Open Collections

UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

The Upper Triassic Kutcho Formation Cassiar Mountains, north-central British-Columbia Thorstad, Linda Elaine 1984

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

Item Metadata

Download

Media
831-UBC_1984_A6_7 T56.pdf [ 10.67MB ]
Metadata
JSON: 831-1.0052826.json
JSON-LD: 831-1.0052826-ld.json
RDF/XML (Pretty): 831-1.0052826-rdf.xml
RDF/JSON: 831-1.0052826-rdf.json
Turtle: 831-1.0052826-turtle.txt
N-Triples: 831-1.0052826-rdf-ntriples.txt
Original Record: 831-1.0052826-source.json
Full Text
831-1.0052826-fulltext.txt
Citation
831-1.0052826.ris

Full Text

THE UPPER TRIASSIC KUTCHO FORMATION CASSIAR MOUNTAINS, NORTH-CENTRAL BRITISH COLUMBIA by LINDA ELAINE THORSTAD B.Sc., The U n i v e r s i t y of B r i t i s h Columbia, 1977 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE i n THE FACULTY OF GRADUATE STUDIES (Department of G'eological S c i e n c e s ) We accept t h i s t h e s i s as conforming to the r e q u i r e d s t a n d a r d THE © UNIVERSITY OF BRITISH COLUMBIA August 1984 L i n d a E l a i n e T h o r s t a d , 1984 In presenting t h i s thesis i n p a r t i a l f u l f i l m e n t of the requirements for an advanced degree at the University of B r i t i s h Columbia, I agree that the Library s h a l l make i t f r e e l y available for reference and study. I further agree that permission for extensive copying of t h i s thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. I t i s understood that copying or publication of t h i s thesis for f i n a n c i a l gain s h a l l not be allowed without my written permission. Department of C^mi(l€Uti 'SdMlUS The University of B r i t i s h Columbia 1956 Main Mall Vancouver, Canada V6T 1Y3 Date )E-6 (3/81) ABSTRACT The s t r a t i g r a p h i c , l i t h o l o g i c , s t r u c t u r a l and c h e m i c a l c h a r a c t e r i s t i c s of the Kutcho F o r m a t i o n , an i n f o r m a l l y named Upper T r i a s s i c v o l c a n o - s e d i m e n t a r y r o c k sequence i n the Cry Lake map a r e a of n o r t h - c e n t r a l B r i t i s h C o l u m b i a , a r e p r e s e n t e d and d i s c u s s e d i n d e t a i l . The Kutcho F o r m a t i o n and o v e r l y i n g Upper T r i a s s i c Sinwa L i m e s t o n e and Lower J u r a s s i c I n k l i n F o r m a t i o n form the K i n g Salmon assemblage which makes up a west v e r g e n t , f a u l t - b o u n d e d a l l o c h t h o n whose basement i s p a r t of t h e a n c i e n t P a c i f i c ocean f l o o r r e p r e s e n t e d by the Cache Cr e e k Group. Major and t r a c e element c h e m i s t r y of the Kutcho v o l c a n i c r o c k s d e m o n s t r a t e s t h a t t h e y a r e a c a l c - a l k a l i n e s u i t e , formed w i t h i n a v o l c a n i c i s l a n d a r c which was c o n t e r m i n o u s w i t h the N o r t h American c o n t i n e n t . The s u i t e i s d i s t i n c t i v e i n t h a t i t i s composed m a i n l y of a b i m o d a l a s s e m b l a g e of b a s a l t / b a s a l t i c a n d e s i t e and r h y o d a c i t e / r h y o l i t e . U n l i k e most a n c i e n t and p r e s e n t v o l c a n i c i s l a n d a r c s , a n d e s i t i c r o c k s a r e r a r e . C h e m i c a l l y anomalous r o c k s ( b a s i c s c h i s t u n i t ) d i s p l a y marked a l k a l i n e c h a r a c t e r i s t i c s . Metasomatism, a s s o c i a t e d w i t h d e f o r m a t i o n and r e m o b i 1 i z a t i o n of Page i i c o p p e r - z i n c K u r o k o - t y p e v o l c a n o g e n i c m a s s i v e s u l p h i d e d e p o s i t s , may i n p a r t a c c o u n t f o r the a l k a l i n e n a t u r e of the b a s i c s c h i s t . A Rb-Sr w h o l e - r o c k i s o c h r o n of 210 + 10 Ma, w i t h S r 8 7 / S r 8 6 i n i t i a l r a t i o of 0 . 7 0 4 2 , d a t e s Kutcho v o l c a n i s m as Upper T r i a s s i c . The K i n g Salmon assemblage was i s o c l i n a l l y f o l d e d , metamorphosed, and t h r u s t s o uthwestward a l o n g the K i n g Salmon f a u l t i n T o a r c i a n to M i d d l e B a j o c i a n (Lower to p r e - M i d d l e J u r a s s i c ) t i m e . Rocks d e v e l o p e d a s t r o n g p e n e t r a t i v e a x i a l p l a n a r c l e a v a g e which i s s u b p a r a l l e l to the the s o l e of the K i n g Salmon t h r u s t . Metamorphic r e c r y s t a l l i z a t i o n a t 300 to 450 d e g r e e s C e n t i g r a d e p r o d u c e d g r e e n s c h i s t f a c i e s m i n e r a l a s s e m b l a g e s . The Kutcho F o r m a t i o n , and o t h e r c o e v a l T r i a s s i c i s l a n d a r c s e q u e n c e s , were p r o b a b l y formed w i t h i n an e x t e n s i v e i s l a n d a r c to the e a s t of t h e Cache c r e e k s u b d u c t i o n complex. P o s i t i o n i n g of Kutcho and r e l a t e d T a k l a , S t u h i n i , and S i t l i k a a r c systems to the west of the Cache Creek s u b d u c t i o n complex was a c c o m p l i s h e d by d e x t r a l , t r a n s c u r r e n t m o t i o n s i n p o s t L a t e T r i a s s i c t i m e . The sout h w e s t v e r g e n c e of f a u l t s b o u n d i n g the K i n g Salmon assemblage may have been the r e s u l t of emplacement and u n d e r t h r u s t i n g of the a r c and r e l a t e d s u b d u c t i o n s e q u e n c e s by the e x o t i c t e r r a n e , known as S t i k i n i a , i n l a t e M i d d l e J u r a s s i c t i m e . Page i i i TABLE OF CONTENTS. Page 0. COPYRIGHT STATEMENT i 0. ABSTRACT i i 1. INTRODUCTION 1 1.1 Focus 1 1.2 L o c a t i o n and A c c e s s 1 1.3 P h y s i o g r a p h i c S e t t i n g 3 1.4 P r e v i o u s and P r e s e n t G e o l o g i c a l Work 4 1.5 Acknowledgements 5 2. GENERAL GEOLOGY 7 7 9 11 11 13 14 14 Page i v 2.1 G e n e r a l T e c t o n i c S e t t i n g 2.2 R e g i o n a l G e o l o g y 2.2.1 P r e - M e s o z o i c Rocks 2.2.2 M e s o z o i c Rocks 2.2.2.1 Kutcho F o r m a t i o n 2.2.2.2 Sihwa F o r m a t i o n 2.2.2.3 I n k l i n F o r m a t i o n Page 2.2.3 I n t r u s i v e Rocks 15 3. STRATIGRAPHY AND PETROLOGY OF THE KUTCHO FORMATION 16 3.1 S t r a t i g r a p h i c Summary 16 3.1.1 B a s a l t i c to D a c i t i c T u f f and B r e c c i a 19 3.1.2 F e l d s p a r Q u a r t z - E y e S e r i c i t e S c h i s t 19 3.1.3 C h l o r i t e S c h i s t 21 3.1.4 B r e c c i a 22 3.1.5 B a s i c S c h i s t 22 3.1.6 T u f f and A r g i l l i t e 24 3.1.7 C o n g l o m e r a t e 25 4. METAMORPHISM 26 4.1 I n t r o d u c t i o n 26 4.2 Metamorphic R e c o n s t i t u t i o n 26 4.3 M e t a s o m a t i c C h e m i c a l Changes 30 4.4 M i n e r a l Assemblages and Metamorphic C o n d i t i o n s 31 4.5 Metamorphic T e x t u r e s 34 4.6 T i m i n g of Metamorphism 34 Page v Page 5. CHEMISTRY OF THE KUTCHO FORMATION 36 5.1 I n t r o d u c t i o n 36 5.2 A n a l y t i c a l T e c h n i q u e and E r r o r 37 5.3 C l a s s i f i c a t i o n of V o l c a n i c Rocks of t h e Kutcho F o r m a t i o n T a k l a F o r m a t i o n and Cache Creek Group 39 5.3.1 G e n e r a l S t a t e m e n t 39 5.3.2 Rock Names 41 5.3.2.1 N o r m a t i v e C o l o u r Index v e r s u s N o r m a t i v e A n o r t h i t e 42 5.3.2.2 N o r m a t i v e A l b i t e - A n o r t h i t e - O r t h o c l a s e P r o j e c t i o n 44 5.3.2.3 S i 0 2 v e r s u s Z r / T i 0 2 46 5.3.3 C a l c - A l k a l i n e v e r s u s A l k a l i n e 48 5.3.3.1 AFM Diagram 48 5.3.3.2 A l k a l i v e r s u s S i l i c a Diagram 50 5.3.3.3 A1203 v e r s u s N o r m a t i v e A n o r t h i t e 52 5.3.3.4 O l i v i n e - N e p h e l i n e - Q u a r t z P r o j e c t i o n 52 5.3.4. T e c t o n i c E n v i r o n m e n t 55 5.3.4.1. T i t a n i u m v e r s u s Z i r c o n i u m Diagram 56 Page v i Page 5.3.4.2 MgO- F e O ( t o t a l ) - A1203 Diagram 56 5.4 Major Element C h e m i s t r y of Rocks of the Kutcho F o r m a t i o n and Other R e l a t e d Rocks 58 5.4.1 S i 0 2 60 5.4.2 A1203 66 5.4.3 Fe203 66 5.4.4 FeO 69 5.4.5 MgO 70 5.4.6 CaO 71 5.4.7 Na20 71 5.4.8 K20 72 5.4.9 T i 0 2 73 5.4.10 P205 73 5.4.11 MnO 74 5.4.12 Summary of Major Element Data 75 5.5 T r a c e Element C h e m i s t r y of Rocks of the Kutcho F o r m a t i o n and Other R e l a t e d r o c k s 76 5.5.1 Vanadium 76 5.5.2 Chromium and N i c k e l 80 5.5.3 C o b a l t 80 Page v i i Page 5.5.4 Copper 81 5.5.5 S t r o n t i u m 81 5.5.6 Z i r c o n i u m 82 5.5.7 Barium 82 5.5.8 Y t t r i u m 83 5.5.9 Summary of T r a c e Element Data 83 5.6 Summary of C h e m i c a l Data 84 5.7 T a k l a v e r s u s Kutcho C h e m i s t r y 89 6. AGE OF THE KUTCHO FORMATION 90 6.1 S t r a t i g r a p h i c R e l a t i o n s of the K u t c h o , Sinwa and I n k l i n F o r m a t i o n s 90 6.2 P a l e o n t o l o g i c a l E v i d e n c e 92 6.3 Rb-Sr D a t i n g 92 6.3.1 A n a l y t i c a l Method and R e s u l t s 93 6.3.2 I s o c h r o n Date 96 Page v i i i Page 7. STRUCTURE • 98 7.1 I n t r o d u c t i o n 98 7.1.1 S t e r e o n e t P r o j e c t i o n s 98 7.2 S t r u c t u r e 100 7.2.1 F o l d s 101 7.2.2 F o l i a t i o n 102 7.2.3 Minor f o l d s 107 7.2.4 F a u l t s 107 7.2.5 D i s c u s s i o n of G e o l o g i c Cross S e c t i o n s 108 7.3 S t r u c t u r a l Comparison Between the King Salmon Assemblage and Cache Creek Group 110 7.4 Timing of Deformation 113 7.5 Summary 114 8. ECONOMIC GEOLOGY 115 8.1 Kutcho Creek Massive S u l p h i d e Deposit 115 Page i x Page 8.2 G e n e r a l D e s c r i p t i o n 116 8.3 Summary 117 9. TECTONIC IMPLICATIONS 118 BIBLIOGRAPHY 122 LIST OF APPENDICES Appendix I P e t r o l o g y 160 Appendix I I Rock Sample D e s c r i p t i o n s 214 T a b l e I I . 1 L o c a t i o n , F i e l d Name and I r v i n e - B a r a g a r Name f o r Rocks of the Kutcho F o m a t i o n , Cry Lake Map Area 215-217 T a b l e I I . 2 L o c a t i o n , F i e l d Name and I r v i n e - B a r a g a r Name f o r Rocks of the B a s i c S c h i s t - Kutcho F o r m a t i o n , Cry Lake Map Area 218 T a b l e I I . 3 L o c a t i o n , F i e l d Name and I r v i n e - B a r a g a r Name f o r Rocks of the E a g l e h e a d Area ( C . l Page x Page to C . 6 ) , f o r Rocks of the T a k l a F o r m a t i o n ( F . l t o F.6) and f o r Rocks of the Cache Creek Group ( G . l to G.8), Cry Lake Map Area and Dease Lake Map Area 219 T a b l e I I . 4 L o c a t i o n , F i e l d Name and I r v i n e - B a r a g a r Name f o r Rocks N o r t h of the Kutcho F a u l t (D.T to D.10) and Rocks of the I n k l i n F o r m a t i o n ( E . l to E . 2 ) , Cry Lake Map A r e a 220 Appendix I I I Rock G e o c h e m i c a l Data 221 T a b l e I I I . l C h e m i c a l A n a l y s e s and N o r m a t i v e M i n e r a l s For Rocks of the Kutcho F o r m a t i o n , Cry Lake Map A r e a , B r i t i s h C o l u m b i a 222-225 T a b l e I I I . 2 C h e m i c a l A n a l y s e s and N o r m a t i v e M i n e r a l s f o r Rocks pf the B a s i c S c h i s t - Kutcho F o r m a t i o n , Cry Lake Map A r e a , B r i t i s h C o lumbia 226-227 Table" I I I . 3 C h e m i c a l A n a l y s e s and N o r m a t i v e M i n e r a l s f o r Rocks of the E a g l e h e a d Area ( C . l to C.6) and f o r Rocks of t h e T a k l a F o r m a t i o n ( F . l to F . 6 ) , Cry Lake Map Area and Dease Page x i Page Lake Map A r e a , B r i t i s h C olumbia 228 T a b l e I I I . 4 C h e m i c a l A n a l y s e s and N o r m a t i v e M i n e r a l s f o r Rocks N o r t h of the Kutcho F a u l t ( D . l to D.10) and f o r Rocks of the I n k l i n F o r m a t i o n ( E . l , E . 2 ) , Cry Lake Map A r e a , B r i t i s h C o l u m b i a 229 T a b l e I I I . 5 C h e m i c a l A n a l y s e s and N o r m a t i v e M i n e r a l s f o r Rocks of the Cache Creek Group, Cry Lake Map A r e a , B r i t i s h C olumbia 230 Appendix IV CIPW N o r m a t i v e V a l u e s 231 CIPW N o r m a t i v e V a l u e s f o r Rocks of the Kutcho F o r m a t i o n and Other R e l a t e d Rocks 232 Appendix V Geolog y and S u l p h i d e M i n e r a l o g y of the Kutcho Creek M a s s i v e S u l p h i d e D e p o s i t 233 Page x i i LIST OF FIGURES Page F i g u r e 1.1 L o c a t i o n Map of Cry Lake P r o j e c t A r e a , N o r t h - C e n t r a l B r i t i s h C o l u m b i a 2 F i g u r e 2.1a T e c t o n o s t r a t i g r a p h i c Map of the C a n a d i a n C o r d i l l e r a 8 F i g u r e 2.1b S t r u c t u r a l E l e m e n t s of the Cry Lake Map Area 8 F i g u r e 2.2 G e o l o g i c Map: D i s t r i b u t i o n of the K i n g Salmon Assemblage and R e l a t e d Rocks, Cry Lake Map , A « , X Area <P-oe-k-e-f F i g u r e 2.3 S t r a t i g r a p h i c R e l a t i o n s of M e s o z o i c Rocks of the Cry Lake Map A r e a , B r i t i s h C o l u m b i a 12 F i g u r e 3.1 D i a g r a m m a t i c F a c i e s R e l a t i o n s h i p s Between Rocks of the Kutcho F o r m a t i o n 17 F i g u r e 4.1 Key Assemblages D e f i n i n g Metamorphic Grade of Rocks o f the Kutcho F o r m a t i o n 32 F i g u r e 5.1 N o r m a t i v e C o l o u r Index v e r s u s N o r m a t i v e A n o r t h i t e Diagram 43 Page x i i i Page F i g u r e 5. 2 A l b i t e - A n o r t h i t e - O r t h o c l a s e Diagram 45 F i g u r e 5. 3 S i 0 2 v e r s u s Z r / T i 0 2 Diagram 47 F i g u r e 5. 4 AFM Diagram 49 F i gure 5. 5 A l k a l i s v e r s u s S i l i c a Diagram 51 F i g u r e 5. 6 A1203 % v e r s u s N o r m a t i v e A n o r t h i t e Diagram 53 F i g u r e 5. 7 O l i v i n e - N e p h e l i n e - Q u a r t z P r o j e c t i o n 54 F i g u r e 5. 8 T i t a n i u m ( p p m ) v e r s u s Z i r c o n i u m ( p p m ) Diagram • 57 F i g u r e 5. 9 MgO - F e O ( t o t a l ) - A1203 Diagram 59 F i g u r e 5. 10a F r e q u e n c y (N) v e r s u s S i 0 2 % Diagram ( i n c l u d i n g r o c k s of the b a s i c s c h i s t ) 65 F i g u r e 5. 10b F r e q u e n c y (N) v e r s u s S i 0 2 % Diagram ( e x c l u d i n g r o c k s of t h e b a s i c s c h i s t ) 65 F i g u r e 5. 11a H a r k e r V a r i a t i o n Diagrams of Major E l e m e n t s 67 F i g u r e 5. l i b H a r ker V a r i a t i o n Diagrams of Major E l e m e n t s 68 F i g u r e 5. 12a H a r k e r V a r i a t i o n Diagrams of T r a c e E l e m e n t s 78 F i g u r e 5 . 12b H a r k e r V a r i a t i o n Diagrams' of T r a c e E l e m e n t s 79 F i g u r e 6 . 1A-C I s o c h r o n Diagrams f o r Rocks of the T a k l a and Kutcho F o r m a t i o n s , N o r t h - C e n t r a l B r i t i s h C olumbia 97 Page x i v Page F i g u r e 7.1 Map: L o c a t i o n of Samples, S t r u c t u r a l Domains and C r o s s - S e c t i o n s F i g u r e 7.2A-D M e l l i s C o n t o u r e d P l o t s of P o l e s to Bedding f o r Rocks of the K i n g Salmon A l l o c h t h o n , Cry Lake Map Area F i g u r e 7.3A-C M e l l i s C o n t o u r e d P l o t s of P o l e s to F o l i a t i o n f o r Rocks of the K i n g Salmon A l l o c h t h o n , Cry Lake Map A r e a F i g u r e 7.3D-G M e l l i s C o n t o u r e d P l o t s of P o l e s to F o l i a t i o n f o r Rocks of the K i n g Salmon A l l o c h t h o n , Cry. Lake Map Area F i g u r e 7.4 G e o l o g i c C r o s s - S e c t i o n s A c r o s s the Ki n g Salmon A l l o c h t h o n F i g u r e 7. 5A-C M e l l i s C o n t o u r e d P l o t s of P o l e s to F o l i a t i o n and B e d d i n g , and Axes to Minor F o l d s f o r Rocks of the Cache Creek Group, Cry Lake Map Area P-crtrirrt 103 105 106 109 111 F i g u r e 9.1 Upper T r i a s s i c to M i d d l e J u r a s s i c T e c t o n i c E lements of N o r t h - C e n t r a l B r i t i s h Columbia 121 Page xv LIST OF TABLES Page T a b l e 4.1 Summary of Replacement M i n e r a l o g y and T e x t u r e s of V o l c a n i c Rocks of the Kutcho F o r m a t i o n 28 T a b l e 5.1 T a b l e 5.2 T a b l e 5.3 T a b l e 5.4 T a b l e 5.5 T a b l e 5.6 Major Element C h e m i s t r y f o r M e s o z o i c and O l d e r Rocks of the Cry Lake Map Area 61 Average Major ( i n %) and T r a c e Element ( i n ppm) C o n c e n t r a t i o n s f o r O r o g e n i c Rocks of A c i d i c C o m p o s i t i o n 62 Average Major ( i n %) and T r a c e Element ( i n ppm) C o n c e n t r a t i o n s f o r O r o g e n i c Rocks of I n t e r -m e d i a t e C o m p o s i t i o n 63 Average Major ( i n %) and T r a c e Element ( i n ppm) C o n c e n t r a t i o n s of O r o g e n i c Rocks of B a s i c C o m p o s i t i o n 64 T r a c e Element C h e m i s t r y f o r Rocks of the Kutcho F o r m a t i o n and Other R e l a t e d Rocks 76 Summary of C h e m i c a l R e s u l t s 86-88 T a b l e 6.1 Rb-Sr Data f o r Rocks of the Kutcho F o r m a t i o n 94 T a b l e 6.2 Rb-Sr Data f o r Rocks of the T a k l a F o r m a t i o n 95 Page x v i CHAPTER 1 INTRODUCTION 1.1 Focus T h i s s t u d y f o c u s e s on the "Kutcho F o r m a t i o n " , an i n f o r m a l l y named Upper T r i a s s i c v o l c a n i c and v o l c a n i c l a s t i c r o c k s equence, i t s d e s c r i p t i o n , i t s r e l a t i o n s to a d j a c e n t f o r m a t i o n s i n the K i n g Salmon a l l o c h t h o n , and to o t h e r r o c k s of the Cry Lake map a r e a . P a r t i c u l a r a t t e n t i o n i s p a i d to c o n t a c t r e l a t i o n s w i t h the Cache Creek Group, i n f e r e n c e of Permian to M e s o z o i c t e c t o n i c e v e n t s (Monger e t a l . , 1972),and p h y s i c a l and c h e m i c a l f e a t u r e s t h a t c h a r a c t e r i z e the Kutcho F o r m a t i o n . 1 . 2 L o c a t i o n and A c c e s s The Cry Lake map a r e a (NTS: 104 I; 58 to 59 d e g r e e s n o r t h l a t i t u d e and 128 to 138 d e g r e e s west l o n g i t u d e ) l i e s i n the Page 1 . 1 : L o c a t i o n Map o f C r y L a k e P r o j e c t A r e a , N o r t h - C e n t r a l B r i t i s h C o l u m b i a . Page 2 C a s s i a r M o u n t a i n s of n o r t h - c e n t r a l B r i t i s h C o l u m b i a . I t i s i m m e d i a t e l y e a s t of Dease Lake, B.C. and a p p r o x i m a t e l y 120 km s o u t h of Watson Lake, Yukon T e r r i t o r y ( F i g . 1.1). A c c e s s i s l a r g e l y by a i r t r a n s p o r t or w i n t e r c a t t r a i l s . The C a s s i a r - S t e w a r t Highway runs a l o n g the w e s t e r n m a r g i n of the Cry Lake map a r e a and a w i n t e r c a t t r a i l r uns from Dease Lake to L e t a i n and H o t t a h Lakes ( F i g . 2.2). A i r c h a r t e r s a r e a v a i l a b l e a t Dease Lake and Watson Lake. A h e l i c o p t e r i s a l s o a v a i l a b l e a t E d d o n t e n a j o n Lake, 20 km s o u t h w e s t of the map a r e a ( F i g . 1.1). There a r e s c h e d u l e d f l i g h t s between Dease Lake and Watson Lake. S u p p l i e s and accommodation a r e a v a i l a b l e at Watson Lake and to a l i m i t e d degree a t Dease Lake and E d d o n t e n a j o n Lake. 1 . 3 P h y s i o g r a p h i c S e t t i n g The C a s s i a r M o u n t a i n s i n the Cry Lake map a r e a a r e p r e d o m i n a n t l y r i d g e s and a l p i n e v a l l e y s w i t h e l e v a t i o n s r a n g i n g from 1215 to 2300 m. T r e e l i n e r o u g h l y f o l l o w s the 1525 m c o n t o u r so t h a t a p p r o x i m a t e l y 30 p e r c e n t of the map a r e a i s t r e e c o v e r e d . Maximum r e l i e f i s 1070 m. Page 3 E x t e n s i v e g l a c i a t i o n has s c u l p t e d the t e r r a i n l e a v i n g U-shaped v a l l e y s , c i r q u e s , m o r a i n e s , l a t e r a l c h a n n e l s and t i l l r a n g i n g from 3 to 15 m t h i c k . G l a c i a l movement was from s o u t h to n o r t h . Poor d r a i n a g e w i t h abundant swamps i s t y p i c a l of low l y i n g a r e a s . The w e a t h e r - l i m i t e d work s e a s o n e x t e n d s from June to l a t e September. Summer weather i s v a r i a b l e w i t h f r e q u e n t p r e c i p i t a t i o n and o c c a s i o n a l snow above 1524 m. 1.4 P r e v i o u s and P r e s e n t G e o l o g i c a l Work The Cry Lake map a r e a was f i r s t mapped by the G e o l o g i c a l Survey of Canada i n 1956 w i t h f u r t h e r l o c a l i n v e s t i g a t i o n s i n 1957, 1960 and 1961 ( G a b r i e l s e , 1962). Rocks of the Kutcho f o r m a t i o n a t t r a c t e d the a t t e n t i o n of e x p l o r a t i o n g e o l o g i s t s i n the e a r l y 1970's when a m a s s i v e s u l p h i d e d e p o s i t was d i s c o v e r e d as a r e s u l t of r e g i o n a l g e o c h e m i c a l s a m p l i n g . I n i t i a l s t a k i n g of the p r o p e r t y i n 1972 by Sumac Mines L t d . was f o l l o w e d s h o r t l y t h e r e a f t e r w i t h s t a k i n g by I m p e r i a l O i l Page 4 L t d . Work from 1972 to 1977 was l a r g e l y r e s t r i c t e d to the a r e a of d i s c o v e r y i n the e a s t e r n p a r t of the. K i n g Salmon a l l o c h t h o n ( F i g . 2.2). A. P a n t e l e y e v and D. P e a r s o n of the B r i t i s h C olumbia M i n i s t r y of E n e r g y , Mines and P e t r o l e u m R e s o u r c e s worked i n t e r m i t t e n t l y on the l o c a l g e o l o g y of the d e p o s i t from 1974 to 1977 ( P a n t e l e y e v and P e a r s o n , 1974, 1975; P a n t e l e y e v , 1976). The g e o l o g y of the C r y Lake map a r e a has been r e e x a m i n e d by the G e o l o g i c a l S u r v e y of Canada d u r i n g the 1977, 1978 and 1979 f i e l d s e a s o n s ( G a b r i e l s e , 1978; Monger and T h o r s t a d , 1978; T h o r s t a d , 1979, and T i p p e r , 1978). D u r i n g t h i s p e r i o d the w r i t e r ' s mapping c o n c e n t r a t e d on Upper P a l e o z o i c and M e s o z o i c r o c k s e q u e n c e s , w i t h s p e c i a l emphasis on the Kutcho F o r m a t i o n . 1.5 Acknowledgments The G e o l o g i c a l S u r v e y of Canada p r o v i d e d l o g i s t i c a l s u p p o r t d u r i n g 1977 to 1979 f i e l d work and s u b s e q u e n t l a b o r a t o r y and d r a f t i n g s u p p o r t . S p e c i a l a p p r e c i a t i o n i s e x t e n d e d to H. G a b r i e l s e and J.W.H. Monger f o r t h e i r i n v a l u a b l e h e l p . The w r i t e r a cknowledges C . I . Godwin and R.L. A r m s t r o n g f o r t h e i r a d v i c e d u r i n g the p r e p a r a t i o n of t h i s p a p e r . Sumac Mines and I m p e r i a l O i l , i n p a r t i c u l a r C. S c o t t and D. B r i d g e , p r o v i d e d Page 5 l o g i s t i c a l s u p p o r t , access to the Kutcho Creek p r o p e r t y , and much i n f o r m a t i o n . A p p r e c i a t i o n i s a l s o extended to A. P a n t e l e y e v of the B r i t i s h Columbia Mines and Petroleum Resources Branch f o r s t i m u l a t i n g d i s c u s s i o n s and data t h a t has been i n c l u d e d i n t h i s r e p o r t . Page 6 C h a p t e r 2 GENERAL GEOLOGY 2.1 G e n e r a l T e c t o n i c S e t t i n g The C o r d i l l e r a has been d i v i d e d i n t o two major s t r u c t u r a l b e l t s ( F i g s . 2.1a and b ) : the Co l u m b i a n Orogen c o m p r i s e d of the E a s t e r n M a r g i n a l B e l t , the Omineca C r y s t a l l i n e B e l t and the P a c i f i c Orogen c o m p r i s e d of the I n t e r m o n t a n e B e l t , the C o a s t C r y s t a l l i n e B e l t and the I n s u l a r B e l t . S e v e r a l t e c t o n o s t r a t i g r a p h i c b e l t s d e f i n e d f o r the C a n a d i a n C o r d i l l e r a (Monger e t a l . , 1972, Wheeler and G a b r i e l s e , 1972; S u t h e r l a n d Brown et a l . , 1971) a r e encompassed i n the Cry Lake map a r e a . The E a s t e r n M a r g i n a l B e l t i s p r e d o m i n a n t l y composed of m i o g e o c l i n a l s e d i m e n t s , i n c l u d i n g t h i c k c a r b o n a t e and s h a l e s equences t h a t c o n t a i n both c o a r s e and f i n e e l a s t i c s ; the Omineca C r y s t a l l i n e B e l t , which s t r a d d l e s the m i o g e o c l i n e - e u g e o c l i n e boundary, i s marked by many M e s o z o i c g r a n i t i c i n t r u s i o n s and r e g i o n a l metamorphism. The H i n t e r l a n d B e l t c o m p r i s e s a sequence of Upper P a l e o z o i c a r c and o c e a n i c r o c k s (Monger, 1977) and lower Page 7 FIGURE 2 . 