach Map-Area, B r i t i s h Columbia, Geological Survey of Canada Memoir #158. Johnson, R.D., 1974. Dispersal of recent sediments and mine t a i l i n g i n a s h a l l o w - s i l l e d f j o r d , Rupert I n l e t , B r i t i s h Columbia, unpubl. Ph.D. Thesis, Dept. of Geol. S c i . , Univ. of B r i t i s h Columbia, Vancouver, B.C. Canada. 322 J^rgensen, B.B. 1983. Processes at the sediment-water i n t e r f a c e . Ch. 18 i n The Major Biogeochemical Cycles and  Their Interactions (B. Bolin and R.B. Cook, eds.), pp.477-515. SCOPE. Khalid, R.A., W.H. Patrick and R.P. Gambrell, 1978. E f f e c t of dissolved oxygen on chemical transformations of heavy metals, phosphorus, and nitrogen i n an estuarine sediment. Est. Coast. Mar. S c i . 6:21-35. Klinkhammer, G.P. (no date). Separation and determination of cadmium, ir o n , copper, n i c k e l and zinc i n one m i l l i l i t e r seawater samples. Unpubl. Rep. Klinkhammer, G.P., 1980. Early diagenesis i n sediments from the eastern equatorial P a c i f i c , I I . Pore water metal r e s u l t s . Earth Planet. S c i . L e t t . 49:81-101. Klinkhammer, G.P., D.T. Heggie & D.W. Graham, 1982. Metal diagenesis i n o x i c marine sediments. Earth Planet. S c i . L e t t . 61:211-219. Krantzberg, G a i l , 1985. The influence of bioturbation on phy s i c a l , chemical and b i o l o g i c a l parameters i n aquatic environments: a review. Environ. Poll.(A)39:99-122. Krauskopf, K.B. 1979. Introduction to Geochemistry, 2nd ed.. McGraw-Hill, 617 p. Krom, M.D. and R.A. Berner, 1981. The diagenesis of phosphate i n anoxic marine sediments. Limnol. Oceanogr. 25(5):797:806. Krom, M.D. and E.R. Sholkovitz, 1977. Nature and reactions of dissolved organic matter i n the i n t e r s t i t i a l waters of marine sediments. Geochim. Cosmochim. Acta 41:1565-1573. Levings, CD., 1980. Benthic biology of a dissolved oxygen defi c i e n c y event i n Howe Sound, B.C. In Fiord Oceanography (H.J. Freeland, D.M. Farmer and CD. Levings, eds.) NATO Conference series IV: Marine Sciences. Plenum Press, NY, pp. 515-522. Levings, CD. and N.G. McDaniel, 1973. B i o l o g i c a l observations from the submersible PISCES IV near Brit a n n i a Beach, Howe Sound, B.C. Fi s h . Res. Bd. Can. Tech. Rep. No. 409. 23 p. Levings, CD. and N.G. McDaniel, 1976. I n d u s t r i a l disruption of invertebrate communities on beaches i n Howe Sound, B.C. Fis h , and Mar. Serv. Tech. Rep. No. 663. 92 p. 323 Levings, CD. and N.G. McDaniel, 1980. Data report on ef f e c t s of dissolved oxygen deficiency i n bottom waters of Howe Sound: trawl data January 1978 to March 1979 and Oceanographic data August 1977 to March 1979. Can. Data Rep. F i s h . & Aquat. S c i No. 217. Dept. of Fish e r i e s and Oceans. 87 p. L i s s , P.S. 1983. The exchange of biogeochemically important gases across the ai r - s e a i n t e r f a c e . Ch. 15 In The Major  Bioqeochemical Cycles and Their Interactions (B. Bolin and R.B. Cook, eds.) 1983 SCOPE. Loring, D.H., 1982. Geochemical factors c o n t r o l l i n g the accumulation and di s p e r s a l of heavy metals i n the Bay of Fundy sediments. Can. J . of Earth S c i . 19(5):930-944. Losher, A.J., 1985. The geochemistry of sediments and mine t a i l i n g s i n the A l i c e Arm area. M.Sc. Thesis, University of B r i t i s h Columbia, Vancouver, B.C. Canada. Luther I I I , G.W., Z. Wilk, R.A. Ryans and A.L. Meyerson, 1986. On the speciation of metals i n the water column of a polluted estuary. Mar. P o l l . B u l l . 17(12):535-542. Mackenzie, R.C, G.F. Walker, and R. Hart, 1949. I l l i t e i n decomposed granite at B a l l a t e r , Aberdeenshire. Mineralog. Mag., 28:704-714. Mackin, J.E. and R.C. A l l e r , 1984. Ammonium adsorption i n marine sediments. Limnol. Oceanogr. 29(2):250-257. Malone, Ph. G., and K.M. Towe, 1970. Microbial carbonate and phosphate p r e c i p i t a t e s from seawater cu l t u r e s . Mar. Geol. 9:301-309. Mantoura, R.F.C, A. Dickson and J.P. Ril e y , 1978. The complexation of metals with humic materials i n natural waters. Est. Coast. Mar. S c i . 6:387-408. Martens, C.S. and R.C. Harriss, 1970. I n h i b i t i o n of apatite p r e c i p i t a t i o n i n the marine environment byu magnesium ions. Geochim. Cosmochim. Acta 34:621-625. Martens, C.S., R.A. Berner, and J.K. Rosenfeld, 1978. I n t e r s t i t i a l water chemistry of anoxic Long Island Sound sediments. 2. Nutrient regeneration and phosphate removal. Limnol. Oceanogr. 23(4):605-617. Mason, B. and C. B. Moore, 1982. P r i n c i p l e s of Geochemistry, 4th ed. Wiley & Sons, N.Y. 344 p. 324 Mathews, W.H. 1958. Geology of the Mount G a r i b a l d i map-area, southwestern B r i t i s h Columbia, Canada, 1. Igneous and metamorphic rocks; 2. Geomorphology and Quaternary volcanics. Geol. Soc. Am. B u l l . 69:161-178; 179-198. Mathews, W.H. and F.P Shepard, 1962. Sedimentation of Fraser River d e l t a , B r i t i s h Columbia. Am.Assoc.Petrol. Geol.Bull.46:1416-1443 McDaniel, N.G., 1973. A survey of the benthic macroinvertebrate fauna and s o l i d pullutants i n Howe Sound, F i s h . Res. Bd. Can. Tech. Rep. No. 385. 64 p. McDaniel, N.G., CD. Levings, D. Goyette, and D. Brothers, 1978. Otter trawl catches at disrupted and i n t a c t habitats i n Howe Sound, Je r v i s I n l e t , and Bute I n l e t , B.C., August 1976 to December 1977. F i s h . Mar. Serv. Data Rep. 92. McKinney, R.E. & R.A. Conway, 1957. Chemical oxygen i n a b i o l o g i c a l waste treatment. Sewage In d u s t r i a l Wastes 29:1097-1106. McMurchy, R.C, 1934. Structure of c h l o r i t e s . Ztsch. Krist.,88:420-432. McNichol, A.P., C. Lee and E.R.M. D r u f f e l , 1988. Carbon c y c l i n g i n coastal sediments: 1. A quantitative estimate of the remineralization of organic carbon i n the sediments of Buzzards Bay, MA. Geochim. Cosmochim. Acta 52:1531-1543. Milliman, J.D., 1980. Sedimentation i n the Fraser River and i t s estuary, wouthwestern B r i t i s h Columbia (Canada). Est. Coast. Mar. S c i . 10:609-633. Morris, R.J. and S.E. Calvert, 1977. Geochemical studies of organic-rich sediments from the Namibian Shelf - I. The organic f r a c t i o n s . In Voyage of Discovery (M.V. Angel, ed.), Deep-Sea Res. suppl. to Vol. 24, 647-665. MUller, P.J., 1977. C/N r a t i o s i n P a c i f i c deep-sea sediments: E f f e c t of inorganic ammonium and organic nitrogen compounds sorbed by cla y s . Geochim. Cosmochim. Acta 41:765-776. Myers, CR. and K.H. Nealson, 1988. Microbial reduction of manganese oxides: interactions with i r o n and sulphur. Geochim. Cosmochim. Acta 52:2727-2732. Nriagu, J.O. 1972. S t a b i l i t y of v i v i a n i t e and ion-pair formation i n the system Fe3(P0 4)2-H3P0 4-H20. Geochim. Cosmochim. Acta 36:459-470. 325 Oakley, S.M., P.O. Nelson, and K.J. Williamson, 1981. Model of trace-metal p a r t i t i o n i n g i n marine sediments. Env. S c i . & Technol. 15:474-480. O'Connor, T.D. & D.R. Kester, 1975. Adsorption of copper and cobalt from fresh and marine systems. Geochim. Cosmochim. Acta 39:1531-1543. Olausson, E. and I. Cato (eds.), 1980. Chemistry and  Biogeochemistry of Estuaries. Wiley & Sons, 452 p. Parsons, T.R., Y. Maita and CM. L a l l i , 1984. A Manual of Chemical and B i o l o g i c a l Methods f o r Seawater Analysis. Pergamon Press, Oxford, U.K., 173 p. Pedersen, T.F. 1979. The geochemistry of sediments of the Panama Basin, Eastern Equatorial P a c i f i c Ocean. Ph.D. Thesis, Univ. of Edinburgh. Pedersen, T.F., 1983. Dissolved heavy metals i n a lac u s t r i n e mine t a i l i n g s deposit - Buttle Lake, B.C. Mar. P o l l . B u l l . 14:249-254. Pedersen, T.F., 1984. I n t e r s t i t i a l water metabolite chemistry i n a marine mine t a i l i n g s deposit, Rupert I n l e t , B.C. Can. J. Earth S c i . 21(1):l-9. Pedersen, T.F., 1985. Early diagenesis of copper and molybdenum i n mine t a i l i n g s and natural sediments i n Rupert and Holberg I n l e t s , B.C. Can. J . Earth S c i . 22:1474-1484. Pedersen, T.F. & A.J. Losher, 1988. Diagenetic processes i n aquatic mine t a i l i n g s deposits i n B r i t i s h Columbia. In: Chemistry and Biology of S o l i d Waste, W. Salomons and U. Forstner (eds.), Springer-Verlag, B e r l i n , pp.238-258. Pedersen, T.F. & N.B. Price, 1982. The geochemistry of manganese carbonate i n Panama Basin sediments. Geochim. Cosmochim. Acta 46:59-68. Pedersen, T.F., S.J. Malcolm & E.R. Sholkovitz, 1985. A lightweight gravity corer for undisturbed sampling of soft sediments. Can. J. Earth S c i . 22:133-135. Pedersen, T.F., J.S. Vogel & J.R. Southon, 1986. Copper and manganese i n hemipelagic sediments at 21°N, East P a c i f i c Rise: diagenetic contrasts. Geochim. Cosmochim. Acta 50:2019-2031. 326 P e l l e t i e r , C.A., 1982. Environmental data handling and long-term trend monitoring at Island Copper Mine. In D.V. E l l i s (ed.) Marine T a i l i n g s Disposal Ann Arbor S c i . Publ., Ann Arbor Press, Ann Arbor, Mich. P e t r i e , L. and N. Holman, 1983. PISCES 14 Submersible Dives 1973-1982. Regional Programme Report: 83-20. Dept. of Environment, Environmental Protection Service, P a c i f i c Region. Pharo, C.H., 1972. Sediments of the Central and Southern S t r a i t of Georgia, B.C. Ph.D. Thesis, Dept. of Geol. University of B r i t i s h Columbia, 265 p. Pickard, G.L., 1961. Oceanographic features of i n l e t s i n the B r i t i s h Columbia mainland coast: J . F i s h . Res. Bd. Can. 18:907-999. Powys, R.I. 1987. A high resolution study of varved sediments from Saanich I n l e t . M.Sc. Thesis, Univ. of B r i t i s h Columbia. Presley, B.J., Y. Kolodny, A. Nissenbaum and I.R. Kaplan, 1972. Early diagenesis i n a reducing f j o r d , Saanich Inl e t , B r i t i s h Columbia - I I . Trace element d i s t r i b u t i o n i n i n t e r s t i t i a l water and sediment. Geochim. Cosmochim. Acta 36:1073-1090. Pri c e , N.B. 1973. Chemical diagenesis i n sediments. Technical Report WHOI:73-79. Unpubl. MS. June 1973. Premuzic, E.T., CM. Benkovitz, J.S. Gaffney, and J . J . Walsh, 1982. The nature and d i s t r i b u t i o n of organic matter i n the surface sediments of world oceans and seas. Org. Geochem. 4:63-77. Rankama, K., and T. Sahama 1950. Geochemistry. Chicago Univ. Press. Redfield, A.C. 1958. The b i o l o g i c a l control of chemical factors i n the environment. Amer. S c i . 46:206-226. Redfield, A.C, B.H. Ketchum, and F.A. Richards, 1963. The influence of organisms on the composition of seawater. In The Seas. Vol. 2, p. 26-77. Interscience. Reeburgh, W.S. 1983.. Rates of biogeochemical processes i n anoxic sediments. Ann. Rev. Earth Planet. S c i . 11:269-298. 327 Reynolds, R.C. 1963. Matrix corrections i n trace element analysis by x-ray fluorescence: estimation of the mass absorption c o e f f i c i e n t by Compton sc a t t e r i n g . Amer. Mineral. 48:1133. Reynolds, R.C. 1967. Estimation of mass absorption c o e f f i c i e n t s by Compton sc a t t e r i n g : improvements and extensions of the method. Amer. Mineral. 52:1493-1502. Richards, F.A., 1965. Anoxic basins and f j o r d s . In Chemical  Oceanography, Vol. 1 (J.P. Riley and G. Skirrow, eds.) pp 611-645. Academic Press, New York. Rice, D.L. and K.R. Tenore, 1981. Dynamics of carbon and nitrogen during the decomposition of d e t r i t u s derived from estuarine macrophytes. Est. Coast. Shelf S c i . 13(6):681-690 Ridgway, I.M. and N.B. Price, 1987. Geochemical associations and post-depositional mobility of heavy metals i n coastal sediments: Loch Et i v e , Scotland. Mar. Chem 21:229-248. Rosenfeld, J.K. 1979. Amino acid diagenesis and adsorption i n nearshore anoxic sediments. Limnol. Oceanogr. 24(6):1014-1021. Sato, Y., S. Okabe and T. Takematsu, 1989. Major elements i n manganese and i r o n oxides p r e c i p i t a t e d from seawater. Geochim. Cosmochim. Acta 53:1883-1887. Sawlan, J . J . & J.W. Murray, 1983. Trace metal remobilization i n the i n t e r s t i t i a l waters of red clay and hemipelagic marine sediments. Earth Planet. S c i . L e t t . 64:213-230. Schmidt, R.L. 1978. Copper i n the marine environment. Part 1 and 2. CRC C r i t . Revs. Environ. Control:101-152; 247-291. Schofield, S.J. 1918. Britannia Map Area. Trans. Can. Min. Inst., pp. 56B-59B. Shaw, T.J., J.M. Gieskes, and R.A. Jahnke, 1990. Early diagenesis i n d i f f e r i n g depositional environments: The response of t r a n s i t i o n metals i n pore water. Geochim. Cosmochim. Acta 54:1233-1246. Shea, D. and G.R. Helz, 1988. The s o l u b i l i t y of copper i n s u l f i d i c waters: S u l f i d e and p o l y s u l f i d e complexes i n equilibrium with c o v e l l i t e . Geochim. Cosmochim. Acta 52:1815-1825. Sholkovitz, E.R., 197 3. I n t e r s t i t i a l water chemistry of the Santa Barbara Basin sediments. Geochim. Cosmochim. Acta 37:2043-2073. 328 Sinex, S.A. and G.R. Helz, 1981. Regional geochemistry of trace elements i n Chesapeake Bay sediments. Environ. Geol.3:315-323. Skei, J . , 1983. Why sedimentologists are interested i n . f j o r d s . Sed. Geol. 36:75-80. Spear, P.A. 1981. Zinc i n the aquatic environment: chemistry, d i s t r i b u t i o n , and toxicology. NRCC, Publ. No. 17589, 11-31. Stevenson, F.J. and C.-N. Cheng, 1972. Organic geochemistry of the Argentine basin sediments: Carbon-nitrogen r e l a t i o n s h i p s and Quaternary c o r r e l a t i o n s . Geochim. Cosmochim. Acta 36:653-671. Stevenson, F.J. and S.N. T i l o , 1969. Nitrogenous constituents i n deep-sea sediments. In Advances i n Organic Geochemistry  1966 (G.D. Hobson and G.C. Speers, eds.), Pergamon Press, Oxford, p. 227-253. Stumm, W. and J.O. Leckie, 1970. Phosphate exchange with sediments: i t s r o l e i n the productivity of surface waters. In Advances i n Water P o l l u t i o n Research, v.2, p.26/1-26/16. Stumm, W. and J . J . Morgan, 1970. Aquatic Chemistry, Wiley, New York, 583 p. Suess, E. 1979. Mineral phases formed i n anoxic sediments by microbial decomposition of organic matter. Geochim. Cosmochim. Acta 43:339-352. Suess, E. 1980. Pa r t i c u l a t e organic carbon flux i n the oceans - Surface productivity and oxygen u t i l i z a t i o n . Nature 288:260-263. Suess, E. 1981. Phosphate regeneration from sediments of the Peru continental margin by d i s s o l u t i o n of f i s h debris. Geochim. Cosmochim. Acta 45:577-588. Suess, E. and P.J. Miiller, 1981. Interaction between K+ and NH4+ i n marine pore solutions and sediments. Geochim. Cosmochim. Acta 45: S y v i t s k i , J.P.M. and R.D. Macdonald, 1982. Sediment character and provenance i n a complex f j o r d ; Howe Sound, B r i t i s h Columbia. C.J. Earth S c i . 19(5):1025-1044. Tabata, S., 1972. The movement of Fraser River-influenced surface water i n the S t r a i t of Georgia as deduced from a series of a e r i a l photographs. Mar. S c i . Dir., Pac. Reg., Pac. Mar. S c i . Rep. 72-6, 69 p. 329 Tabata, S., L.F. Giovando, J.A. Strick l a n d , and J. Wong, 1970. Current v e l o c i t y measurements i n the S t r a i t of Georgia -1967. F i s h . Res. Bd. Can. Tech. Rep. No. 109, 145 p. Taylor, S.R. 1965. The appl i c a t i o n of trace element data ro problems i n petrology, In Physics and Chemistry of the  Earth, 6 (L.H. Ahrens, F.H. Press and S.K. Runcorn, eds.), Pergamon Press, London. Tenneco O i l and Minerals Ltd., 1966. Sediment i n Howe Sound, B.C.; an open marine i n l e t . From Recent Sediments and Their Environment of Deposition, S t r a i t of Georgia and Fraser River Delta, May 1966. Unpubl. Rep.) Tessier, A., R. Carignan, B. Dubreuil and F. Rapin, 1989. P a r t i t i o n i n g of zinc between the water column and the oxic sediments i n lakes. Geochim. Cosmochim Acta 53:1511-1522. Thomas, D.J. 1975. D i s t r i b u t i o n of zinc and copper i n Georgia S t r a i t , B r i t i s h Columbia: E f f e c t s of the Fraser River and Sediment Exchange Reactions. M.Sc. Thesis, Dept. of Oceanography, Univ. of B r i t i s h Columbia, 110 p. Thomas, D.J. and E.V. G r i l l , 1977. The e f f e c t of exchange reactions between Fraser River sediment and seawater on dissolved Cu and Zn concentrations i n the S t r a i t of Georgia. Est. Coast. Mar. S c i 5:421-427. Thompson, J.A.J. & F.T. McComas, 1974. Copper and zinc l e v e l s i n submerged mine t a i l i n g s at Britannia Beach, B.C. F i s h . Res. Bd. Can. Tech. Rep. No. 437. 33 p. Thompson, J.A.J. & D.W. Paton, 1976. Further studies of mine t a i l i n g s d i s t r i b u t i o n i n Howe Sound, B.C. Fi s h . Res. Bd. Can. Man. Rep. No. 1383. 15 p. Thompson, J.A.J. & D.W. Paton, 1978. Copper i n sediment i n t e r s t i t i a l waters and overlying waters of Howe Sound, B.C. F i s h . & Mar. Serv. Tech. Rep. No. 775. Thomson, R.E. 1981. Oceanography of the B r i t i s h Columbia  Coast. Can. Dept. Fis h . & Oceans, 291 pp. Tipping, E., D.W. Thompson, M. Ohnstad, and N.B. Hetherington, 1986. E f f e c t s of pH on the release of metals from naturally-occurring oxides of Mn and Fe. Env. Technol. L e t t . 7:109-114. 330 Troup, B.N. and O.P. Bricker, 1975. Processes a f f e c t i n g the transport of materials from continents to oceans. Ch. 8 i n Marine Chemistry i n the Coastal Environment (T.M. Church, ed.). ACS Symposium Series 18, Washington, D.C. van Aggelen, G. and B. Moore, 1986. (Anaconda Britannia Mines) Copper Beach Estates Ltd. Environmental Impact Assessment: 1986 Update Survey. Prep, for B.C. Min. Environ. von Breymann, M and E. Suess, 1988. Mg i n the marine sedimentary environment: Mg-NH* ion exchange. Chem. Geol. 70:359-371. Waldichuk, M., 1978. Disposal of mine wastes into the sea. Mar. P o l l . B u l l . 9:141-143. Waldichuk, M., 1987. P o l l u t i o n by abandoned mines. Mar. P o l l . B u l l . 18(8):422-423. Ward, A.B. & D.L. S u l l i v a n , 1980. A review of e x i s t i n g and h i s t o r i c a l dumpsites i n the P a c i f i c Region. Env. Prot. Serv. Env. Canada, P a c i f i c Region. Reg. Prog. Rep 80-5 pp 89-91. Water Quality I n s t i t u t e , Denmark, 1979. Testing of methods to mitigate the release of metals from Agfardliskavsa Fjord sediments, Marmorilik, Pro j . Rep. for Greenex A/S, Copenhagen, Denmark. Water Quality I n s t i t u t e , Denmark, 1980. Laboratory assays on the features of s i l t and t a i l i n g material from Marmorilik. Project Rep. for Greenex A/S. Copenhagen, Denmark. Westerlund, S.F.G., L.G. Anderson, P.O.J. H a l l , A. I v e r f e l d t , M.M. Rutgers van der Loeff, and B. Sundby, 1986. Benthic fluxes of cadmium, copper, n i c k e l , zinc and lead i n the coast a l environment. Geochim. Cosmochim. Acta 50:1289-1296. Wiley, M.L. (ed.), 1978. Estuarine Interactions. Academic Press, London, 603 p. Willey, Joan D and R.A. F i t z g e r a l d , 1980. Trace metal geochemistry i n sediments from the Miramichi estuary, New Brunswick. Can. J . of Earth S c i . 