1 b FIGURE 2 . l a FIGURE 2.1a: T e c t o n o s t r a t i g r a p h i c Map of the Canadian C o r d i l l e r a ( m o d i f i e d from S u t h e r l a n d Brown et a l . , 1971) FIGURE 2.1b: S t r u c t u r a l Elements of the Cry Lake Map Area ( m o d i f i e d from Monger and T h o r s t a d , 1978, a f t e r Wheeler and G a b r i e l s e , 1972) Page 8 M e s o z o i c i s l a n d a r c v o l c a n i c and i n t e r - a r c s e d i m e n t a r y r o c k s (Monger and T h o r s t a d , 1978). The I n t e r m o n t a n e B e l t i s s t r u c t u r a l l y s e p a r a t e d from the Columbian Orogen, but has s i m i l a r r o c k s to t h o s e of the H i n t e r l a n d B e l t . The C o a s t C r y s t a l l i n e and I n s u l a r B e l t s a r e d o m i n a n t l y a M e s o z o i c p l u t o n i c t e r r a n e and an Upper P a l e o z o i c to M e s o z o i c v o l c a n o - s e d i m e n t a r y s e q u e n c e , r e s p e c t i v e l y . The K i n g Salmon a l l o c h t h o n and s t r u c t u r a l l y r e l a t e d r o c k s , on which t h i s s t u d y c o n c e n t r a t e s , a r e p a r t of the H i n t e r l a n d B e l t and I n t e r m o n t a n e B e l t . 2 . 2 R e g i o n a l G e o l o g y The Kutcho F o r m a t i o n i s the l o w e s t s t r a t i g r a p h i c u n i t i n a sequence of r o c k s c a l l e d the K i n g Salmon assemblage (Monger and T h o r s t a d , 1978). These r o c k s l i e w i t h i n the K i n g Salmon a l l o c h t h o n , a s o u t h w e s t t r a n s p o r t e d t h r u s t p l a t e which i s bounded to the s o u t h by the K i n g Salmon t h r u s t f a u l t and to the n o r t h by the N a h l i n f a u l t ( F i g . 2.2). The N a h l i n f a u l t , j u x t a p o s e s M i s s i s s i p p i a n to T r i a s s i c Cache Creek Group on i t s n o r t h s i d e a g a i n s t the T r i a s s i c to Lower J u r a s s i c K i n g Salmon a s s e m b l a g e . The K i n g Salmon assemblage i s i n t u r n t h r u s t on Upper T r i a s s i c to J u r a s s i c v o l c a n o - s e d i m e n t a r y r o c k s (Monger and T h o r s t a d , 1978; T i p p e r , 1978). Page 9 The K i n g Salmon a l l o c h t h o n and Cache Creek s t r u c t u r a l b e l t a r e t r u n c a t e d to the n o r t h and e a s t by the n o r t h w e s t t r e n d i n g , d e x t r a l , s t r i k e - s l i p Kutcho f a u l t ( G a b r i e l s e , 1978). The a r e a n o r t h of the Kutcho f a u l t i s u n d e r l a i n by the C a s s i a r b a t h o l i t h of the Omineca C r y s t a l l i n e B e l t and P r o t e r o z o i c and P a l e o z o i c m i o g e o c l i n a l r o c k s of the E a s t e r n M a r g i n a l B e l t . In a d d i t i o n , two a r e a s of M e s o z o i c r o c k s l i e j u s t n o r t h of the Kutcho f a u l t . In t h e s o u t h e a s t c o r n e r of the map a r e a ( F i g . 2.2) a s m a l l a r e a of Upper T r i a s s i c a u g i t e p o r p h y r y i s p r e s e n t . In the E a g l e h e a d Lakes a r e a ( F i g . 2.2) a l i n e a r b e l t of r o c k s of the Kutcho F o r m a t i o n u n d e r l i e s a l i m e s t o n e of unknown age. T h i s b e l t i s t r u n c a t e d by an i n t r u s i v e c o n t a c t or a s p l a y -of the Kutcho f a u l t . Rocks t e n t a t i v e l y a s s i g n e d to t h e Kutcho F o r m a t i o n a r e mapped i n the a r e a bounded by F l a t and F a u l k n e r C r e e k s and T u r n a g a i n R i v e r west of W o l v e r i n e Lakes ( F i g . 2 . 2 ) . South of the K i n g Salmon a l l o c h t h o n the H o t a i l u h b a t h o l i t h , a M e s o z o i c c o m p o s i t e b a t h o l i t h ( A n d e r s o n , 1978), i n t r u d e s M e s o z o i c r o c k s . I t has been s u g g e s t e d t h a t e a r l y phases of t h i s b a t h o l i t h may be i n t r u s i v e e q u i v a l e n t s of the Kutcho s u i t e ( G a b r i e l s e , p e r s . comm., 1978). Page 10 2.2.1 P r e - M e s o z o i c Rocks P r e - M e s o z o i c r o c k s , which o c c u r o n l y n o r t h of the Kutcho f a u l t , are p r e d o m i n a n t l y P r o t e r o z o i c c a r b o n a t e , g r i t and s h a l e and P a l e o z o i c p l a t f o r m and s l o p e l i t h o l o g i e s t h a t i n c l u d e , i n s t r a t i g r a p h i c o r d e r , P r o t e r o z o i c c a r b o n a t e and s h a l e , Lower Cambrian Atan l i m e s t o n e and q u a r t z i t e , C a m b r o - O r d o v i c i a n K e c h i k a s h a l e , s l a t e and wavy banded l i m e s t o n e , and S i l u r i a n to M i s s i s s i p p i a n c a r b o n a t e and c l a s t i c . The S y l v e s t e r Group, an a l l o c h t h o n of P a l e o z o i c to T r i a s s i c c h e r t , s l a t e , l i m e s t o n e , b a s i c v o l c a n i c and u l t r a m a f i c r o c k s r e s t s on the M i d d l e P a l e o z o i c c l a s t i c . The Cache Cr e e k Group, a M i s s i s s i p p i a n ( ? ) to T r i a s s i c ( ? ) o c e a n i c a s s e m b l a g e , i s i n v a r i a b l y i n f a u l t c o n t a c t w i t h o t h e r r o c k u n i t s of the map a r e a . 2.2.2 M e s o z o i c Rocks M e s o z o i c r o c k s a r e dominant s o u t h w e s t of the N a h l i n f a u l t . The K i n g Salmon a l l o c h t h o n spans the w i d t h of the map a r e a , t r e n d i n g west to n o r t h w e s t p a r a l l e l w i t h the r e g i o n a l s t r u c t u r a l t r e n d . Lower M e s o z o i c r o c k s w i t h i n t h e K i n g Salmon assemblage ( F i g . 2.3) i n c l u d e the Upper T r i a s s i c Kutcho F o r m a t i o n (a v o l c a n o - s e d i m e n t a r y s e q u e n c e ) , the Upper T r i a s s i c Sinwa L i m e s t o n e , and the Lower J u r a s s i c I n k l i n Formatiom (a g r e y w a c k e - p h y 1 1 i t e Page 11 SOUTHWEST NORTHEAST O Ooo Oo o a o O O O o O O O O O 0 ° Q 1 1 ~ Q Q Q <J O O O o O ° • . ' O o . . L E G E N D l - M J * VOLCANIC AND SEDIMENTARY ROCKS KING u"R-IJ VOLCANIC ROCKS ALLOCHTHON JURASSIC TRIASSIC o _ o— o o SALMON o o o o I V V V | INKLIN FORMATION u-RSINWA •FORMATION uR KUTCHO FORMATION FIGURE 2.3: S t r a t i g r a p h i c R e l a t i o n s of Mesozoic Rocks of the Cry Lake Map Area, B r i t i s h Columbia Page 12 s e q u e n c e ) . The Sinwa and I n k l i n F o r m a t i o n s have g r a d a t i o n a l c o n t a c t s w i t h c o n g l o m e r a t e s of the upper Kutcho F o r m a t i o n . L i m e s t o n e l e n s e s become e v i d e n t i n the upper Kutcho c o n g l o m e r a t e which g r a d e s i n t o m a s s i v e Sinwa F o r m a t i o n . In p l a c e s the Sinwa L i m e s t o n e i s a b s e n t and t h e s e l e n s e s a r e the o n l y i n d i c a t i o n of l i m e s t o n e d e p o s i t i o n . In a r e a s where the Sinwa l i m e s t o n e i s a b s e n t , i t i s d i f f i c u l t to d e f i n e s t r a t i g r a p h i c b o u n d a r i e s because the upper Kutcho c o n g l o m e r a t e s grade i n t o the b a s a l c o n g l o m e r a t e s of the I n k l i n F o r m a t i o n . 2.2.2.1 Kutcho F o r m a t i o n The Kutcho F o r m a t i o n i s an Upper T r i a s s i c , i s l a n d a r c d e r i v e d v o l c a n i c l a s t i c s e q u e n c e . O l d e s t known r o c k s of the sequence a r e b a s a l t i c to d a c i t i c t u f f and b r e c c i a , o v e r l a i n by d a c i t i c to r h y o l i t i c t u f f and b r e c c i a . S e d i m e n t a r y r o c k s i n c l u d i n g t u f f a c e o u s a r g i l l i t e , a r g i l l i t e and c o n g l o m e r a t e cap the se q u e n c e . The sequence may be up to 1000 m t h i c k . Page 13 2.2.2.2 Sinwa F o r m a t i o n The t h i c k n e s s o f the Sinwa L i m e s t o n e r a n g e s from 0 to 250 m i n the map a r e a . The Sinwa L i m e s t o n e i s grey to w h i t e , w e l l - f o l i a t e d and g e n e r a l l y c r y s t a l l i n e , but l o c a l l y m i c r i t i c . Commonly i t i s f e t i d and p y r i t i c . L a y e r i n g i s p o o r l y d e f i n e d and may have been d e s t r o y e d by the w e l l d e v e l o p e d f o l i a t i o n . D e f i n i t i v e i n d e x f o s s i l s i n the Sinwa a r e r a r e i n the map a r e a . Only one b i v a l v e ( M i n e t r i g o n i a ) and one s c l e r a c t i n i a n c o r a l have been t e n t a t i v e l y i d e n t i f i e d ( T o z e r , 1977 p e r s . comm.; Monger, 1978, p e r s . comm.). 2.2.2.3 I n k l i n F o r m a t i o n The I n k l i n F o r m a t i o n (Monger and T h o r s t a d , 1978) i s composed of i n t e r c a l a t e d greywacke, dark g r e y to b l a c k s h a l e and s i l t s t o n e and b l a c k p h y l l i t e . A b a s a l c o n g l o m e r a t e i s g e n e r a l l y p r e s e n t and c o n g l o m e r a t e l a y e r s and l e n s e s are common t h r o u g h o u t L a y e r i n g i s e v i d e n t i n g r e y w a c k e - s h a l e and/or p h y l l i t e s equences but i s o f t e n o b s c u r e d by the w e l l d e v e l o p e d f o l i a t i o n . D i s s e m i n a t e d p y r i t e c u b e s , i n amounts up to 5 p e r c e n t , a r e u b i q u i t o u s . Page 14 2.2.3 I n t r u s i v e Rocks Dykes of v o l c a n i c r o c k s of t h e Mount B l a i r " F o r m a t i o n " , p a r t of the M e s o z o i c v o l c a n o - s e d i m e n t a r y sequence s o u t h of the K i n g Salmon f a u l t (Erdman, 1978), c u t the Kutcho F o r m a t i o n i n the s o u t h e a s t e r n p a r t of the K i n g Salmon a l l o c h t h o n . These c r o s s - c u t t i n g r e l a t i o n s h i p s a r e s i g n i f i c a n t i n e s t a b l i s h i n g the t i m i n g of d e f o r m a t i o n . Dykes a r e g e n e r a l l y f r e s h , n o n - f o l i a t e d h o r n b l e n d e f e l d s p a r p o r p h y r i e s and may c o n t a i n g r e y to mauve, a m e t h y s t i n e q u a r t z . Some r a r e , p o o r l y f o l i a t e d h o r n b l e n d e f e l d s p a r p o r p h y r y dykes a r e a l s o p r e s e n t . A K-Ar date f o r h o r n b l e n d e i n the d i o r i t i c phase of the p l u t o n i c s u i t e r e l a t e d to the B l a i r F o r m a t i o n i s 159 + 6 Ma (Erdman, 1978). V o l c a n i c r o c k s and t h e i r f e e d e r dykes a r e assumed to be the same age as the d i o r i t e s . Page 15 CHAPTER 3 STRATIGRAPHY AND PETROLOGY OF THE KUTCHO FORMATION 3.1 S t r a t i g r a p h i c Summary The Kutcho F o r m a t i o n i s composed p r e d o m i n a n t l y of v o l c a n i c l a s t i c r o c k s w i t h i n t e r c a l a t e d s e d i m e n t s and s u b o r d i n a t e f l o w r o c k ( F i g . 3 . 1 ) . The base of the s e c t i o n i s not e x p o s e d . N o r t h of the Kutcho f a u l t , " K u t c h o - l i k e " r o c k s appear to be r e s t i n g on r o c k s c o r r e l a t e d w i t h m i d d l e P a l e o z o i c s e d i m e n t s , though the c o n t a c t s between t h e s e u n i t s a r e unexp o s e d . Kutcho l i t h o l o g i c u n i t s a r e deformed and l e n t i c u l a r . Near the Kutcho C r e e k d e p o s i t g r o s s s t r a t i g r a p h y has been d e f i n e d by P e a r s o n and P a n t e l e y e v (1975) and B r i d g e ( u n p u b . ) ; the f o l l o w i n g s t r a t i g r a p h i c sequence r e p r e s e n t s a c o m p i l a t i o n of t h e i r d a t a as w e l l as o b s e r v a t i o n s made by the a u t h o r d u r i n g f i e l d mapping. In the e a s t e r n K i n g Salmon a l l o c h t h o n , where the Kutcho Creek m a s s i v e s u l p h i d e d e p o s i t o c c u r s , e x c e l l e n t e x p o s u r e s of the Kutcho f o r m a t i o n p r o v i d e a ty p e a r e a . B r i e f p e t r o g r a p h i c d e s c r i p t i o n s of r o c k u n i t s a r e i n c l u d e d i n the t e x t and more d e t a i l e d d e s c r i p t i o n s i n Appendix I . Page 16 L — QUARTZ EYE SERICITE SCHIST J LIMESTONE CONGLOMERATE ~ —— ARGILLITE o O O A -<7 BRECCIA FIGURE 3.1: Diagrammatic F a c i e s R e l a t i o n s h i p s Between Rocks of the Kutcho Formation (True t h i c k n e s s e s are not shown; c o n t a c t s are g r a d a t i o n a l and u n i t s tend to be l e n t i c u l a r . ) Page 17 The l o w e s t u n i t exposed i n the t y p e a r e a i s a b a s a l t i c to d a c i t i c t u f f and b r e c c i a , which i s o v e r l a i n by d a c i t i c to r h y o l i t i c t u f f and b r e c c i a . The l a t t e r u n i t s have been metamorphosed to q u a r t z - e y e and q u a r t z f e l d s p a r s e r i c i t e s c h i s t . A l e n s o i d , m a s s i v e s u l p h i d e u n i t which i s i n t e r c a l a t e d w i t h c a r b o n a t e and c a l c a r e o u s q u a r t z s e r i c i t e s c h i s t o v e r l i e s t h e s e r o c k s . Q u a r t z - e y e f e l d s p a r s e r i c i t e s c h i s t ( o r i g i n a l l y c r y s t a l and l a p i l l i t u f f s and minor b r e c c i a s ) w i t h minor b a s a l t l e n s e s o v e r l i e the m a s s i v e s u l p h i d e . A b a s i c v o l c a n i c l a s t i c or f l o w ( b a s i c s c h i s t ) o v e r l i e s and i n p a r t t r u n c a t e s the m a s s i v e s u l p h i d e i n the a r e a of the d e p o s i t ( B r i d g e , 1977, p e r s . comm.). I n t e r l a y e r e d i n t e r m e d i a t e to a c i d i c t u f f and a r g i l l i t e r e s t on and have g r a d a t i o n a l c o n t a c t s w i t h u n d e r l y i n g a c i d i c f r a g m e n t a l r o c k s , b a s i c s c h i s t and o v e r l y i n g c o n g l o m e r a t e . C o n g l o m e r a t e , t u f f and a r g i l l i t e a r e f a c i e s e q u i v a l e n t s . The c o n g l o m e r a t e a p p e a r s to be t h i c k e s t i n the w e s t e r n r e g i o n of the type a r e a , and t u f f and a r g i l l i t e dominate i n the e a s t . Both c o n g l o m e r a t e and a r g i l l i t e cap the sequence and have g r a d a t i o n a l c o n t a c t s w i t h the o v e r l y i n g Upper T r i a s s i c Sinwa L i m e s t o n e , or where Sinwa L i m e s t o n e i s a b s e n t , t h e y a r e g r a d a t i o n a l w i t h r o c k s of the Lower J u r a s s i c I n k l i n F o r m a t i o n . Page 18 3.1.1 B a s a l t i c to D a c i t i c T u f f and B r e c c i a Up to 215 m of the b a s a l u n i t has been o b s e r v e d . L i t h o l o g i e s i n c l u d e m a s s i v e t u f f , f e l d s p a r ( w i t h or w i t h o u t r e l i c t a u g i t e or h o r n b l e n d e ) c r y s t a l t u f f and c h a o t i c b r e c c i a s w i t h f r a g m e n t s t h a t range from 1 to 35 cm. Rocks a r e g e n e r a l l y w e l l f o l i a t e d , form m a s s i v e , r e s i s t a n t , d ark grey to green o u t c r o p s , and show l i t t l e e v i d e n c e of b e d d i n g . Rare l e n s e s of a c i d i c t u f f a r e found t h r o u g h o u t the s e q u e n c e . E p i d o t e i s u b i q u i t o u s and i n some l a y e r s f r a g m e n t s a r e p r e f e r e n t i a l l y e p i d o t i z e d w h i l e i n o t h e r s e p i d o t e forms 1 to 20 cm s u b s p h e r i c a l c l o t s of r a d i a t i n g c r y s t a l s . These e p i d o t e c l o t s may be i n t e r p r e t e d as a l t e r e d f r a g m e n t s or e p i d o t i z e d c o r e s of p i l l o w s w i t h i n f l o w s . In t h i n s e c t i o n p h e n o c r y s t s and m a t r i x a r e a l t e r e d . P l a g i o c l a s e i s e x t e n s i v e l y a l t e r e d to e p i d o t e , c a r b o n a t e and l e s s e r s e r i c i t e and c h l o r i t e . M a f i c m i n e r a l s a r e pseudomorphed by c h l o r i t e and/or b i o t i t e , and the f i n e m a t r i x i s r e p l a c e d by c h l o r i t e , e p i d o t e , c a r b o n a t e and minor s e r i c i t e . 3.1.2 F e l d s p a r Q u a r t z - E y e S e r i c i t e S c h i s t F e l d s p a r q u a r t z - e y e s e r i c i t e s c h i s t ; q u a r t z - e y e s e r i c i t e s c h i s t and s e r i c i t e s c h i s t a r e c o n s i d e r e d to be the metamorphic Page 19 e q u i v a l e n t s of d a c i t i c to r h y o l i t i c t u f f s and b r e c c i a s . These s c h i s t s o c c u r both above and below the m a s s i v e s u l p h i d e s . In the h a n g i n g w a l l t h e y a r e up to 245 m t h i c k ; i n the f o o t w a l l they a r e a p p r o x i m a t e l y 320 m t h i c k . A d i s t i n c t n o r t h - s o u t h f a c i e s change i s r e c o g n i z e d i n the f o o t w a l l of the d e p o s i t by t h e g r a d a t i o n of l a p i l l i c r y s t a l t u f f i n t o q u a r t z f e l d s p a r c r y s t a l t u f f ( B r i d g e , 1977, p e r s . comm.) L i t h o l o g i e s a r e a l l f r a g m e n t a l ( t u f f , a g g l o m e r a t e and b r e c c i a ) and t h e r e may be as many as seven f i n i n g upward c y c l e s i n the s i l i c i c f o o t w a l l s c h i s t . B r e c c i a s a r e g e n e r a l l y m o n o l i t h o l o g i c . Fragments range from 2 to 20 cm and a r e h i g h l y f l a t t e n e d but l e s s f o l i a t e d t h an t h e i r m a t r i x . Some mauve q u a r t z f e l d s p a r f r a g m e n t s , p a r t i a l l y r e p l a c e d by h e m a t i t e were o b s e r v e d i n some b r e c c i a s . T u f f s c o n t a i n v a r i a b l e amounts ( f r o m 5 to 40 p e r c e n t ) of q u a r t z and f e l d s p a r c r y s t a l s t h a t range from 1 to 20 mm i n s i z e . Q u a r t z and f e l d s p a r a r e g e n e r a l l y s u b h e d r a l and w h i t e to p a l e b l u e - g r e e n . The c o l o u r of f e l d s p a r , which v a r i e s from b l u e to g r e e n over s h o r t v e r t i c a l i n t e r v a l s , may be the r e s u l t of s e r i c i t i z a t i o n . D o l o m i t e l e n s e s , 10 to 20 cm l o n g , a r e e v i d e n t t h r o u g h o u t the s e c t i o n and have been f l a t t e n e d and a t t e n u a t e d i n the p l a n e of the f o l i a t i o n . S e c o n d a r y d o l o m i t e rhombic p r o p h y r o b l a s t s a r e c h a r a c t e r i s t i c of the m a t r i c e s of t h e s e r o c k s . D i s s e m i n a t e d p y r i t e and l i m o n i t i c boxwork a f t e r p y r i t e a r e Page 20 u b i q u i t o u s . Rocks may have abundan t s e c o n d a r y h e m a t i t e . B e d d i n g i s p o o r l y d e f i n e d . In t h i n s e c t i o n q u a r t z , f e l d s p a r and s e r i c i t e d o m i n a t e . V a r y i n g amounts of q u a r t z and f e l d s p a r o c c u r as augen or g r a n u l a r a g g r e g a t e s and a r e r e p l a c e d by s e r i c i t e and c a r b o n a t e , and s e r i c i t e , c a r b o n a t e and c h l o r i t e , r e s p e c t i v e l y . The m a t r i x i s d o m i n a n t l y f i n e s e r i c i t e , q u a r t z and f e l d s p a r w i t h l e s s e r c h l o r i t e . 3.1.3 C h l o r i t e S c h i s t C h l o r i t e s c h i s t o c c u r s as t h i n l a y e r s and l e n s e s t h r o u g h o u t b a s a l t i c to d a c i t i c t u f f and b r e c c i a of the lower u n i t ( F i g . 3.2). A l e n s of c h l o r i t e s c h i s t v a r y i n g i n t h i c k n e s s from 1 to 61 m i s a l s o f ound i n the a c i d i c s c h i s t s of the f o o t w a l l . U n d e r l y i n g the c h l o r i t e s c h i s t i s a t h i n ( a p p r o x i m a t e l y 2.7 m t h i c k ) m i n e r a l i z e d r h y o l i t e b r e c c i a w i t h d i s s e m i n a t e d s u l p h i d e s ( B r i d g e , 1978, p e r s . comm.). In t h i n s e c t i o n c h l o r i t e s c h i s t i s d o m i n a n t l y a mass of c h l o r i t e , e p i d o t e c l o t s and f i n e f e l d s p a r w i t h minor amounts of Page 21 se r i c i te w e l l dev and t r e m o l i t e - a c t i n o l i t e . e l o p e d f o l i a t i o n . D o l o m i t i c rhombs d e f l e c t the 3.1.4 B r e c c i a In the ty p e a r e a a l e n s of b r e c c i a w i t h i n q u a r t z - e y e f e l d s p a r s c h i s t o u t c r o p s on a r i d g e j u s t n o r t h of the s u l p h i d e d e p o s i t . The b r e c c i a i s m o n o l i t h o l o g i c w i t h f r a g m e n t s of q u a r t z - e y e f e l d s p a r s e r i c i t e s c h i s t i n a m a t r i x of s i m i l a r c o m p o s i t i o n . T h i s u n i t i s u n i q u e i n t h a t f r a g m e n t s a r e a p p a r e n t l y more competent t h a n t h o s e i n o t h e r f r a g m e n t a l u n i t s . Fragments range from 2 to 30 cm i n s i z e and may c o n s t i t u t e from 20 to 70 p e r c e n t of the r o c k . Both f r a g m e n t s and m a t r i x a r e p e t r o g r a p h i c a l l y s i m i l a r to f e l d s p a r q u a r t z - e y e s e r i c i t e s c h i s t s . 3.1.5 B a s i c S c h i s t A w e l l - f o l i a t e d , b a s i c t u f f , s i m i l a r i n l i t h o l o g y to b a s i c r o c k s of the l o w e s t s t r a t i g r a p h i c u n i t c r o p s out as l e n s e s w i t h i n the t y p e a r e a , but i s not p r e s e n t e l s e w h e r e . These l e n s e s o c c u r w i t h i n t u f f and a r g i l l i t e and have s h a r p or g r a d a t i o n a l c o n t a c t s . They a r e g e n e r a l l y from 1 to 3 m t h i c k ( e x c e p t i o n a l l y up Page 22 to 450 m) w i t h v a r i a b l e l e n g t h s . The t h i c k e s t l e n s i s g e n e r a l l y c o n c o r d a n t w i t h and caps the s u l p h i d e member, but th e y l o c a l l y o c c u r a t the same s t r a t i g r a p h i c h o r i z o n as the s u l p h i d e ( B r i d g e , 1978, p e r s . comm.). L i t h o l o g i e s i n c l u d e f e l d s p a r c h l o r i t e s c h i s t , f e l d s p a r a u g i t e c h l o r i t e s c h i s t and a u g i t e c h l o r i t e s c h i s t . Weathered s u r f a c e s a r e g e n e r a l l y dark g r e e n and show l i t t l e e v i d e n c e of t e x t u r a l v a r i a b i l i l i t y , but f r e s h s u r f a c e s exposed i n c o r e samples a r e t e x t u r a l l y h e t e r o g e n e o u s . P y r i t e and p y r r h o t i t e a r e d i s s e m i n a t e d t h r o u g h o u t the u n i t . S u l p h i d e s a r e f l a t t e n e d and p r e f e r e n t i a l l y d i s t r i b u t e d i n the p l a n e of the f o l i a t i o n . I n t e r n a l l a y e r i n g i s d e f i n e d by v a r i a t i o n i n s i z e , shape and c o n c e n t r a t i o n of c r y s t a l s . L a y e r s v a r y i n c o m p o s i t i o n from f i n e c h l o r i t e s c h i s t to c o a r s e f e l d s p a r - r i c h ( w i t h or w i t h o u t m a f i c c r y s t a l s ) c h l o r i t e s c h i s t s to a u g i t e c h l o r i t e s c h i s t i n which f e l d s p a r c r y s t a l s a r e r a r e . Some f r a g m e n t a l t e x t u r e s a r e o b s e r v e d ( f r a g m e n t s r a n g e from 1 to 10 mm), s u g g e s t i n g t h a t the r o c k s a r e both f l o w s and t u f f s . In t h i n s e c t i o n p l a g i o c l a s e i s the dominant p h e n o c r y s t and i s e x t e n s i v e l y a l t e r e d to s e r i c i t e , e p i d o t e , c a r b o n a t e and c h l o r i t e . O r i g i n a l m a f i c g r a i n s and the f i n e m a t r i x a r e r e p l a c e d by b i o t i t e , e p i d o t e , c h l o r i t e , t r e m o l i t e - a c t i n o l i t e and c a r b o n a t e . F i n e g r a i n e d p o t a s s i u m f e l d s p a r o c c u r s t h r o u g h o u t the m a t r i x . Page 23 The o r i g i n of the b a s i c l e n s e s has not been e s t a b l i s h e d u n e q u i v o c a l l y . P e a r s o n and P a n t e l e y e v (1975) c o n s i d e r e d the l e n s e s to be i n t r u s i v e because of c r o s s - c u t t i n g r e l a t i o n s h i p s . However, t e x t u r a l i n h o m o g e n e i t y , l o c a l f r a g m e n t a l n a t u r e , i n t e r n a l l a y e r i n g and g r a d a t i o n a l c o n t a c t s w i t h a d j a c e n t r o c k s s u g g e s t t h a t t h e s e r o c k s a r e f l o w s w i t h a p y r o c l a s t i c component. 