17(2):254-265. Wright, P.L. 1972. The geochemistry of Recent sediments of the Barents Sea. Ph.D. Thesis, University of Edinburgh, Scotland. 331 APPENDICES 332 APPENDIX I. Surface Sample and Core Locations CORE NO. LENGTH WATER LATITUDE LONGITUDE (cm) DEPTH (m) HS 1 60 238 49° 22 'N 123° 19 'W HS 2 50 245 49° 23'N 123° 18'W HS 3 62 143 49° 23 'N 123° 26 'W HS 4 59.5 241 49° 24 'N 123° 18'W HS 4-B 57 235 49° 24'N 123° 16'W HS 5 32 228 49° 24.53'N 123° 25'W HS 5-B 38 95 49° 25'N 123° 28 'W HS 6 38 122. 5 49° 25'N 123° 26'W HS 7 59.5 242 49° 25'N 123° 16'W HS 8 15 252. 8 49° 25.23'N 123° 22 'W HS 9 54 190 49° 25.5'N 123° 25'W HS 10 53 240 49° 25.68'N 123°: 15.12'W HS 11 >10 251 49° 25.75'N 123° 20'W HS 11-B 66 187 49° 26'N 123° 24 'W HS 12 >10 247 49° 26'N 123° 18 'W HS 13 20 95 49° 26.5'N 123° 27 'W HS 14 54 152 49° 26.5'N 123° 25 'W HS 15 55 159 49° 26.5'N 123° 23'W HS 16 60 241 49° 26.26'N 123°16.14'W HS 16-B 70 249 49° 27 'N 123° 17 'W HS 17 30 131 49° 27.5'N 123° 27.5'W 333 CORE NO. LENGTH WATER LATITUDE LONGITUDE (cm) DEPTH (m) HS 18 40 249 49° 28'N 123° 17 'W HS 19 62 168 49° 28.5'N 123° 28'W HS 20 42 214 49° 28.58'N 123° 17.69'N HS 21 55 247 49° 28.65'N 123° 16.12'W HS 22 42 205 49° 29.5'N 123° 27 'W HS 22-B 56 242 49° 29.5'N 123° 16 'W HS 23 42 214 49° 30'N 123° 28'W HS 24 55 241 49° 30.04 'N 123° 19.14 'W HS 25 60 238 49° 30'N 123° 16.5'W HS 26 42.5 223 49° 30.65'N 123° 28.7 'W HS 2 "60 230 49° 31'N 123° 19.5'W HS 28 "60 223 49° 31'N 123° 16.5'W HS 29 57 234 49° 3.1.5 'N 123° 27 'W HS 30 "60 228 49° 31.5'N 123° 20.5'W HS 31 62 229 49° 32 'N 123° 25'W HS 32 "60 218 49° 32 'N 123° 20 'W HS 33 62.5 234 49° 32.25'N 123° 25 'W HS 34 55 174 49° 32.25'N 123° 16.5'W HS 35 57 227 49° 32.5'N 123° 23 'W HS 36 "60 220 49° 32.5'N 123° 21'W HS 37 "30 169 49° 32 .5 'N 123° 15.5'W HS 38 "30 154 49° 32.75'N 123° 15 'W 334 CORE NO. LENGTH WATER (cm) DEPTH HS 39 58 227 HS 40 "60 210 HS 41 52 165 HS 42 60 141 HS 43 62 154 HS 44 55 175 HS 45 54 74 HS 46 32 148 HS 47 "30 128 HS 48 "30 215 HS 49 "60 180 HS 49-B "60 198 HS 50 "60 183 HS 50-B 45 102 HS 51 30 227 HS 52 25 168 HS 53 27 143 HS 54 30 274 HS 55 18 178 HS 56 20 155 HS 57 45 287 HS 58 57 148 LATITUDE LONGITUDE 49° 33'N 123° 22 'W 49° 33 'N 123° 20 'W 49° 33'N 123° 17.5'N 49° 33.21'N 123° 16.19'W 49° 33.25'N 123° 17'W 49° 33.5'N 123° 18 'W 49° 33.3'N 123° 16'W 49° 33.3'N 123° 15 'W 49° 33.75'N 123° 16.5'W 49° 33.75'N 123° 15.52'W 49° 34 'N 123° 20 'W 49° 33.5'N 123° 20.5'W 49° 34 'N 123° 19 'W 49° 34 'N 123° 17 'W 49° 34 'N 123° 19 'W 49° 34.25'N 123° 18 'W 49° 34.25'N 123° 16.5'W 49° 34.25'N 123° 15.5'W 49° 34.25'N 123° 14.5 'W 49° 34.5'N 123° 19 'W 49° 34.5'N 123° 15 'W 49° 34.75'N 123° 18'W 335 CORE NO. LENGTH WATER LATITUDE LONGITUDE (cm) DEPTH (m) HS 59 66 285 49° 34.75'N 123° 15.3'W HS 60 64.5 290 49° 35'N 123° 15'W HS 61 60 290 49° 35.25'N 123° 14.3'W HS 62 75 290 49° 35.5'N 123° 15'W HS 63 28 234 49° 35.5 'N 123° 13.9oW HS 64 66 282 49° 35.75'N 123° 14.5'W HS 65 35 283 49° 36'N 123° 14 'W HS 66 60 280 49° 36.45'N 123° 14.45'W HS 67 14 243 49° 36'N 123° 13.6'W HS 68 45 278 49° 37 'N 123° 14.25'W HS 69 34 278 49° 36.93'N 123° 13.93'W HS 70 35 275 49° 36.94 'N 123° 13.35'W HS 71 44 272 49° 37.26'N 123° 13.03'W HS 72 16 271 49° 37.38'N 123° 14.37'W HS 73 20 263 49° 37.44 'N 123° 13.55'W HS 74 25 265 49° 37.77 'N 123° 13.96'W HS 75 12 190 49° 37.52'N 123° 13'W HS 76 22 256 49° 37.75'N 123° 13.5'W HS 77 33 254 49° 38 'N 123° 14.5 'W HS 78 25 250 49° 38'N 123° 13.25'N HS 79 32 245 49° 38.5'N 123° 15 'W HS 80 20 236 49° 38.5'N 123° 14'W 336 CORE NO. LENGTH WATER LATITUDE LONGITUDE (cm) DEPTH (m) HS 81 41 234 49° 38.75'N 123° 14.5'W HS 82 40 223 49° 39'N 123° 14 'W HS 82-B 48 240 49° 39'N 123° 15'W HS 83 41 234 49° 39.25'N 123° 14.5'W HS 84 80 241 49° 39.5'N 123° 15'W HS 85 45 224 49° 39.5'N 123° 14 'W HS 86 70 227 49° 39.75'N 123° 14.5'W HS 87 43 183 49° 39.75'N 123° 13.5'W HS 88 35 214 49° 40' N 123° 14 'W HS 89 35 192 49° 40'N 123° 13'W HS 90 4 165 49° 40 'N 123° 12 'W HS 91 11 140 49° 40 'N 123° 11 'W HS 92 0 134 49° 40.25'N 123° 11.5 'W HS 93 7 157 49° 40.5'N 123° 12'W 337 APPENDIX I I . CORE DESCRIPTIONS CORE DEPTH(m) LENGTH(cm)INTERVAL DESCRIPTION QUEEN CHARLOTTE CHANNEL - CORES 1.2.4.4B.7. 238 60 245 50 4B 241 235 59.5 57 0-2 2-TD 0-2 2-TD 0- 1 1- 6 6-TD 0-0.5 .5-5 5-TD 242 59.5 0- 1 1- 8 8-TD COLLINGWOOD CHANNEL - 3.5, 143 62 228 32 0-0.25 .25-9 9-TD 0- 1 1- TD g r a y i s h brown s i l t ; organic fragments (twigs, e t c ) ; worm tubes. homogeneous dark grey s i l t y c l a y . o x i c l a y e r , chocolate brown, w i t h worm burrows. dark grey, s i l t y c l a y ; some disturbance of surface l a y e r . brown, organic f l u f f ; l i g h t green grey c l a y ; dark gray c l a y e y mud. brown, muddy ooze, l i g h t grey, b i o t u r b a t e d , grading to medium t o dark grey; o x i d i z e d p o r t i o n s a l l the way down, one worm burrow t o base of core. brown, o x i c w i t h worm tubes. l i g h t gray green c l a y ; dark charcoal-gray c l a y . t h i n brown sludgy top; l i g h t t o medium gray, b i o t u r b a t e d area w i t h o x i d i z e d s e c t i o n s , uniformly medium greenish grey. o x i c - brown organic l a y e r ; homogeneous green gray c l a y , grading t o dark grey; o x i d i z e d worm burrow t o base of core. 338 LARGE BAY SOUTH OF GAMBIER ISLAND - 5B.6.8.9.11B.14.15  CORE DEPTH(m) LENGTH(cm)INTERVAL DESCRIPTION 5B 95 38 0-.25 .25-11 11-38 6 122.5 38 0-1 1-TD 8 252.8 15 0-1 1-10 10- TD 9 190 54 0-0.75 .75-TD 11B 187 66 0-1 1-11 11- TD 14 152 54 0-0.5 • 5-TD very thin brown sludgy top. medium grey, bioturbated, with black bands and clumps (organic matter) and worm burrows; clam shell fragment at 10 cm. uniformly medium greenish grey; oxidized worm burrow to 20 cm. flu f f y , light brown organic layer; trace light green grey clay grading to dark grey. brown, oxic organic layer. light grey-green clay; dark grey clay. light brown oxic top, grading to pale gray-green homogeneous clay, (some disturbance of surface); organic fragments common. brown sludge; bioturbated zone; uniformly medium to dark green grey; core appeared to have oxidized portions right to base; soupy in part; brownish. light brown, oxic; organic fragments, homogeneous gray-green clay. 339 CORE DEPTH(m) LENGTH(cm)INTERVAL DESCRIPTION 15 159 55 0-.9 l i g h t brown o x i c top; some disturbance of i n t e r f a c e . .9-TD pale gray-green c l a y , homogeneous; o c c a s i o n a l black specks ( f e c a l p e l l e t s ? ) CHANNEL BETWEEN GAMBIER & BOWEN - 8,11.12. 8 252.8 15 0-1 brown o x i c organic l a y e r ; 1-10 l i g h t gray-green c l a y ; 10-TD dark grey c l a y . 11 256 55 0-.6 organic brown l a y e r ; .6-9 l i g h t green-grey c l a y . 9-TD dark grey t o black . 12 247 59.5 0-1 brown, o x i c , w i t h worm tubes. 1-9 l i g h t grey-green c l a y ; 9-TD dark brown-grey c l a y . THORNBROUGH CHANNEL- 13,17.19,22,23 .26.29,31.33.35.39 13 95 20 few mm very t h i n o x i c top, l i g h t grey f l u f f . 0-6 l i g h t grey, abundant worm tubes (1mm diameter); o c c a s i o n a l s h e l l fragments up t o mm diameter. 6-TD homogeneous medium green-grey s i l t y c l a y . 17 131 30 few mm very t h i n o x i c l a y e r ; abundant worm tubes, organic fragments. 0-24 brown, grading t o dark grey s i l t y c l a y . 24-TD t r a n s i t i o n t o l i g h t grey c l a y . 19 168 62 0-~5 l i g h t brown o x i c top, worm tubes medium abundant. "5-30 grading i n t o dark grey-green s i l t y c l a y . "30-TD grades t o l i g h t e r grey. 340 CORE DEPTH(m) LENGTH(cm)INTERVAL DESCRIPTION 22 205 42 0-2 pale brown green; heavily bioturbated; grading to 2-7 grading area from pale brown-green 7-30 to dark grey; black specks to 20 cm. Wood f ragme nt s c ommon. 30-TD l i g h t grey-green clay. 23 214 42 0-1 pale brown top; 1-4 l i g h t brown; 4-15 dark grey; black specks common; 15-30 worm burrows;bioturbated layer of gravel and wood chips from 6-8 cm. 30-TD l i g h t grey-green clay. 26 223 42.5 0-1.5 dark grey-green; organic fragments. 1.5-4 l i g h t grey-brown-green; watery 4-34 dark grey; black specks; bioturbated. 34-TD l i g h t grey cl a y . 29 2 34 57 few mm brown f l u f f y organic material; ~0-TD dark green-grey homogeneous mud with black specks and organic fragments; heavily bio-turbated; worm i n 8 mm burrow @ 45 cm. 33 234 62.5 few mm brown f l u f f y organic layer; ~0-TD dark green-grey homogeneous mud; black specks throughout; worm at 6 cm; urchin at 5 cm. 31 229 62 0-0.5 brown f l u f f ; .5-1.5 black (organic) layer. 1.5-TD dark grey-green mud with black specks as above; worm burrows. 341 CORE DEPTH (m) LENGTH (cm) INTERVAL DESCRIPTION 35 227 57 0- 1 1- TD brown organic f l u f f , dark grey-green mud, as above; w i t h b l a c k specks; a l l c l a y (no s i l t ) ; worm burrow t o 20 cm; some small organism at 50 cm. 39 227 58 0- ~ l 1- TD brown organic f l u f f , l i g h t green-grey c l a y w i t h black specks gra-ding t o dark greenish grey mud; sand d o l l a r (3.5 cm diam) @ 2-4 cm; 2 worms i n tubes t o 20 cm. MAIN CHANNEL FROM BOWYER ISLAND TO ANVIL ISLAND -7.10.12.16.16B.18.20.21. 22B.24.25.82 CORE DEPTH(m) LENGTH(cm)INTERVAL DESCRIPTION 242 59.5 10 240 53 12 247 59.5 16 241 '60 16B 249 70 0- 1 brown, o x i c w i t h worm tubes. 1- 8 l i g h t grey-green c l a y . 8- TD dark charcoal-grey c l a y . 0- 1 l i g h t brown organic m a t e r i a l . 1- 7 l i g h t grey-green c l a y , grading t o 7-TD dark charcoal-grey muddy c l a y w i t h black specks. 0- 1 brown, o x i c l a y e r w i t h worm tubes; 1- 9 l i g h t grey-green c l a y ; 9- TD dark c h a r c o a l grey c l a y . 0-2 brown organic l a y e r . 2- TD l i g h t t o dark grey c l a y . 0- 1 chocolate brown ooze. 1- 10 brownish green, b i o t u r b a t e d . 10- 25 medium green-grey w i t h black specks; some d i s c o l o r a t i o n . 342 CORE DEPTH(m) LENGTH(cm)INTERVAL DESCRIPTION 25-TD uniformly dark green grey; 2 worm burrows t o 25 cm; worm burrow w i t h brown o x i d i z e d m a t e r i a l t o TD. 18 249 35 0-1 brown, organic f l u f f . 1-5 l i g h t green-grey c l a y . 5-TD dark grey clayey mud; worm burrows t o 18 cm and 35 cm. 20 245 70 0 - ~ l l i g h t brown organic top l a y e r . 1- 7 l i g h t grey-green c l a y , grading t o . . . 7-TD dark grey c l a y ; worm i n burrow t o 13 cm. 21 247 >50 0-2 brown o r g a n i c - r i c h top. 2- TD l i g h t t o dark gray-green c l a y ; worm i n burrow t o 14.5 cm; another @ "50 cm. 22B 242 56 0-2 l i g h t brown ooze w i t h worm tubes s t i c k i n g out. 2-10 l i g h t green grey, grading t o dark green grey c l a y ; worms at "10 cm. 24 241 55 0-.5 l i g h t brown f l u f f . .5-TD dark grey green c l a y (no l i g h t e r area on t o p ) ; worm burrow t o 8 cm. 25 238 "60 0-1 dark brown organic f l u f f . 1-TD dark grey-green c l a y t o TD; o x i c worm burrow at 10 cm. RAMILLIES CHANNEL - 24 , 27 . 30,32.36.40.49,49B 24 241 55 0->.5-2 l i g h t brown f l u f f . .2-TD dark grey-green c l a y ; no l i g h t e r area on top. 343 CORE DEPTH(m) LENGTH(cm)INTERVAL DESCRIPTION 27 230 "60 0-1 f a i r l y dark brown top, h e a v i l y b i o t u r b a t e d . 1-TD short area of l i g h t grey-green zone grading t o dark green-grey c l a y t o TD. 30 228 "60 0-1 darker top; h e a v i l y b i o t u r b a t e d . 1-6 l i g h t grey-green t r a n s i t i o n a l zone; 6- TD dark grey green zone t o TD. 32 219 "60 0-5 l i g h t brown organic zone o v e r l y i n g h e a v i l y b i o t u r b a t e d l i g h t grey-green c l a y ; 5-TD dark grey-green mud. 36 220 "60 0-1 l i g h t brown organic f l u f f . 1-7 l i g h t grey-green c l a y , grading t o . . . 7- TD dark grey-green mud. 40 210 "60 0-few mm same as above;heavily b i o t u r b a t e d surface zone. "0-TD no l i g h t grey zone; homogeneous dark grey green mud t o TD; "pin cushion" @ 4 cm. 49 180 "60 0-1 brown-grey f l u f f y top; 1-TD homogeneous dark grey-green c l a y ; organic fragments t o 10 cm; worm burrow t o 20 cm; top 2 cm h e a v i l y b i o t u r b a t e d . 49-B 198.2 60 0-.5 top brown-grey, f l u f f y ; •5-TD homogeneous c h a r c o a l grey muddy c l a y ; top 4 cm s l i g h t l y b i o t u r b a t e d ; black c h i p s , organic fragments i n top 2 cm; sc a t t e r e d b l ack specks to 10 cm. 344 MONTAGU CHANNEL - 22B.25.28,34,37.38 CORE DEPTH(m) LENGTH(cm)INTERVAL DESCRIPTION 22B 242 56 0-2 l i g h t brown ooze with worm tubes s t i c k i n g out. 2-10 l i g h t green-grey, grading to dark green grey; worm tubes to 10 cm. 25 238 "60 0-1 dark brown organic f l u f f . 1-TD dark grey-green clay to TD; oxic worm burrow at 10 cm. 28 223 "60 0-4 l i g h t brown organic layer. 4-TD dark green-grey clay; no worm holes; no wood chips. 34 174 "55 0-4 l i g h t brown organic layer. 4-TD dark green-grey clay; no l i g h t layer; 2 worm burrows to 2 0 cm & 22 cm. TD l i g h t grey layer @ bottom of core. 37 169 "30 0-1.5 oxic, brown layer; 1.5-TD dark grey-green clay, s i l t y near bottom of core. 38 154 "30 0-.5 thi n brownish grey top, grading to... .5-TD dark grey clay, homogeneous; worm burrows at surface; sediments very s i l t y to sandy - d i f f i c u l t to extrude. SOUTH OF SILL - 37.38,41.42,43,44,49,50,52,56.58 37 169 "30 0-1.5 oxic, brown layer; 1.5-TD dark grey-green clay, s i l t y near bottom of core. 345 CORE DEPTH (nil- LENGTH (cm) INTERVAL DESCRIPTION 38 154 "30 0-.5 t h i n brownish grey top, grading to... •5-TD dark grey clay, homogeneous; worm tubes at surface; sediments very s i l t y to sandy -d i f f i c u l t to extrude. 41 165 52 few mm t h i n organic layer, grey-brown. "0-1 bioturbated; worm burrows to 4 cm; wood chips at 2-4 cm. 1-TD homogeneous medium grey-green clay; pine needles, wood chips, black specks. 42 141 60 0-.25 t h i n grey-brown oxic layer. .25-TD dark grey-green; worm burrow to 34 cm; oxidized edges. 43 154 62 0-.1 thi n brown layer <1 mm. .1-TD uniform dark grey-green clay;bioturbated 0-4 cm. 44 175 55 0-.1 very t h i n brown top; .1-TD dark grey-green homogeneous clay; bioturbated to 7 cm; wood chips and organic fragments to 12 cm. 49 180 "60 0-1 brown-grey, f l u f f y top. 1-TD homogeneous dark grey-green clay; bioturbated to 2 cm; organic fragments to 10 cm; worm burrow to 2 0 cm. 50 183 60 0-.25 thi n brown f l u f f y top; .25-4 heavily bioturbated; 4-TD homogeneous dark grey-green clay; organic fragments and wood chips i n top 10 cm; worm hole at 9 cm. 346 CORE DEPTH(m) LENGTH(cm)INTERVAL DESCRIPTION 52 168 25 0-1 brown-grey organic l a y e r ; 1- TD l i g h t grey-green c l a y grading t o dark char-coal-grey below 6-7 cm. 56 155 20 0-5 loose tw i g s , leaves i n watery sediments; 5-TD dark green grey, loose, watery c l a y . 58 148 57 0-2 o r g a n i c - r i c h , b i o t u r -bated, w i t h worm tubes. 2- 22 medium grey-green c l a y . 22-TD dark green-grey c l a y . INNER BASIN - SILL AREA - 45.46,47.48.50B.51,53. 45 74 54 0-3 yel l o w brown l a y e r , loose, watery; 3-TD pale grey. 46 148 32 0-2 m u l t i c o l o r e d , l o o s e , watery. 2 t h i n b l a c k l a y e r ; 2- 12 l i g h t green grey c l a y ; worm burrow t o 9 cm. 12-TD c o l o r change t o dark grey. 47 128 30 0-1 yel l o w brown, loose f l u f f . 1-8 l i g h t grey, loose, watery; 8-TD dark grey, m e t a l l i c mud. 48 215 30 0-3 l i g h t yellow-grey, loose, watery; 3- 5 black , o r g a n i c - l o o k i n g l a y e r ; 5-15 l i g h t greenish-grey sediments; 15-TD dark charcoal-grey, m e t a l l i c - l o o k i n g . 347 CORE DEPTH(m) LENGTH(cm)INTERVAL DESCRIPTION 50B 102 45 0-4 l i g h t brown-green ooze. 4-35 dark t o medium grey clayey mud, grading 35-TD t o l i g h t grey c l a y @ 35 cm. 51 227 30 0-6 m u l t i c o l o r e d , loose watery ooze. 6 black l a y e r , very t h i n ; 6-9 l i g h t grey c l a y ; 9-TD dark grey m e t a l l i c sheen. 53 143 27 0-1 loose y e l l o w brown organic f l u f f ; 1-8 pale grey c l a y ; 8-TD d i s t i n c t c o l o r change to dark c h a r c o a l grey t o black; m e t a l l i c sheen, no g r i t t y f e e l . NB. core d i d not t r i p but c o l l e c -ted 27 cm anyway. 55 178 18 0-.5 .5-7.5 7.5-TD l i g h t yellow-brown f l u f f y top; medium greenish grey, dark grey t o black . FLOOR OF INNER BASIN S. OF BRITANNIA BEACH - 54.57.59.60-70,72-76,78. 54 274 30 0-4 4-14 14-TD m u l t i c o l o r e d (brownish ye l l o w , grey, b l a c k ) , loose, watery sludge, black t o dark grey, medium green-grey mud. 57 287 45 0-2 2-7 7-24 24-32 32-TD l i g h t yellow-brown, loose, watery, dark grey-brown mud; black mud; medium grey, grading t o l i g h t grey muddy c l a y . 59 288 66 0-3.5 3.5-7 7-44 4 4-TD loose, yellow-brown, grey, w i t h b l a c k chunks, medium grey-green, bla c k ; s l i g h t smell of H 2S; medium t o l i g h t grey. 348 CORE DEPTH(m) LENGTH(cm)INTERVAL DESCRIPTION 60 290 64.5 0-2 loose watery sludge. 2.5-3 t h i n black band. 3-7 l i g h t grey; 7-14 medium grey; 14-50 black " s l i m e s " , non-m e t a l l i c a t top, m e t a l l i c and dark grey at base; s l i g h t smell of H 2S. 61 290 60 0-5 l i g h t grey-green c l a y ; 5-10 medium grey muddy c l a y ; 10- 11 t h i n l a y e r of twigs and f i b r e s ; 11- 31 dark grey mud w i t h organic fragments throughout, grading t o 31-TD black mud; s l i g h t smell of at base of core. 62 290 75 0-5 m u l t i c o l o r e d banding -0-.5 medium-grey; .5-2 brown; 2-3 l i g h t grey t o cream; 3-4.5 black. 5- 13 medium grey w i t h brown banding. 13- 47 dark grey t o black . 47-TD medium t o dark grey. 63 234 28 0-6 brown, y e l l o w , w i t h black clumps; grey at base of i n t e r v a l . 6- TD dark grey t o bottom of core. 64 282 66 0-1 l i g h t brown ooze; 1-5 l i g h t grey-green; 5-14 dark grey; 14- 44 dark grey, s i l t y , w i t h l i g h t grey bands. 44-TD l i g h t grey; NB. bottom 10 cm f e l l out, d i s t u r b e d top. 349 CORE DEPTH(m) LENGTH(cm,INTERVAL DESCRIPTION 65 283 35 0-4 brown, l i g h t g r e y , l o o s e ; medium g r e y a t base g r a d i n g t o . . . 4-14 d a r k g r e y mud; 14-20 b l a c k mud; 20-TD l i g h t t o medium g r e y c l a y . 66 280 60 0-4 brown, g r e y , s l u d g y t o p . 4-14 medium gr e y c l a y e y mud; 14- TD d a r k g r e y t o b l a c k , s i l t y mud. 67 243 14 0-4 g r e y i s h brown o x i c l a y e r ; 4- TD medium g r e y muddy c l a y . 68 278 45 0-3 b r o w n i s h g r e y , w a t e r y t o p l a y e r . 3-TD medium gr e y mud, g r a d i n g t o d a r k g r e y a t 10 cm. 69 278 34 0-3 a l t e r n a t i n g bands o f brown, b l a c k , brown and cream (from t o p down); 3- 8 medium g r e e n - g r e y . 8-15 d a r k g r e y t o b l a c k . 15- TD medium g r e y ; (NB: e x c e l l e n t c o r e ; c l e a r s u p e r n a t a n t ; photos t a k e n ) . 