3 . 1 . 6 T u f f and A r g i l l i t e G e o g r a p h i c d i s t r i b u t i o n and i n t e r t o n g u i n g r e l a t i o n s h i p s s u g g e s t t h a t t u f f and a r g i l l i t e a r e a f a c i e s e q u i v a l e n t to the c o n g l o m e r a t e t h a t caps the Kutcho s e q u e n c e . T u f f and a r g i l l i t e t h i c k e n m a r k e d l y i n the e a s t e r n p a r t of the t y p e a r e a where they l a r g e l y r e p l a c e c o n g l o m e r a t e . In the west, c o n g l o m e r a t e dominates and t u f f and a r g i l l i t e a r e s u b o r d i n a t e . The t h i c k n e s s of the u n i t r a nges from 1 to 400 m. The t u f f and a r g i l l i t e u n i t i s h e t e r o g e n e o u s and i n c l u d e s : v e r y f i n e g r a i n e d q u a r t z f e l d s p a r s e r i c i t e s c h i s t , f i n e g r a i n e d c h l o r i t e f e l d s p a r s c h i s t , b l a c k to g r e e n s h a l e and s i l t s t o n e w i t h c a l c a r e o u s l e n s e s and g r e y to g r e e n s e r i c i t e s c h i s t and greywacke. D i s s e m i n a t e d p y r i t e and p y r r h o t i t e and l i m o n i t i c box work a f t e r p y r i t e a r e common. Page 24 3.1.7 C o n g l o m e r a t e L i m e s t o n e l e n s e s a r e p r e s e n t t h r o u g h o u t the 10 to 100 m t h i c k c o n g l o m e r a t e a t the top of the Kutcho F o r m a t i o n . C l a s t s i n the c o n g l o m e r a t e range from 0.5 t o 12 cm i n l e n g t h . F i n e g r a i n e d sandy l a y e r s a r e common. C l a s t s appear to have been l a r g e l y d e r i v e d from n e a r b y v o l c a n i c r o c k s . Fragment l i t h o l o g i e s i n c l u d e w h i t e to green q u a r t z - e y e s e r i c i t e s c h i s t , s e r i c i t e s c h i s t , q u a r t z - e y e f e l d s p a r s e r i c i t e s c h i s t and l e s s e r c h l o r i t e s c h i s t , c a r b o n a t e and q u a r t z i t e . M a t r i x c o m p o s i t i o n c l o s e l y a p p r o x i m a t e s t h a t of the a c i d i c c r y s t a l t u f f s , b e i n g composed of q u a r t z , f e l d s p a r , s e r i c i t e and c h l o r i t e . Some c r u d e l a y e r i n g i s e v i d e n t i n the c o n g l o m e r a t e but i t i s g e n e r a l l y o b s c u r e d by the w e l l -d e v e l o p e d f o l i a t i o n . C l a s t s a r e f l a t t e n e d i n the p l a n e of the f o l i a t i o n . F o l i a t i o n i n t h e m a t r i x commonly wraps around t h e s e c l a s t s . Page 25 CHAPTER 4 METAMORPHISM 4 . 1 I n t r o d u c t i o n The Kutcho F o r m a t i o n has been r e g i o n a l l y metamorphosed to the g r e e n s c h i s t f a c i e s . M etamorphic m i n e r a l a s s e m b l a g e s n o t e d w i t h i n m e t a v o l c a n i c r o c k s and m e t a s e d i m e n t a r y r o c k s of the f o r m a t i o n , i n c l u d i n g t h o s e i n the Sinwa L i m e s t o n e , a r e i n d i c a t i v e of l o w - g r a d e metamorphism which accompanied the d e f o r m a t i o n of the King Salmon a s s e m b l a g e . 4.2 Metamorphic R e c o n s t i t u t i o n P r i m a r y m i n e r a l o g i e s of r o c k u n i t s w i t h i n the Kutcho F o r m a t i o n have been p e r v a s i v e l y a l t e r e d by the metamorphism and l o c a l metasomatism which a t t e n d e d f o r m a t i o n of the a l l o c h t h o n . S p e c i f i c metamorphic a s s e m b l a g e s have r e c r y s t a l l i z e d w i t h i n m e t a v o l c a n i c and m e t a s e d i m e n t a r y r o c k s of d i f f e r e n t c o m p o s i t i o n s . L o c a l l y , and i n p a r t i c u l a r , i n c l o s e p r o x i m i t y to t h e Kutcho m a s s i v e s u l p h i d e d e p o s i t , r o c k u n i t s have been s u b j e c t e d to Page 26 h y d r o t h e r m a l metasomatism. M i n e r a l a s s e m b l a g e s n o t e d i n m e t a v o l c a n i c r o c k s a r e g i v e n i n T a b l e 4.1. B a s a l t to b a s a l t i c a n d e s i t e r o c k s a r e c h a r a c t e r i z e d by the a l t e r a t i o n m i n e r a l s c h l o r i t e , e p i d o t e , c a r b o n a t e , t r e m o l i t e - a c t i n o l i t e and b i o t i t e . Most o r i g i n a l m i n e r a l s have been r e p l a c e d . Iron-magnesium m i n e r a l s a r e g e n e r a l l y a l t e r e d to t r e m o l i t e - a c t i n o l i t e , c a r b o n a t e , c h l o r i t e and e p i d o t e . C a l c i c p l a g i o c l a s e i s commonly a l t e r e d to e p i d o t e , m u s c o v i t e - s e r i c i t e , c a r b o n a t e and a l b i t e .Commonly v e r y f i n e g r a i n e d q u a r t z i s found i n the groundmass, because s i l i c a i s g e n e r a l l y r e l e a s e d i n the a l t e r a t i o n of b a s a l t i c r o c k s (Moorehouse, 1959). P o t a s s i u m f e l d s p a r , where p r e s e n t , i s weakly s e r i c i t i z e d . H o r n b l e n d e , i n b a s a l t i c a n d e s i t e s , i s commonly p r o p y l i t i z e d and r e p l a c e d by t r e m o l i t e - a c t i n o l i t e , c h l o r i t e , b i o t i t e , c a l c i t e and opaques. In the b a s i c s c h i s t u n i t , p r o b a b l y a metamorphosed a l k a l i n e v o l c a n i c r o c k , p r i m a r y p l a g i o c l a s e i s a l t e r e d to a l b i t e and e p i d o t e , and pyroxene to h o r n b l e n d e and c h l o r i t e . In a d d i t i o n to abundant p o t a s s i u m f e l d s p a r i n the m a t r i x , d o l o m i t e rhombs a r e common t h r o u g h o u t . These a r e p o s s i b l y the r e s u l t of metasomatism accompanying o r e - f o r m i n g p r o c e s s e s . Page 27 TABLE 4.1: Summary of V o l c a n i c Rocks of the et a l . , 1977) Replacement M i n e r a l o g y and Te x t u r e s of Kutcho Formation (format a f t e r G e l i n a s PRIMARY MINERALS REPLACEMENT MINEF IALS TEXTURES OF SECONDARY MINERALS BASALT TO BASALTIC ANDESITE DACITE TO RHYOLITE CALCIC PLAGIOCLASE ALBITE MUSCOVITE-SERICITE CARBONATE CHLORITE EPIDOTE ALBITE <MUSCOVITE-SERICITE CARBONATE >CHLORITE >EPIDOTE PSEUDOMORPHOUS DECUSSATE OR SHEATH-LIKE RANDON BLEBS TO PSEUDOMORPHS DECUSSATE TO SHEATH-LIKE IRREGULAR BLEBS TO SUBHEDRAL HORNBLENDE TREMOt.ITE-ACTINOI.-ITS CHLORITE BIOTITE CARBONATE SHEATH-LIKE AGGREGATES CLOTS AND SHEATH-LIKE AGGREGATES BOOKS, CLOTS AND SHEATHS IRREGULAR MASSES, PSEUDOMORPHS AUGITE CARBONATE EPIDOTE MUSCOVITE CHLORITE QUARTZ PSEUDOMORPHS, IRREGULAR MASSES PSEUDOMORPHS, IRREGULAR BLEBS IRREGULAR MASSES IRREGULAR MASSES AND SHEATH-LIKE AGGREGATES SMALL IRREGULAR GRAiMS POTASSIUM FELDSPAR MUSCOVITE-SERICITE MUSCOVITE-SERICITE DECUSSATE QUARTZ MUSCOVITE SERICITE CARBONATE IRREGULAR MASSES ALONG FRACTURES IRREGULAR MASSES, PARTIAL PSEUDOMORPHS Page 28 D a c i t i c and r h y o l i t i c r o c k s are c h a r a c t e r i s t i c a l l y a l t e r e d to m u s c o v i t e , s e r i c i t e , carbonate and minor c h l o r i t e . In g e n e r a l s i l i c a - r i c h v o l c a n i c and v o l c a n i c l a s t i c r o c k s of the Kutcho Formation are l e s s a l t e r e d than t h e i r s i l i c a - p o o r c o u n t e r - p a r t s . P l a g i o c l a s e a l t e r a t i o n i s s i m i l a r to t h a t of b a s a l t i c r o c k s ; p l a g i o c l a s e i s r e p l a c e d by m u s c o v i t e , s e r i c i t e and carbonate w i t h l e s s e r amounts of e p i d o t e . Q u a r t z , p l a g i o c l a s e and l e s s a l t e r e d potassium f e l d s p a r are p a r t i a l l y r e p l a c e d by mus c o v i t e , s e r i c i t e and carbonate alo n g f r a c t u r e s and g r a i n b o u n d a r i e s . Large q u a r t z and f e l d s p a r c r y s t a l s are c o r r o d e d , crushed and e x h i b i t undulose e x t i n c t i o n . Annealed c r y s t a l l i n e mosaics of q u a r t z are s u g g e s t i v e of l a t e r r e c r y s t a l l i z a t i o n . A r g i l l i c r o c k s are composed mainly of a f i n e - g r a i n e d q u a r t z , white mica and c h l o r i t e . An a r g i l l a c e o u s l a y e r w i t h i n the b a s i c s c h i s t u n i t c o n t a i n e d the m i n e r a l assemblage q u a r t z , c h l o r i t e , b i o t i t e and s t i l p n o m e l a n e . Limestone l e nses i n upper Kutcho r o c k s and the o v e r l y i n g Sinwa Limestone are composed of r e c r y s t a l l i z e d c a l c i t e , minor q u a r t z , t h i n p a r t i n g s of f e t i d , carbonaceous m a t e r i a l and l o c a l l y d o l o m i t e . Page 29 4.3 M e t a s o m a t i c C h e m i c a l Changes T e x t u r a l e v i d e n c e p o i n t s to m e t a s o m a t i c a l t e r a t i o n of r o c k s of the Kutcho s u i t e . P a r t i c u l a l y w e l l documented, ar e c h e m i c a l changes i n c l o s e p r o x i m i t y to the m a s s i v e s u l p h i d e d e p o s i t ( B r i d g e , 1978, u n pub.). These changes near the o r e body i n c l u d e i n t r o d u c t i o n of S i 0 2 , K20, MgO and CaO and d e p l e t i o n of Na20. More w i d e s p r e a d c h e m i c a l changes i n Kutcho r o c k s , e v i d e n c e d i n a n a l y s e s of v o l a t i l e s , i n c l u d e the i n t r o d u c t i o n of H20 and C02. On a r e g i o n a l s c a l e c a l c i u m , l i b e r a t e d from f e l d s p a r a l t e r a t i o n , has been r e d i s t r i b u t e d as e p i d o t e and e p i d o t e - c a r b o n a t e v e i n s . These a l t e r a t i o n phenomena commonly accompany low grade metamorphism of b a s a l t s and a n d e s i t e s ( B a r t h , 1952; S m i t h , 1968; Ramberg, 1952). Q u a r t z , c h l o r i t e and e p i d o t e v e i n s a r e common and r e f l e c t a d d i t i o n and/or r e m o b i l i z a t i o n of e l e m e n t s . D e s p i t e the abundance of q u a r t z w i t h i n t h e h y d r o t h e r m a l a u r e o l e around the d e p o s i t , B r i d g e (1977, unpub.) s u g g e s t s t h a t t h e r e i s l i t t l e a d d i t i o n of s e c o n d a r y s i l i c a and t h a t most of the s i l i c a o r i g i n a t e d from s i l i c a - r i c h r h y o l i t e s . I n t r o d u c t i o n and/or r e m o b i l i z a t i o n of sodium i s e v i d e n c e d by a l b i t e v e i n i n g . The h i g h degree of s c a t t e r i n H a r k e r v a r i a t i o n d i agrams ( F i g . 5.11 and 5.12) of CaO, Na20 and K20 s u p p o r t s m i c r o s c o p i c e v i d e n c e f o r the m o b i l i t y of t h e s e e l e m e n t s . Page 30 4.4 M i n e r a l A s s e m b l a g e s and M e t a m o r p h i c C o n d i t i o n s Key m i n e r a l a s s e m b l a g e s i n m e t a v o l c a n i c and a r g i l l i c r o c k s of t h e K u t c h o F o r m a t i o n a r e g i v e n i n F i g u r e 4.1. B a s i c g r e e n s c h i s t s commonly c o n t a i n t h e a s s e m b l a g e e p i d o t e / c l i n o z o i s i t e , c h l o r i t e , c a l c i t e , b i o t i t e ( o r s t i l p n o m e l a n e ) , a l b i t e , w h i t e m i c a and m i n o r q u a r t z . A c i d i c m e t a v o l c a n i c r o c k s or q u a r t z - e y e s c h i s t s , c o n t a i n t h e a s s e m b l a g e w h i t e m i c a , p o t a s s i u m f e l d s p a r , q u a r t z , c h l o r i t e , p l a g i o c l a s e and c a l c i t e . A r g i l l i c r o c k s w i t h i n t h e b a s i c s c h i s t u n i t c o n t a i n t h e d i a g n o s t i c a s s e m b l a g e c h l o r i t e , b i o t i t e and s t i l p n o m e l a n e . S t i l p n o m e l a n e i s common i n l o w - g r a d e m a f i c r o c k s but may a l s o o c c u r i n i r o n - r i c h m e t a s e d i m e n t a r y r o c k s ( W i n k l e r , 1 9 7 4 ) . M i n e r a l a s s e m b l a g e s n o t e d i n t h e r o c k s i n d i c a t e t h a t t h e K u t c h o F o r m a t i o n has been metamorphosed w i t h i n t h e q u a r t z - a l b i t e - e p i d o t e - b i o t i t e s u b f a c i e s of t h e g r e e n s c h i s t f a c i e s ( G r eenwood, 1976, u n p u b . ) . The above m i n e r a l a s s e m b l a g e s p e r s i s t o v e r a w i d e p r e s s u r e i n t e r v a l ( 1 t o 7 kb) w i t h i n t h e t e m p e r a t u r e r a n g e 300 t o 450 d e g r e e s C e n t i g r a d e . S t i l p n o m e l a n e a l s o has been shown t o be s t a b l e i n t h e p r e s e n c e o f w h i t e m i c a a t 430 t o 460 d e g r e e s C e n t i g r a d e o v e r t h e p r e s s u r e i n t e r v a l 1 t o 7 kb ( W i n k l e r , Page 31 BARROVIAN OR KYANITE-SILLIMANITE FACIES SERIES GREENSCHIST FACIES: QUARTZ-ALBITE-EPIDOTE-BIOTITE.SUBFACIES FIGURE 4.1: Key Assemblages D e f i n i n g Metamorphic Grade of Rocks of the Kutcho F o r m a t i o n ; shown on ACF, AKF, and AFM Diagrams, f o r the Q u a r t z - A l b i t e - E p i d o t e - B i o t i t e S u b f a c i e s of the G r e e n s c h i s t F a c i e s ( i n d i c a t e d by s t i p p l e d a r e a s ) . ACF d i a g r a m a f t e r M i y a s h i r o ( 1 973); AKF and AFM diagrams a f t e r Greenwood (1976, unpub.) Page 32 1974). D o l o m i t e and q u a r t z i n s i l i c e o u s d o l o m i t i c l e n s e s r e m a i n e d s t a b l e d u r i n g metamorphism as no e v i d e n c e f o r the f o r m a t i o n of e i t h e r t a l c or t r e m o l i t e w i t h i n the l i m e s t o n e s was found . The r e a c t i o n ( 1 ) : d o l o m i t e + q u a r t z + H20 = t a l c + c a l c i t e + C02, o c c u r s o v e r the t e m p e r a t u r e i n t e r v a l of 350 to 470 d e g r e e s C e n t i g r a d e a t 1 kb, f o r a wide v a r i a t i o n i n C02 c o n c e n t r a t i o n s . The r e a c t i o n t e m p e r a t u r e i n c r e a s e s w i t h an i n c r e a s e i n C02 c o n c e n t r a t i o n . The l i m e s t o n e s were p r o b a b l y not s u b j e c t e d to s u f f i c i e n t l y h i g h t e m p e r a t u r e s to provoke the above r e a c t i o n . Metamorphic r e a c t i o n s i n v o l v i n g one or more v o l a t i l e components, such as (1) above, t e n d to be r e l a t i v e l y p r e s s u r e i n s e n s i t i v e , and do not p r o v i d e d e f i n i t i v e e s t i m a t e s of p r e s s u r e c o n d i t i o n s d u r i n g metamorphism. P r e s s u r e s e n s i t i v e m i n e r a l s such as the a l u m i n o - s i l i c a t e p o l y m o r p h s , a n d a l u s i t e , k y a n i t e or s i l l i m a n i t e have not been o b s e r v e d w i t h i n the K i n g Salmon a s s e m b l a g e . P h y s i c a l c h a r a c t e r i s t i c s and the d e f o r m a t i o n a l h i s t o r y of the r o c k s do i n d i c a t e , however, t h a t t h e y have been s u b j e c t e d to c o n s i d e r a b l e s t r a i n , p r o b a b l y under moderate p r e s s u r e . Page 33 4.5 Metamorphic Te x t u r e s F o l d i n g and t h r u s t i n g of the King Salmon assemblage has developed a pronounced, p e n e t r a t i v e f o l i a t i o n w i t h i n the r o c k s . The f o l i a t i o n i s marked by the alignment of micaceous m i n e r a l s , t r e m o l i t e - a c t i n o l i t e l a t h s , and f l a t t e n e d g r a i n s of e p i d o t e and c a r b o n a t e . T e x t u r a l f e a t u r e s noted d u r i n g t h i n s e c t i o n examination i n d i c a t e t h a t c o n s t i t u e n t m i n e r a l s have been s u b j e c t e d to extreme c a t a c l a s i s , presumably d u r i n g f o r m a t i o n of the a l l o c h t h o n . Common c a t a c l a s t i c t e x t u r e s i n c l u d e augen-shaped q u a r t z and f e l d s p a r g r a i n s , h i g h l y comminuted q u a r t z and f e l d s p a r c r y s t a l s , r e c r y s t a l l i z e d m i n e r a l aggregates w i t h i n p r e s s u r e shadows, and bent and f r a c t u r e d t w i n s i n f e l d s p a r and c a l c i t e , c r y s t a l s . 4 . 6 Timing of Metamorphism T e x t u r a l evidence suggests t h a t metamorphic r e c r y s t a l l i z a t i o n took p l a c e throughout the d e f o r m a t i o n a l event which a f f e c t e d the King Salmon assemblage. P r e k i n e m a t i c t e x t u r e s i n c l u d e : bent p l a g i o c l a s e g r a i n s w i t h d e f o r m a t i o n t w i n s , bent p l a t y g r a i n s , and f l a t t e n e d and deformed carbonate g r a i n s . Synkinematic t e x t u r e s i n c l u d e the alignment of p o r p h y r o b l a s t s Page 34 • p a r a l l e l t e x t u r e s f e l d s p a r to and s l i g h t l y d e f l e c t i n g the f o l i a t i o n . P o s t k i n e m a t i c i n c l u d e p o l y g o n a l a r c s of m i c a c e o u s m i n e r a l s , and o v e r p r i n t i n g of the m i c a c e o u s f o l i a t i o n . The f o l d i n g and metamorphism i s b r o a d l y s y n c h r o n o u s w i t h the K i n g Salmon t h r u s t i n g e v e n t . S t r a t i g r a p h i c and s t r u c t u r a l s t u d i e s ( T i p p e r , 1978) have shown t h a t r o c k s of t h e K i n g Salmon a l l o c h t h o n have been t h r u s t over Lower to M i d d l e J u r a s s i c v o l c a n o - s e d i m e n t a r y r o c k s . The Lower J u r a s s i c r o c k s a r e found i n i m b r i c a t e t h r u s t s h e e t s near the s o l e of the K i n g Salmon t h r u s t . Rocks of m i d d l e B a j o c i a n ( M i d d l e J u r a s s i c ) age, however, have not been i n v o l v e d i n t h r u s t i n g . T h r u s t i n g , f o l d i n g and metamorphism t h e r e f o r e p r o b a b l y o c c u r r e d between T o a r c i a n and p r e - m i d d l e B a j o c i a n t i m e . A younger K-Ar d a t e of 120 +_ 10 Ma f o r Kutcho s e r i c i t e may i n d i c a t e t h a t metamorphic r e c r y s t a l l i z a t i o n c o n t i n u e d to E a r l y C r e t a c e o u s t i m e . The main p e r i o d of d e f o r m a t i o n and metamorphism i s p r o b a b l y r e l a t e d to a T o a r c i a n t o p r e - m i d d l e B a j o c i a n o r o g e n i c e v e n t . Minor metamorphic r e c r y s t a l l i z a t i o n may have c o n t i n u e d to E a r l y C r e t a c e o u s t i m e . Page 35 CHAPTER 5 CHEMISTRY 5 . 1 I n t r o d u c t i o n N i n e t y - t w o a n a l y s i s of v o l c a n o - s e d i m e n t a r y r o c k s from the Kin g Salmon assemblage a r e d i s c u s s e d i n t h i s c h a p t e r . For c o m p a r a t i v e p u r p o s e s , s i x a n a l y s e s from the T a k l a F o r m a t i o n and e i g h t a n a l y s e s from the Cache Creek Group a r e a l s o r e v i e w e d . A n a l y s e s c o v e r a wide r a n g e of c o m p o s i t i o n s w i t h i n the s u b a l k a l i n e s e r i e s as d e f i n e d by I r v i n e and B a r a g a r ( 1 9 7 1 ) . Compos i t i o n a l l y r o c k s range from t h o l e i i t i c , c a l c a l k a l i n e and h i g h a l u m i n a b a s a l t to c a l c a l k a l i n e r h y o l i t e . I r v i n e and B a r a g a r (1971) r o c k names have been g i v e n to a l l r o c k s of the Kutcho f o r m a t i o n ( A p p e n d i x I I ) . T h i s n o m e n c l a t u r e i s based on p l o t s of n o r m a t i v e c o l o u r i n d e x v e r s u s n o r m a t i v e p l a g i o c l a s e , and m o d i f i e d as K - r i c h to K-poor as d e f i n e d by a t r i a n g u l a r p l o t of n o r m a t i v e a l b i t e , o r t h o c l a s e and a n o r t h i t e . A l t h o u g h t h i s c l a s s i f i c a t i o n was d e r i v e d from C e n o z o i c to Recent v o l c a n i c r o c k s , many a u t h o r s have used modern i s l a n d a r c n o m e n c l a t u r e f o r o l d e r r o c k s ( e . g . Goodwin, 1977). I r v i n e and Page 36 B a r a g a r (1971) have a l s o a p p l i e d the diagrams to o l d e r r o c k s u i t e s from the • Y e l 1 o w k n i f e G r e e n s t o n e B e l t , N.W.T., and Noranda, Quebec. S e v e r a l p l o t s of c h e m i c a l d a t a have been u t i l i z e d to d e s c r i b e the v o l c a n i c r o c k s . Due to the h i g h m o b i l i t y of components such a s : K20, Na20, CaO, Rb, Sr and to a l e s s e r e x t e n t S i 0 2 and Fe203 d u r i n g s e c o n d a r y p r o c e s s e s such as w e a t h e r i n g and metamorphism ( D a v i e s et a l . , 1979) the v a l i d i t y of i n f o r m a t i o n d e r i v e d from p l o t s i n v o l v i n g t h e s e e l e m e n t s may be q u e s t i o n a b l e . Many a u t h o r s , ( H a r t e t a l . , 1970; G e l i n a s e t a l . , 1977; S t r o n g , 1977) a r g u e , however, t h a t d e s p i t e the h i g h m o b i l i t y of t h e s e e l e m e n t s t h e r e i s l i t t l e change i n o v e r a l l b u l k c o m p o s i t i o n and t h a t u s e f u l g e n e r a l i z a t i o n s may t h e r e f o r e be d e r i v e d . Other l e s s m o b i l e components, i n c l u d i n g T i 0 2 , A1203, P205, Z r , Cr and Co ( D a v i e s e t a l . , 1979; F l o y d and W i n c h e s t e r , 1977) may p r o v i d e more d e f i n i t i v e i n f o r m a t i o n . 5 . 2 A n a l y t i c a l T e c h n i q u e and E r r o r p e r f o r m e d by t h e Su r v e y of Canada, P205, T i 0 2 , and S. C h e m i c a l a n a l y s e s ( A p p e n d i x I I I ) were A n a l y t i c a l C h e m i s t r y S e c t i o n of the G e o l o g i c a l Ottawa. XR.F was used f o r MnO, Na20, CaO, K20, Page 37 FeO, C02 and H20 were d e t e r m i n e d by c h e m i c a l methods; F and CI were a n a l y z e d u s i n g the s p e c i f i c i o n e l e c t r o d e method. T r a c e e l e m e n t s were a n a l y z e d by e m i s s i o n s p e c t r o s c o p y . E s t i m a t e d a c c u r a c i e s f o r major e l e m e n t s a r e +_ 1 % f o r S i 0 2 , A1203, Fe203, MgO, CaO, K20 and T i 0 2 ; + 2 % f o r MnO, Na20, P205 and S, and +_ 10 % f o r Rb. A c c u r a c i e s f o r t r a c e e l e m e n t s a r e +_ 15 %. Minimum d e t e c t a b l e c o n c e n t r a t i o n s a r e : Be 3 ppm; Yb 4 ppm; Ag, Ba and Cr 5 ppm; Cu 7 ppm; N i , Co and Sr 10 ppm; V and Zr 20 ppm; Y 40 ppm; Mn, B and Mo 50 ppm; T i and La 100 ppm; Ce, Zn and Sn 200 ppm; Sb 500 ppm; Pb 700 ppm and As 2000 ppm. Ag, As, Be, Ce, L a , Mo, Pb, Sb, Sn and Yb were below d e t e c t a b l e l i m i t s i n a l l samples a n a l y z e d . Only t h r e e samples showed d e t e c t a b l e B. Page 38 5.3 C l a s s i f i c a t i o n of V o l c a n i c Rocks of the Kutcho F o r m a t i o n  and Cache Creek Group 5.3.1 G e n e r a l S t a t e m e n t S e v e r a l c l a s s i f i c a t i o n schemes f o r d e f i n i n g r o c k names, c h e m i c a l c h a r a c t e r i s t i c s and t e c t o n i c e n v i r o n m e n t s of v o l c a n i c r o c k s a r e i n the l i t e r a t u r e . These a r e based on v a r i o u s p a r a m e t e r s i n c l u d i n g major and t r a c e element c o n c e n t r a t i o n s , c o l o u r i n d i c e s and n o r m a t i v e m i n e r a l s ( I r v i n e and B a r a g a r , 1976; M i d d l e m o s t , 1973; W i n c h e s t e r and F l o y d , 1978; F l o y d and W i n c h e s t e r , 1977; B a r a g a r and Goodwin, 1969). T h i s s e c t i o n c h e m i c a l l y c l a s s i f i e s r o c k s of the Kutcho F o r m a t i o n , T a k l a F o r m a t i o n and Cache Cr e e k Group, and e s t a b l i s h e s a c o n s i s t e n t n o m e n c l a t u r e f o r t h e i r c o n t a i n e d r o c k u n i t s . The b a s i c s c h i s t u n i t of the Kutcho F o r m a t i o n ( F i g . 