70 275 35 0-1 l i g h t brown l a y e r ; 1-5 l i g h t g r e e n i s h g r e y ; 5- 13 medium g r e y ; 13-23 b l a c k ; 23-TD medium g r e y . V e r y c o a r s e sand i n medium gr e y mud m a t r i x ; c o r e would not e x t r u d e ; capped and f r o z e n as i s f o r l a t e r e x t r u s i o n . 71 272 44 0-4 brown-grey, soupy l a y e r ; 4- 4.5 b l a c k band; 4.5-TD medium g r e y mud g r a d i n g t o d a r k g r e y mud @ ~15 cm. 350 CORE DEPTH(m) LENGTH(cm)INTERVAL DESCRIPTION 72 271 16 0-.5 brown organic top; .5-1 cream-colored band; 1- 12 dark grey mud; 12-TD medium grey. 7 3 263 20 0-2 brown sludgy top. 2- 7 medium grey c l a y ; 7-9.5 black band; 9.5-15 dark grey mud; 15-TD medium grey, sandy, shiny. 74 265 25 0-.75 brownish grey organic f l u f f . .75-1 black band; 1-3 chocolate brown; 3- 3.5 cream-colored band; 3.5-7 l i g h t grey c l a y ; 7-18 dark grey t o bl a c k mud; 18-TD medium grey c l a y e y mud. 75 190 12 0-1 top l i g h t grey-brown ooze; 1-TD s i l t y above; very sandy at base; core would not extrude; d i v i d e d core i n t o 0-5, 5-10, and 10-12 cm s e c t i o n s . 76 256 22 0-1 brown, organic; 1- 2 cream-colored band; 2- 15 dark grey mud grading t o 15-TD medium grey slimy mud. 78 250 25 0-2 interbedded brown, black, cream-colored bands. 2-15 medium grey. 15-TD black t o dark grey mud. FLOOR OF INNER BASIN - N. OF BRITANNIA BEACH - 77. 79-93. 77 254 33 0-2 brown organic f l u f f ; t h i n cream-colored band at base of i n t e r v a l . 2-10 l i g h t grey w i t h abundant black f e c a l p e l l e t s (<.5 mm) . 10-28 dark grey t o blac k ; wood de b r i s at 20 cm. 351 CORE DEPTH(m) LENGTH(cm)INTERVAL DESCRIPTION 28-TD 79 245 32 few mm "0-2.5 2.5-3 3-7 7-9 9-20 20-TD 80 236 20 0-TD 81 234 41 0-.5 .5-5 5-14 14-30 30-41 82 223 40 0-5 5-20 20-TD 82B 240 48 few mm "0-7 medium grey; whole core very fine sandy and s i l t y . brown f l u f f ; l i g h t grey; black band; dark grey; black s t r i n g -er (organic material) at base of i n t e r v a l , l i g h t grey clay; dark grey to black mud; black, with abundant wood fragments to base of core. rocks, pebbles, wood chips etc. very sandy. Dumpsite; core recovered a f t e r 3 t r i e s ; could not extrude - frozen and thawed out i n lab upside down, which somewhat homogenized i t . brown f l u f f . l i g h t grey, with black band at base of i n t e r v a l medium grey. dark grey; black. greyish brown; loose, with organic fragments, black wood specks. l i g h t grey grading to dark grey; very fine sandy/silty. dark grey; very coarse sand i n black muddy matrix to TD. pale olive-brown ooze, l i g h t green grey; black layer (.5 cm thick) at middle (4.5 cm) of i n t e r v a l . 352 CORE DEPTH(m) LENGTH(cm)INTERVAL DESCRIPTION 7-17 l i g h t green grey f very f i n e s a n d y / s i l t y , grading t o medium t o dark grey mud; wood chips abundant. 17-31 black s i l t y mud. 31-TD bl a c k , f i n e r - g r a i n e d s i l t i n mud. 83 234 41 0-4.5 loo s e , grey-green, brown ooze; black band at base of i n t e r v a l ; 4.5-TD l i g h t t o medium grey, grading t o grey t o black; very f i n e sandy from 13 cm t o TD; organic f i b r e s and wood specks abundant. SQUAMISH DELTA - 84,85.86,87.88,89,90.91.93. 84 241 80 0-1 watery organic ooze. 1-TD a l l b l a c k ; bubbles from "20 cm down; wood chips at 14 cm t o depth. 85 224 45 0-2.5 yellow-brown organic ooze. 2.5-6 l i g h t grey; w i t h black lamina at base of i n t e r v a l . 6-14 l i g h t t o medium grey w i t h black laminae, grading t o dark grey. 14-TD wood chips and f i n e t o medium sand g r a i n s i n black muddy matrix 86 227 70 0-2 s o f t brown-grey ooze. 2-5-13 l i g h t grey, grading t o dark grey-black; wood chips and organic d e b r i s 6-13 cm. 13-TD black , (methanogenic?) -bubbles; m e t a l l i c , f i n e -grained muddy sand below 20 cm. A very c l e a r , undisturbed core. 353 CORE DEPTH(m) LENGTH(cm)INTERVAL DESCRIPTION 87 183 43 0-1 s o f t brown ooze, w i t h worm tubes s t i c k i n g out. I- 11 l i g h t grey, w i t h b l a c k specks ( f e c a l p e l l e t s ) ; worm burrows t o 4 cm. I I - 20 m e t a l l i c - l o o k i n g ( p y r i t e specks?). 20-29-TD black at 20 cm, t o medium grey, t o dark grey at 29 t o base. 88 214 35 0-.5 s o f t grey-brown ooze. .5-9 l i g h t grey w i t h 1 cm black band at 7-8 cm. 9-TD dark grey t o bl a c k , w i t h m e t a l l i c sheen and organic f i b r e s ; medium to dark grey, very f i n e sand (beach sand); s h e l l at 19-20 cm. 89 192 35 0-1 yellow-brown, s o f t ooze, wi t h worm tubes and f e c a l p e l l e t s 1-7 l i g h t grey w i t h b l a c k chunks and bands grading t o . . . 7-25 medium grey mud; embedded l a y e r of very f i n e - g r a i n e d "beach" sand at 15-16 cm. 25-TD dark grey mud; embedded worm at 33 cm. 90 165 4 0-4 very f i n e sand; s i l t y mud. 91 140 11 0-.5 brown-grey ooze. .5-TD very f i n e - g r a i n e d s i l t y mud, brownish grey w i t h p y r i t e specks; l e s s s i l t y towards base. 92 134 0 no recovery, unconsolidated sand. 93 157 7 few mm t h i n l a y e r l i g h t brown ooze. ~0-TD very f i n e sand, l i g h t brown. 354 APPENDIX III. Table A. Major elements i n surface sediments, Howe Sound, B.C., presented as wt.%. A l l values have been c o r r e c t e d for s a l t content Sample * S i XA1 *T1 %Fe *Ca *Mg %K SNa %? 1 27. 40 8 .03 0.49 5.24 2 27. 40 8 .22 0.48 5.16 3 24. 91 7 .32 0.41 4.88 4 25. 68 7 .64 0.44 5.01 4-B 25. 91 7 .64 0.46 5.04 5 25. 24 7 .47 0.41 5.01 5-B1 25. 76 7 .38 0.39 4.25 6 25. 29 7 .53 0.41 4.77 7 25. 74 7 .66 0.44 5.13 8 25. 38 7 .53 0.42 5.09 9 24. 69 7 .42 0.40 4.96 10 25. 75 7 .78 0.43 5.10 11 25. 35 7 .58 0.43 5.04 11-B 25. 23 7 .59 0.41 4.87 12 25. 24 7 .57 0.43 4.98 13 26. 31 7 .27 0.35 3.87 14 25. 01 7 .43 0.40 4.81 15 25. 70 7 .83 0.43 4.84 16 25. 58 7 .84 0.43 5.01 16-B 26. 66 8 .08 0.47 5.28 17 24. 33 7 .24 0.38 4.06 I S 25. 09 7 .63 0.41 4.93 19 23. 31 7 .09 0.38 4.22 20 25. 39 7 .71 0.42 5.04 21 25. 05 7 .58 0.41 4.92 22 21. 79 6 .50 0.35 3.91 22-B 25. 26 7 .75 0.41 4.92 23 23. 61 6 .89 0.35 4.09 24 24. 84 7 .58 0.41 4.86 25 25. 32 7 .86 0.42 4.96 26 23. 24 6 .95 0.37 4.09 27 25. 58 7 .91 0.42 5.01 28 24. 97 7 .82 0.41 5.03 29 24. 25 7 .41 0.38 4.49 30 24. 65 7 .71 0.40 4.88 31 23. 99 7 .37 0.38 4.61 32 25. 07 7 .90 0.41 4.92 33 23. 90 7 .36 0.39 4.61 1. 71 1.60 1 .71 0 .49 0.16 1. 66 1.72 1 .77 0 .40 0.16 1. 64 1.73 1 .69 2 .16 0.14 1. 62 1.81 1 .69 1 .89 0.16 1. 65 1.81 1 .64 1 .78 0.17 1. 70 1.91 1 .54 2 .34 0.15 2. 08 1.72 1 .42 2 .00 0.13 1. 85 1.93 1 .61 1 .92 0.16 1. 62 1.83 1 .61 1 .49 0.15 1. 65 1.88 1 .65 1 .54 0.15 1. 71 1.82 1 .68 1 .84 0.14 2. 17 1.89 1 .68 1 .89 0.14 1. 65 1.87 1 .73 1 .91 0.14 1. 69 1.84 1 .73 1 .79 0.13 1. 64 1.79 1 .70 2 .07 0.16 2. 54 1.65 1 .33 2 .54 0.14 1. 70 1.82 1 .69 1 .89 0.16 1. 80 2.03 1 .69 1 .16 0.12 1. 75 1.88 1 .61 1 .11 0.13 1. 66 1.90 1 .83 1 .74 0.15 2. 10 1.64 1 .31 2 .03 0.15 1. 70 1.82 1 .54 1 .65 0.14 2. 11 1.77 1 .29 2 .00 0.15 1. 75 1.85 1 .56 2 .25 0.14 1. 72 1.84 1 .50 1 .77 0.15 1. 95 1.58 1 .32 2 .18 0.16 2. 25 1.92 1 .64 1 .63 0.13 2. 22 1.69 1 .33 2 .15 0.13 1. 82 1.95 1 .63 2 .29 0.14 2. 01 1.89 1 .70 1 .90 0.15 2. 70 1.68 1 .35 1 .61 0.14 1. 94 1.94 1 .71 1 .70 0.14 2. 12 1.90 1 .77 2 .45 0.15 2. 30 1.87 1 .51 1 .63 0.13 2. 16 2.06 1 .58 2 .02 0.13 2. 03 2.12 1 .36 0 .82 0.14 2. 06 2.02 1 .57 1 .94 0.15 2. 13 1.91 1 .45 2 .34 0.13 contInued... 355 APPENDIX I I I . Table A. Major elements In surface sediments, Howe Sound (cont'd) Sample %Si Ul STi %Fe *Ca XMg %K *Na *P 34 25.44 8.22 0.43 5.10 2.23 1.96 1.58 1.69 0.17 35 24.37 7.64 0.39 4.80 2.16 2.07 1.59 2.51 0.14 36 25.08 7.97 0.40 4.90 2.16 1.98 1.58 2.07 0.15 37 25.13 8.06 0.41 4.76 2.92 1.94 1.69 2.40 0.15 38 25.99 8.41 0.42 4.50 2.43 1.93 1.71 2.58 0.12 39 24.93 7.74 0.41 4.71 2.13 1.95 1.62 2.72 0.13 40 25.12 8.16 0.42 4.80 2.16 2.03 1.58 2.37 0.12 41 25.37 8.49 0.42 4.88 2.40 2.00 1.54 2.35 0.17 42 25.66 8.51 0.42 4.83 2.39 1.99 1.68 2.71 0.13 44 24.76 8.41 0.42 4.84 2.35 1.96 1.54 2.44 0.14 45 26.00 8.71 0.42 4.78 2.72 2.11 1.62 2.69 0.14 46 25.42 8.47 0.41 4.76 2.55 2.05 1.55 1.75 0.16 47 25.47 8.35 0.40 4.80 2.61 1.98 1.70 2.88 0.16 48 24.90 8.35 0.40 4.52 3.40 1.92 1.66 2.75 0.16 49 25.79 8.31 0.42 4.91 2.33 1.97 1.72 2.27 0.17 49- B 25.17 8.11 0.41 4.81 2.16 1.97 1.69 2.15 0.17 50 25.50 8.43 0.42 4.92 2.35 1.95 1.74 2.50 0.16 50- B 26.16 8.80 0.44 4.65 2.68 2.12 1.77 2.64 0.13 51 25.94 8.60 0.41 4.59 2.67 1.87 1.68 2.59 0.14 52 28.09 9.20 0.45 5.62 2.56 2.23 1.91 3.25 0.21 53 25.47 8.56 0.41 4.94 2.71 2.05 1.68 2.30 0.16 54 27.32 9.26 0.42 4.67 3.20 1.96 1.55 2.95 0.15 55 26.26 8.79 0.42 4.56 2.55 1.99 1.78 2.93 0.12 57 25.53 8.59 0.42 4.79 2.91 1.99 1.62 2.65 0.19 58 25.27 8.28 0.41 4.86 2.42 1.95 1.62 2.56 0.20 59 25.08 8.37 0.39 4.70 2.87 1.96 1.59 2.88 0.18 60 25.92 8.71 0.40 4.59 2.99 1.91 1.49 2.41 0.16 61 25.96 8.65 0.41 4.64 3.08 1.93 1.60 2.93 0.17 62 25.16 8.62 0.40 4.67 2.80 2.01 1.51 2.73 0.18 63 25.83 8.57 0.40 4.42 2.59 1.89 1.57 2.52 0.14 64 26.51 8.87 0.41 4.86 3.07 2.00 1.91 3.05 0.15 66 25.06 8.57 0.40 4.53 3.01 1.93 1.58 2.86 0.18 67 26.15 8.41 0.39 4.84 2.46 2.05 1.68 1.82 0.12 68 25.26 8.56 0.41 4.53 3.11 1.99 1.58 2.89 0.14 69 24.87 8.43 0.39 4.45 2.97 1.95 1.54 2.31 0.19 70 25.94 8.45 0.42 4.88 2.91 1.97 1.71 2.33 0.20 71 26.09 8.32 0.38 4.76 2.75 1.93 1.53 2.69 0.16 72 25.50 8.87 0.39 4.47 3.25 1.94 1.53 3.06 0.14 cont inued... 