3.1) i s t r e a t e d s e p a r a t e l y t h r o u g h o u t the d i s c u s s i o n because i t d i s p l a y s anomalous c h e m i c a l c h a r a c t e r i s t i c s . S a m p l e names and l o c a t i o n s and a n a l y t i c a l d a t a from the t h e s i s a r e a a r e i n A p p endix I I and I I I , r e s p e c t i v e l y . C o n d i e (1976) s u g g e s t s t h a t l i t t l e or no change i n c o n c e n t r a t i o n o c c u r s f o r T i , Y, Z r , Zn, C r , V, S r , Co and Ni Page 39 d u r i n g metamorphism and D a v i e s e t a l . , (1979) c o n c u r t h a t Y, Zr Cr , Co, Ni and T i a r e r e l a t i v e l y immobile d u r i n g s e c o n d a r y p r o c e s s e s ; S r , however, i s v e r y m o b i l e . I t i s r e a s o n a b l e to assume, t h e n , t h a t most of the above t r a c e element c o n c e n t r a t i o n s of the Kutcho s u i t e a r e l i t t l e a f f e c t e d by metamorphism and w e a t h e r i n g and may c a u t i o u s l y be compared to d a t a from modern o r o g e n i c z o n e s . Immobile t r a c e e l e m e n t s such as C r , T i , Z r , Y and more m o b i l e Sr have been used by F l o y d and W i n c h e s t e r (1977) and P e a r c e (1974) to c l a s s i f y and d e f i n e e n v i r o n m e n t s of d e p o s i t i o n f o r v o l c a n i c r o c k s . W i n c h e s t e r and F l o y d (1976) s t a t e t h a t the " u t i l i z a t i o n of immobile e l e m e n t s e n a b l e s a more m e a n i n g f u l i n t e r p r e t a t i o n t o be p l a c e d on a n c i e n t v o l c a n i c s u i t e s i n terms of magma type and degree of d i f f e r e n t i a t i o n " . A d v a n t a g e s to the use of such immobile e l e m e n t s i n c l u d e t h e i r l a r g e v a r i a t i o n i n c o n c e n t r a t i o n between magma t y p e s , t h e i r i n s e n s i t i v i t y to s e c o n d a r y p r o c e s s e s , and the r e l a t i v e ease w i t h which t h e y can be measured ( P e a r c e , 1974). Drawbacks i n t h e i r use a r e t h a t t h e i r a p p l i c a t i o n i s l i m i t e d to r o c k s of b a s i c c o m p o s i t i o n s and the f a c t t h a t e l e m e n t s o f t e n o c c u r i n c o n c e n t r a t i o n s below d e t e c t a b l e l i m i t s f o r s t a n d a r d a n a l y t i c a l e quipment. Rocks of t h e Kutcho F o r m a t i o n a r e m e t a s o m a t i z e d , the most Page 40 O b v i o u s r e s u l t of which i s a b n o r m a l l y h i g h amounts of c a l c i t e (up to 24 p e r c e n t CaO) i n the v o l c a n i c r o c k s . E n r i c h m e n t and d e p l e t i o n of CaO, Na20 and K20 i n r o c k s near m a s s i v e s u l p h i d e m i n e r a l i z a t i o n may a l s o have s i g n i f i c a n t l y a l t e r e d o r i g i n a l b u l k c o m p o s i t i o n s . CIPW n o r m a t i v e m i n e r a l s , p r e s e n t e d i n Appendix I I I , a r e not d i s c u s s e d i n d e t a i l due to m e t a s o m a t i c c h a n g e s . 5.3.2 Rock Names Rocks have been named u s i n g both a d e s c r i p t i v e f i e l d term and the I r v i n e and B a r a g a r c l a s s i f i c a t i o n ( A p p e n d i x I I ) . The b a s i s f o r the I r v i n e and B a r a g a r n o m e n c l a t u r e has been d i s c u s s e d i n i n t r o d u c t o r y comments, but f u r t h e r comment on the r e l i a b i l i t y of the c l a s s i f i c a t i o n s ystem i s i n o r d e r . The c l a s s i f i c a t i o n scheme i s based on the p a r a m e t e r s Na20, CaO, and K20 c o n c e n t r a t i o n s , but c o n c e n t r a t i o n s of t h e s e e l e m e n t s may change d u r i n g metamorphism making a p p l i c a t i o n of t h i s c l a s s i f i c a t i o n system s u s p e c t ( P e a r c e , 1975). The I r v i n e and B a r a g a r c l a s s i f i c a t i o n can be u s e f u l , but c a r e must be t a k e n . Examples i l l u s t r a t i n g c l a s s i f i c a t o r y problems i n c l u d e : a c h l o r i t e , s e r i c i t e s c h i s t (48.3 % S i 0 2 ) c l a s s i f i e d as a c a l c - a l k a l i n e d a c i t e and a c o a r s e - b l a d e d f e l d s p a r and c h l o r i t e s c h i s t (53.5 % S i 0 2 ) c l a s s i f i e d as a c a l c - a l k a l i n e r h y o l i t e . Both samples have anomalous K20 and CaO c o n c e n t r a t i o n s . N e v e r t h e l e s s Page 41 t h i s method i s g e n e r a l l y u s e f u l . U s i n g t h i s c l a s s i f i c a t i o n scheme, r o c k s of the Kutcho s u i t e a r e p r e d o m i n a n t l y c a l c - a l k a l i n e b a s a l t to r h y o l i t e . Rocks of the T a k l a F o r m a t i o n a r e t h o l e i i t i c and c a l c - a l k a l i n e b a s a l t and a n d e s i t e ; t h o s e of the Cache Cre e k Group a r e d o m i n a n t l y t h o l e i i t i c b a s a l t s . 5.3.2.1 N o r m a t i v e C o l o u r Index V e r s u s N o r m a t i v e A n o r t h i t e N o r m a t i v e c o l o u r i n d e x p l o t t e d a g a i n s t n o r m a t i v e a n o r t h i t e ( F i g . 5.1) can be a u s e f u l method f o r d i s c r i m i n a t i n g v a r i o u s magma t y p e s ( I r v i n e and B a r a g a r , 1971; B a r a g a r and Goodwin, 1969). N o r m a t i v e a n o r t h i t e may be a f f e c t e d by s e c o n d a r y p r o c e s s e s ( I r v i n e and B a r a g a r , 1976) making t h i s p l o t s u s p e c t f o r use i n a l t e r e d v o l c a n i c t e r r a n e s . D e s p i t e the degree of a l t e r a t i o n and s u b s e q u e n t m o b i l i t y of Na20 and CaO i n A r c h e a n r o c k s , B a r a g a r and Goodwin (1976) use t h i s p l o t to d i f f e r e n t i a t e r o c k t y p e s i n a l t e r e d v o l c a n i c t e r r a n e s . Data have been p l o t t e d on a n o r m a t i v e c o l o u r i n d e x v e r s u s n o r m a t i v e a n o r t h i t e d i a g r a m ( F i g . 5 . 1 ) . S o l i d l i n e s a t d i a g o n a l s to axes of the dia g r a m a r e d i v i s i o n s between r o c k t y p e s as d e f i n e d by I r v i n e and B a r a g a r ( 1 9 7 1 ) . Dashed l i n e s p a r a l l e l i n g d iagram axes r e p r e s e n t the f o u r f i e l d s of B a r a g a r and Goodwin ( 1 9 7 6 ) . Page 42 Irvine and Baragar _ 1971 Baragar and Goodwin , 1969 Ab + An LEGEND • KUTCHO FORMATION o BASIC SCHIST "x ROCKS NORTH OF THE KUTCHO FAULT + TAKLA FORMATION 4 CACHE CREEK GROUP FIGURE 5.1: N o r m a t i v e C o l o u r Index v e r s u s N o r m a t i v e A n o r t h i t e Diagram; Rocks of the Cry Lake Map Area Page 43 Most r o c k s from the Kutcho s u i t e p l o t i n F i g u r e 5.1 i n the b a s a l t or r h y o l i t e f i e l d s but d a c i t e i s a l s o common. The l i m i t s of t h i s p l o t , when d e a l i n g w i t h h i g h l y a l t e r e d or anomalous r o c k s , i s w e l l i l l u s t r a t e d i n the i n t e r p r e t a t i o n of samples of the b a s i c s c h i s t u n i t . C o m p o s i t i o n a l l y , s i l i c a v a l u e s a r e t h o s e of b a s a l t s and b a s a l t i c a n d e s i t e s , y e t due to low CaO c o n c e n t r a t i o n s , and t h e r e f o r e low n o r m a t i v e a n o r t h i t e , t h e s e r o c k s p l o t m a i n l y i n the r h y o l i t e and d a c i t e f i e l d s . Rocks of the T a k l a F o r m a t i o n p l o t g e n e r a l l y i n the b a s a l t and a n d e s i t e f i e l d s ; r o c k s of the Cache Cre e k Group p l o t l a r g e l y i n the b a s a l t f i e l d . 5.3.2.2 N o r m a t i v e A l b i t e - A n o r t h i t e - O r t h o c l a s e P r o j e c t i o n Data p l o t t e d i n F i g u r e 5.2, a n o r m a t i v e a l b i t e -a n o r t h i t e - o r t h o c l a s e p r o j e c t i o n ( I r v i n e and B a r a g a r , 1976), s u g g e s t s t h a t r o c k s of the Kutcho F o r m a t i o n a r e h e t e r o g e n e o u s . Samples p l o t e r r a t i c a l l y i n the s o d i c , a v e r a g e and p o t a s s i u m r f i e l d s i r r e s p e c t i v e of r o c k t y p e s . The a p p a r e n t h e t e r o g e n e i t y a f u n c t i o n of a l t e r a t i o n . Thus a l t e r e d r o c k s c a n n o t be p l o t t e d e f f e c t i v e l y on the n o r m a t i v e a l b i t e - a n o r t h i t e - o r t h o c l a s e p r o j e c t i o n . T h i s i s e x e m p l i f i e d by samples from the b a s i c s c h i u n i t t h a t p l o t m a i n l y i n d a c i t e and r h y o l i t e f i e l d s . Rocks of i c h i s s t the Page 44 FIGURE 5.2: A l b i t e - A n o r t h i t e - O r t h o c l a s e Diagram f o r Rocks of the Cry Lake Map Area ( d i a g r a m a f t e r I r v i n e and B a r a g a r , 1976) Page 45 T a k l a Cache p l o t s F o r m a t i o n p l o t e r r a t i c a l l y on the p r o j e c t i o n . Rock Creek Group p l o t d o m i n a n t l y i n K - r i c h b a s a l t f i e l d as K-poor b a s a l t and one p l o t s as s o d i c r h y o l i t e ) . s of the s ( one 5.3.2.3 S i 0 2 V e r s u s Z r / T i 0 2 The S i 0 2 v e r s u s Z r / T i 0 2 d i a g r a m ( F i g . 5.3) has been used by F l o y d and W i n c h e s t e r (1977) and W i n c h e s t e r and F l o y d (1976) to d e f i n e b o t h r o c k t y p e and a l k a l i n e v e r s u s s u b a l k a l i n e c h e m i s t r y . R e s u l t s d e r i v e d from t h i s p l o t a r e s i m i l a r to t h o s e d e r i v e d from the p l o t of n o r m a t i v e c o l o u r i n d e x v e r s u s n o r m a t i v e a n o r t h i t e d e f i n e d by I r v i n e and B a r a g a r (1976) w i t h most samples of the Kutcho s u i t e p l o t t i n g i n the s u b a l k a l i n e b a s a l t and r h y o l i t e f i e l d s . T here i s a marked absence of sample p o i n t s i n the a n d e s i t e f i e l d . Samples of the b a s i c s c h i s t p l o t m a i n l y i n a l k a l i n e b a s a l t f i e l d s w i t h one sample i n the t r a c h y b a s a l t -n e p h e l i n e f i e l d . These r e s u l t s c o n t r a s t m a r k e d l y from r e s u l t s d e r i v e d from the n o r m a t i v e c o l o u r i n d e x v e r s u s n o r m a t i v e a n o r t h i t e d iagram ( F i g . 5.1) i n which samples from the b a s i c s c h i s t p l o t d o m i n a n t l y i n the r h y o l i t e and d a c i t e f i e l d s d e s p i t e t h e i r low s i l i c a c o n c e n t r a t i o n . The T a k l a F o r m a t i o n p l o t s d o m i n a n t l y i n the a n d e s i t e f i e l d . The Cache Creek Group g e n e r a l l y p l o t s i n the a n d e s i t e f i e l d . The S i 0 2 v e r s u s Z r / T i 0 2 d i a g r a m p r o v i d e s an Page 46 84 80 76 72 68 64 CN O fr" 56 52 48 44 40 RHYOLITE R H Y O O A C I T E D A C I T E . ANDEStTE C O M M E N D I T E P A N T E U E R I T E LEGEND S U B A U A T I N E / B A S A L T ' J l_ 1 1 1 1 1 / / B A S A N I T E M T R A C H Y B A S A N I T I C N E P H E L E N I T E ' I I I I l - l I I I . . •00' 005 .01 .05 I Z r / T i 0 2 J — i i i — i i.o • KUTCHO FORMATION o BASIC SCHIST x ROCKS NORTH OF THE KUTCHO FAULT + TAKLA FORMATION • CACHE CREEK GROUP FIGURE 5.3: S i 0 2 v e r s u s Z r / T i 0 2 Diagram f o r Rocks of the Cry Lake Map A r e a Page 47 e f f e c t i v e c l a s s i f i c a t i o n scheme f o r a l t e r e d r o c k s e n c o u n t e r e d i n the t h e s i s a r e a . 5.3.3 C a l c - A l k a l i n e V e r s u s A l k a l i n e Rocks of t h e Kutcho s u i t e a r e d o m i n a n t l y c a l c - a l k a l i n e , but the b a s i c s c h i s t u n i t i s g e n e r a l l y a l k a l i n e . S e v e r a l d i a g r a m s , i n v o l v i n g d i f f e r e n t e l e m e n t a l p a r a m e t e r s have been employed t o d e t e r m i n e the c h a r a c t e r of t h e Kutcho s u i t e and i n c l u d e the AFM dia g r a m ( I r v i n e and B a r a g a r , 1976), a l k a l i s v e r s u s s i l i c a d i a g r a m ( I r v i n e and B a r a g a r , 1976; MacDonald and K a t s u r a , 1964), A1203 v e r s u s n o r m a t i v e a n o r t h i t e diagram ( I r v i n e and B a r a g a r , 1976), and o l i v i n e - n e p h e l i n e - q u a r t z diagram ( I r v i n e and B a r a g a r , 1976). 5.3.3.1 AFM Diagram Data p l o t t e d on an AFM Diagram ( F i g . 5.4) s u g g e s t s r o c k s of the Kutcho s u i t e , i n c l u d i n g t h o s e of the b a s i c s c h i s t , a r e d o m i n a n t l y c a l c - a l k a l i n e . A l i m i t e d number of samples p l o t w i t h i n the t h o l e i i t i c f i e l d d e f i n e d by I r v i n e and B a r a g a r ( 1 9 7 6 ) . T h o l e i i t i c b a s i c r o c k s a r e common i n modern a r c e n v i r o n m e n t s , Page 48 N a 20+ K 20 FIGURE 5.4: AFM Diagram f o r Rocks of the Cry Lake Map Area ( a f t e r I r v i n e and B a r a g a r , 1971) Page 49 p a r t i c u l a r l y i n i n i t i a l s t a g e s of development ( M i y a s h i r o , 1974). D e s p i t e the h i g h m o b i l i t y of a l k a l i s d u r i n g w e a t h e r i n g and metamorphism ( D a v i e s e t a l . , 1979) t h i s p l o t i s used e x t e n s i v e l y f o r the c l a s s i f i c a t i o n of a l t e r e d v o l c a n i c s u i t e s and a p p e a r s r e a s o n a b l y e f f e c t i v e a c c o r d i n g to I r v i n e and B a r a g a r ( 1 9 7 6 ) . T h i s i s because o f the ease w i t h which the major element c o n c e n t r a t i o n s can be measured, and because of the abundance of e x i s i t i n g d a t a p l o t t e d on AFM diagrams t h a t a r e a v a i l a b l e f o r c o m p a r a t i v e p u r p o s e s . Sample d a t a from the Kutcho a r e a s t r o n g l y r e s e m b l e s p l o t s of modern, o r o g e n i c , c a l c - a l k a l i n e s u i t e s ( M c B i r n e y , 1969; I r v i n e and B a r a g e r , 1971; P i c h l e r and Z e i l , 1969). 5.3.3.2 A l k a l i s v e r s u s S i l i c a Diagram Data p l o t t e d on the a l k a l i s v e r s u s s i l i c a d i a g r a m ( F i g . 5.5) show t h a t r o c k s of the Kutcho s u i t e are d o m i n a n t l y s u b a l k a l i n e . The b a s i c s c h i s t p l o t s i n the a l k a l i n e f i e l d as do r o c k s of the T a k l a F o r m a t i o n (Monger, 1976) and N i c o l a F o r m a t i o n ( P r e t o , 1976). Rocks of the Cache Cr e e k Group a r e s u b a l k a l i n e . Page 50 LEGEND • KUTCHO FORMATION _ i i L — a I - I I 1 1 L-40 49 30 5 5 60 63 70 75 30 % SiC>2 FIGURE 5.5: A l k a l i s v e r s u s S i l i c a Diagram f o r Rocks of the Cry Lake Map A r e a ( a f t e r I r v i n e and B a r a g a r , 1971) Page 51 5.3.3.3 A1203 v e r s u s N o r m a t i v e A n o r t h i t e Data p l o t t e d on an A1203 v e r s u s N o r m a t i v e A n o r t h i t e d i a g r a m ( F i g . 5.6) a r e randomly d i s t r i b u t e d i n both the c a l c - a l k a l i n e and t h o l e i i t i c f i e l d s as d e f i n e d by I r v i n e and B a r a g a r ( 1 9 7 6 ) . The h i g h m o b i l i t y of CaO, Na20 and low to moderate m o b i l i t y o f A1203 d u r i n g a l t e r a t i o n ( P e a r c e , 1974) p r o b a b l y a c c o u n t s f o r the deg r e e of s c a t t e r and the e r r a t i c d i s t r i b u t i o n of d a t a . Rocks of the Cache Cr e e k Group p l o t d o m i n a n t l y i n the. t h o l e i i t i c f i e l d and c o n c u r w i t h t h o s e from the AFM d i a g r a m . In g e n e r a l the p a r a m e t e r s of the A1203 v e r s u s N o r m a t i v e A n o r t h i t e diagram appear to be too s e n s i t i v e to a l t e r a t i o n d u r i n g s e c o n d a r y p r o c e s s to a l l o w use when d e a l i n g w i t h a l t e r e d r o c k s such as t h o s e c o n s i d e r e d i n t h i s t h e s i s . 5.3.3.4 O l i v i n e - N e p h e l i n e - Q u a r t z P r o j e c t i o n The o l i v i n e - n e p h e l i n e - q u a r t z p r o j e c t i o n ( I r v i n e and B a r a g a r , 1976; Yoder and T i l l e y ; 1962) i s f o r c l a s s i f y i n g b a s a l t i c r o c k s , but i t a p p e a r s to be e f f e c t i v e i n c l a s s i f y i n g r o c k s of more s i l i c i c c o m p o s i t i o n s . I r v i n e and B a r a g a r (1976) s u g g e s t t h a t the diagram g i v e s good d i s c r i m i n a t i o n between r o c k t y p e s , even w i t h Page 52 CALC A L K A L I N E F I E L D 2 2 h I r v ine-t -Baragar 1971 20k/ • o o r 4 • ° ^ # > . c o • • 12 r «. i n _ THOLEI IT IC FIELD I O C 1 1 L 1 i I i i L_ 90 80 70 60 50 40 30 20 10 A n % = A n / A n + A b x 100 LEGEND • KUTCHO FORMATION o BASIC SCHIST x ROCKS NORTH OF THE KUTCHO FAULT + TAKLA FORMATION 4 CACHE CREEK GROUP FIGURE 5.6: A1203 % v e r s u s N o r m a t i v e A n o r t h i t e Diagram f o r Rocks of the Cry Lake Map Area ( a f t e r I r v i n e and B a r a g a r , 1971) Page 53 Ol FIGURE 5.7: O l i v i n e - N e p h e l i n e - Q u a r t z P r o j e c t i o n of V o l c a n i c r o c k s of the Cry Lake Map A r e a . Heavy s o l i d l i n e d i v i d e s f i e l d s of a l k a l i n e and s u b a l k a l i n e r o c k s ( I r v i n e and B a r a g a r , 1971). L i g h t s o l i d l i n e i s the t r a c e of the " c r i t i c a l p l a n e of s i l i c a s a t u r a t i o n " (Yoder and T i l l e y , 1971). Page 54 a l t e r e d r o c k s . The o l i v i n e - n e p h e l i n e - q u a r t z p r o j e c t i o n ( F i g . 5.7) c h a r a c t e r i z e s r o c k s from the Kutcho s u i t e , i n c l u d i n g samples from the b a s i c s c h i s t u n i t , as s u b a l k a l i n e . In c o n t r a s t , the b a s i c s c h i s t i s c l a s s i f i e d as a l k a l i n e on the a l k a l i s v e r s u s s i l i c a d i a g r a m . Rocks of t h e Cache Cr e e k Group a l s o p l o t i n t h e s u b a l k a l i n e f i e l d . 5.3.4 T e c t o n i c E n v i r o n m e n t The t e c t o n i c e n v i r o n m e n t of v o l c a n i c s u i t e s can be a s c e r t a i n e d u s i n g d i a g r a m s i n c l u d i n g T i ppm v e r s u s Zr ppm ( P e a r c e , 1975; P e a r c e and Cann, 1973); T i ppm v e r s u s Cr ppm ( P e a r c e , 1975); Zr ppm v e r s u s Cr ppm (Bloxam and L e w i s , 1972); Zr ppm v e r s u s T i 0 2 % (Bloxam and L e w i s , 1972); T i 0 2 %- Zr ppm- Cr ppm (Bloxam and L e w i s , 1972); MgO - F e O ( t o t a l ) - A1203 ( P e a r c e e t a l . , 1976), and T i 0 2 - K20 - P205 ( P e a r c e et a l . , 1975; Y e l l u r , 1977). As argued i n S e c t i o n 5.3, T i , Z r , Y and Cr a r e u s e f u l w i t h a l t e r e d r o c k s (Bloxam and L e w i s , 1972; P e a r c e , 1975) t h o s e i n v o l v i n g K20 a r e s u s p e c t . The T i ppm v e r s u s Zr ppm ( P e a r c e and Cann, 1973; P e a r c e , 1975) and MgO - F e O ( t o t a l ) - A1203 ( P e a r c e et a l . , 1976) diagrams p r o v e d most u s e f u l i n t h i s s t u d y . Page 55 5.3.4.1 " T i t a n i u m v e r s u s Z i r c o n i u m " Diagram The T i ppm v e r s u s Zr ppm d i a g r a m ( F i g . 5.8) has o n l y been a p p l i e d to r o c k s of b a s a l t i c c o m p o s i t i o n ( P e a r c e , 1974; P e a r c e and Cann, 1973). T i and Zr c o n c e n t r a t i o n s i n r o c k s w i t h more a c i d i c c o m p o s i t i o n s g e n e r a l l y do not p l o t i n f i e l d s d e f i n e d by P e a r c e ( 1 9 7 4 ) . Many d a t a p o i n t s f o r r o c k s of the Kutcho s u i t e , i n c l u d i n g two b a s i c s c h i s t a n a l y s e s , a r e out of the c o m p o s i t i o n a l range of the d i a g r a m . Rocks of the Kutcho s u i t e p l o t d o m i n a n t l y i n the i s l a n d a r c b a s a l t and c a l c - a l k a l i n e f i e l d s . The b a s i c s c h i s t u n i t p l o t s as c a l c - a l k a l i n e , c o n f l i c t i n g w i t h r e s u l t s from F i g u r e 5.5 t h a t i n d i c a t e d an a l k a l i n e c h a r a c t e r . The c a l c - a l k a l i n e n a t u r e of r o c k s of the Kutcho s u i t e c o n c u r s w i t h r e s u l t s from F i g u r e 5.7. In F i g u r e 5.8 r o c k s of t h e T a k l a F o r m a t i o n p l o t i n the c a l c - a l k a l i n e b a s a l t f i e l d ; r o c k s of the Cache Creek Group p l o t i n the i s l a n d a r c b a s a l t and the ocean f l o o r b a s a l t f i e l d s . 5.3.4.2 MgO - F e O ( t o t a l ) - A1203 Diagram MgO, FeO, Fe203 and A1203, o n l y s l i g h t l y m o b i l e d u r i n g metamorphism and w e a t h e r i n g ( P e a r c e , 1975), a r e r e a s o n a b l e Page 56 1 0 , 0 0 0 . 9 6 0 0 -A + B- I s l a n d A r c B a s a l t F i e l d B + C- C a l c a l k a l i n e B a s a l t F i e l d B + D - Ocean F l o o r B a s a l t S 8 0 0 _ 8 0 0 0 -7 2 0 0 -( **• ) Arrows i n d i c a t e rocks w i t h g r e a t e r than 62% S i 0 2 . 16 B o • 7 — J— i — i — i J L i i i ' • • • • so I I I I I I t i l l LEGEND • KUTCHO FORMATION o BASIC SCHIST x ROCKS NORTH OF THE KUTCHO FAULT + TAKLA FORMATION • CACHE CREEK GROUP 100 I S O ppm Zr 2 5 0 FIGURE 5.8: Titaniurn(ppm) v e r s u s Z i r c o n i u m ( p p m ) Diagram f o r Rocks of the Cry Lake Map Area ( a f t e r P e a r c e , 1974) Page 57 p a r a m e t e r s to use i n d e f i n i n g t e c t o n i c e n v i r o n m e n t s . Samples w i t h low s i l i c a (51 to 56 % S i 0 2 ) appear to be s e n s i t i v e t e c t o n i c i n d i c a t o r s ( P e a r c e e t a l . , 1976). The MgO - F e O ( t o t a l ) - A1203 di a g r a m of F i g u r e 5.9 has been subduvuded u s i n g C e n o z o i c r o c k s , but a l s o has been a p p l i e d to A r c h e a n r o c k s w i t h some s u c c e s s ( P e a r c e e t a l . , 1976). Low s i l i c a samples from t h e Kutcho s u i t e p l o t l a r g e l y i n t h e " o r o g e n i c f i e l d " d e f i n e d by P e a r c e et a l . , (1976) and o n l y a few d a t a o v e r l a p i n t o the "ocean f l o o r and r i d g e " and " c o n t i n e n t a l " f i e l d s . The d i a g r a m i s not i n t e n d e d f o r s i l i c a - r i c h s a m p l e s . Rocks of the T a k l a F o r m a t i o n p l o t both i n the ocean f l o o r and c a l c - a l k a l i n e b a s a l t f i e l d s ; t h o s e of the Cache Creek Group p l o t i n the "ocean f l o o r and r i d g e " f i e l d . 5.4 Major Element C h e m i s t r y o f Rocks of the Kutcho F o r m a t i o n  and O t h e r R e l a t e d Rocks Harker v a r i a t i o n d i a grams have been p l o t t e d i n F i g u r e s 5.11 and 5.12 f o r major and minor e l e m e n t s f o r r o c k s of the Kutcho s u i t e . Data from Monger of the G e o l o g i c a l S u r v e y of Cana.da have a l s o been p l o t t e d f o r r o c k s of the T a k l a F o r m a t i o n and Cache Page 58 FeO Total FIGURE 5.9: MgO - FeO ( t o t a l ) - A1203 Diagram f o r Rocks of the Cry Lake Map A r e a . S o l i d l i n e s d i v i d e t e c t o n i c e n v i r o n m e n t s ( a f t e r P e a r c e e t a l . , 1977) Page 59 Creek Group f o r c o m p a r a t i v e p u r p o s e s . T a b l e 5.1 g i v e s a v e r a g e . c o n c e n t r a t i o n s of e l e m e n t s i n b a s i c , i n t e r m e d i a t e and a c i d i c r o c k s . Major element d i a g r a m s show l i t t l e d e v i a t i o n s from f a m i l i a r t r e n d s ( C a r m i c h a e l , T u r n e r and Verhoogen, 1974). A1203, Fe203, FeO, MgO, CaO and T i 0 2 a l l d e c r e a s e i n c o n c e n t r a t i o n w i t h i n c r e a s i n g S i 0 2 . Na20 and K20 f o r r o c k s of the Kutcho F o r m a t i o n do not i n c r e a s e m a r k e d l y i n c o n c e n t r a t i o n w i t h i n c r e a s i n g S i 0 2 as i s g e n e r a l l y e x p e c t e d , but a r e randomly s c a t t e r e d as a r e s u l t of t h e i r m o b i l i t y i n metamorphic e n v i r o n m e n t s ( D a v i e s et a l . , 1979). I n d i v i d u a l major element t r e n d s a r e d i s c u s s e d below. 5.4.1 S i 0 2 T here i s a d i s t i n c t p a u c i t y of i n t e r m e d i a t e (55 to 62 % ) S i 0 2 v a l u e s , ( F i g . 5.10a and b) c o r r e s p o n d i n g to the a v e r a g e a n d e s i t e r a n g e d e f i n e d by Manson ( 1 9 6 7 ) . The s u i t e i s d i f f e r e n t from r e c e n t mature i s l a n d a r c s where a l a r g e p e r c e n t a g e of r o c k s a r e a n d e s i t i c ( M i y a s h i r o , 1974; M c B i r n e y , 1969; D i c k i n s o n , 1968). Page 60 TABLE 5.1: Major Element C h e m i s t r y f o r M e s o z o i c and O l d e r Rocks of the Cry Lake Map Area OR FORMATION AVGE. MAX. MIN. A ,2°3 9 15.49(1)* 19.7 12.4 I 15.41(2)' 16.5 12.0 A 12.94(3)* 16.5 10.0 B 2.84(1)* 6.02 1.2 I 1.22(2)* 1.8 9.5 A 0.98(3)* 2.06 0.10 FeO 8 6.51(1)* 12.9 3.00 I 2.93(3)* 6.30 0.20 A 2.04(3)* 5.10 0.10 MgO B 7.29(1)* 16.20 2.00 I 2.41(2)* 4.50 0.46 A 1.59(3)* 4.42 0.14 CaO a 7.58(11* 10.20 0 i 6.80(2)" 12.30 3.37 A 2.13(31* 6.12 0.03 Sa,0 3 2.83(1)* 4.00 0 I 3.00(2)" 4.70 0.50 A 4.31(3)* 7.20 0.41 KjO B 0.80(1)* 2.63 0 I 1.51(2)* 3.46 0.45 A 1.96(3)* 3.40 O.03 TIOj 3 1.08(1)* 2.23 0.33 I 0.65(2)* 1.89 0.24 A 0.39(3)* .60 0.12 P2°5 B 0.16(1)* .57 a 06 I 0.16(2)* .45 O.OS A 0.13(3)* .34 0 MnO 8 0.21(1)* .45 O.01 I 0.11(2)* .13 0.05 A 0.07(31* .21 0.01 co2 3 0.81(1)* 10.40 0 I 4.72(1)* 9.00 0.40 A 0.77(3)* 6.37 0 H20 B 4.18(1)* 6.70 0.38 I 2.67(2)* 4.00 O.30 A 1.68(3)* 2.80 O.40 BASIC SCHIST AVGE• MAX. MIN. TAKLA N. KUTCHO AVGE. MAX. MIN. AVGE. MAX. MIN. 13.16 15.37(51*18.00 11.50 15.09(7) 16.50 13.20 2.71(4)" S.40 O.40 1.3(5)* 3.80 1.00 6.01(4)* 8.05 1.20 6.93(51*12.00 1.34 2.53(4)* 4.50 N/D 2.48(5)* 5.40 0.80 3.90(4)* 5.34 1.48 1.19(51* 3.60 0.17 1.26(7)* 2.00 O.60 1.37(7)* 2.00 0.62(7)* 2.00 0.03 1.52(7)* 3.95 0 4.20(7)* 5.80 2.00 2.13(7)* 3.56 0.20 .67(4)* 0.73 0.59 0.84(5)* 1.17 0.50 3.69(4)* 8.B O.06 0.08(5)* 0.50 N/0 0.25(71* 0.50 O.02 0.06(71*0.10 0.07(71* 0.19 0.03 0.61(7)* 2.60 CACHE CREEK AVGE. MAX. MIN. 14.23(7)* 14.90(8)" 16.60 12.80 2.2(7)* 4.50 O.80 3.50(81* 6.19(71* 7.90 4.40 5.50(8)* 8.02(71*12.00 5.22 5.47(81* 8.22(71*10.90 5.07 7.39(8)* 2.57(7)* 5.90 0.90 2.60(8)* 0.38.7)* 1.73 0 0.04(8)* 0.80(7)* 2.19 O.30 0.49(81* 0.06(7)* 0.25 0 0.02(81* 0.13(7)* 0.18 O.02 0.09(8)* 0.79(7)* 4.20 0 0(8)* 3.76(7)* 5.6C 2.60 2.3(8)* 1.31(7)* 2.40 O.09 NUMBER OF SAMPLES 8-3asic vo lcanic rocks I-Intermedlate vo lcanic rocks (1) N 21 (5) N 6 A - A c l d i c volcanic rocks (2) ft 6 (6) It 7 (3) N 28 (7) N 7 (4) N 13 18) N 1 Page 61 TABLE 5.2: Average C o n c e n t r a t i o n s f o r Major ( i n %) and T r a c e Element ( i n ppm) O r o g e n i c Rocks of A c i d i c C o m p o s i t i o n REFERENCE ENVIRON-MENT ARC DACITE AVGE. DACITE AVGE. RHY. CA RHY ALKALI RHY AVGE. RHY ARC DACITE NEW ZEAL. RHY KURIL DAC S i0 2 66.8 64.9 74.0 73.66 74.57 66.27 65.1 75.3 AU)3 18.2 16.0 13.3 13.45 12.58 15.39 16.5 13.5 Fe 20 3 1.3 3.2 1.3 1.25 1.30 2.14 FeO 1.0 1.0 0.5 0.75 1.02 3.86 1.68 MgO 1.5 • 1.7 0.3 0.32 0.11 1.57 1.48 0.25 CaO 3.2. 4.7 1.5 1.13 0.61 3.65 4.15 1.49 Na20 5.0 4.2 4.0 2.99 4.13 4.13 4.60 4.12 K20 1.0 1.8 3.5 • 5.35 4.73 3.01 2.05 3.3^ "502 0.20 0.60 0.25 0.17 0.17 0.66 0.51 0.27 P2°5 0.04 0.07 0.17 580 ppm 870 ppm MnO 0.03 0.05 0.07 Ba 750 400 900 520 810 610 Ba 8 15 3 9 n.d. 17 Cu 5 22 6 25 Cr 5 10 2 13 1.7 12 Rb 15 40 100 44 108 Sr 200 500 150 460 125 V 68 8.5 176 Y 25 30 10 20 25 Zr 80 100 160 100 160 390 Nl 1 8 1 5 n.d. 12 Page 62 TABLE 5.3: Average Major ( i n %) and T r a c e Element ( i n ppm) C o n c e n t r a t i o n s f o r O r o g e n i c Rocks of I n t e r m e d i a t e C o m p o s i t i o n REFER-ENCE EKV1R ARC CA ARC C0NT. C0NT. OCEAN AN- CENO- CA IS.ARC . TC.0L. LOW LOW HIGH IS. 15. • LOW LOW -K AVGE. HIGH KUR KAM-OiihENT MARG. INT. ANO NON DEAN ZOIC S iO t so. S l O i ARC ARC AND AND K CHATKA ARC THOL. ALEUT • •JAPAN JAPAN PX HB. AND ANO ANO BAS-AND TAN AR ARC AND sio 2 57.3 59.5 58.70 53.65 58.05 58.31 59.93 58.17 57.4 57.4 51.43 55.3 55.4 60.3 59.20 59.14 54.9 3V.3 59.5 60.8 A ,2°3 17.4 17.2 17.29 17.43 17.15 13.77 16.82 17.26 17.7 15.6 13.05 17.6 19.1 16.8 16.82 16.87 17.5 17.4 17.2 16. a Fe 20 3 2.5 2.5 2.97 3.21 3.30 3.37 1 6.72 3.07 3.20 3.48 3.36 3.5 2.6 3.0 2.90 2.93 7.30 6.10 5.13 FeO 2.7 5.0 3.96 3.48 2.54 6.48 J 4.18 3.30 5.01 9.74 5.0 4.5 4.3 4.50 3.38 2.18 3.52 3.42 2.15 MgO 3.5 3.4 3.14 3.28 2.16 2.27 3.93 3.24 3.45 3.38 5.28 4.8 5.1 3.0 3.20 3.55 4.71 8.65 7.03 5.60 ) CaO 8.7 7.0 7.14 6.26 5.13 5.58 6.64 6.93 7.40 6.14 8.76 9.1 7.7 6.3 6.S8 6.50 8.49 2.63 3.68 4.10 w>20 2.6 3.7 3.24 3.82 4.57 3.91 3.57 3.21 3.40 4.20 3.18 2.9 3.1 3.6 3.30 3.61 3.43 0.70 1.60 3.25 K20 .70 1.6 1.27 1.89 3.60 1.88 1.87 1.61 1.25 0.43 1.84 1.0 1.6 2.1 1.29 1.85 1.10 0.58 0.70 0.77 T10 2 0.58 0.70 0.81 0.79 1.10 1.71 0.92 1.80 0.65 1.25 2.60 0.8 0.7 0.6 0.76 0.70 0.82 110 270 400 390 200 P 2 O 5 0.17 0.18 1.43 1.46 0.44 0.19 0.17 0.23 10 31 S3 29 39 MnO 0.12 0.10 0.13 0.23 0.14 0.13 70 24 13 34 41 Ba 100 270 m Co 20 24 Cu 50 30 Cr 40 55 3 6 Rb 10 30 22 Sr V 90 110 15 18 540 219 200 14 28 60 14 430 100 22 92 28 10 31 B8 26 63 215 385 620 195 175 160 2S0 320 25 21 20 10 110 170 110 250 5 18 3 33 41 Page 63 TABLE 5.4: Average Major ( i n %) and T r a c e Element ( i n ppm) C o n c e n t r a t i o n f o r O r o g e n i c Rocks of B a s i c C o m p o s i t i o n REFER-ENCE o 2: U3 a o a a ALEUT- KURILE CIR- WEST JAPAN JAPAN 1 OIRILE : HIGH CAL- ISL. ABYSSAL CAL-RISE ARC CA C0NT IAN JAPAN UM US ARC ARC ARC AL CALK ARC TH0L. CALK ARC ARC ARC ISL. SA TH. TH. BAS BAS 8 AS TH0L. BAS ARC ARC ARC BAS BAS BAS FIJI S i 0 2 49.8 51.1 50.2 50.3 50.7 51, .2 55.0 51.16 52.54 50.82 53.99 51.7 53-70 45-70 47-62 51.4 Al 2 0 3 16 16.1 17.7 14.3 18.1 19, .4 19.2 17.37 17.48 17.6G 13.39 16.9 17.7 Fe 20 3 2.0 3.0 3.9 3.5 3.0 3, .6 2.0 3.43 3.20, 3.20 3.23 3.20 FeO 7.5 7.3 6.3 9.3 6.8 5. ,7 5.7 6.16 5.44 7.20 6.17 10.4 3.30 MgO 7.5 5.1 5.4 5.9 5.6 5, .3 4.5 6.14 5.85 6.15 3.86 6.5 3.45 CaO 11.2 10.8 9.8 • 9.7 11.5 10. .1 9.2 10.27 8.82 10:60 9.24 11.0 7.40 Na20 2.8 2.0 2.7 2.5 2.7 2. .6 3.2 2.63 3.20 1.84 2.31 3.1 3.40 K20 0.14 0.3 0.9 0.8 0.5 1. ,0 0.5 0.84 1.04 0.32 0.66 0.4 1.25 T' C2 1.5 0.83 1.0 2.2 1.1 1. ,1 0.7 0.88 1.14 0.81 0.92 0.5 0.5-1.2 0.5-1.5 1.0-2.5 0.65 P2°5 NA NA NA NA 0.19 0.26 0.09 0.14 MnO NA NA NA NA 0.17 0.14 0.13 0.14 Ba 11 60 100 200 130 115 270 30-150 6-30 270 0 32 20 40 40 56 40 Cu 70 80 80 100 63 35 Cr 300 50 50 100 89 40 3 6 Rb 1 5 10 30 9. 6 30 3-10 0.2-5.0 0.22-Sr 135 225 300 350 328 380 100-200 70-150 540 V 520 255 Y 3 0 2 0 23 30 20 Zr 100 60 100 200 100 100 Ni 100 25 50 100 61 25 18 0-30 30-200 8 8 Zn 7 5 8 0 8 0 9 0 N o t e - N A - N o t A n a l y z e d Page 64 Frequency (N) 2 2 2 0 1 8 1 6 1 4 1 2 1 0 8 6 4 2 0 4 5 - 5 0 5 0 - 5 5 5 5 - 6 0 6 0 - 6 5 6 5 - 7 0 7 0 - 7 5 75-80 30-83 FIGURE 5.10a % SiO^ 1 2 ' 1 Frequency (N) 1 0 8 6 4 2 0 1 FIGURE 5.10b 4 5 - 5 0 5 0 - 5 5 5 5 - 6 0 6 0 - 6 5 6 5 - 7 0 7 0 - 7 5 7 5 - 8 0 3 0 - 8 5 % SiO„ FIGURE 5.10a: F r e q u e n c y ( i n c l u d i n g r o c k s o f the FIGURE 5.10b: F r e q u e n c y ( e x c l u d i n g r o c k s of the (N) v e r s u s S i 0 2 % Diagram b a s i c s c h i s t ) (N) v e r s u s S i 0 2 % Diagram b a s i c s c h i s t ) Page 65 5.4.2 A1203 L i n e a r l y d e c r e a s i n g A1203 ( F i g . 5.11) c o r r e s p o n d s to i n c r e a s i n g S i 0 2 c o n c e n t r a t i o n s i n F i g u r e 5.11a. The a v e r a g e v a l u e s of 15.49, 15.41 and 12.94 p e r c e n t A1203 f o r b a s i c , i n t e r m e d i a t e and a c i d i c r o c k s , r e s p e c t i v e l y , a r e summarized i n T a b l e 5.1. Jakes and White (1972) s u g g e s t a v e r a g e c o n c e n t r a t i o n s f o r b a s a l t and a n d e s i t e of t h o l e i i t i c and c a l c - a l k a l i n e s u i t e s to be 12 to 16 p e r c e n t and 16 to 20 p e r c e n t A1203 r e s p e c t i v e l y . A c c e p t e d f i g u r e s f o r i s l a n d a r c a s s e m b l a g e s a r e about 16 p e r c e n t , 17.4 p e r c e n t , 16 p e r c e n t and 13.3 p e r c e n t A1203 r e s p e c t i v e l y f o r b a s a l t , a n d e s i t e , d a c i t e and r h y o l i t e ( C o n d i e , 1976) or 17.29 p e r c e n t A1203 f o r a n d e s i t e ( M c B i r n e y , 1969) ( T a b l e s 5.2, 5.3 and 5.4). An a v e r a g e c o n c e n t r a t i o n o f 15.37 p e r c e n t A1203 f o r b a s i c r o c k s of the T a k l a F o r m a t i o n i s s i m i l a r to r o c k s of t h e Kutcho s u i t e . A1203 v a l u e s p l o t t e d f o r r o c k s of the Cache Creek Group are s i m i l a r to t h o s e of the Kutcho s u i t e . 5.4.3 Fe203 A p l o t of Fe203 % v e r s u s S i 0 2 % ( F i g . 5.11a ) shows an e r r a t i c d i s t r i b u t i o n of d a t a p o i n t s . T h i s i s p r o b a b l y due to a l t e r a t i o n , as Fe203 i s r e l a t i v e l y m o b i l e i n b o t h w e a t h e r i n g and Page 66 BASIC 8 F e O * / . g 12 10 MgOU INTERMEDIATE • • * • • • ACIDIC Si o 2 FIGURE 5.11a: Ha r k e r V a r i a t i o n Diagrams of Major E l e m e n t s of Rocks of the Cry Lake Map A r e a , B r i t i s h C o l u m b i a . V e r t i c a l dashed l i n e s d i v i d e r o c k s i n t o b a s i c , i n t e r m e d i a t e and a c i d i c f i e l d s to f a c i l i t a t e d i s c u s s i o n of d a t a i n t e x t . B a s i c r o c k s c o n t a i n l e s s t h a n 56 % S i 0 2 ; a c i d i c r o c k s c o n t a i n g r e a t e r than 62 % S i 0 2 . Page 67 VoNojO 4 % Ti02 2 9 r 2 .0 % "2O5 woo WO 2S0C 200 ppm M nO 10  ;oo SO i SASIC • • • INTERMEDIATE! I • ACIOIC * .1 I* 1 : • :-f 19 « *h * FIGURE 5.11b: H a r k e r V a r i a t i o n Diagrams of Major E l e m e n t s f o r Rocks of the Cry Lake Map A r e a , B r i t i s h C o l u m b i a Page 68 metamorphic e n v i r o n m e n t s ( M i y a s h i r o , 1974). In g e n e r a l i r o n c o n t e n t d e c r e a s e s w i t h i n c r e a s i n g S i 0 2 c o n c e n t r a t i o n s ( T a b l e 5 . 1 ) . C o n c e n t r a t i o n s a r e s i m i l a r to a v e r a g e s f o r o r o g e n i c s u i t e s ( T a b l e s 5.2 to 5 . 4 ) . Samples of the b a s i c s c h i s t have an a v e r a g e c o n c e n t r a t i o n of 2.71 p e r c e n t Fe203, w h i l e b a s i c r o c k s of the T a k l a F o r m a t i o n have lower c o n c e n t r a t i o n s a v e r a g i n g 1.80 p e r c e n t Fe203. Rocks of the Cache Cr e e k Group have s i m i l a r c o n c e n t r a t i o n s ( T a b l e 5 . 1 ) . 5.4.4 FeO FeO d e c r e a s e s i n F i g u r e 5.11a w i t h i n c r e a s i n g S i 0 2 p e r c e n t a g e s . C o n c e n t r a t i o n s i n T a b l e 5.1 a v e r a g e 6.51, 2.93 to 2.04 p e r c e n t FeO f o r b a s i c , i n t e r m e d i a t e and a c i d i c r o c k s . These a r e s i m i l a r to a v e r a g e c o n c e n t r a t i o n s , summarized i n T a b l e s 5.2 to 5.4, f o r r o c k s i n i s l a n d a r c s . M i y a s h i r o and F u n i k o (1975) s u g g e s t t h a t w i t h advanced c r y s t a l l i z a t i o n FeO c o n c e n t r a t i o n s d e c r e a s e i n c a l c - a l k a l i n e r o c k s and i n c r e a s e i n t h o l e i i t i c r o c k s . Thus on t h i s b a s i s the Kutcho s u i t e f o l l o w s a c a l c - a l k a l i n e t r e n d . A verage c o n c e n t r a t i o n s of 5.66 and 6.85 p e r c e n t FeO f o r r o c k s of the b a s i c s c h i s t and T a k l a F o r m a t i o n s , r e s p e c t i v e l y , a r e Page 69 shown i n T a b l e 5.1; r o c k s of the Cache Creek Group have a v e r a g e c o n c e n t r a t i o n s of 6.19 p e r c e n t FeO. A l l a r e s i m i l a r to the Kutcho s u i t e . 5.4.5 MgO MgO d e c r e a s e s w i t h i n c r e a s i n g S i 0 2 c o n c e n t r a t i o n ( F i g . 5.11a). Average c o n c e n t r a t i o n s f o r b a s i c , i n t e r m e d i a t e and a c i d i c r o c k s a r e 7.29, 2.41 and 1.59 p e r c e n t MgO, r e s p e c t i v e l y . These v a l u e s g e n e r a l l y c o r r e s p o n d to a v e r a g e v a l u e s r e p o r t e d f o r o r o g e n i c r e g i o n s as shown i n T a b l e s 5.2, 5.3 and 5.4. An a v e r a g e c o n c e n t r a t i o n of 4.84 p e r c e n t MgO f o r r o c k s of the b a s i c s c h i s t i s lower than the a v e r a g e f o r b a s i c r o c k s of the Kutcho s u i t e . Rocks o f the T a k l a F o r m a t i o n have an a v e r a g e c o n c e n t r a t i o n of 6.64 p e r c e n t MgO. B a s i c r o c k s of the Cache Creek Group have a s l i g h t l y h i g h e r MgO c o n t e n t than t h o s e of the Kutcho (8.02 p e r c e n t MgO). Page 70 5.A.6 CaO CaO v a l u e s ( F i g . 5.11b) g e n e r a l l y d e c r e a s e w i t h i n c r e a s i n g S i 0 2 c o n c e n t r a t i o n s . P r o n o u n c e d s c a t t e r i n b a s i c members may be due t o h i g h e r i n i t i a l c o n c e n t r a t i o n s of CaO, i n t r o d u c t i o n of s e c o n d a r y CaO, and m o b i l i t y of CaO d u r i n g w e a t h e r i n g and metamorphism ( M i y a s h i r o , 1974). The a v e r a g e CaO v a l u e s ( T a b l e 5.1) of 7.5 , 6.80 and 2.3 p e r c e n t f o r b a s i c , i n t e r m e d i a t e and a c i d i c r o c k s , r e s p e c t i v e l y , a r e s i m i l a r to a v e r a g e v a l u e s of o r o g e n i c l a v a s ( T a b l e s 5.2 to 5 . 4 ) . Rocks o f the b a s i c s c h i s t a v e r a g e 6.01 p e r c e n t CaO. B a s i c r o c k s of the T a k l a F o r m a t i o n a v e r a g e 6.93 p e r c e n t CaO and i n t e r m e d i a t e r o c k s of the Cache Creek Group have and a v e r a g e c o n c e n t r a t i o n of 7.39 p e r c e n t CaO ( T a b l e 5.1). 5.4.7 Na20 Na20 v a l u e s ( F i g . 5.11b) i n c r e a s e w i t h i n c r e a s i n g S i 0 2 c o n c e n t r a t i o n s . A v e r a g e s of 2.8, 3.0 and 4.3 p e r c e n t Na20 f o r b a s i c , i n t e r m e d i a t e and a c i d i c r o c k s , r e s p e c t i v e l y , a r e g i v e n i n T a b l e 5.1. S c a t t e r of d a t a may be due to Na20 m o b i l i t y d u r i n g s e c o n d a r y p r o c e s s e s ( D a v i e s e t a l . , 1979). Rocks o f the b a s i c s c h i s t and of the T a k l a F o r m a t i o n have Page 71 a v e r a g e c o n c e n t r a t i o n s of 2.53 and 2.48 p e r c e n t Na20, r e s p e c t i v e l y ( T a b l e s 5 . 1 ) . Rocks o f the Cache Cr e e k Group have an a v e r a g e c o n c e n t r a t i o n of 2.60 p e r c e n t Na20. 5.4.8 K20 An i n c r e a s e of K20 w i t h i n c r e a s i n g S i 0 2 c o n c e n t r a t i o n s i s c h a r a c t e r i s t i c ( C a r m i c h a e l e t a l . , 1974) and i s a p p a r e n t f o r r o c k s of the Kutcho s u i t e i n F i g u r e 5.11b. Average v a l u e s of 0.80, 1.51 and 1.96 p e r c e n t K20 f o r b a s i c , i n t e r m e d i a t e and a c i d i c r o c k s , r e s p e c t i v e l y , a r e g i v e n i n T a b l e 5.1. The a v e r a g e K20 v a l u e (3.90 p e r c e n t ) f o r the b a s i c s c h i s t i s s i g n i f i c a n t l y h i g h e r than o t h e r b a s i c r o c k s of the Kutcho s u i t e . These h i g h c o n c e n t r a t i o n s of K20 i n the b a s i c s c h i s t a r e a l s o h i g h compared to a v e r a g e v a l u e s f o r b a s i c " i s l a n d a r c " r o c k s which range from 0.3 ( C o n d i e , 1976) to 1.25 p e r c e n t K20 ( J a k e s and G i l l , 1970) as shown i n T a b l e 5.4. These h i g h v a l u e s may be a t t r i b u t e d to the s t r a t i g r a p h i c p r o x i m i t y of t h i s u n i t to the o r e zone c h a r a c t e r i z e d by an e n r i c h m e n t h a l o of K20 ( B r i d g e , 1977, unpub.). K20 v a l u e s , a v e r a g e 1.19 p e r c e n t f o r r o c k s of the T a k l a F o r m a t i o n , A v e r a g e K20 v a l u e s ( T a b l e 5.1) f o r r o c k s of the Cache Creek Group a r e 0.70 p e r c e n t . Page 72 5.4.9 T i 0 2 T i 0 2 c o n c e n t r a t i o n s d e c r e a s e w i t h i n c r e a s i n g S i 0 2 ( F i g . 5.11), p a r a l l e l i n g d e f i n e d t r e n d s of d e c r e a s i n g T i 0 2 w i t h advanced f r a c t i o n a t i o n f o r c a l c - a l k a l i n e and t h o l e i i t i c r o c k s ( M i y a s h i r o and F u n i k o , 1975). T i 0 2 v a l u e s a v e r a g e 1.08, 0.65 and 0.39 p e r c e n t f o r b a s i c , i n t e r m e d i a t e and a c i d i c r o c k s ( T a b l e 5.1), r e s p e c t i v e l y , and a r e s i m i l a r to a v e r a g e c o n c e n t r a t i o n s f o r r o c k s of i s l a n d a r c a s s e m b l a g e s ( T a b l e s 5.'2 to 5 . 4 ) . T i 0 2 v a l u e s f o r r o c k s of the b a s i c s c h i s t a r e lower than t h o s e of the Kutcho s u i t e , a v e r a g i n g 0.67 p e r c e n t T i 0 2 ( T a b l e 5.1). Rocks of the T a k l a F o r m a t i o n have an a v e r a g e c o n c e n t r a t i o n of 0.84 p e r c e n t f o r b a s i c r o c k s . Data summarized i n T a b l e 5.1 f o r r o c k s of the Cache Creek Group show an a v e r a g e c o n c e n t r a t i o n of 0.49 p e r c e n t T i 0 2 . 5.4.10 P205 No s y s t e m a t i c v a r i a t i o n i n P205 c o n c e n t r a t i o n s a r e a p p a r e n t f o r r o c k s of the Kutcho s u i t e . Average c o n c e n t r a t i o n s Page 73 f o r b a s i c , i n t e r m e d i a t e and a c i d i c r o c k s a r e 0.16, 0.16 and 0.13 p e r c e n t r e s p e c t i v e l y . C o n c e n t r a t i o n s of P205 i n b a s i c , i n t e r m e d i a t e and a c i d i c v o l c a n i c r o c k s of o r o g e n i c i s l a n d a r c s a r e i n T a b l e s 5.2 to 5.4. B a s i c s c h i s t a n a l y s e s a r e u n i q u e l y h i g h i n P205, and a v e r a g e 0.78 p e r c e n t . T h i s h i g h c o n c e n t r a t i o n i s not c h a r a c t e r i s t i c of c a l c - a l k a l i n e a r c d e r i v e d r o c k s ( C a r m i c h a e l et  a l . , 1974). H i g h P205 c o n c e n t r a t i o n s c o u p l e d w i t h h i g h K20 v a l u e s a r e more c h a r a c t e r i s t i c of a l k a l i b a s a l t s ( M c B i r n e y , 1969). Rocks of the T a k l a Group have an a v e r a g e P205 c o n c e n t r a t i o n of 0.20 p e r c e n t , s i m i l a r to b a s i c r o c k s of the Kutcho s u i t e . Rocks of the Cache Cr e e k Group have an a v e r a g e c o n c e n t r a t i o n of 0.02 p e r c e n t P205. 5.4.11 MnO F i g u r e 5.12b shows a d e p l e t i o n of manganese o x i d e (MnO) w i t h i n c r e a s i n g S i 0 2 c o n c e n t r a t i o n . Average c o n c e n t r a t i o n s a r e 2300, 1000 and 800 ppm MnO f o r b a s i c , i n t e r m e d i a t e and a c i d i c r o c k s , r e s p e c t i v e l y ( T a b l e 5.5). S c a t t e r i n the d a t a may be from m e t a s o m a t i c i n t r o d u c t i o n of manganese near the m a s s i v e s u l p h i d e Page 74 5.5 T r a c e Element C h e m i s t r y of Rocks of the Kutcho F o r m a t i o n and Other R e l a t e d Rocks Harker v a r i a t i o n d i a grams f o r t r a c e element d a t a of the Kutcho s u i t e show g e n e r a l l y s c a t t e r e d d i s t r i b u t i o n s , p a r t i c u l a r l y f o r more b a s i c r o c k s . D e s p i t e t h i s s c a t t e r , some s y s t e m a t i c v a r i a t i o n s i n element c o n c e n t r a t i o n s a r e a p p a r e n t . V, N i , C r , Co, Mn and, to a l e s s e r degree Cu, d e c r e a s e i n c o n c e n t r a t i o n w i t h i n c r e a s i n g S i 0 2 . A d i s c u s s i o n of t r a c e element c o n c e n t r a t i o n s f o r r o c k s of the Kutcho s u i t e and the b a s i c s c h i s t f o l l o w s . A b r i e f c o m p a r i s o n of d a t a f o r r o c k s of the T a k l a F o r m a t i o n and Cache Creek Group i s a l s o i n c l u d e d . 5.5.1 Vanadium A s t e a d y d e c r e a s e i n V c o n c e n t r a t i o n s ( F i g . 5.12) o c c u r s w i t h i n c r e a s i n g S i 0 2 c o n c e n t r a t i o n s i n r o c k s of the Kutcho F o r m a t i o n , as e x e m p l i f i e d by a v e r a g e s of 264.6, 68.5 and 53.9 ppm vanadium i n b a s i c , i n t e r m e d i a t e and a c i d i c s a mples, r e s p e c t i v e l y ( T a b l e 5 . 5 ) . An a v e r a g e of 199 ppm V f o r samples of the b a s i c s c h i s t i s lower than an a v e r a g e of 249 ppm V f o r b a s i c r o c k s of the T a k l a F o r m a t i o n ; t h e s e a r e c l o s e to a v e r a g e v a l u e s d e t e r m i n e d f o r the Kutcho F o r m a t i o n . Page 76 d e p o s i to tho t ( B r i d g e , 1978, p e r s . se f o r modern o r o g e n i c comm.). A v e r a g e s , however r o c k s ( T a b l e s 5.2 to 5 . 4 ) . a r e c l o s e Average c o n c e n t r a t i o n s of 1700 and 1900 ppm MnO f o r b a s i c s c h i s t and b a s i c r o c k s of the T a k l a F o r m a t i o n a r e s i m i l a r to t h o s e from r o c k s of the Kutcho F o r m a t i o n . B a s i c r o c k s of t h e -Cache Creek Group have lower MnO. c o n t e n t s . 5.4.12 Summary Major element t r e n d s f o r r o c k s of the Kutcho F o r m a t i o n , e x c l u d i n g the b a s i c s c h i s t u n i t , g e n e r a l l y p a r a l l e l a c c e p t e d t r e n d s d e f i n e d f o r b a s i c to a c i d i c c a l c - a l k a l i n e v o l c a n i c r o c k s of i s l a n d a r c s . A v e r a g e element c o n c e n t r a t i o n s f o r g i v e n s i l i c a v a l u e s , a r e summarized i n T a b l e s 5.2 to 5.4, a r e s i m i l a r to t h o s e f o r o r o g e n i c zones ( C o n d i e , 1976; M c B i r n e y , 1969; M i y a s h i r o , 1975; Ewart, 1976). H a r k e r v a r i a t i o n p l o t s g i v e l i t t l e d e f i n i t i v e i n f o r m a t i o n as to the n a t u r e of the Kutcho r o c k s . A n o t a b l e e x c e p t i o n i s the b a s i c s c h i s t u n i t i n which h i g h K20 and P205 c o n c e n t r a t i o n s f o r g i v e n s i l i c a v a l u e s may p o i n t to an a l k a l i n e c h a r a c t e r ( M c B i r n e y , 1969). Page 75 T A B L E 5 . 5 : T r a c e E l e m e n t C h e m i s t r y f o r Rocks o f t h e K u t c h o F o r m a t i o n and O t h e r R e l a t e d R o c k s HOCK FORMATION KUTCHO FORMATION BASIC SCHIST TAKLA H. KUTCHO CACHE CREEK GROUP AVGE. MAX. MIN. AVGE. MAX. MIN. AVGE. MAX. MIN. AVGE. MAX. MIN. AVGE. MAX. MIN. 3a 8 ! A 177.0 (1) 1403.0 (2) 484.2 (3) 073 2310 2020 12.1 40.0 la.a 635.8(4)* 1230 170 338.2(5)- 522 112 925.2 (6)- 1490 172 128.0 292 (7)-(a i -304 6. Co 3 I A 30.3 (1) 3.2 (2) 2.0 ( 3 ) 525 12.8 24.2 0 0 0 21.2(4)- 46 .3 0 27.1(5)- 70.2 13.1 0 (6>- 0 0 ao . i 30.8 m -fa)-374 17. Cr B I A 133.5 (1) 3.7 (2) 3.71(3) 830 14.8 127 0 0 0 109.2(4)- 927 0 1.15(6)- u.s 0 338.3 70.4 (7)-(81-726 51 Ni B I A 44.2 (1) 0 (2>-2.93(3)' 117 0 42.7 0 0 0 23.5(4)- 318 0 65.7(5)- 24.6 0 1.07(61- 10.7 0 106.2 S2.9 (7)-(a>-282 5, Cu 3 ! A 68.7 (1) 4.0 (2)> 14.2 (3)-326 8.2 55.7 0 0 0 214.2(4)- 400 15.7 30.0(5)- 61.7 0 27.2 (61- 119 0 106.7 15.6 (7)* (S i-461 7. Zn 3 1 A 71.0 (1)' 40.0 (2)' 28.3 (3|-371 120 110 0 0 0 76.3(4)- 120 10 51.7(5)- 110 0 25.0 (6)- 50 0 33.7 0 m -l a ) -90 0 RO 8 I A 6.67(1)-17.S (2)-11.7 ( ] ) • 40 50 90 0 0 0 61.3(4)- no 0 13.3(5)- 80 0 84.0 (6)- 250 0 7.14(7)-0 (81-50 0 Sr 8 I A 200 (1)' 230.7 (2)-157 (3)' 576 353 903 29 48.9 0 455.2(4)- 1160 139 368.8(5)- 518 228 329.8 (61- 603 92.1 112.7 56.1 (71-(81-321 35 V B 1 A 264.6 (1)' 68.5 (2|-53.5 (31-582 100 313 43.9 34.8 0 199.1(4)- 305 37.9 248.7(5)- 328 173 32.5 (61- 121 0 224.1 33.9 (7) -(8) -276 181 Zr S [ A 165.5 (1)> 96.0 (2)' 141.6 (3) 385 140 1000 0 0 0 68.9(4)- 224 0 54.7(5)- 93.2 0 101.0 (6)- 212 0 67.7 64.6 (71-(81-159 0 • NUMBER Of SAM PL£5 (1) 21 (5) 6 (21 4 (6) 10 (3) 18 (7) 7 (4) 16 (8) 1 Page 77 ppm x ppm Nj ppm Cr 4 0 0 300 2 0 0 o 3 0 0 2 0 0 ISO 100 90 BASIC / • • —4. INTERMEDIATE, 3 • * • • * . ppm Co • • 4 * • ACIDIC % Si02 FIGURE 5.12a: Ha r k e r V a r i a t i o n Diagrams of T r a c e E l e m e n t s of Rocks of the Cry Lake Map A r e a , B r i t i s h C o l u m b i a . V e r t i c a l l i n e s d i v i d e r o c k s i n t o b a s i c , i n t e r m e d i a t e and a c i d i c f i e l d s to f a c i l i t a t e d i s c u s s i o n of d a t a i n t e x t . B a s i c r o c k s c o n t a i n l e s s t h an 56 % S i 0 2 ; a c i d i c r o c k s c o n t a i n g r e a t e r than 62 % S i 0 2 . Page 78 p pm Cu ppm Sr ppm Z f 240 160 tsoo 1000 500 0 1200 1000 800 600 400 2400 2000 1600 ppm B '200 600 400 ppm Y 1 BASIC .INTERMEDIATE: • 1 1 ACIDIC ° 1 1 * °o 1 I o I 1 • • * • • • ! 