356 APPENDIX I I I . Table A. Major elements In surface sediments, Howe Sound (cont'd). Sample *Si U l XTi %Fe *Ca *Mg *K %Na *P 73 25. 66 8 .74 0.40 4. 51 3.06 1 .95 1 .60 3. 02 0.16 74 25. 36 8 .50 0.39 4. 59 3.16 1 .90 1 .49 2. 56 0.18 75 26. 06 8 .16 0.38 5. 09 2.75 1 .90 1 .59 2. 60 0.13 76 25. 85 8 .74 0.40 4. 44 3.15 2 .01 1 .54 1. 10 0.15 77 25. 31 8 .52 0.38 4. 52 3.29 1 .84 1 .50 2. 68 0.20 78 26. 46 8 .53 0.39 4. 50 3.14 1 .90 1 .50 1. 46 0.14 79 25. 49 8 .71 0.39 4. 39 3.80 1 .98 1 .52 2. 50 0.16 80 26. 94 8 .83 0.40 4. 13 3.46 1 .78 1 .51 o i. . 76 0.12 81 25. 56 8 .63 0.38 4. 53 3.61 1 .89 1 .47 3. 28 0.18 82 24. 60 7 .41 0.30 3. 19 3.31 1 .21 1 .11 2. 73 0.10 82-B 25. 59 8 .69 0.41 4. 36 4.19 1 .86 1 .59 2. 70 0.14 83 25. 01 8 .34 0.38 4. 20 4.03 1 .77 1 .44 2. 96 0.14 84 23. 70 7 .61 0.35 3. 91 6.23 1 .64 1 .32 2. 66 0.10 85 25. 86 8 .84 0.40 4. 69 3.61 1 .88 1 .44 2. 95 0.19 86 23. 55 7 .76 0.35 4. 00 5.96 1 .66 1 .22 2. 79 0.16 87 26. 39 8 .53 0.39 4. 53 3.48 1 .80 1 .41 2. 92 0.16 88 25. 45 8 .48 0.39 4. 54 4.08 1 .75 1 .44 2. 97 0.18 89 26. 23 8 .70 0.39 4. 64 3.45 1 .77 1 .37 3. 06 0.17 90 27. 15 8 .75 0.40 4. 26 3.86 1 .87 1 .32 3. 12 0.12 91 27. 41 8 .73 0.40 4. IS 3.78 1 .69 1 .19 3. 09 0.13 93 28. 17 8 .77 0.37 4. 05 4.25 1 .68 1 .09 2. 51 0.12 357 APPENDIX I I I T a b l e B. Major element t o aluminum r a t i o s , s u r f a c e s e d i m e n t s , Howe Sound, B.C. A l l v a l u e s have been c o r r e c t e d f o r s e a s a l t . Ca i s p r e s e n t e d on a c a r b o n a t e - f r e e b a s i s . Lower b a s i n Sample^ U l S i / A I T i / A I F e / A l C a / A l Mg/Al K / A l Na/ A l P / A l 1 8.03 3.41 0.061 0.65 0.16 0.20 0.21 0.06 0.02 2 8.22 3.33 0.059 0.63 0.15 0.21 0.22 0.05 0.02 3 7.32 3.40 0.057 0.67 0.19 0.24 0.23 0.30 0.02 4 7.64 3.36 0.058 0.66 0.16 0.24 0.22 0.25 0.02 4- B 7.64 3.39 0.060 0.66 0.18 0.24 0.21 0.23 0.02 5 7.47 3.38 0.055 0.67 0.19 0.26 0.21 0.31 0.02 5- B 7.38 3.49 0.053 0.58 0.26 0.23 0.19 0.27 0.02 6 7.53 3.36 0.054 0.63 0.22 0.26 0.21 0.26 0.02 7 7.66 3.36 0.058 0.67 0,17 0.24 0.21 0.19 0.02 8 7.53 3.37 0.056 0.68 0.17 0.25 0.22 0.20 0.02 9 7.42 3.33 0.054 0.67 0.19 0.25 0.23 0.25 0.02 10 7.78 3.31 0.056 0.66 0.22 0.24 0.22 0.24 0.02 11 7.58 3.34 0.057 0.66 0.18 0.25 0.23 0.25 0.02 11-B 7.59 3.32 0.054 0.64 0.19 0.24 0.23 0.24 0.02 12 7.57 3.34 0.057 0.66 0.19 0.24 0.22 0.27 0.02 14 7.43 3.37 0.054 0.65 0.20 0.25 0.23 0.25 0.0 15 7.83 3.28 0.055 0.62 0.20 0.26 0.22 0.15 0.02 16 7.84 3.26 0.055 0.64 0.18 0.24 0.20 0.14 0.02 16-B 8.08 3.30 0.059 0.65 0.17 0.23 0.23 0.22 0.02 18 7.63 3.29 0.054 0.65 0.18 0.24 0.20 - 0.22 0.02 20 7.71 3.29 0.054 0.65 0.19 0.24 0.20 0.29 0.02 21 7.5S 3.30 0.054 0.65 0.18 0.24 0.20 0.23 0.02 22-B 7.75 3.26 0.053 0.64 0.20 0.25 0.21 0.21 0.02 24 7.58 3.28 0.054 0.64 0.21 0.26 0.21 0.30 0.02 25 7.86 3.22 0.053 0.63 0.21 0.24 0.22 0.24 0.02 27 7.91 3.23 0.053 0.63 0.21 0.24 0.22 0.21 0.02 28 7.82 3.19 0.053 0.64 0.23 0.24 0.23 0.31 0.02 30 7.71 3.20 0.051 0.63 0.23 0.27 0.20 0.26 0.02 31 7.37 3.25 0.051 0.63 0.24 0.29 0.18 0.11 0.02 32 7.90 3.17 0.052 0.62 0.23 0.26 0.20 0.25 0.02 33 7.36 3.25 0.052 0.63 0.25 0.26 0.20 0.32 0.02 34 8.22 3.09 0.052 0.62 0.26 0.24 0.19 0.21 0.02 35 7.64 3.19 0.051 0.63 0.23 0.27 0.21 0.33 0.02 36 7.97 3.15 0.050 0.61 0.25 0.25 0.20 0.26 0.02 39 7.74 3.22 0.053 0.61 0.24 0.25 0.21 0.35 0.02 40 8.16 3.08 0.051 0.59 0.25 0.25 0.19 0.29 0.02 49 8.31 3.10 0.051 0.59 0.27 0.24 0.21 0.27 0.02 49-B 8.11 3.10 0.050 0.59 0.25 0.24 0.21 0.27 0.02 Mean 7.73 3.28 0.054 0.64 0.21 0.25 0.21 0.24 0.02 cont i n u e d . . . 358 APPENDIX I I I . Table B (cont'd) Major element to aluminum ratios, surface sediments Howe Sound, B.C. Thornbrough Channel Sample XA1 Si/Al Tl/Al Fe/Al Ca/Al Mg/Al K/Al Na/Al P/Al 13 7.27 3.62 0.049 0.53 0.33 0.23 0.18 0.35 0.02 17 7.24 3.36 0.052 0.56 0.27 0.23 0.18 0.28 0.02 19 7.09 3.29 0.053 0.60 0.27 0.25 0.18 0.28 0.02 22 6.50 3.35 0.054 0.60 0.27 0.24 0.20 0.34 0.02 23 6.89 3.42 0.051 0.59 0.28 0.24 0.19 0.31 0.02 28 6.95 3.34 0.053 0.59 0.32 0.24 0.19 0.23 0.02 29 7.41 3.27 0.052 0.61 0.27 0.25 0.20 0.22 0.02 Mean 7.05 3.38 0.052 0.58 0.29 0.24 0.19 0.29 0.02 S i l l Sample XA1 Si/Al Ti/Al Fe/Al Ca/Al Mg/Al K/Al Na/Al P/Al 34 8. 22 3.09 0.052 0.62 0.26 0.24 0.19 0.21 0.02 37 8. 06 3.12 0.051 0.59 0.26 0.24 0.21 0.30 0.02 38 8. 41 3.09 0.050 0.54 0.27 0.23 0.20 0.31 0.01 41 8. 49 2.99 0.050 0.57 0.27 0.24 0.18 0.28 0.02 42 8. 51 3.02 0.050 0.57 0.27 0.23 0.20 0.32 0.01 44 8. 41 2.94 0.050 0.58 0.26 0.23 0.18 0.29 0.02 45 8. 71 2.99 0.048 0.55 0.31 0.24 0.19 0.31 0.02 46 8. 47 3.00 0.049 0.56 0.29 0.24 0.18 0.21 0.02 47 8. 35 3.05 0.048 0.58 0.31 0.24 0.20 0.34 0.02 48 8. 35 2.98 0.048 0.54 0.31 0.23 0.20 0.33 0.02 50 8. 43 3.02 0.050 0.58 0.27 0.23 0.21 0.30 0.02 50-B 8. 80 2.97 0.049 0.53 0.30 0.24 0.20 0.30 0.01 52 9. 20 3.05 0.049 0.61 0.27 0.24 0.21 0.35 0.02 53 8. 56 2.97 0.048 0.58 0.31 0.24 0.20 0.27 0.02 5S 8. 28 3.05 0.049 0.59 0.28 0.24 0.20 0.31 0.02 Mean 8. 48 3.02 0.049 0.57 0.30 0.24 0.20 0.29 0.02 cont inued... 359 APPENDIX I I I . T a b l e B ( c o n t ' d ) Major element to aluminum r a t i o s , s u rface sediments Howe Sound, B.C. Upper Basin Sample U l S i / A l T i / A l Fe/Al Ca/Al Mg/Al K/Al Na/Al P/Al 51 8.60 3.02 0.047 0.53 54 9.26 2.95 0.046 0.50 55 8.79 2.99 0.048 0.52 57 8.59 2.97 0.048 0.56 59 8.37 3.00 0.046 0.56 60 8.71 2.97 0.046 0.53 61 8.65 3.00 0.047 0.54 62 8.62 2.92 0.046 0.54 63 8.57 3.01 0.046 0.52 64 8.87 2.99 0.046 0.55 66 8.57 2.92 0.047 0.53 67 S.41 3.11 0.047 0.58 68 8.56 2.95 0.047 0.53 69 8.43 2.95 0.046 0.53 70 S.45 3.07 0.049 0.58 71 8.32 3.14 0.046 0.57 72 8.87 2.87 0.044 0.50 73 8.74 2.94 0.046 0.52 74 8.50 2.98 0.046 0.54 75 8.16 3.20 0.047 0.62 76 8.74 2.96 0.046 0.51 77 8.52 2.97 0.045 0.53 7S 8.53 3.10 0.046 0.53 73 8.71 2.93 0.045 0.50 80 8.83 3.05 0.045 0.47 81 8.63 2.96 0.044 0.53 82 7.41 3.32 0.040 0.43 82-B 8.69 2.95 0.048 0.50 83 8.34 3.00 0.045 0.50 0. 31 0.22 0.20 0. 30 0.02 0. 34 0.21 0.17 0. 32 0.02 0. 29 0.23 0.20 0. 33 0.01 0. 31 0.23 0.19 0. 31 0.02 0. 33 0.23 0.19 0. 34 0.02 0. 33 0.22 0.17 0. 28 0.02 0. 34 0.22 0.18 0. 34 0.02 0. 31 0.23 0.18 0. 32 0.02 0. 30 0.22 0.18 0. 29 0.02 0. 33 0.23 0.22 0. 34 0.02 0. 32 0.22 0.18 0. 33 0.02 0. 29 0.24 0.20 0. 22 0.01 0. 35 0.23 0.19 0. 34 0.02 0. 32 0.23 0.18 0. 27 0.02 0. 32 0.23 0.20 0. 28 0.02 0. 32 0.23 0.18 0. 32 0.02 0. 34 0.22 0.17 0. 34 0.02 0. 33 0.22 0.18 0. 35 0.02 0. 34 0.22 0.18 0. 30 0.02 0. 33 0.23 0.19 0. 32 0.02 0. 35 0.23 0.18 0. 13 0.02 0. 36 0.22 0.18 0. 32 0.02 0. 35 0.22 0.18 0. 17 0.02 0. 36 0.23 0.17 0. 29 0.02 0. 38 0.20 0.17 0. 31 0.01 0. 38 0.22 0.17 0. 38 0.02 0. 40 0.16 0.15 0. 37 0.01 0. 37 0.21 0.18 0. 31 0.02 0. 39 0.21 0.17 0. 36 0.02 Mean 8.57 3.01 0.046 0.53 0.34 0.22 0.18 0.31 0.02 Del t a Sample %M S i / A l T l / A l Fe/Al Ca/Al Mg/Al K/Al Na/Al P/Al 84 7.61 3.11 0.046 0.51 85 8.84 2.93 0.046 0.53 86 7.76 3.04 0.045 0.52 87 8.53 3.09 0.045 0.53 88 8.48 3.00 0.046 0.54 89 8.70 3.01 0.045 0.53 90 8.75 3.10 0.046 0.49 91 8.73 3.14 0.045 0.48 93 8.77 3.21 0.043 0.46 0.38 0.22 0. 17 0.35 0,01 0.39 0.21 0. 16 0.33 0.02 0.38 0.21 0. 16 0.36 0.02 0.40 0.21 0. 16 0.34 0.02 0.38 0.21 0. 17 0.35 0.02 0.38 0.20 0. 16 0.35 0.02 0.44 0.21 0. 15 0.36 0.01 0.43 0.19 0. 14 0.35 0.01 0.48 0.19 0. 12 0.29 0.01 Mean 8.46 3.07 0.045 0.51 0.41 0.21 0.16 0.34 0.02 360 APPENDIX I I I . Table C. Major element concentrations In Howe Sound core samples, presented as wt. per cent. A l l values corrected for salt content. Ca presented on a carbonate-free basis. Core No. Depth(cm) %Si U l %Ti %Fe %Ca %Mg *K XNa *P HS 16-B 0-1 26. 8.08 0. 47 5. 28 1 .38 1. 90 1 .83 1. 74 0. 15 1-2 no sample 2 4 2C. 9 8.25 0. 48 5. 21 1 .41 1. 98 1 .89 1. 92 0. 12 4-6 26. 4 8.03 0. 46 5. 21 1 .52 1. 96 1 .85 1. 89 0. 11 6 8 26. 3 7.99 0. 46 5. 12 1 .14 1. 91 1 .85 1. 85 0. 11 8-10 26. 7 8.22 0. 48 5. 21 1 .44 1. 97 1 .81 1. 88 0. 10 10-12 no sample 12-14 26. 3 8.08 0. 45 5. 20 1 .42 2. 00 1 .97 2. 03 0. 09 14-16 26. .8 8.24 0. 47 5. 29 1 .50 2. 03 1 .96 2. 06 0. 10 16-18 27. 0 8.51 0. 47 5. 14 1 .48 2. 11 2 .00 2. 22 0. 10 18-20 no sample 20 25 20. 9 8.39 0. 46 5. 28 1 .50 o i. . 05 2 .04 2. 00 0. 10 25-30 26. 8 8.43 0. 47 5. 25 1 .75 2. 03 2 .02 2. 05 0. 09 HS 64 0-1 26 .5 8.87 0. 41 4.86 2. 97 2. 00 1 .91 3. 05 0. 15 1-2 26 . 7 9.21 0. 44 4.73 3. 09 2. 09 1 .72 2. 86 0. 13 2-4 no sample 4-6 27 .3 8.93 0. 40 4.23 3. 63 1. 81 1 .48 3. 09 0. 13 6-8 26 .6 9.01 0. 43 4.54 3. 35 1. 90 1 .56 2. 91 0. 13 8-10 27 .7 8.82 0. 39 4.10 3. 68 1. 75 1 .37 2. 91 0. 12 10-12 28 .2 8.85 0. 38 4.01 3. 94 1. 58 1 .20 2. 89 0. 12 12-14 27 .5 8.78 0. 38 3.98 3. 36 1. 79 1 .35 2. 89 0. 12 14-16 26 .1 8.95 0. 43 4.95 2. 67 2. 21 1 .76 2. 48 0. 13 16-18 26 .6 8.72 0. 41 5.28 2. 39 2. 27 1 .86 2. 14 0. 16 18-20 no sample 20-25 27 .3 8.84 0. 40 5.21 2. 63 2. 23 1 .75 2. 54 0. 12 25-30 26 .6 8.68 0. 42 5.09 2. 48 2. 37 1 .80 2. 18 0. 