1 o * 1 X X > • i 1 , • i m %*:*• * ' 1 . • i • • X* X * X • • i. * » * • ° 1 • # l • • • ° •» • 14 • i • *• • • • xx.i .x •« • • • • . x * • • • • ° i X X - x • • •" i • • • X • X X • • • X * x • •• * ! ! • -1 - • • * i i • % SiO-) FIGURE 5.12b: H a r k e r V a r i a t i o n diagrams of T r a c e E l e m e n t s of Rocks of the Cry Lake Map A r e a . Page 79 5.5.2 Chromium and N i c k e l Chromium and N i r a r e l y o c c u r i n d e t e c t a b l e amounts i n s i l i c a - r i c h samples ( F i g . 5.12a). B a s i c r o c k s w i t h s i l i c a v a l u e s l e s s t han 55 p e r c e n t have low c o n c e n t r a t i o n s of Cr and Ni a v e r a g i n g 133 and 44 ppm r e s p e c t i v e l y . Both Cr and N i d e c r e a s e w i t h i n c r e a s i n g S i 0 2 c o n c e n t r a t i o n s . Samples of the b a s i c s c h i s t have a v e r a g e s of 23 ppm Ni and 109 ppm Cr ( T a b l e 5 . 5 ) . At g i v e n S i 0 2 v a l u e s , Cr and N i c o n c e n t r a t i o n s f o r r o c k s of the Cache Cr e e k Group a r e a p p a r e n t l y h i g h e r than t h o s e f o r r o c k s of the Kutcho s u i t e . 5.5.3 C o b a l t For the s i l i c a r ange below 55 p e r c e n t , i n which Co i s p r e s e n t i n d e t e c t a b l e c o n c e n t r a t i o n s , d a t a a v e r a g e s 31 ppm f o r r o c k s of the Kutcho s u i t e ( F i g . 5.12a). Samples of the b a s i c s c h i s t have an a v e r a g e of 21 ppm Co. Data f o r a v e r a g e c o n c e n t r a t i o n s of Co i n b a s i c a r c - d e r i v e d r o c k s i s shown i n T a b l e 5.4. Rocks of the Cache Cr e e k Group appear to have h i g h e r c o b a l t c o n c e n t r a t i o n s than t h e Kutcho s u i t e . Page 80 5.5.4 Copper Copper c o n c e n t r a t i o n s i n r o c k s of the Kutcho F o r m a t i o n ( F i g . 5.12b) d e c r e a s e weakly w i t h i n c r e a s i n g S i 0 2 c o n t e n t . C o n c e n t r a t i o n s a v e r a g e 69, 4 and 14 ppm i n b a s i c , i n t e r m e d i a t e and a c i d i c r o c k s , r e s p e c t i v e l y ( T a b l e 5 . 5 ) . Rocks of the b a s i c s c h i s t have t r a c e element c o n c e n t r a t i o n s s i m i l a r to o t h e r r o c k s of the Kutcho s u i t e , but have m a r k e d l y h i g h e r copper c o n c e n t r a t i o n s t h a t a v e r a g e 214 ppm. Copper c o n c e n t r a t i o n s f o r r o c k s of the Cache Creek Group a r e s i m i l a r to v a l u e s f o r the Kutcho F o r m a t i o n . 5.5.5 S t r o n t i u m S t r o n t i u m i n r o c k s of the Kutcho F o r m a t i o n show l i t t l e e n r i c h m e n t or d e p l e t i o n ( F i g . 5.12b) w i t h v a r i a t i o n i n s i l i c a c o n t e n t . Average c o n c e n t r a t i o n s of 200, 231 and 157 ppm are found i n b a s i c , i n t e r m e d i a t e and a c i d i c r o c k s f o r r o c k s of the Kutcho s u i t e . A l a c k of a p p a r e n t t r e n d i s t y p i c a l of c a l c - a l k a l i n e , i s l a n d a r c s u i t e s ( J a k e s and White, 1972). B a s i c r o c k s of the T a k l a F o r m a t i o n have an a v e r a g e Page 81 c o n c e n t r a t i o n of 369 113 ppm) i n r o c k s of than t h o s e i n Kutcho ppm S r . S t r o n t i u m c o n c e n t r a t i o n s ( a v e r a g i n g the Cache Creek Group appear to be l o w e r , r o c k s . 5.5.6 Z i r c o n i u m Z i r c o n i u m a v e r a g e s f o r r o c k s of the Kutcho F o r m a t i o n 165, 96 and 142 ppm i n b a s i c , i n t e r m e d i a t e and a c i d i c r o c k s , r e s p e c t i v e l y . Z i r c o n i u m c o n c e n t r a t i o n s f o r r o c k s of the Kutcho s u i t e do not e x h i b i t t r e n d s ( F i g . 5.12b). Samples of the b a s i c s c h i s t , T a k l a F o r m a t i o n s and Cache Creek Groups have low Zr c o n c e n t r a t i o n s (69, 55 and 68 ppm, r e s p e c t i v e l y ) w i t h r e s p e c t to t h o s e of the Kutcho F o r m a t i o n . 5.5.7 Barium Barium v a l u e s f o r r o c k s of the Kutcho F o r m a t i o n ( F i g . 5.12b) a v e r a g e 177, 1403 and 484 ppm f o r b a s i c , i n t e r m e d i a t e and a c i d i c r o c k s ( T a b l e 5.5) , r e s p e c t i v e l y . Average c o n c e n t r a t i o n s f o r Ba i n modern o r o g e n i c s u i t e s a r e p r e s e n t e d i n T a b l e s 5.2 to 5.4. Barium c o n c e n t r a t i o n s i n the b a s i c s c h i s t u n i t , a v e r a g i n g Page 82 636 ppm, are h i g h e r than f o r b a s i c r o c k s of the Kutcho F o r m a t i o n . A l t h o u g h t h e y a r e not d i s s i m i l a r to a v e r a g e v a l u e s f o r c a l c - a l k a l i n e s u i t e s ( T a y l o r , 1969), t h e y c h e m i c a l l y r e s e m b l e th e s h o s h o n i t i c s u i t e s of J a k e s and White (1972) which have a v e r a g e v a l u e s of 600 ppm barium a t about 54 p e r c e n t S i 0 2 . B a s i c r o c k s of the T a k l a F o r m a t i o n a l s o have h i g h e r barium c o n c e n t r a t i o n s (338 ppm) than t h o s e of the Kutcho s u i t e . Rocks of the Cache Creek Group have v a l u e s s i m i l a r to t h o s e of the Kutcho s u i t e . 5.5.8 Y t t r i u m A l i m i t e d number of samples from the Kutcho F o r m a t i o n c o n t a i n e d d e t e c t a b l e Y. R e s t r i c t e d d a t a f o r Kutcho r o c k s show no a p p a r e n t t r e n d s . C o n c e n t r a t i o n s a r e w i t h i n a v e r a g e r a n g e s of 30 to 50 ppm Y f o r modern o r o g e n i c r o c k s (Bloxam and L e w i s , 1972). Data f o r r o c k s of the b a s i c s c h i s t , T a k l a F o r m a t i o n and Cache Creek Group a r e not d i s s i m i l a r from t h o s e of the Kutcho s u i t e . 5.5.9 Summary of T r a c e Element Data T r a c e element d a t a f o r r o c k s of the Kutcho s u i t e i s l i m i t e d as many of the e l e m e n t s o c c u r i n c o n c e n t r a t i o n s below Page 83 d e t e c t a b l e l i m i t s . H a r k e r v a r i a t i o n p l o t s of t r a c e element d a t a y i e l d e d l i t t l e s i g n i f i c a n t i n f o r m a t i o n . In g e n e r a l Ba, Z r , Y and Sr e x h i b i t no a p p a r e n t i n c r e a s e or d e c r e a s e w i t h changes i n S i 0 2 c o n c e n t r a t i o n s ; MnO and V d e c r e a s e i n c o n c e n t r a t i o n as S i 0 2 i n c r e a s e s ; Cu c o n c e n t r a t i o n s a r e s l i g h t l y h i g h e r i n b a s i c r o c k s . Chromium, Co and N i a r e found above d e t e c t a b l e l i m i t s o n l y i n b a s i c r o c k s . T r a c e e lement c o n c e n t r a t i o n s i n the b a s i c s c h i s t u n i t a r e s i m i l a r to o t h e r u n i t s of the Kutcho s u i t e w i t h the e x c e p t i o n of Ba which i s c o n s i s t e n t l y h i g h e r i n t han o t h e r b a s i c r o c k s . 5. 6 Summary of C h e m i c a l Data Major and minor element g e o c h e m i s t r y of r o c k s of the Kutcho v o l c a n i c s u i t e i s s i m i l a r to t h a t of modern o r o g e n i c v o l c a n i c s e r i e s as d e f i n e d by Ewart ( 1 9 7 6 ) , C a r m i c h a e l e t a l . ( 1 9 7 4 ) , T a y l o r (1969) and M c B i r n e y ( 1 9 6 9 ) . A summary of p l o t s i n c l u d e d i n t h i s e x a m i n a t i o n of the c h e m i s t r y i s p r e s e n t e d i n T a b l e 5.6. A r a t h e r u n i q u e c h a r a c t e r i s t i c t h a t d i s t i n g u i s h e s the Kutcho v o l c a n i c s u i t e from " a v e r a g e " modern o r o g e n i c s u i t e s i s the a p p a r e n t l a c k of a n d e s i t e s which ar e g e n e r a l l y most abundant i n v o l c a n i c i s l a n d a r c s ( D i c k i n s o n , 1966; T a y l o r , 1969; and M c B i r n e y , 1969). R a t h e r , the Kutcho r o c k s t e n d to be b i m o d a l w i t h b a s a l t / b a s a l t i c a n d e s i t e and r h y o d a c i t e / r h y o l i t e b e i n g the major Page 84 v o l c a n i c r o c k t y p e s . A wide range of CaO, Na20 and K20 c o n c e n t r a t i o n s f o r a g i v e n S i 0 2 c o n c e n t r a t i o n , c o u p l e d w i t h the documented m o b i l i t y of t h e s e e l e m e n t s d u r i n g s e c o n d a r y p r o c e s s e s ( P e a r c e , 1974) and h i g h C02 and H20 c o n c e n t r a t i o n s a l l r e f l e c t a l t e r a t i o n i n r o c k s of the Kutcho v o l c a n i c s u i t e . The s u i t e i s c h a r a c t e r i s t i c a l l y c a l c - a l k a l i n e and r o c k s were d e r i v e d i n an i s l a n d a r c s e t t i n g . A n o t a b l e e x c e p t i o n i s the b a s i c s c h i s t u n i t which may be t r a n s i t i o n a l l y a l k a l i n e and s i m i l a r to r o c k s of the T a k l a F o r m a t i o n (Monger, 1977a) as shown i n S e c t i o n s 5.3 to 5.6. T h i s may be the r e s u l t of metasomatism a d j a c e n t to m a s s i v e s u l p h i d e d e p o s i t s . Major and t r a c e element d i s t r i b u t i o n f o r r o c k s of the Cache Cr e e k Group a r e s i m i l a r to t h o s e of t h e Kutcho v o l c a n i c s u i t e , but d i f f e r i n t h a t r o c k s of the Cache Creek Group a r e d o m i n a n t l y t h o l e i i t i c . P l o t s of e l e m e n t s s u g g e s t t h a t the r o c k s o r i g i n a t e d i n an o c e a n i c e n v i r o n m e n t . Page 85 BLE 5 . 6 : Summary o f C h e m i c a l R e s u l t s INTERPRETATION COMHENTS HARKER VARIATION DIAGRAM (F IG. S . i . 5 * ) ELEMENT TRENOS ELEMENTS FOLLOW GENERALLY ACCEPTED TRENOS FOR OROGENIC SUITES. THERE IS SOME SCATTER IN MOBILE ELEMENTS. IRVINE BARAGAR CLASSIFICATION ROCK NAMES IRVINE AND BARAGAR, 1976 CLASSIFICATION IS GENERALLY EFFECTIVE, BUT IS DEPENDENT ON MOBILE ELEMENTS SO PROBLEMS OO ARISE. ROCKS WITH ANOMALOUS CONCENTRATIONS OF CERTAIN ELEMENTS CANNOT BE CLASSIFIED. NORMATIVE COLOUR INDEX VERSUS NORMATIVE ANORTHITE (F IG. 5.1) DISCRIMINATION OF MAGMA TYPE IRVINE AND BARAGAR, 197S; BARAGAR AND GOODWIN, 1976 PLOT IS GENERALLY EFFECTIVE BUT IS OEPENOENT ON MOBILE ELEMENTS SO THAT CAUTION MUST 8E EXERCISED WHEN DEALING WITH ALTERED ROCKS. ROCKS WITH ANOMALOUS ELEMENT CONCENTRATIONS ( 1 . 6 . LOW CaO IN BASIC SCHIST UNIT) DO NOT PLOT WITHIN REASONABLE FIELOS. NORMATIVE ALBITE -ANORTHITE - ORTHOCLASE PROJECTION (F IG. 5.2) DISCRIMINATION OF MAGMA TYPE IRVINE ANO BARAGAR, 1976 ONLY MOOERATELY EFFECTIVE IN DIFFERENTIATING BASALT TO RHYOLITE COMPOSITIONS, INEFFECTIVE IN "K-RICH-K-POOR" CLASSIFICATION. PLOT INVOLVES PARAMETERS KjO, NSjO ANO CaO THAT ARE VERY MOBILE DURING ALTERATION. (FIG. 53) • DISCRIMINATIONS OF MAGMA TYPE ANO ALKALINE VERSUS .SUBALKALINE COMPOSITIONS FLOYO ANO WINCHESTER, USEFUL ANO EFFECTIVE CLASSIFICATION SCHEME FOR ALTERED 1978; WINCHESTER AND ROCKS AS-INVOLVES PARAMETERS (Z r and T IOj ) THAT ARE FLOYO, 1977 RELATIVELY IMMOBILE OURING SECONDARY PROCESSES. S10 2 CAN BE MOBILE OURING ALTERATION. THEREFORE SOME CAUTION MUST BE EXERCISED. AFM DIAGRAM (FIG 5 CALCALKALINE VERSUS THOLEIITIC IRVINE ANO BARAGAR. 1976 DESPITE THE HIGH MOBILITY OF PARAMETERS INVOLVED,PLOT IS GENERALLY EFFECTIVE IN DIFFERENTIATING VOLCANIC SUITES. PLOT IS ADVANTAGEOUS IN THAT MAJOR ELEMENT CONCENTRATIONS CAN BE EASILY MEASURED AND ABUNDANT DATA IS AVAILABLE FOR COMPARATIVE PURPOSES. ALKALIS VERSUS SILICA DIAGRAM (FIG. 5.3) ALKALINE VERSUS SUBALKALINE COMPOSITIONS IRVINE ANO BARAGAR, 1976 MACDONALD AND KATSURA, 1964; MACDONALD. 1968 ONLY MODERATELY EFFECTIVE. DUE TO HIGH MOBILITY OF ALKALIS DURING SECONDARY PROCESSES DATA POINTS ARE SCATTERED. NORMATIVE ANORTHITE (F IG. 5 . j J CLINOPYROXENE - OLIVINE NEPHELINE -OUARTZ TETRAHEDRON (F IG. 5.7) CALCALKALINE VERSUS THOLEIITIC COMPOSITIONS ALKALINE VERSUS SUBALKALINE COMPOSITIONS IRVINE ANO BARAGAR, 1976 IRVINE ANO BARAGAR, 1976; YODER ANO TILLEY, 1962 PARAMETERS ( i . TO ALTERATION DURING SECONDARY PROCESSES TO APPLY DIAGRAM TO ALTERED SUITES. A DISADVANTAGE OF THIS PLOT IS ITS GENERALLY LIMITED APPLICATION TO LOW SILICA ROCKS. IRVINE ANO 8ARAGAR (1976) SUGGEST DIAGRAM GIVES GOOO DISCRIMINATION EVEN WHEN DEALING WITH ALTERED ROCKS. Page 86 TABLE 5.6: Summary of C h e m i c a l R e s u l t s ( c o n t i n u e d ) OIAGRAM INTERPRETATION REFERENCE COMMENTS TITANIUM VERSUS ZIRCONIUM (FIG. 5.S) TITANIUM VERSUS CHROMIUM (NOT INCLUOED) ZIRCONIUM VERSUS CHROMIUM (NOT INCLUOED) DISCRIMINATION OF TECTONIC ENVIRONMENT DISCRIMINATION OF TECTONIC ENVIRONMENT - OCEAN aOOR BASALT VERSUS ISLANO ARC THOLEIITE DISCRIMINATION OF TECTONIC ENVIRONMENT AND MAGMA TYPE PEARCE, 1975; PEARCE' AND CANN. 1973; STRONG 19 PEARCE. 1975 SLOXAM AND LEWIS. 1972 DIAGRAM HAS LIMITED APPLICATION FOR ROCKS OF BASALTIC COMPOSITIONS, BUT USEFUL WHEN DEALING WITH ALTERED ROCKS OF THESE COMPOSITIONS AS PARAMETERS ARE RELATIVELY IMMOBILE DURING SECONDARY PROCESSES. DIAGRAM HAS LIMITED APPLICATION TO SASALTIC ROCKS AND IN THESE COMPOSITIONS CHROMIUM WAS COMMONLY BELOW DETECTABLE LIMITS FOR DATA. PLOT IS AOVANTAGEOUS IN DEALING WITH ALTERED SUITES AS CHROMIUM ANO TITANIUM ARE IMK08ILE DURING SECONDARY PROCESSES. DIAGRAM HAS LIMITED APPLICATION TO BASALTIC ROCKS ANO CHROMIUM WAS COMMONLY BELOW OETECTABLE LIMITS FOR KUTCHO SUITE. BOTH CHROMIUM ANO ZIRCONIUM ARE IMMOBILE DURING ALTERATION SO DIAGRAM IS USEFUL IN DEALING WITH ALTERED ASSEMBLAGES. ZIRCONIUM VERSUS TIO-J (NOT INCLUOED) DISCRIMINATION OF TECTONIC ENVIRONMENT ANO MAGMA TYPE BLOXAM AND LEWIS, 1972; FLOYO ANO WINCHESTER, 1975 DIAGRAM HAS APPLICATION LIMITED TO BASALTIC ROCKS BUT IS USEFUL FOR EXAMINING ALTEREO ASSEMBLAGES. FIELD OF ALKALI BASALT WELL DEFINED, BUT POOR DISCRIMINATION BETWEEN OCEANIC THOLEIITE, ISLANO ARC THOLEIITE ANO CALCALKALINE BASALTS. (13) DIAGRAM (NOT INCLUDED) DISCRIMINATION OF TECTONIC SETTING PEARCE. 1975 OIAGRAM HAS APPLICATION LIMITED TO BASALTIC ROCKS BUT IS USEFUL IN DEALING WITH ALTERED ASSEMBLAGES AS Zr, TiOj AND Y ARE RELATIVELY IMMOBILE OURING SECONDARY PROCESSES. THE MAIN DISADVANTAGE IS THAT YTTRIUM IS COMMONLY BELOW STANDARD OETECTABLE LIMITS. (NOT INCLUDED) DISCRIMINATION OF TECTONIC SETTING BLOXAM AND LEWIS, 1972 OIAGRAM HAS APPLICATION LIMITED TO ROCKS OF BASALTIC COMPOSITION. THE "OCEANIC THOLEIITE FIELD" IS WELL OEFINED, BUT THERE IS POOR DISCRIMINATION BETWEEN ALKALI, ISLANO ARC THOLEIITE AND CALCIUM BASALTS. USEFUL FOR ALTERED ROCKS DUE TO RELATIVE IMMOBILITY OF ZIRCONIUM, CHROMIUM, ANO TITANIUM DURING SECONDARY PROCESSES. -Sr/, (NOT INCLUOED) MgO-FeO total -(FIG. 5.« ) DISCRIMINATION OF TECTONIC SETTING DISCRIMINATION OF TECTONIC SETTING PEARCE. 1975; STRONG 1977; CONOIE, 1976; CONDIE AND MOORE, 1977 PEARCE ET AL., 1976 DIAGRAM HAS APPLICATION LIMITED TO BASALTIC ROCKS. STRONTIUM TENDS TO BE QUITE MOBILE OURING SECONDARY PROCESSES SO THAT IT HAS ONLY LIMITED USE WHEN DEALING WITH ALTERED ROCKS. ALTHOUGH DIAGRAM HAS BEEN APPLIED TO ARCHEAN ROCKS, (CONOIE, 1976). MgO.FeO total ANO A l ^ ARE ONLY SLIGHTLY MOBILE OURING SECONDARY PROCESSES SO THAT DIAGRAM IS USEFUL WHEN DEALING WITH ALTERED VOLCANIC ROCKS. ACCORDING TO PEARCE ET AL., (1976) LOW SILICA ROCKS ARE MOST SENSITIVE INDICATIONS OF TECTONIC ENVIRONMENT AND FIELOS HAVE BEEN OEFINED FROM ROCKS OF THIS COMPOSITION. THE MgO-FsO total-AljO OIAGRW GIVES GOOD DISCRIMINATION FOR LOW SILICA ROCKS. Page 87 TABLE 5.6: Summary of C h e m i c a l R e s u l t s ( c o n t i n u e d ) INTERPRETATION REFERENCE COMMENTS TIOJ-KJO-PJOJ (FIG. DISCRIMINATION OF TECTONIC SETTING. OCEANIC VERSUS NON OCEANIC PEARCE ET AL., YELLUR. 1977 THE DIAGRAM HAS APPLICATION LIMITED TO ROCKS OF "PRIMITIVE BASALTIC COMPOSITION", LE. FRACTIONATEO AND ALKALINE ROCKS MUST NOT BE PLOTTED. KjO IS ALSO HIGHLY MOBILE DURING ALTERATION SO THAT THE DIAGRAM CANNOT BE APPLIED TO ALTERED ASSEMBLAGE. THE ADVANTAGE OF THIS PLOT IS THE RELATIVE EASE WITH WHICH DATA CAN SE OBTAINED. (NOT INCLUDED) (NOT INCLUDED) DISCRIMINATION OF TECTONIC ENVIRONMENT AND ALKALINE VERSUS THOLEIITIC COMPOSITIONS DISCRIMINATION OF TECTONIC ENVIRONMENT FLOYD ANO WINCHESTER, 1975 FLOYD AND WINCHESTER, 1975 P2Oj ANO T102) THE DIAGRAM IS RESTRICTED TO ROCKS OF BASALTIC COMPOSITION AND IS ADVANTAGEOUS IN USING PARAMETERS (Zr THAT ARE EASILY AND COMMONLY DETERMINED DURING ANALYSES THESE ELEMENTS ARE ALSO RELATIVELY IMMOBILE OURING ALTERATION. THE DIAGRAM PROVIDES GOOD DISCRIMINATION OF ALKALINE VERSUS THOLEITTIC ROCKS BUT POOR DISCRIMINATION OF OCEANIC VERSUS CONTINENTAL BASALTS. THE DIAGRAM IS LIMITED TO BASALTIC ROCKS ANO HAS PARAMETERS (Nb ANO Y) THAT ARE COMMONLY BELOW LIMITS OF DETECTION. IT PROVIDES GOOD DISCRIMINATION BETWEEN ALKALINE BASALTS AND OCEANIC THOLEIITES AND ONLY POOR DISCRIMINATION CONTINENTAL THOLEIITES AND ALKALINE BASALTS. (NOT INCLUDED) DISCRIMINATION OF MAGMA TYPE aOYO ANO WINCHESTER, 1975 DIAGRAM IS RESTRICTED TO BASALTIC ROCKS ANO NIOBIUM ANO YTTRIUM ARE OFTEN BELOW LIMITS OF DETECTION, DIAGRAM PROVIOES GOOD DISCRIMINATION OF THOLEIITIC VERSUS ALKALINE -BASALTS AND POOR DISCRIMINATION BETWEEN CONTINENTAL AND OCEANIC ROCKS. (NOT INCLUDED) DISCRIMINATION OF MAGMA TYPE aOYO ANO WINCHESTER. 1978; WINCHESTER AND FLOYO, 1977 DIAGRAM IS USEFUL FOR DISCRIMINATION OF ALTERED ROCKS OUE TO IMMOBILITY OF PARAMETERS DURING SECONOARY PROCESSES, ANO MAY BE APPLIED TO ROCKS OF ALL COMPOSITIONS. THE PRIMARY DISADVANTAGE IS AVAILABILITY OF OATA FOR GALLIUM CONCENTRATIONS. (NOT INCLUDED) DISCRIMINATION OF MAGMA TYPE DISCRIMINATION OF MAGMA TYPE WINCHESTER ANO FLOYO, 1977 AS PER "Zr/T10,Nb/Y DIAGRAM". WINCHESTER AND aOYO. 1977 OIAGRAM IS EFFECTIVE FOR VOLCANIC ROCKS OF ALL COMPOSITIONS ANO IS PARTICULARLY EFFECTIVE WHEN DEALING WITH ALTERED SUITES. (Ce, Zr AND TlOjARE IMMOBILE OURING ALTERATION). THE LACK OF AVAILABLE DATA FOR CERIUM IS A SERIOUS DISADVANTAGE. (NOT INCLUOEO) DISCRIMINATION OF MAGMA TYPE FLOYD ANO WINCHESTER, 1978 WINCHESTER ANO aOYO. 1977 OIAGRAM IS USEFUL IN ALTERED ROCKS DUE TO IMMOBILITY OF PARAMETERS AND IS APPLICABLE TO ROCKS OF ALL COMPOSITIONS Page 88 5.7 T a k l a V e r s u s Kutcho C h e m i s t r y Rocks of the T a k l a F o r m a t i o n a r e a p p a r e n t l y contemporaneous w i t h t h o s e of the Kutcho F o r m a t i o n , b e i n g L a t e T r i a s s i c i n age (Monger, 1976). Only l i m i t e d d a t a f o r r o c k s of the T a k l a F o r m a t i o n i s p l o t t e d i n t h i s t h e s i s and c o n c l u s i o n s i n t h i s s e c t i o n a r e l a r g e l y based on d a t a from Monger ( 1 9 7 7 a ) . Rocks of the T a k l a F o r m a t i o n a r e a l k a l i n e w h i l e r o c k s of the Kutcho F o r m a t i o n a r e s u b a l k a l i n e . P erhaps the most o b v i o u s d i f f e r e n c e between the two v o l c a n i c s u i t e s i s the range of s i l i c a c o n c e n t r a t i o n s . Rocks of the Kutcho F o r m a t i o n e x h i b i t a wide range of S i 0 2 v a l u e s from 45 p e r c e n t to g r e a t e r than 80 p e r c e n t . T a k l a r o c k s have a l i m i t e d r ange of 40 to 60 p e r c e n t S i 0 2 . A c o m p a r i s o n of d a t a f o r major element c h e m i s t r y ( d a t a f o r Kutcho F o r m a t i o n shown i n F i g . 5.11a and b ) , p l o t t e d on H a r k e r v a r i a t i o n d i a g r a m s , shows s i m i l a r element c o n c e n t r a t i o n s f o r g i v e n s i l i c a c o n c e n t r a t i o n s . Page 89 CHAPTER 6 AGE OF KUTCHO FORMATION On the b a s i s of i t s s i l i c e o u s c h a r a c t e r the Kutcho F o r m a t i o n was o r i g i n a l l y c o r r e l a t e d w i t h a c i d i c v o l c a n i c r o c k s of the Permian A s i t k a Group (Monger, 1977b). S t r a t i g r a p h i c e v i d e n c e and a Rb-Sr i s o c h r o n age of 210 + 10 Ma, s u g g e s t a L a t e T r i a s s i c age f o r the r o c k s . Rocks of the Kutcho F o r m a t i o n t h u s a r e p r o b a b l y contemporaneous w i t h the Upper T r i a s s i c T a k l a F o r m a t i o n (Monger, 1976). 6.1 S t r a t i g r a p h i c R e l a t i o n s of t h e K u t c h o , Sinwa and I n k l i n F o r m a t i o n s s e d i m e n t a r y r o c k s of the Kutcho F o r m a t i o n , l i m e s t o n e c o r r e l a t e d w i t h the Upper T r i a s s i c Sinwa L i m e s t o n e , and a g r e y w a c k e - p h y l l i t e sequence c o r r e l a t e d w i t h the Lower J u r a s s i c I n k l i n F o r m a t i o n . These g r a d a t i o n a l c o n t a c t s a r e s i g n i f i c a n t i n d e f i n i n g the age of the u n d e r l y i n g Kutcho F o r m a t i o n . The upper c o n g l o m e r a t e of the Kutcho F o r m a t i o n g r a d e s i n t o and i s i n p a r t a f a c i e s e q u i v a l e n t of G r a d a t i o n a l c o n t a c t s e x i s t between upper v o l c a n o -Page 90 both o v e r l y i n g u n i t s . In c e r t a i n l o c a t i o n s the Sinwa F o r m a t i o n i s t h i n to a b s e n t and the d i s t i n c t i o n between c o n g l o m e r a t e of the Kutcho and I n k l i n F o r m a t i o n s becomes p o s s i b l e o n l y as greywacke and p h y l l i t e become abundant h i g h e r i n the s e c t i o n . S t r a t i g r a p h i c r e l a t i o n s s u g g e s t t h a t c o n g l o m e r a t e of the Kutcho F o r m a t i o n i s L a t e T r i a s s i c i n age. I f the c o n g l o m e r a t e does not r e p r e s e n t any major h a i t u s t h e n an Upper T r i a s s i c age may be i n f e r r e d f o r the e n t i r e Kutcho F o r m a t i o n . C o n g l o m e r a t e of the Kutcho F o r m a t i o n does not appear to r e p r e s e n t a major h a i t u s i n d e p o s i t i o n . I t i s d i f f i c u l t to a s c e r t a i n whether a major u n c o n f o r m a b l e s u r f a c e u n d e r l i e s the c o n g l o m e r a t e due to the h i g h l y l e n s o i d n a t u r e and extreme s t r u c t u r a l t h i n n i n g and t h i c k e n i n g of u n i t s . A l t h o u g h t h e r e i s a marked t h i c k e n i n g of c o n g l o m e r a t e i n a w e s t e r l y d i r e c t i o n i n the main a r e a of e x p o s u r e i n the Kutcho F o r m a t i o n , i t does not appear to c u t down s e c t i o n and t r u n c a t e u n d e r l y i n g v o l c a n o - s e d i m e n t a r y r o c k s but r a t h e r i n t e r f i n g e r s w i t h t u f f and a r g i l l i t e to the e a s t . T u f f and a r g i l l i t e , and c o n g l o m e r a t e c o n t a i n v o l c a n i c l a s t i c l a y e r s and l e n s e s t h a t a r e l i t h o l o g i c a l l y i d e n t i c a l to the u n d e r l y i n g q u a r t z - e y e f e l d s p a r s e r i c i t e s c h i s t member; t h i s s u g g e s t s s t r a t i g r a p h i c c o n t i n u i t y between c o n g l o m e r a t e , t u f f and a r g i l l i t e , and u n d e r l y i n g v o l c a n i c l a s t i c r o c k s . Page 91 The above e v i d e n c e of c o n t i n u i t y of d e p o s i t i o n between the c o n g l o m e r a t e and u n d e r l y i n g u n i t s of the Kutcho F o r m a t i o n , and c o n g l o m e r a t e w i t h o v e r l y i n g Upper T r i a s s i c Sinwa L i m e s t o n e and Lower J u r a s s i c I n k l i n F o r m a t i o n i n the Cry Lake map a r e a s u p p o r t s a L a t e T r i a s s i c age f o r r o c k s of the Kutcho F o r m a t i o n . 6 . 2 P a l e o n t o l o g i c a l E v i d e n c e The Kutcho F o r m a t i o n i s a p p a r e n t l y d e v o i d of f o s s i l s . T h i s may be a t t r i b u t e d to the degree of d e f o r m a t i o n of r o c k s or to t h e i r a b sence i n the f i r s t p l a c e . F o s s i l s c o l l e c t e d from l i m e s t o n e of the Upper T r i a s s i c Sinwa L i m e s t o n e i n c l u d e c r i n o i d columns, one c o r a l and one b i v a l v e i d e n t i f i e d as M i n e t r i g o n i a s p . deemed " p r o b a b l e Upper T r i a s s i c " by E. T o z e r (1978, w r i t t e n comm.) of the G e o l o g i c a l S u r v e y of Canada. A s c l e r a c t i n i a n c o r a l i d e n t i f i e d by Monger i n the a r e a of the Kutcho d e p o s i t (Monger, 1977; p e r s . comm.) s u g g e s t s a M e s o z o i c age. The age of t h i s l i m e s t o n e i s i m p o r t a n t because i t l i e s i n g r a d a t i o n a l c o n t a c t w i t h c o n g l o m e r a t e of the Kutcho F o r m a t i o n ; thus i t d e f i n e s a l a t e T r i a s s i c age f o r the c o n g l o m e r a t e . Page 92 6.3 Rb-Sr D a t i n g - Method and R e s u l t s Rb and Sr c o n c e n t r a t i o n s were d e t e r m i n e d by r e p l i c a t e a n a l y s i s of p r e s s e d powder p e l l e t s u s i n g X-ray f l u o r e s c e n c e . U.S. G e o l o g i c a l S u r v e y r o c k s t a n d a r d s were used f o r c a l i b r a t i o n ; mass a b s o r p t i o n c o e f f i c i e n t s were o b t a i n e d from Mo K Compton s c a t t e r i n g measurements. Rb/Sr r a t i o s have a p r e c i s i o n of 2 per c e n t (1 sigma ) and c o n c e n t r a t i o n s a p r e c i s i o n of 5 per c e n t (1 s i g m a ) . Sr i s o t o p i c c o m p o s i t i o n was measured on u n s p i k e d samples p r e p a r e d u s i n g s t a n d a r d i o n exchange t e c h n i q u e s . The mass s p e c t r o m e t e r (60 degree s e c t o r , 30 cm r a d i u s , s o l i d s o u r c e ) i s of U.S. N a t i o n a l Bureau of S t a n d a r d s d e s i g n , m o d i f i e d by H. F a u l . Data a c q u i s i t i o n i s d i g i t i z e d and automated u s i n g a NOVA computer. E x p e r i m e n t a l d a t a have been n o r m a l i z e d to a 8 6 Sr/88Sr r a t i o of 0.1194 and a d j u s t e d so t h a t the NBS s t a n d a r d SrC03 (SRM987) g i v e s a 87Sr/ 86Sr r a t i o of 0.71022 + 2, and the Eimer and Amend Sr a r a t i o of 0.70800 + 2. The p r e c i s i o n of a s i n g l e 8 7 S r/86Sr r a t i o i s 0.00013 at 1 sigma. Rb-Sr d a t e s are based on a Rb decay c o n s t a n t of 1.42 x 10-11 y - 1 . The r e g r e s s i o n s a r e c a l c u l a t e d a c c o r d i n g to the t e c h n i q u e of York ( 1 9 7 6 ) . Page 93 TABLE 6.1 Rb-Sr Data For Rocks of the Kutcho F o r m a t i o n , Cry Lake Map A r e a , B r i t i s h C olumbia (1 A n a l y s e s were p e r f o r m e d by R.L. A r m s t r o n g , the U n i v e r s i t y of B r i t i s h C o l u m b i a on samples p r o v i d e d by A. P a n t e l e y e v ) Sample Number Descr ipt ion Location Latitude Longi tude JSI02 ppmSr ppmRb RO/Sr « b 8 7 / s r 8 ' S r 8 7 / S r 8 6 A.12 Quartz-eye fe ld spar -s e r l c l t e s ch i s t Cry Lake Hap Area ss°ir 12a°20* 69.0 197 18.3 0.093 .268 .7048 A . U Quartz-eye s e r i c i t e scn i s t Cry Lake Map Area 5a012' 128°24' 68.4 29.1 14.7 0.504 1.46 .7086 A.2d Feldspar -quart*z-eye s e r i c i t e scn i s t Cry Lake Map Area 58°10' I 2S°15 ' 61.1 57.6 3.6 0.149 0.432 .7054 A.32 Fe ld spa r -quar tz -eye s e r i c i t e scn i s t Cry Lake Map Area 58°13' 128°24 1 68.5 69.1 3.7 0.053 0.153 .7049 A.47 ' Quartz - feldspar - c h l o r i t e , s e r i c i t e sch i s t Cry Lake Map Area 58°10' I2a°20' 73.64 46.3 1.4 0.030 0.087 .7044 A.48 ' Ch lor i te scnist Cry Lake Map Area 58°11' 128°20' 50.87 147.0 1.0 0.007 0.020 .7042 A.S3 Quartz - f e ld spa r - s e r i c i t e sch i s t Cry Lake Map Area 58°13/ 128 023' 75.70 136.4 8.7 0.063 0.182 .7048 AP.63 1 Quartz - fe ldspar Cry Lake Mao Area 51.1 2.3 0.046 0.133 .7047 Page 94 TABLE 6.2: Rb-Sr Data f o r Rocks of the T a k l a F o r m a t i o n * , M c C o n n e l l Creek Map A r e a , B r i t i s h Columbia (* A n a l y s e s were p e r f o r m e d by R.L. A r m s t r o n g , the U n i v e r s i t y o B r i t i s h C olumbia on samples p r o v i d e d by J . Monger) Sample Number Descr ipt ion Location Lat i tude Longitude XSIO; ppmSr ppmftb R l » s r R b " / S r a 6 S r 3 7 / S r 8 6 MV-75-14a Savage Mountain Formation McConnell Map Ar ia Creek 5 6 0 3 5 ' 30" 126°2S' 48.4 259 27.8 0.107 0.310 .7044 NV-75-82 Savage Mountain Formation McConnall Mao Aroa Creek 56°33'30" 12S°33' 49.1 470 36.0 0.077 0.222 . 7050 MV-75-141C Savage Mountain Formation McConnell Map Area Creek S5°32' 126029' 49.3 382 28.8 0.075 0.217 .7049 108-RML-75 Savaga Mountain Formation McConnel1 Map Area Creek S6°36' I26°32 ' 47.3 291 16.7 0.057 0.165 .7048 ua-am.-75 Savage Mountain Formation McConnell Map Area Creek S6°3S' 126°32' 49.2 417 17.9 0.043 0.124 .7046 MV-75-209C Moosevale Formation McConnel1 Map Area Creek S6°41 ' 126°54' 57.3 312 42.9 0.138 0.399 .7050 MV-7S-22a Mootovale Formation McConnell Mao Area Creek 56040' 126052' 41.2 202 14.4 0.071 0.205 .7043 MV-322-66 Jennings Map Area River SB°56' 130°30' - 130 49.3 0.379 1.097 .7076 99A1-75-RW0 East of Plnchl Fault McConnell River 56°44'30" 126°33' - 217 25.5 0.118 0.341 .7049 I29A-75-RUU East of Plnchl Fault McConnell River S6°25' I 2 6 ° l l ' 49.8 240 3.9 0.016 0.046 .7040 Page 95 Both a c i d i c and b a s i c samples were a n a l y z e d to g e n e r a t e i s o c h r o n d a t a . Samples showing l i t t l e a l t e r a t i o n and e x h i b i t i n g a wide r a n g e of Rb/Sr r a t i o s were c h o s e n . B a s i c r o c k s were found to be low i n Sr and Rb/Sr r a t i o and were u n s u i t a b l e f o r g e n e r a t i n g an i s o c h r o n . A Rb-Sr i s o c h r o n c a l c u l a t e d f o r r o c k s of the Kutcho F o r m a t i o n g i v e s an age of 210 _+ 10 Ma ( F i g . 6.1A). Sample d a t a a r e i n T a b l e s 6.1 and 6.2. The i s o c h r o n date i s s i m i l a r to a 223 +_ 28 Ma i s o c h r o n g e n e r a t e d f o r T a k l a F o r m a t i o n samples c o l l e c t e d by Monger and run by R.L. A r m s t r o n g ( F i g . 6.2). A 215 + 14 Ma age i s g e n e r a t e d by c o m b i n i n g Rb-Sr da t a f o r the T a k l a and Kutcho F o r m a t i o n s ( F i g . 6.1C). A p r e v i o u s l y r e p o r t e d date of 275 + 30 Ma age f o r the Kutcho F o r m a t i o n ( P a n t e l e y e v , 1975) was based on l i m i t e d d a t a ( A r m s t r o n g , 1978, p e r s . comm.) and i s no l o n g e r v i a b l e . Page 96 rati foi ro» ror TUB 114 f IWTUU. RATIO • 0-701* tO-COX ro4 ro* Fig.B idTTIAi. KApO tooa UilTlALfWMl • 070*0 >^ * * 100002 Rb / Sr L E O E N O O Kvtcho Formation • Taklo roinoijofi FIGURE 6.1A-C: I s o c h r o n Diagrams f o r Rocks of the T a k l a and Kutcho F o r m a t i o n s , N o r t h - C e n t r a l B r i t i s h C o l u m b i a ( d a t a i n T a b l e s 6.1 and 6.2) 6.1A: Rb-Sr I s o c h r o n Diagram f o r Rocks of the Kutcho F o r m a t i o n i n the C r y Lake Map Area 6.IB: Rb-Sr I s o c h r o n Diagram f o r Rocks of the T a k l a F o r m a t i o n M c C o n n e l l Creek Map A r e a . Data from R.L. A r m s t r o n g ( p e r s . comm. 1979). Samples c o l l e c t e d by J . Monger. 6.1C: Rb-Sr I s o c h r o n diagram of Combined Data From F i g u r e s 6.1A and 6.IB f o r Rocks of the Kutcho and T a k l a F o r m a t i o n s . Page 97 CHAPTER 7 STRUCTURE 7 .1 I n t r o d u c t i o n R o cks o f t h e K i n g Salmon a s s e m b l a g e , o f w h i c h t h e K u t c h o F o r m a t i o n i s an i n t e g r a l component, e x h i b i t v a r y i n g d e g r e e s o f d e f o r m a t i o n . These r o c k s a r e f o l d e d by a s i n g l e phase o f d e f o r m a t i o n , p r o b a b l y r e l a t e d t o t h e major t h r u s t i n g e v e n t t h a t e m p l a c e d t h e a l l o c h t h o n . . T h i s a l l o c h t o n was l a t e r c u t by v e r t i c a l and s t r i k e - s l i p f a u l t s . The f o l l o w i n g t e x t d i s c u s s e s s t r u c t u r a l c h a r a c t e r i s t i c s , d e t e r m i n e d by f i e l d mapping and s t e r e o n e t a n a l y s i s , o f t h e K i n g Salmon a s s e m b l a g e . I t c o n t r a s t s t h e s e w i t h s t r u c t u r e s o f o t h e r r o c k s o f M e s o z o i c age and of t h e Cache C r e e k Group. 7.1.1 S t e r e o n e t P r o j e c t i o n s S t r u c t u r a l d a t a , i n c l u d i n g measurements o f b e d d i n g , f o l i a t i o n and m i n o r f o l d s , were p l o t t e d and c o n t o u r e d on s t e r e o n e t s u s i n g a com p u t e r p r o g r a m ( W o o d s w o r t h , 1977, p e r s . Page 98 comm.). To f a c i l i t a t e s t u d y , the map a r e a was d i v i d e d i n t o s t r u c t u r a l domains shown i n F i g u r e 7.1 ( p o c k e t ) . P o l e s to b e d d i n g , f o l i a t i o n and minor f o l d s a r e p l o t t e d on e q u a l a r e a s t e r e o n e t p r o j e c t i o n s on which the M e l l i s and Schmidt or g r i d methods of c o n t o u r i n g were u s e d . In both methods a c i r c u l a r c o u n t e r t h a t c o v e r e d one per c e n t of the a r e a was u s e d . In the for m e r method the c i r c l e c e n t e r was s u p e r i m p o s e d on each p l o t t e d p o i n t and the number of o v e r l a p p i n g c i r c l e s f o r each p o i n t i s the c o n t o u r v a l u e , w h i l e i n the l a t t e r the c i r c l e i s c e n t e r e d a t g r i d i n t e r s e c t i o n s a l o n g a s q u a r e cm g r i d s u p e r i m p o s e d on the s t e r e o n e t ; the number of p o i n t s w i t h i n the c i r c l e i s the c o n t o u r v a l u e . T h e r e a r e some d i s a d v a n t a g e s to both s y s t e m s . F a l s e c o n c e n t r a t i o n s of d a t a may appear a t p o l e s u s i n g the M e l l i s method,, but c o u n t e r i n g t h i s f a c t i s i t s u s e f u l l n e s s when l i m i t e d amounts of d a t a a r e a v a i l a b l e ( T u r n e r and W e i s s , 1963). The Schmidt method i s b e t t e r f o r g r e a t e r q u a n t i t i e s of d a t a ( g r e a t e r than 400 p o i n t s : T u r n e r and Weiss, 1963) but p r o v i d e d l i t t l e u s e f u l i n f o r m a t i o n f o r t h i s s t u d y because of the number of d a t a p o i n t s c o l l e c t e d was s i g n i f i c a n t l y l e s s than 400. " P l a n e A v e r a g e " and " L i n e A v e r a g e " programs, i n which the a v e r a g e p l a n e to p o l e s and a v e r a g e l i n e to p o l e s i s d e t e r m i n e d f o r c o n t o u r e d d a t a by the computer, were used to c a l c u l a t e a v e r a g e b e d d i n g , f o l i a t i o n and minor f o l d axes r e s p e c t i v e l y . Page 99 7.2 S t r u c t u r e Rocks of the K i n g Salmon assemblage a r e t y p i f i e d by u p r i g h t to o v e r t u r n e d , s o u t h w e s t e r l y v e r g e n t i s o c l i n a l f o l d s which ar e b e l i e v e d by the a u t h o r to be contemporaneous w i t h the K i n g Salmon t h r u s t f a u l t . I m b r i c a t e t h r u s t s a s s o c i a t e d w i t h the N a h l i n and K i n g Salmon f a u l t s s u g g e s t the p o s s i b i l i t y of i n t e r n a l t h r u s t s w i t h i n t h e major t h r u s t s h e e t . T h e i n t e r n a l t h r u s t s a r e commonly a s s o c i a t e d w i t h i s o c l i n a l f o l d s ( B a d g l e y , 1965). D o c u m e n t a t i o n of t h e s e t h r u s t s i s d i f f i c u l t due to a t t e n u a t i o n of f o l d l i m b s , l a c k of d i s t i n c t s t r a t i g r a p h i c u n i t s and poor o u t c r o p . The i n t e n s i t y and s t y l e of d e f o r m a t i o n d e c r e a s e s both i n a n o r t h e a s t e r l y d i r e c t i o n away from the K i n g Salmon f a u l t and n o r t h w e s t e r l y a l o n g the b e l t . In the s o u t h e a s t , h i g h a m p l i t u d e , o v e r t u r n e d , i s o c l i n a l f o l d s w i t h w e l l d e f i n e d a x i a l p l a n e f o l i a t i o n and i m b r i c a t e t h r u s t s h e e t s near the s o l e of the K i n g Salmon f a u l t a r e common. As the b e l t i s t r a v e r s e d to the n o r t h w e s t , open, s i m i l a r - s t y l e f o l d s w i t h weakly d e v e l o p e d a x i a l f o l i a t i o n s p r e d o m i n a t e . I m b r i c a t e zones a r e uncommon or u n d e f i n e d i n t h i s a r e a . S t r i k e - s l i p or normal f a u l t s , p e r p e n d i c u l a r to the main t h r u s t s o c c u r t h r o u g h o u t the b e l t . Page 100 7.2.1 F o l d s I s o c l i n a l f o l d s a r e dominant, but open, u p r i g h t , s i m i l a r - s t y l e f o l d s a r e a l s o p r e s e n t . F o l d s are b e s t o u t l i n e d by the Sinwa L i m e s t o n e which p r o v i d e s a c o n v e n i e n t marker h o r i z o n t h r o u g h o u t the b e l t . I s o c l i n a l f o l d s a r e g e n e r a l l y t i g h t w i t h h i g h l y a t t e n u a t e d f o l d l i m b s and h i n g e s , t r a n s p o s e d l a y e r i n g and s u s p e c t e d t h r u s t s w i t h i n h i n g e r e g i o n s . F o l d s have a m p l i t u d e s of one to f o u r km and w a v e l e n g t h s of "0.5 t o 2 km. Major f o l d axes p l u n g e g e n t l y to the n o r t h w e s t and g e n e r a l l y c a n n o t be t r a c e d a l o n g s t r i k e f o r g r e a t d i s t a n c e s . In t h e e a s t e r n p a r t of the map a r e a ( F i g . 2.2), where d e f o r m a t i o n i s most i n t e n s e , f o l d a m p l i t u d e s i n c r e a s e and w a v e l e n g t h s d e c r e a s e to g i v e t i g h t e r , more condensed s t r u c t u r e s . T h e r e , a l a r g e , s o u t h v e r g e n t , west p l u n g i n g a n t i c l i n e w i t h s m a l l e r p a r a s i t i c f o l d s on i t s s o u t h e r n l i m b dominates the s t r u c t u r e . Beds a r e moderate to s t e e p l y d i p p i n g i n t h i s a r e a , but d r i l l h o l e i n f o r m a t i o n s u g g e s t s t h e y t e n d to f l a t t e n at depth to 45 degree d i p s ( B r i d g e , p e r s . comm., 1978). Due t o extreme t r a n s p o s i t i o n of l a y e r i n g and the m a s s i v e and f r a g m e n t a l c h a r a c t e r of r o c k s w i t h i n the Kutcho F o r m a t i o n i t Page 101 i s d i f f i c u l t to o b s e r v e b e d d i n g . As the degree of d e f o r m a t i o n d e c r e a s e s b e d d i n g becomes more d i s t i n c t . S t e r e o n e t p l o t s of p o l e s to b e d d i n g c o n c u r w i t h f i e l d o b s e r v a t i o n s . E a s t - w e s t t r e n d s w i t h a s i n g u l a r c o n c e n t r a t i o n of p o l e s , t y p i f y the e a s t e r n p a r t of the b e l t ( F i g . 1.2k) and g i v e way t o n o r t h w e s t e r l y t r e n d s i n the c e n t r a l and w e s t e r n p a r t s of the b e l t ( F i g . 7.2B and C ) . In the c e n t r a l zone ( F i g . 7.2B) p o l e s to b e d d i n g show two main c o n c e n t r a t i o n s and a r e more e v e n l y d i s t r i b u t e d a l o n g a g r e a t c i r c l e i n d i c a t i v e of the more open f o l d s t r u c t u r e s exposed i n the n o r t h e a s t e r n l i m i t s of the b e l t where most of the d a t a were c o l l e c t e d . In the w e s t e r n p a r t of the map a r e a ( F i g . 7.2C) two c o n c e n t r a t i o n s of p o l e s to b e d d i n g o c c u r on the same s i d e of the p l o t , s u g g e s t i v e of i s o c l i n a l f o l d s . F i g u r e 7.2D summarizes b e d d i n g measurements from the e n t i r e b e l t and g i v e s an a v e r a g e p l a n e of 107 d e g r e e s w i t h 56 degree n o r t h e a s t e r l y d i p . 7.2.2 F o l i a t i o n P e n e t r a t i v e a x i a l p l a n a r f o l i a t i o n i s common i n r o c k s of the K i n g Salmon a s s e m b l a g e . The f o l i a t i o n becomes l e s s extreme as the i n t e n s i t y of d e f o r m a t i o n d e c r e a s e s a l o n g and a c r o s s the b e l t . A g e n e r a l w e s t - n o r t h w e s t e r l y t r e n d w i t h moderate to s t e e p Page 102 NN A . NN FIGURE 7.2A-D: M e l l i s C o n t o u r e d P l o t s of P o l e s to B e d d i n g P l a n e s f o r Rocks of the K i n g Salmon A l l o c h t h o n , Cry Lake Map A r e a , B.C. 7 .2A: P o l e s to 35 P l a n e s ( S u b s e c t i o n I A ) ; Avg P l a n e i s 088o/46oNW 7 .2B: P o l e s t o 50 P l a n e s ( S u b s e c t i o n I D ) ; Avg P l a n e i s 116o/64oNE 7 .2C: P o l e s to 53 P l a n e s ( S u b s e c t i o n I E ) ; Avg P l a n e i s 099o/51oNE 7 . 2D: P o l e s to 104 P l a n e s ( S u b s e c t i o n s IB , ID , and IE) ; Average P l a n e i s 107o/56oNE Page 103 n o r t h e r l y d i p s c h a r a c t e r i z e s the f o l i a t i o n t h r o u g h o u t most of the b e l t . F o l i a t i o n d i p s tend to s t e e p e n i n a n o r t h e a s t e r l y d i r e c t i o n a c r o s s the b e l t . T h i s a p p a r e n t f a n n i n g of the f o l i a t i o n i s a l s o e v i d e n t f a r t h e r n o r t h e a s t i n t o r o c k s of the Cache Cr e e k Group where s t e e p s o u t h w e s t e r l y d i p s a r e dominant. F o l i a t i o n a t t i t u d e s i n the d i s c r e t e b l o c k of Kutcho F o r m a t i o n n o r t h of the main b e l t ( F i g . 7 . 3 G ) a r e s i m i l a r to the r e g i o n a l t r e n d f o r the main b e l t , but s t e e p d i p s a r e p r e d o m i n a n t l y i n a s o u t h w e s t e r l y d i r e c t i o n . S t e r e o n e t p r o j e c t i o n s of p o l e s to f o l i a t i o n show a r e l a t i v e h omogeneity of a t t i t u d e s w i t h i n the b e l t ( F i g . 7.3A, B, C, D and E ) , w i t h o n l y s l i g h t changes a l o n g i t . In the e a s t e r n p a r t of the b e l t ( F i g . 7.3A), e a s t - w e s t s t r i k e s and m o d e r a t e l y s t e e p n o r t h e r l y d i p s a r e dominant w i t h some f l a t t e n i n g of d i p s near the l e a d i n g edge of the K i n g Salmon t h r u s t . In c e n t r a l and west zones of the b e l t n o r t h w e s t e r l y s t r i k e s and s t e e p n o r t h e a s t e r l y d i p s p r e v a i l , but s t e e p s o u t h w e s t e r l y d i p s a r e a l s o p r e s e n t ( F i g . 7.3 B, D and E ) . An o b v i o u s e x c e p t i o n to the r e l a t i v e l y homogeneous a t t i t u d e s i s e v i d e n t i n F i g u r e 7.3C, i n which the a v e r a g e p l a n e of f o l i a t i o n i s s i g n i f i c a n t l y d i f f e r e n t and i s i n t e r p r e t e d as a r o t a t e d f a u l t b l o c k . F i g u r e 7.3F, a c u m u l a t i v e p l o t of p o l e s to f o l i a t i o n g i v e s an a v e r a g e p l a n e of 108 d e g r e e s w i t h a d i p of 70 d e g r e e s n o r t h w e s t . Page 104 N N a. c. FIGURE 7.3A-C: M e l l i s C o n t o u r e d P l o t s f o r P o l e s to F o l i a t i o n f o r Rocks of the K i n g Salmon A l l o c h t h o n , Cry Lake Map A r e a , B. C. 7.3A: P o l e s to 103 P l a n e s ( S u b s e c t i o n I A ) ; Avg P l a n e i s 093o/71oNE 7.3B: P o l e s to 73 P l a n e s ( S u b s e c t i o n I B ) ; Avg P l a n e i s 112o/74oNE 7.3C: P o l e s to 34 P l a n e s ( S u b s e c t i o n I C ) ; Avg P l a n e i s 140o/67oNE Page 105 I S- G . FIGURE 7.3D-G M e l l i s C o n t o u r e d P l o t s f o r P o l e s to F o l i a t i o n f o r Rocks of the K i n g Salmon A l l o c h t h o n , Cry Lake Map Area ( c o n t ' d . ) 7.3D: P o l e s to 37 P l a n e s ( S u b s e c t i o n I D ) ; Avg P l a n e i s 109o/75oNE 7.3E: P o l e s to 45 P l a n e s ( S u b s e c t i o n I E ) ; Avg P l a n e i s 107o/69oNE 7.3F: P o l e s to 292 P l a n e s ( S u b s e c t i o n s IA, IB, IC, ID, and I E ) ; Average P l a n e i s 108o/70oNE 7.3G: P o l e s to 32 P l a n e s ( S u b s e c t i o n I I ) ; Average P l a n e i s 130/80 SW Page 106 In summary, n o r t h w e s t e r l y t r e n d s w i t h s t e e p n o r t h e a s t e r l y d i p s f a n n i n g to s t e e p s o u t h w e s t e r l y d i p s c h a r a c t e r i z e the f o l i a t i o n . F o l i a t i o n p a r a l l e l s the l e a d i n g edge of the Ki n g Salmon T h r u s t . Both f o l i a t i o n and the l e a d i n g edge of the t h r u s t p a r a l l e l the r e g i o n a l g r a i n i n the Cry Lake map a r e a . 7.2.3 Minor F o l d s Minor f o l d s a r e r e a d i l y o b s e r v e d i n weathered f l o a t but are not so e v i d e n t i n o u t c r o p . A l i m i t e d number of minor f o l d , measurements show n o r t h w e s t e r l y t r e n d s w i t h s h a l l o w p l u n g e s . 7.2.4 F a u l t s Rocks o f t h e Kutcho F o r m a t i o n a r e a f f e c t e d by l o w - a n g l e t h r u s t f a u l t s and h i g h - a n g l e , s t r i k e - s l i p and normal f a u l t s ( F i g . 2.2). The a l l o c h t h o n o u s K i n g Salmon assemblage i s f l o o r e d by the major K i n g Salmon t h r u s t f a u l t and i s bounded to the n o r t h by the N a h l i n f a u l t . The N a h l i n f a u l t v a r i e s i n c h a r a c t e r a l o n g i t s s t r i k e l e n g t h ( G a b r i e l s e , 1978, p e r s . comm.), but has a major t h r u s t component i n the Cry Lake map a r e a . I m b r i c a t e t h r u s t s a t the l e a d i n g edge of the K i n g Salmon f a u l t i n d i c a t e the p o t e n t i a l Page 107 f o r numerous t h r u s t s i n h i g h l y a t t e n u a t e d f o l d h i n g e s w i t h i n the a s s e m b l a g e . The e n t i r e b e l t i s d i s r u p t e d by numerous n o r t h to n o r t h e a s t t r e n d i n g , h i g h - a n g l e normal or l e f t - l a t e r a l , s t r i k e - s l i p f a u l t s . The major d e x t r a l s t r i k e - s l i p Kutcho f a u l t s e p a r a t e s the K i n g Salmon assemblage and r e l a t e d Cache Creek r o c k s from Omineca C r y s t a l l i n e t e r r a n e to the n o r t h e a s t o f t h e map a r e a . 7.2.5 D i s c u s s i o n of G e o l o g i c C r o s s - S e c t i o n s The g e o l o g i c c r o s s - s e c t i o n s ( F i g . 7.4) i l l u s t r a t e the s t r u c t u r a l s t y l e of r o c k s of the K i n g Salmon assemblage showing o v e r t u r n e d , g e n e r a l l y i s o c l i n a l f o l d s , s t e e p f o l i a t i o n s ( f o l i a t i o n a t t i t u d e s a r e i n d i c a t e d by t h i n l i n e s t h a t t r a n s e c t the t o p o g r a p h y at marked a n g l e s ) , and t h r u s t f a u l t s . S e c t i o n A to A T shows the i m b r i c a t e t h r u s t i n g at the l e a d i n g edge of the major t h r u s t as w e l l as an i n t e r n a l t h r u s t w i t h i n the K i n g Salmon a s s e m b l a g e . To the n o r t h , r o c k s of the Cache C r e e k Group (MPc) a r e t h r u s t s o u t h e r l y over the K i n g Salmon a s s e m b l a g e . S e c t i o n s B to B', and E to E l , E2 to E3 i l l u s t r a t e the f a n n i n g of c l e a v a g e d i p s n o r t h e a s t e r l y a c r o s s the b e l t i n t o r o c k s of the Cache Creek Group. F o l d s t y l e s a r e w e l l i l l u s t r a t e d i n S e c t i o n s C to C' and D to D', Page 108 LEGEND Tertiary Aluvfum Lower Jurassic Inklin Formation Upper Tr iass ic Sinwa Formation Upper Tr iass ic Kutcho Formation Upper Tr iass ic Takla Formation Tr iass ic to Jurassic Volcanic and Sedimentary Rocks Hiss iss ippian to Permian Cache Creek Group Middle Paleozoic Sediments GEOLOGIC SYMBOLS Topography Contact {definite, aoDroximate. Inferred) — A r r o w indicates d i rect ion of movement on fault T ^ A Strike s l i p fault \ Cleavage FIGURE 7 . 