10 361 APPENDIX I I I . Table E. Concentrations of minor elements in surface sediments, (0-2 cm), Howe Sound, B.C. Concentrations presented as ppm (ug/g). A l l values corrected for dilution by seasalt. Sample Ba Co Cr Cu Mn Ni Pb Rb Sr V Y Zn Zr 1 700 32 125 64 1368 50 38 71 230 189 23 140 122 2 678 37 124 58 1548 45 36 68 228 190 22 131 113 3 664 30 106 66 943 45 48 67 240 181 22 160 102 4 655 21 114 55 2508 42 35 67 234 187 22 128 108 4-B 629 26 114 61 1884 44 34 65 227 174 22 127 109 5 665 26 98 68 2663 46 42 66 264 177 20 171 97 5-B 626 22 80 76 766 36 38 52 316 142 23 140 104 6 658 23 93 83 837 45 44 63 302 158 23 166 102 7 658 27 113 67 2117 50 38 67 239 180 24 145 108 8 675 26 96 67 4873 46 41 64 249 177 23 164 102 9 759 25 108 81 1096 45 46 65 260 189 23 176 100 10 649 23 103 60 2404 45 32 63 247 173 23 131 107 11 653 50 103 56 3507 42 41 65 245 180 24 141 102 11-B 671 20 97 68 932 39 48 68 267 180 23 161 96 12 625 22 101 66 3371 44 39 69 259 175 21 147 105 13 628 18 73 73 809 26 31 45 415 135 23 117 119 14 700 25 95 81 827 42 46 65 272 182 22 163 94 15 712 20 96 86 846 44 49 65 274 181 "23 184 100 16 668 25 100 63 2557 41 37 68 252 191 22 147 104 16-B 672 28 102 63 3666 51 30 64 250 211 23 140 109 17 62S 27 74 81 854 28 40 50 317 157 21 132 94 IS 673 27 92 62 6216 34 32 62 261 190 20 138 97 39 706 25 81 92 954 27 44 53 308 185 19 147 88 20 635 20 92 65 5430 39 35 64 275 193 23 153 101 21 677 27 93 66 8288 43 41 68 287 193 23 152 102 22 644 28 78 96 1578 31 44 49 293 190 20 163 84 22-B 684 28 87 78 2964 44 38 66 304 188 21 169 101 23 639 30 73 89 4513 30 40 47 320 178 19 160 90 24 712 28 80 76 7706 37 41 60 294 182 19 161 97 25 650 29 85 75 5957 37 38 62 303 174 21 157 99 26 621 51 77 78 1698 24 40 48 310 183 21 144 105 27 687 32 79 84 4093 35 36 58 302 180 22 166 92 28 707 25 81 69 7745 33 37 58 332 174 21 146 95 29 665 46 75 93 5875 31 43 52 301 198 23 174 101 30 719 28 76 92 4430 37 42 61 330 184 19 187 94 31 675 35 66 100 8341 33 43 57 323 180 21 190 89 32 727 32 77 95 3330 40 42 61 340 173 20 185 97 33 675 29 68 93 7530 33 38 55 303 183 21 186 93 cont inued... 362 APPENDIX I I I . Table E. Concentrations of minor elements in surface sediments, Howe Sound, B.C. (cont'd). Sample Ba Co Cr Cu Mn Ni Pb Rb Sr V Y Zn Zr 34 796 32 70 102 2185 33 37 59 382 174 20 168 96 35 699 30 69 96 8369 36 39 56 331 182 21 192 93 36 723 24 71 99 4286 39 38 60 345 179 21 184 96 37 787 32 70 104 1150 33 36 55 381 170 19 165 97 38 839 24 64 137 1014 28 37 55 404 171 19 167 103 39 720 26 71 95 4106 35 35 56 323 182 21 181 94 40 751 33 70 110 1144 34 37 56 351 173 20 182 97 41 760 26 56 113 1476 32 32 55 401 163 19 168 97 42 800 29 67 127 1075 29 36 57 390 172 18 175 101 44 796 27 59 104 1229 28 36 56 394 166 19 163 95 45 927 24 47 152 1158 24 37 51 443 164 19 171 96 46 819 28 59 113 1019 21 31 54 418 165 16 142 90 47 873 25 54 125 1954 22 36 53 441 169 19 150 92 48 825 25 50 128 975 24 31 51 469 163 19 152 95 49 805 27 65 104 1274 31 35 56 388 164 18 162 93 49-B 788 21 70 89 1368 22 35 56 367 182 20 155 88 50 843 23 68 114 1218 34 40 58 413 177 20 179 95 50-B 840 29 50 138 1193 22 36 55 478 159 20 165 93 51 835 35 55 120 1019 21 34 55 472 165 20 152 85 52 792 20 64 101 1103 24 35 58 420 172 19 151 86 53 836 27 51 128 1062 22 34 54 474 164 19 157 93 54 856 21 46 83 1197 16 21 44 539 163 20 121 97 55 884 19 51 161 1013 21 37 52 441 174 19 175 95 56 405 73 30 34 477 7 25 21 291 95 10 56 70 57 771 26 45 110 3371 24 26 48 501 173 18 147 95 58 74G o o i. o 63 93 1127 22 34 54 419 166 17 144 94 59 788 34 42 104 3947 23 26 50 497 162 18 144 93 60 837 26 46 98 1381 23 20 45 511 158 19 136 104 61 745 35 45 89 1840 21 24 43 497 146 18 128 96 62 824 35 45 116 6850 24 27 49 501 157 17 153 97 63 816 22 50 134 992 21 28 50 450 159 20 152 97 64 882 27 44 84 2465 23 13 45 506 202 19 117 85 65 761 30 38 127 3848 18 21 42 561 152 19 127 103 66 799 33 46 103 10256 18 24 47 542 169 18 138 90 67 1054 15 55 245 1060 18 42 48 413 150 15 208 98 68 750 43 37 117 12486 20 22 46 542 144 17 137 101 69 821 39 46 100 6539 21 20 49 583 165 20 144 93 cont inued... 363 APPENDIX I I I . T a b l e E. C o n c e n t r a t i o n s of minor e l e m e n t s i n s u r f a c e s e d i m e n t s . Howe Sound, B.C. ( c o n t ' d ) . Sample Ba Co Cr Cu Mn N i Pb Rb Sr V Y Zn Zr 70 816 28 39 148 2147 25 21 44 469 188 19 142 91 71 1111 20 45 299 1049 18 55 53 430 157 22 284 104 72 830 53 44 117 3677 27 19 45 545 170 18 144 103 73 811 30 41 146 2005 26 27 46 523 158 17 153 105 74 777 37 45 120 2712 21 21 44 519 157 17 141 101 75 882 30 54 316 1018 28 31 42 451 161 19 211 109 76 781 41 38 115 1749 23 20 44 527 150 18 142 105 77 809 41 39 120 5258 28 19 42 535 166 18 135 107 78 S76 26 45 180 1118 26 25 39 509 159 17 169 111 79 810 28 47 124 2070 25 19 42 535 162 17 131 108 SO 79S 45 35 74 1050 22 10 37 532 181 18 95 102 81 807 38 46 98 1717 20 16 39 531 157 17 118 104 82 642 49 35 76 1108 17 16 24 493 121 17 97 122 8 2 B 768 21 38 97 1509 23 15 40 534 195 19 103 87 83 755 30 47 91 1258 19 20 37 526 149 17 117 103 84 726 32 55 144 950 25 26 36 500 138 17 130 108 85 830 32 47 100 1907 23 22 39 565 161 18 122 109 86 704 26 50 123 967 21 21 37 530 139 18 122 102 87 745 33 43 85 1000 20 18 35 574 149 ' 19 112 119 SS 723 27 45 100 1018 24 18 36 558 142 19 119 103 89 752 23 42 86 1097 18 15 34 567 144 18 114 114 90 732 28 39 69 997 21 12 31 618 141 20 97 129 91 655 25 35 62 921 24 17 28 606 141 20 99 138 93 667 38 41 53 910 21 14 25 648 141 19 85 148 364 APPENDIX I I I . Table F. Concentrations of minor elements w i t h depth i n Cores 16-B and 64, Howe Sound, B.C. Concentrations presented as ppm (ug/g). A l l values c o r r e c t e d for d i l u t i o n by s e a s a l t . Core No. Marker Depth(cm) Depth Ba Co Cr Cu Mn Ni Pb Rb Sr V Y Zn Zr HS 16-B 0-1 0.5 672 28 102 63 3666 51 30 64 250 211 23 140 109 1-2 1.5 733 40 110 67 1684 49 30 66 243 220 24 142 109 2-4 3 705 27 100 68 1627 51 28 66 242 223 24 145 110 4-6 5 672 38 99 71 1418 53 32 67 239 215 24 152 111 6-8 7 684 20 102 71 1309 52 29 68 240 218 22 154 110 8-10 9 699 27 99 76 1191 54 35 68 249 219 26 165 109 12-14 13 826 27 109 80 1277 50 32 67 246 237 23 166 108 14-16 15 756 30 99 81 1169 50 31 67 242 222 24 171 109 16-18 17 718 25 98 95 1230 51 27 71 251 214 o o U sJ 162 108 18-20 19 72S 16 94 87 1289 48 27 70 246 221 24 150 104 20-25 22.5 701 24 91 84 1267 45 24 70 251 215 21 140 104 25-SO 27. S 727 26 93 81 1288 48 20 69 259 229 21 120 104 Mean 718 27 100 77 1535 50 29 68 246 220 23 151 108 Std.Dev 41 6 6 9 661 2 4 2 6 7 1 14 2 HS 64 Marker Depth(cm) Depth Ba Co Cr Cu Mn Ni Pb Rb Sr V Y Zn Zr 0- 1 1- 2 2- 4 4-6 6-8 8-10 10-12 12-14 14-16 16-18 18-20 20-25 25-30 0.5 1.5 3 5 7 9 11 13 15 22.5 882 786 717 710 777 753 657 720 883 17 1150 19 1174 1148 L 1 21 44 37 23 35 30 31 20 36 26 37 36 33 33 35 36 37 30 39 22 36 16 42 27.5 1200 27 36 84 2465 73 1409 54 1077 57 1029 78 1117 61 l l l l 58 1030 77 2831 166 3777 308 2982 310 1933 285 1910 359 1448 23 13 23 14 21 9 21 12 21 12 17 13 19 9 20 15 28 23 25 34 25 34 23 38 25 54 45 506 43 516 32 578 33 566 38 540 30 588 26 586 33 566 49 466 48 417 45 420 46 447 48 428 202 19 188 19 174 IS 170 19 183 19 176 18 161 21 165 20 194 19 194 20 197 20 202 20 192 20 117 83 109 8S 87 104 87 97 102 94 S7 101 82 113 98 94 164 92 254 104 319 105 322 102 408 99 Mean Std.Dev. l l l l 26 38 286 2410 115 7 2 64 849 25 37 47 436 196 20 293 100 1 10 1 18 4 0 81 5 365 APPENDIX I I I . T a b l e G. C o n c e n t r a t i o n s of minor e l e m e n t s w i t h d e p t h i n c o r e s 70, 80, and 82-B, Howe Sound, B.C. C o n c e n t r a t i o n s p r e s e n t e d as ppm ( u g / g ) . A l l v a l u e s c o r r e c t e d f o r d i l u t i o n by s e a s a l t . Core No. Depth (cm) Ba Co Cr Cu Mn Ni Pb Rb Sr V Y Zn Zr HS 70 0-1 816 28 39 148 2147 25 21 44 469 188 19 142 91 1-2 831 26 41 136 2065 27 18 45 472 194 20 138 89 2-4 829 37 37 110 1379 23 17 43 502 182 20 126 97 4-6 845 36 37 90 1133 22 13 39 531 184 19 109 94 6-8 817 34 39 178 1391 27 21 44 470 182 21 144 91 8-10 873 42 38 148 1731 24 20 46 476 194 19 151 90 10-15 861 20 38 140 1396 24 17 46 471 191 17 141 94 15-20 800 34 34 82 970 23 13 44 445 158 17 115 94 KS 80 0-1 79S 45 35 74 1020 22 10 37 532 182 18 95 103 1-2 763 22 33 47 980 IS 10 31 565 151 15 79 101 2-4 731 43 34 45 965 18 7 32 542 158 18 79 98 4-6 757 43 31 60 933 19 12 35 523 158 19 90 102 6-8 751 26 32 78 976 20 11 34 539 163 18 95 91 S-10 712 25 22 54 819 19 8 29 551 ' 135 15 73 92 10-15 702 45 31 54 880 16 6 29 553 145 16 70 90 HS 82-B 0-2 768 21 38 97 1509 23 15 40 534 195 19 103 87 2-4 S3S 16 39 95 1679 24 14 42 539 197 19 106 89 4-6 799 22 36 58 1130 22 8 35 594 186 19 95 102 6-8 671 16 36 36 925 19 6 23 628 165 18 65 127 8-10 715 8 35 48 9CG 21 7 28 610 164 19 80 121 10-15 712 22 36 64 1019 23 14 32 591 179 19 97 110 15-20 679 24 34 43 910 19 7 27 624 153 16 71 102 20-25 659 26 30 43 865 19 9 23 617 154 18 67 113 25-30 810 17 41 84 1104 19 12 38 526 177 18 101 100 30-35 800 14 39 98 1043 23 11 42 509 179 17 113 88 35-40 720 23 32 78 949 18 11 36 465 158 17 94 87 40-41 803 18 38 136 1045 22 13 40 526 174 20 121 94 366 APPENDIX I I I . T a b l e H. Carbon and n i t r o g e n abundances i n Howe Sound s u r f a c e s e d i m e n t s . Samples a r e grouped by r e g i o n . Lower B a s i n *C %C Sample T o t a l C a r b o n a t e O r g a n i c T o t a l C/N C/N M o l a r 1 2.02 0.11 1.91 0.16 11.60 13.49 2 2.12 0.13 1.99 0.17 11.43 13.29 3 2.46 0.08 2.38 0.21 11.24 13.06 4 2.02 0.11 1.91 0.32 6.04 7.02 4B 2.95 0.08 2.88 0.14 20.35 23.66 5 2.48 0.09 2.40 0.26 9.35 10.87 5B 3.91 0.05 3.86 0.25 15.20 17.67 6 3.39 0.06 3.33 0.22 15.20 17.67 7 1.94 0.10 1.84 0.14 12.71 14.78 S 2.32 0.10 2.22 0.18 12.35 14.35 9 2.79 0.09 2.69 0.22 12.39 14.40 10 1.88 0.14 1.74 0.12 14.08 16.37 11 2.21 0.09 2.11 0.19 11.08 12.87 11-B 2.79 0.08 2.71 0.20 13.50 15.69 12 2.41 0.0.7 2.34 0.16 14.97 17.40 13 3.88 0.03 3.85 0.21 18.68 21.71 14 2.81 0.06 2.75 0.21 12.90 14.99 15 2.73 0.08 2.65 0.18 15.06 17.50 16 2.06 0.10 1.95 0.15 13.37 15.54 16-B 1.88 0.09 1.80 0.17 10.69 12.43 18 2.04 0.10 1.94 0.15 12.87 15.00 20 2.06 0.08 1.98 0.16 12.59 14.60 21 2.12 0.10 2.02 0.16 12.82 14.90 22-B 2.17 0.21 1.97 0.15 13.16 15.30 24 2.24 0.08 2.16 0.19 11.63 13.50 25 2.18 0.11 2.07 0.18 11.38 13.20 27 2.29 0.08 2.21 0.18 12.36 14.40 28 1.99 0.10 1.88 0.18 10.75 12.50 30 2.37 0.11 2.26 0.18 12.87 15.00 31 3.53 0.07 3.45 0.22 15.75 18.30 32 2.07 0.06 2.01 0.15 13.04 15.16 33 3.41 0.09 3.32 0.19 17.02 19.79 34 1.72 0.04 1.69 0.16 10.31 11.98 35 2.95 0.12 2.83 0.22 12.89 14.99 36 2.32 0.06 2.26 0.17 13.00 15.11 39 2.47 0.07 2.40 0.17 13.85 16.10 40 2.03 0.04 1.98 0.15 12.87 15.00 49 1.81 0.04 1.78 0.16 11.42 13.30 49-B 1.94 0.04 1.90 0.16 12.00 13.90 Mean 2.43 0.09 2.34 0.18 12.94 15.05 cont i n u e d . . . 367 APPENDIX I I I . Table H (cont'd) Carbon and nitrogen abundances in Howe Sound Thornbrough Channel XC XC XC XN Sample Total Carbonate Organic Total C/N C/N Molar 13 3.88 0.03 3.85 0.21 18.68 21.70 17 5.57 0.04 5.53 0.23 23.83 27.70 19 6.74 0.05 6.69 0.27 25.08 29.20 22 9.28 0.06 9.22 0.36 25.88 30.10 23 5.98 0.09 5.90 0.24 24.50 28.50 26 6.67 0.15 6.52 0.26 24.88 28.90 29 4.28 0.09 4.19 0.21 19.72 22.90 Mean 6.06 0.07 5.99 0.25 23.22 27.00 S i l l XC XC XC XN Sample Total Carbonat e Organic Total C/N C/N Molar 34 37 38 41 A O t i, 44 45 4C 47 48 50 50 B 52 c n \Js3 56 58 1.72 1.93 1.54 1.71 1.41 1.64 1.33 1.70 1.69 1.87 79 38 89 1.53 22.15 3.14 0.04 0.24 0.04 0.03 0.03 0.04 0.02 0.03 0.02 0.23 0.03 0.01 0.03 0.03 0.01 0.03 1.69 68 51 68 38 1.60 31 67 0.16 0.13 0.13 0.14 0.11 0.13 0.10 0.15 1.67 1.64 1.76 1.37 1.86 1.50 22.14 3.12 0. 0. 0. 0. 0. 0. 0. 0. 10 13 13 09 13 09 44 15 10.31 12.97 11.93 11.87 12.10 11.-89 12.79 11.38 16.65 13.12 13.12 14.45 14.24 1C.35 50.24 20.31 12.00 15.10 13.90 13.80 14.10 13.80 14.90 13.20 19.40 15.30 15.20 16.80 16.60 19.00 58.40 23.60 Mean 3.03 0.05 2.97 0.15 15.86 18.44 cont inued 368 APPENDIX I I I . Table II (cont'd) Carbon and nitrogen abundances in Howe Sound Upper Basin %C %C %C Sample Total Carbonate Organic Total C/N C/N Molar 51 1.62 0.01 1.60 0.13 11.88 13.80 54 1.13 0.02 1.11 0.09 12.74 14.80 55 1.40 0.01 1.39 0.09 15.06 17.50 57 1.75 0.08 1.67 0.10 16.33 19.00 59 1.50 0.04 1.46 0.10 14.98 17.41 60 1.35 0.03 1.32 0.11 12.52 14.55 61 1.43 0.04 1.39 0.10 13.76 16.00 62 1.62 0.05 1.57 0.11 14.38 16.71 63 1.65 0.02 1.63 0.11 15.41 17.92 64 1.14 0.03 1.11 0.08 14.65 17.03 65 1.25 0.04 1.21 0.10 12.40 14.40 66 1.43 0.07 1.37 0.11 12.43 14.45 67 1.25 0.01 1.24 0.08 16.04 18.65 68 1.19 0.04 1.15 0.07 17.00 19.76 69 1.45 0.07 1.39 0.09 15.43 17.94 70 1.75 0.05 1.69 0.12 14.69 17.08 71 1.51 0.02 1.49 0.09 16.50 19.18 72 1.19 0.08 1.12 0.07 15.64 18.18 73 1.28 0.05 1.24 0.07 16.59 19.28 74 1.48 0.07 1.41 0.09 16.37 19.03 75 1.40 0.02 1.38 0.0S 17.60 20.46 76 1.26 0.02 1.24 0.07 17.80 20.69 77 1.61 0.08 1.53 0.09 17.77 20.66 78 1.30 0.04 1.26 0.09 13.81 16.06 79 1.69 0.20 1.48 0.08 19.14 22.10 80 1.91 0.04 1.87 0.07 28.45 33.10 81 2.36 0.10 2.26 0.08 27.16 31.60 82 6.47 0.10 6.37 0.08 75.67 88.00 82-B 1.84 0.29 1.55 0.08 18.66 21.70 83 2.93 0.23 2.70 0.09 29. S4 34.70 Mean 1.70 0.07 1.64 0.09 18.69 21.72 Delta %C %C %c XN Sample Total Carbonate Organic Total C/N C/N Molar 84 3.97 0.99 2.98 0.09 33.54 39.00 85 1.20 0.04 1.15 0.06 19.93 23.20 86 3.58 0.90 2.69 0.11 25.05 29.10 87 1.04 0.03 1.01 0.06 18.02 20.90 88 1.84 0.25 1.59 0.07 21.46 25.00 89 1.18 0.03 1.15 0.06 20.24 23.50 90 0.45 0.01 0.44 0.02 18.14 21.10 91 0.97 0.01 0.96 0.04 22.69 26.40 93 0.69 0.01 0.68 Mean 1.66 0.25 1.40 0.06 22.38 26.03 369 APPENDIX I I I . T a b l e I . T o t a l , o r g a n i c , and c a r b o n a t e c a r b o n , and t o t a l n i t r o g e n i n Cores HS 16-B and HS 64, Howe Sound, B.C. A l l v a l u e s a r e c o r r e c t e d f o r d i l u t i o n by s e a s a l t . Core No. Marker XC XC XC XN C/N Depth(cm) Depth T o t a l C arbonat e O r g a n i c T o t a l ( M o l a r ) HS 16-B 0-1 0.5 1.88 0.09 1.80 0.17 12.5 1-2 1.5 1.89 0.09 1.80 0.17 12.6 2-4 3 1.87 0.09 1.78 0.16 13.1 4-6 5 1.75 0.05 1.70 0.15 12.8 6-8 7 1.72 0.15 1.56 0.16 11.6 8-10 9 1.61 0.09 1.53 0.13 13.6 12-14 13 1.56 0.09 1.47 0.12 14.3 14-16 15 1.49 0.07 1.42 0.13 13.1 16-18 17 1.40 0.07 1.33 0.11 13.5 18-20 19 1.38 0.07 1.30 0.11 13.5 20-25 22.5 1.26 0.07 1.19 0.11 13.1 25-30 27.5 1.12 0.02 1.10 0.10 12.3 HS 64 0-1 0.5 1.14 0.03 1.11 0.08 17.1 1-2 1.5 0.86 0.01 0.85 0.05 20.1 2-4 3 0.54 0.02 0.52 0.02 24.8 4-6 5 0.60 0.02 0.58 0.04 18.4 6-8 7 0.84 0.03 0.81 0.04 22.6 8-10 9 0.60 0.06 0.54 0.03 23.8 10-12 11 0.45 0.03 0.41 0.03 17.4 12-14 13 0.74 0.06 0.68 0.03 24.0 14-16 15 1.14 0.05 1.08 0.06 21.9 16-18 17 0.87 0.04 0.83 0.04 21.9 18-20 19 0.77 0.02 0.74 0.03 26.5 20-25 22.5 0.74 0.02 0.71 0.04 20.0 25-30 27.5 0.60 0.02 0.58 0.04 16.6 370 APPENDIX I I I . T a b l e J . T o t a l , o r g a n i c , and c a r b o n a t e c a r b o n , and t o t a l n i t r o g e n i n Cores 70, 80 and 82-B, Howe Sound, B.C. A l l v a l u e s a r e c o r r e c t e d f o r d i l u t i o n by s e a s a l t . Core No. %C %C %C %N C/N Depth(cm) T o t a l C a r b o n a t e O r g a n i c T o t a l ( M o l a r ) HS 70 0-1 1.75 0.05 1.69 0.12 17.1 1-2 1.60 0.05 1.55 0.10 17.3 2-4 1.20 0.03 1.17 0.08 17.5 4-6 0.94 0.03 0.91 0.05 23.0 6-8 1.43 0.05 1.38 0.11 14.7 8-10 1.37 0.04 1.32 0.09 17.2 10-15 1.09 0.08 1.01 0.06 18.4 15-20 0.80 0.02 0.78 0.04 25.3 IIS so 0-1 1.91 0.04 1.87 0.07 33.2 1-2 1.98 0.13 1.86 0.02 92.6 2-4 1.11 0.47 0.63 0.03 28.0 4-6 0.99 0.04 0.95 0.04 20.2 6-S 1.17 0.06 1.11 0.03 37.3 8-10 1.60 0.01 1.59 0.03 53.7 10-15 2.05 0.01 2.04 0.01 78.1 HS 82-B 0-2 1.84 0.29 1.55 0.08 21.8 2-4 1.45 0.19 1.26 0.08 19.3 4-6 0.64 0.02 0.63 0.03 21.8 6-8 0.31 0.02 0.29 0.01 25.9 8-10 0.36 0.02 0.35 0.02 22.0 10-15 1.12 0.07 1.05 0.04 30.9 15-20 0.68 0.04 0.64 0.03 27.2 20-25 0.32 0.04 0.28 0.02 17.8 25-30 1.80 0.28 1.52 0.06 32.3 30-35 1.91 0.17 1.73 0.07 30.8 35-40 2.91 0.22 2.69 0.04 73.4 40-41 1.45 0.13 1.32 0.04 37.0 371 APPENDIX I I I . Table K. Nutrients and a lka l in i ty in porewater, Core HS 16-B, Lower basin. Depth [NH3], uM [P04], [S04], TA 0.25 72.5 6.63 I .S. I .S. 0.75 104.6 I .S. I .S. I .S. 1. 5 139.6 18 . 49 27 . 59 3. 41 2.5 179.8 28.73 I ,S. I .S. 3.5 209.3 31. 97 27.41 3. 49 4.5 230.7 44.90 25.51 3.65 5.5 305.9 55.14 21. 89 4. 46 6 . 5 335 . 4 I .S. 22.01 4.33 8 394. 4 42. 72 22. 69 4.19 10 456.1 44.66 23.83 3.84 12 517.8 42. 72 22.11 3.86 14 601 .0 57.16 23.71 4.00 16.5 665. 3 45. 52 25.53 4.14 19 . 5 737 . 7 39. 59 25 . 64 4. 30 22.5 775.3 38 . 41 26.02 4. 43 25.5 831 . 6 41. 32 26 . 42 4. 64 28 . 5 826.2 34. 42 25.14 4. 46 31. 5 863.8 33 . 88 27.26 4.65 34.5 810.1 30. 32 26. 37 4.56 37 .5 879.9 29 . 91 25. 34 4.78 41 925.4 28.15 25.41 4.90 45 938.8 27.56 24. 56 4.90 I.S. = insufficient sample 372 APPENDIX I I I . Table L . Nutrients and a lka l in i ty in porewaters, Core # HS 64, Inner basin. Depth [NH3],uM [P04],uM [S04], mM TA 0.4 27 .7 9.87 26.2 2.74 1.2 44. 1 13.11 24.1 3.10 2.2 73.9 16. 36 24.5 3.42 3.2 79.5 19.11 25.2 3. 68 4.2 117 . 5 73. 96 24.1 4.43 5.2 109 . 3 94. 41 25 .1 4.44 6.2 171 . 9 113.85 25.6 5. 06 7.2 169.2 130.56 23. 9 4.89 8.6 191.0 135.51 25.9 5.03 10.6 207 . 3 132.31 24. 4 4.61 12.6 226.4 125.82 24.1 5.00 14.6 267 . 2 124.32 24.7 5. 42 16.6 297 .1 133.05 23.4 6.06 18.8 346.1 30. 07 22.9 7 .68 20. 6 403.2 29. 57 20 7 . 95 22 . 6 24. 6 555.6 60. 49 16. 5 10. 45 26.6 615.4 42.29 19.8 11.58 28.6 678.0 9.62 15.1 9.81 30.6 789 . 6 33 . 56 17 . 7 13.21 32.6 835. 8 32.81 17 . 5 8.38 35.1 914.7 49.02 16.6 13.91 37 . 6 901.1 30. 32 I .S. I .S. 39.6 1012.7 29. 32 16.1 17 . 42 I .S. = insufficient sample 373 APPENDIX I I I . T a b l e M. D i s s o l v e d t r a c e m e t a l d a t a from HS 16-B Depth Fe(uM) Mn(uM) Cu(nM) Pb(nM) Zn(nM) 0. 25 2.33 129 215 0.6 32480 0.75 2.08 249 54 1.7 780 1.5 2. 36 320 13 0.6 240 2.5 6.73 327 21 0.7 51 3 . 5 2.54 356 49 0.6 44 4.5 4.98 385 11 0.7 32 5.5 4. 30 425 11 1.0 68 6.5 17.1 469 15 15 50 8 17.8 436 22 0.0 77 10 32.1 364 8 0.0 25 12 31 . 3 297 12 0.0 24 14 19.5 281 10 0.5 30 16. 5 22. 4 256 5 0. 6 95 19.5 19.9 185 2 0.3 60 22. 5 11. 3 158 38 0.6 75 25. 5 29.9 138 6 0.3 2480 28. 5 5. 26 145 3 0.2 12 31 .5 4.33 116 3 0.0 49 34.5 5. 51 98 0 0.0 80 37 . 5 8.24 86 1 0.0 14 41 1. 93 82 6 0.0 34 45 2.76 75 2 0.0 70 374 APPENDIX I I I . Table N. Dissolved trace metal data from HS 64 Depth Fe(uM) Mn(uM) Cu(nM) Pb(nM) Zn(nM) 0.4 0. 43 206 1.1 1.93 254 2.1 1.85 333 3.1 3.07 336 4.1 117 207 5.1 12.4 145 6.1 17 . 5 143 7.1 17 . 9 161 8 . 6 29.9 184 10.6 65.5 136 12.6 66.2 152 14.6 87 . 3 139 16.6 141 129 18.6 4.50 97 20.6 12 . 3 89 22.6 2.30 77 24.6 113 88 26.6 166 80 28 . 6 59 . 6 68 30.6 155 59 32.6 211 56 35.1 200 45 37 . 6 135 39 39.6 799 66 I .S. = insufficient sample 132 1.45 1620 13.8 0.19 826 13.8 0.29 28.7 13.8 2.66 243 298 1. 45 59.6 13.8 0.00 1560 11.9 0. 39 321 15.7 1. 45 229 5.97 0.39 183 6.59 0. 39 260 20. 4 0.97 2217 8.95 0.-05 99.4 15.7 0. 00 61.2 33.0 0.97 78.0 4.08 0. 00 39.8 23. 6 1 .93 275 13.8 0. 00 85.6 39. 3 0.97 45.9 13.8 0.10 3.82 15.7 0.34 8.79 11.9 0.6S 11.3 7.38 0.00 0.00 23.6 6.76 413 I .S. I .S. I .S. 375 

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
http://iiif.library.ubc.ca/presentation/dsp.831.1-0053297/manifest

Comment

Related Items