4 : G e o l o g i c C r o s s - S e c t i o n s A c r o s s the K i n g Salmon A l l o c h t h o n , Cry Lake Map Area ( C r o s s - S e c t i o n L o c a t i o n s Are Shown on F i g u r e 7 . 1 i n P o c k e t ) No v e r t i c a l e x a g e r a t i o n j i MPe 1.6 0 MILES 0 KM Page 109 showing o v e r t u r n e d , g e n e r a l l y i s o c l i n a l f o l d s . In S e c t i o n D to D' the l a r g e a r e a of I n k l i n F o r m a t i o n i s o p e n l y f o l d e d i n k e e p i n g w i t h the a p p a r e n t d e c r e a s e i n d e f o r m a t i o n a l o n g and a c r o s s the b e l t . 7.3 S t r u c t u r a l C omparison Between the K i n g Salmon Assemblage  and Cache Creek Group A l t h o u g h s i m i l a r i n c e r t a i n r e s p e c t s , the s t r u c t u r a l s t y l e of r o c k s of the K i n g Salmon assemblage and Cache Creek Group show marked c o n t r a s t s . T h e s t r u c t u r e of both b e l t s a r e s i m i l a r because both have been s u b j e c t e d to the same l a s t major d e f o r m a t i o n a l e v e n t . S t r u c t u r a l d a t a f o r r o c k s of the Cache Creek Group ( F i g . 7 .5 ) g i v e s t r o n g e v i d e n c e f o r at l e a s t two phases of d e f o r m a t i o n , the l a t t e r of which i s contemporaneous w i t h the s i n g l e e v e n t a f f e c t i n g r o c k s of the K i n g Salmon a s s e m b l a g e . S p e c i f i c s t r u c t u r a l s t y l e s a r e compared and c o n t r a s t e d below. , The s i n g l e most o b v i o u s s t r u c t u r a l d i f f e r e n c e i s the c o n t r a s t i n f o l i a t i o n s t y l e . The K i n g Salmon assemblage i s c h a r a c t e r i z e d by one p e n e t r a t i v e c l e a v a g e g i v i n g r i s e to d i s t i n c t i v e , p l a t y t a l u s i n which c l e a v a g e - b e d d i n g r e l a t i o n s h i p s a r e commonly w e l l d i s p l a y e d . The Cache Creek Group has at l e a s t Page 110 A. C. FIGURES 7.5A-C: M e l l i s C o n t o u r e d P l o t s of P o l e s to F o l i a t i o n and B e d d i n g , and Axes of Minor F o l d s f o r Rocks of the Cache Creek Group, Cry Lake Map Area 7.5A: P o l e s to 159 F o l i a t i o n P l a n e s ( S u b s e c t i o n I I I ) ; Average P l a n e i s 117o/84oNE 7.5B: P o l e s to 47 B e d d i n g P l a n e s ( S u b s e c t i o n I I I ) ; Average P l a n e i s 107o/67oNE 7.5C: Minor F o l d s - 30 L i n e s ( S u b s e c t i o n I I I ) ; Average L i n e i s 292o/28oNW Page 111 two c l e a v a g e s , one t h a t i s w e l l d e f i n e d and p a r a l l e l s t h a t of the King'Salmon assemblage and a second one t h a t i s l e s s d i s t i n c t and g e n e r a l l y t r e n d s e a s t - w e s t ( F i g . 7.5A). T h i s o l d e r c l e a v a g e i s cut by the more p r o m i n a n t one (Monger, 1977, p e r s . comm.). M u l t i p l e c l e a v a g e s i n r o c k s of the Cache Creek Group g i v e a b l o c k y t a l u s . The c o n t r a s t i n c l e a v a g e s t y l e s and s u b s e q u e n t d i f f e r e n c e i n t a l u s has p r o v e n u s e f u l i n d i f f e r e n t i a t i n g n o n d e s c r i p t g r e e n s t o n e s of b o t h u n i t s d u r i n g f i e l d mapping. Where l a y e r i n g i s e v i d e n t i n r o c k s of the Cache Creek Group t i g h t i s o c l i n a l r e f o l d e d f o l d s a r e o b s e r v e d , s u b s t a n t i a t i n g the p r e s e n c e of m u l t i p l e phases of d e f o r m a t i o n . B e d d i n g i n r o c k s of t h e Cache C r e e k Group ( F i g . 7.5B) shows an a v e r a g e a t t i t u d e s i m i l a r to t h a t i n the K i n g Salmon a s s e m b l a g e . Minor f o l d s a r e d i f f i c u l t to r e c o g n i z e i n g r e e n s c h i s t r o c k s but a r e e a s i l y r e c o g n i z e d i n c h e r t - a r g i l l i t e s equences of the Cache C r e e k Group. D a t a , p r e s e n t e d i n F i g u r e 7.5C, shows s c a t t e r f o r minor f o l d a x e s , but t h e s e g e n e r a l l y p l u n g e s h a l l o w l y to the w e s t - n o r t h w e s t . In summary, s t r u c t u r a l s i m i l a r i t i e s e x i s t between r o c k s of the Cache C r e e k Group and t h o s e of the K i n g Salmon assemblage as t h e y a r e both a f f e c t e d by the same l a s t d e f o r m a t i o n a l e v e n t . In c o n t r a s t to the K i n g Salmon a s s e m b l a g e , the Cache Creek Group has been a f f e c t e d by more than one phase of d e f o r m a t i o n . Page 112 7.4 T i m i n g of D e f o r m a t i o n S t r a t i g r a p h i c and s t r u c t u r a l e v i d e n c e a l l o w s t e m p o r a l c o n s t r a i n t s to be p l a c e d on the d e f o r m a t i o n a l e v e n t which a f f e c t e d r o c k s of the K i n g Salmon a s s e m b l a g e . The K i n g Salmon t h r u s t f a u l t c a r r i e s r o c k s up to Lower J u r r a s i c age over Upper T r i a s s i c to M i d d l e J u r a s s i c v o l c a n o - s e d i m e n t a r y r o c k s to the s o u t h . Lower J u r a s s i c beds a r e i n v o l v e d i n complex i m b r i c a t e t h r u s t s h e e t s below the s o l e of the K i n g Salmon t h r u s t f a u l t . M i d d l e B a j o c i a n s e d i m e n t s and v o l c a n i c s a r e u n i n v o l v e d i n the t h r u s t i n g . Sinwa L i m e s t o n e c l a s t s i n Lower J u r a s s i c c o n g l o m e r a t e s ( p r e t h r u s t i n g ) a r e f i n e - g r a i n e d and m a s s i v e whereas Sinwa L i m e s t o n e c l a s t s i n M i d d l e B a j o c i a n c o n g l o m e r a t e s ( p o s t - t h r u s t i n g ) a r e c o a r s e l y c r y s t a l l i n e , v e i n e d and s h e a r e d ( T i p p e r , 1978). Movement on the K i n g Salmon t h r u s t t h e r e f o r e o c c u r r e d between e a r l y T o a r c i a n and M i d d l e B a j o c i a n t i m e . F o l d i n g , development of p e n e t r a t i v e c l e a v a g e , and metamorphism a r e c o n s i d e r e d to be contemporaneous w i t h t h r u s t i n g . The s u b p a r a l l e l o r i e n t a t i o n of f o l i a t i o n s and f o l d axes to the l e a d i n g edge of the K i n g Salmon t h r u s t , and t i g h t i s o c l i n a l f o l d s o v e r t u r n e d i n the d i r e c t i o n of t h r u s t i n g s u p p o r t t h i s h y p o t h e s i s . The f a b r i c of metamorphic m i n e r a l s i n r o c k s of the Kutcho F o r m a t i o n s u g g e s t t h a t metamorphic r e c r y s t a l l i z a t i o n was l a r g e l y s y n k i n e m a t i c w i t h the f o l d i n g and t h r u s t i n g e v e n t . An upper l i m i t Page 113 on the age of d e f o r m a t i o n of 159 + 6 Ha i s d e f i n e d by the undeformed to s l i g h t l y s h e a r e d dykes r e l a t e d to v o l c a n i c r o c k s of the Mount B l a i r " F o r m a t i o n " (Erdman, 1978). In summary, a v a i l a b l e e v i d e n c e s u g g e s t s t h a t r o c k s of the K i n g Salmon a l l o c h t h o n were f o l d e d and t h r u s t i n t o t h e i r p r e s e n t l o c a t i o n i n e a r l y T o a r c i a n to M i d d l e B a j o c i a n t i m e . Metamorphic r e c r y s t a l l i z a t i o n may have c o n t i n u e d to the E a r l y C r e t a c e o u s . 7 . 5 Summar y Rocks of t h e K i n g Salmon assemblage a r e i s o c l i n a l l y f o l d e d w i t h a s i n g l e , p e n e t r a t i v e f o l i a t i o n and l i e w i t h i n an a l l o c h t h o n f l o o r e d by the K i n g Salmon t h r u s t f a u l t . Macro and m i c r o s c o p i c t e c t o n i c f a b r i c s p a r a l l e l the r e g i o n a l g r a i n of the Cry Lake map a r e a . Rocks of t h e Cache C r e e k Group appear to be e q u a l l y i n v o l v e d i n t h e o r o g e n i c event t h a t a f f e c t e d the K i n g Salmon a s s e m b l a g e . S t r u c t u r a l s t y l e of t h e K i n g Salmon a l l o c h t h o n i s a n a l o g o u s to s t r u c t u r a l s t y l e of the A p p a l a c h i a n s i n New E n g l a n d , U.S.A. (Thompson and N o r t o n , 1968). Page 114 . v, CHAPTER 8 ECONOMIC GEOLOGY 8.1 Kutcho C r e e k M a s s i v e S u l p h i d e D e p o s i t The Kutcho C r e e k v o l c a n o g e n i c m a s s i v e s u l p h i d e d e p o s i t , h o s t e d by v o l c a n i c r o c k s of the Kutcho F o r m a t i o n , has many a f f i n i t i e s to Kuroko d e p o s i t s h o s t e d i n C e n o z o i c r o c k s of Japan ( T a t s u m i , 1970; I s h i h a r a , 1 9 74). A r e p o r t of the g e o l o g y and m a s s i v e s u l p h i d e m i n e r a l o g y i s a t t a t c h e d ( A p p e n d i x V ) ; more d e t a i l e d r e p o r t s a r e a v a i l a b l e ( T h o r s t a d , 1979; Weber, 1977; B r i d g e , 1977). The d e p o s i t was d i s c o v e r e d by a r e g i o n a l g e o c h e m i c a l program i n the e a r l y 1970's and has been f u r t h e r e x p l o r e d and a s s e s s e d w i t h g e o l o g i c a l mapping, diamond d r i l l i n g , e l e c t r o m a g n e t i c s , g r a v i t y , i n d u c e d p o l a r i z a t i o n , and c h a r g e p o t e n t i a l methods. The Kutcho Creek d e p o s i t i s a v o l c a n o g e n i c , s t r a t a b o u n d m a s s i v e s u l p h i d e body w i t h c o p p e r , z i n c , i r o n and minor amounts s i l v e r as the p r i n c i p a l c o m m o d i t i e s . S u l p h i d e m i n e r a l s i n c l u d e p y r i t e , s p h a l e r i t e , c h a l c o p y r i t e , c h a l c o c i t e , b o r n i t e w i t h minor Page 115 amounts of g a l e n a , d i g e n i t e , t e t r a h e d r i t e - t e n n a n t i t e , c o v e l l i t e and p y r r h o t i t e . In the e a s t e r n p a r t of the Cry Lake map a r e a ( F i g . 2.2) the m i n e r a l i z e d s t r a t i g r a p h i c member i s exposed at s u r f a c e a l o n g the h i n g e of an o v e r t u r n e d a n t i c l i n e . 8 . 2 G e n e r a l D e s c r i p t i o n The c o p p e r , z i n c , i r o n , m a s s i v e s u l p h i d e u n i t l i e s w i t h i n a f e l s i c sequence of v o l c a n i c l a s t i c r o c k s t h a t have c a r b o n a t e l e n s e s and l a y e r s t h r o u g h o u t . A s e r i e s of s e m i c o n t i n u o u s s u l p h i d e l e n s e s o c c u r a l o n g a s t r i k e l e n g t h of 3.5 km and can be d i v i d e d i n t o f o u r main zones ( B r i d g e , 1977): the o r e - g r a d e " K u t c h o " zone, a f i n e - g r a i n e d , p y r i t i c "Sumac West" zone, and two "Esso West" zones t h a t a r e t e x t u r a l l y s i m i l a r to the Kutcho zone. These a r e a l l b e l i e v e d t o o c c u r on the f l a n k s of p y r o c l a s t i c r h y o l i t e domes ( B r i d g e , 1977) T h i n l e n s e s of m a s s i v e s u l p h i d e and d i s s e m i n a t e d p y r i t e a r e common i n bo t h f o o t w a l l and h a n g i n g w a l l s of the main d e p o s i t . M a s s i v e s u l p h i d e l e n s e s i n h a n g i n g w a l l r o c k s may be the r e s u l t of l a t e r m i n e r a l i z i n g e v e n t s or r e m o b i l i z a t i o n of co p p e r s u l p h i d e s from the main ore zone which r e p l a c e d p r e e x i s t i n g p y r i t e l e n s e s . Page 116 There i s no marked v e r t i c a l m i n e r a l z o n a t i o n ( B r i d g e s , p e r s . comm., 1977) a l t h o u g h the d e p o s i t may be s l i g h t l y c o p p e r r i c h a t i t s top and z i n c r i c h a t i t s base. T h e r e i s , however, a d i s t i n c t l a t e r a l z o n a t i o n w i t h c o p p e r to z i n c r a t i o s a v e r a g i n g 0. i n m a s s i v e s u l p h i d e and d e c r e a s i n g l a t e r a l l y to an a v e r a g e of 0.1 i n e x h a l i t e f a c i e s of c h e r t and c h e r t y v o l c a n i c l a s t i c s ( B r i d g e , 1977, p e r s . comm.). 8.3 Summar y A s s o c i a t i o n w i t h a c i d i c v o l c a n i c r o c k s , o c c u r r e n c e near the end of a v o l c a n i c c y c l e ( i n d i c a t e d by i t s p r o x i m i t y to the t u f f and a r g i l l i t e h o r i z o n ) and d i f f u s e f o o t w a l l c o n t a c t s a r e t y p i c a l Kuroko f e a t u r e s . The s t r a t i f o r m n a t u r e and p r e s e n c e of s e d i m e n t a r y f e a t u r e s such as l a y e r i n g , g r a d e d b e d d i n g and p o s s i b l l o a d s t r u c t u r e s p o i n t to a s y n g e n e t i c o r i g i n f o r the d e p o s i t . Page 117 CHAPTER 9 TECTONIC IMPLICATIONS S t r a t i g r a p h i c and s t r u c t u r a l r e l a t i o n s h i p s n o t e d i n the s t u d y a r e a a r e of c o n s i d e r a b l e i m p o r t a n c e i n r e l a t i n g the t e c t o n i c e v o l u t i o n of the C a n a d i a n C o r d i l l e r a to a u n i f y i n g p l a t e - t e c t o n i c model. V o l c a n o - s e d i m e n t a r y sequences n o t e d w i t h i n the H i n t e r l a n d B e l t of B r i t i s h C olumbia a r e a complex c o l l a g e of P a l e o z o i c and M e s o z o i c v o l c a n i c a r c s and ocean b a s i n s which were g e n e r a l l y formed c o n t e r m i n o u s w i t h the w e s t e r n m a r g i n of the c o n t i n e n t . S p a t i a l r e l a t i o n s h i p s and s p e c i a l c h a r a c t e r i s t i c s of r o c k a s s e m b l a g e s i n the map a r e a , and e l s e w h e r e i n the C o r d i l l e r a , c o m p l i c a t e s i m p l e models of c o n t i n e n t a l f o r m a t i o n by a c c r e t i o n of w e s t e r l y y o u n g i n g i s l a n d a r c s formed d u r i n g P a l e o z o i c to Recent time . The P a l e o z o i c to e a r l y T r i a s s i c Cache Cr e e k Group i s c o n s i d e r e d t o be a n c i e n t P a c i f i c ocean f l o o r , emplaced a l o n g the c r a t o n i c m a r g i n i n the L a t e T r i a s s i c . E x o t i c Permian T e t h y a n f u s u l i n i d s , c a t a c l a s t i c d e f o r m a t i o n a l s t y l e w i t h t r e n d s t r a n s g r e s s i v e to c o n t i n e n t a l m a r g i n s , and b l u e s c h i s t - t y p e Page 118 metamorphism c h a r a c t e r i z e the group (Monger et a l . , 1978). Cache Creek Group p r o b a b l y became i n a c t i v e as a s u b d u c t i o n i n E a r l y J u r a s s i c t i m e . The complex Assemblages i n the H i n t e r l a n d B e l t of r o c k s which a r e c l o s e l y r e l a t e d to the s u b d u c t i o n complex r e p r e s e n t e d by the Cache Creek Group i n c l u d e : the Kutcho F o r m a t i o n , the T a k l a F o r m a t i o n , the S t u h i n i F o r m a t i o n and the S i t l i k a Assemblage ( P a t t e r s o n , 1974) of c e n t r a l and n o r t h e r n B r i t i s h C o l u m b i a . S y n c h r o n o u s a r c r o c k s i n s o u t h e r n B r i t i s h C o l u m b i a i n c l u d e the N i c o l a F o r m a t i o n and the P a v i l i o n Group. V o l c a n i c i s l a n d a r c s p r o b a b l y e x t e n d e d a l o n g much of the w e s t e r n m a r g i n of N o r t h A m e r i c a d u r i n g the T r i a s s i c . The s o u t h e r n i s l a n d a r c s , now l y i n g to the e a s t of the Cache C r e e k Group a r e c o n s i d e r e d to have formed more or l e s s i n p l a c e on the c r a t o n i c s i d e of the s u b d u c t i o n complex. The n o r t h e r n i s l a n d a r c s , which a r e g e n e r a l l y west of the Cache c r e e k Group, a r e c o n s i d e r e d to have been d i s p l a c e d to the west of the s u b d u c t i o n complex by d e x t r a l t r a n s c u r r e n t m o t i o n s i n p o s t - L a t e T r i a s s i c time (Monger, 1978). D e f o r m a t i o n i n n o r t h - c e n t r a l B r i t i s h C o l u m b i a t h a t e f f e c t e d t h i s d i s p l a c e m e n t o c c u r r e d i n l a t e s t T r i a s s i c to L a t e J u r a s s i c time (Monger et a l . , 1978). C o r r o b o r a t i n g e v i d e n c e f o r Page 119 t h e s e c o n c l u s i o n s a r e p r e s e n t e d i n t h i s s t u d y ; i n p a r t i c u l a r , the d o c u m e n t a t i o n of s t r u c t u r a l f e a t u r e s r e l a t e d to the K i n g Salmon and N a h l i n f a u l t s . The t i m i n g of t h r u s t i n g and metamorphism of the K i n g Salmon assemblage i n d i c a t e s t h a t i t was emplaced i n i t s p r e s e n t p o s i t i o n , west o f the Cache C r e e k Group, by the M i d d l e B a j o c i a n . The w e s t e r l y v e r g e n c e of the major f a u l t s may be e v i d e n c e of emplacement from the s o u t h w e s t of a n o t h e r e x o t i c t e r r a n e known as the " S t i k i n e B l o c k " or " S t i k i n i a " (Monger et a l . , 1978). T h i s b l o c k (composed o f : the Upper P a l e o z o i c S t i k i n e a s s e m b l a g e ; p a r t of the Upper T r i a s s i c T a k l a F o r m a t i o n , the S t u h i n i and Lewes R i v e r Groups, and the Lower to M i d d l e J u r a s s i c H a z e l t o n Group and p r e - J u r a s s i c t e r r a n e s i n A l a s k a ) i s e x o t i c because i t o c c u r s west of the o c e a n i c Cache C r e e k Group and c o n t a i n s f u s i l i n i d s s i m i l a r to t h o s e of n o r t h e r n C a l i f o r n i a which a r e m a r k e d l y d i f f e r e n t from the Cache C r e e k Group. C r u s t a l s h o r t e n i n g as a r e s u l t of emplacement of S t i k i n i a a g a i n s t the c r a t o n may have been as much as 100 to 200 km (Monger e t a l . , 1978). The K i n g S a l m o n - N a h l i n f a u l t s may a l s o r e p r e s e n t an e a r l y M e s o z o i c s u t u r e r e a c t i v a t e d by westward movement of the c o n t i n e n t . F i g u r e 9.1 s c h e m a t i c a l l y p r e s e n t s the complex t e m p o r a l and s p a t i a l r e l a t i o n s h i p s of r o c k a s s e m b l a g e s mapped i n n o r t h - c e n t r a l B r i t i s h C o l u m b i a . Page 120 U. TRIASSl f FIGURE 9.1: Upper T r i a s s i c to M i d d l e J u r a s s i c T e c t o n i c E l e m e n t s i n N o r t h - C e n t r a l B r i t i s h C o l u m b i a N.A.- N o r t h American c r a t o n O.C.B.- Omineca C r y s t a l l i n e B e l t : bounded by both e a s t e r l y and w e s t e r l y v e r g e n t t h r u s t s , due to under t h r u s t i n g of o l d e r a r c s to the west and the N o r t h American c r a t o n to the e a s t K.S.A.- K i n g Salmon A l l o c h t h o n : Upper T r i a s s i c to Lower J u r a s s i c i s l a n d a r c 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 emplaced west of the "C.C.G. S u b d u c t i o n Complex" by d e x t r a l , t r a n s c u r r e n t f a u l t i n g ; i n c l u d e s the Kutcho Sinwa and I n k l i n F o r m a t i o n s C.C.G.- Cache C r e e k Group: o c e a n i c assemblage B.R.F.- B r i d g e R i v e r F o r m a t i o n : s u b d u c t i o n complex Page 121 BIBLIOGRAPHY Anderson , C.A. 1977: T i m i n g of M e s o z o i c P l a t e T e c t o n i c s i n S o u t h w e s t e r n B r i t i s h C o l u m b i a ; G e o l o g i c a l A s s o c i a t i o n of Canada 1977, Program and A b s t r a c t s , p. 4. 1969: M a s s i v e S u l p h i d e D e p o s i t s and V o l c a n i s m , Economic G e o l o g y , v. 64, pp. 129-143 An d e r s o n , R.G. 1979: D i s t r i b u t i o n and Emplacement H i s t o r y of P l u t o n s W i t h i n the H o t a i l u h B a t h o l i t h i n the Cry Lake and S p a t s i z i Map A r e a s , N o r t h - C e n t r a l B r i t i s h C o l u m b i a ; G e o l o g i c a l S u r v e y of Canada, Paper 79-1A, pp. 393-395. 1978: P r e l i m i n a r y R e p o r t on the H o t a i l u h B a t h o l i t h , I t s D i s t r i b u t i o n , Age and C o n t a c t R e l a t i o n s h i p s i n the Cry Lake, S p a t s i z i and Dease Lake Map A r e a s N o r t h - C e n t r a l B r i t i s h C o l u m b i a ; G e o l o g i c a l Survey of Canada, Paper 78-1A, p. 29-31. Page 122 A r m s t r o n g , R.L. 1971: I s o t o p i c and C h e m i c a l C o n s t r a i n t s on Models of Magma G e n e s i s i n V o l c a n i c A r c s ; E a r t h and P l a n e t a r y S c i e n c e L e t t e r s , v. 12, p. 137-142. B a d g l e y , P.C. 1965: S t r u c t u r a l and T e c t o n i c P r i n c i p l e s ; Harper and Row P u b l i s h e r s , New Yor k , 515 pp. Baker, P.E. 1968: C o m p a r a t i v e V o l c a n o l o g y and P e t r o l o g y of the A t l a n t i c I s l a n d A r c s ; B u l l e t i n of V o l c a n o l o g y , v. 32, p. 189-206. B a r a g a r , W.R.A. 1972: Some P h y s i c a l and C h e m i c a l A s p e c t s of P r e c a m b r i a n V o l c a n i c B e l t s of the C a n a d i a n S h i e l d ; ±n_ I r v i n g , E. (ed) "The A n c i e n t Ocean L i t h o s p h e r e " . Department of Energy Mines and R e s o u r c e s , E a r t h P h y s i c s B r a n c h P u b l i c a t i o n v.42, p. 129-140. B a r a g a r , W.R.A. and Goodwin, A.M. 1969: A n d e s i t e s and Archean V o l c a n i s m of the C a n a d i a n S h i e l d ; i n M c B i r n e y , A. R. ( e d ) , P r o c e e d i n g s of the A n d e s i t e Page 123 C o n f e r e n c e : Oregon Department of Geolog y and M i n e r a l M i n e r a l I n d u s t r y , V. 65, p. 121-141. B a r t h , T.F.W. 1952: T h e o r e t i c a l P e t r o l o g y : A Tex t b o o k on the O r i g i n and the E v o l u t i o n of Rock; John W i l e y and Sons, N.Y. B e l o u s s o v , V.V. and R u d i t c h , E.M. 1961: I s l a n d A r c s i n the Development of E a r t h ' s S t r u c t u r e ; J o u r n a l of G e o l o g y , v. 69, p. 647-658. B i l l i n g s , M.P. 1960: S t r u c t u r a l G e o l o g y ; P r e n t i c e H a l l , New Y o r k , 514 pp. B l a c k a d a r , R.G., Dumych, H., and G r i f f i n , P . J . 1979: Guide to A u t h o r s - A Guide f o r the P r e p a r a t i o n of G e o l o g i c a l Maps and R e p o r t s ; G e o l o g i c a l S u r v e y of S u r v e y of Canada, M i s c e l l a n e o u s R e p o r t 29. Bloxam, T.W., and L e w i s , A.D. 1972: T i , Zr and Cr i n Some B r i t i s h P i l l o w Lavas and T h e i r P e t r o g e n e t i c A f f i n i t i e s ; N a t u r e P h y s i c a l S c i e n c e , v. 237, p. 134. B r i d g e , D.A. Page 124 1979: Geology and M i n e r a l i z a t i o n at the Kutcho Creek Cu-Zn D e p o s i t , N o r t h e r n B r i t i s h C o l u m b i a ; A b s t r a c t G e o s c i e n c e Forum, W h i t e h o r s e , Yukon T e r r i t o r y 1978: Geology of t h e Kutcho C r e e k M a s s i v e S u l p h i d e D e p o s i t , N o r t h e r n B r i t i s h C o l u m b i a . (unpub. i n t e r n a l r e p o r t f o r Esso M i n e r a l s L t d . ) B r i d g e , D.A., Maar, J.M. and Oddy, R.D. 1977: G e o l o g y of the Kutcho C r e e k M a s s i v e S u l p h i d e D e p o s i t , N o r t h e r n B r i t i s h C o l u m b i a , G e o l o g i c a l A s s o c i a t i o n of Canada, Program w i t h A b s t r a c t s v. 2, p. 9. B u r c h f i e l , B., and D a v i s , G. 1975: N a t u r e and C o n t r o l s of C o r d i l l e r a n O r o g e n e s i s , Westerm U n i t e d S t a t e s : E x t e n s i o n s of an E a r l i e r S y n t h e s i s ; A merican J o u r n a l of E a r t h S c i e n c e V. 275-A, P. 363 -396 . Burk, C.A., and Drake, C.L. ( e d s ) 1974: The G e o l o g y of C o n t i n e n t a l M a r g i n s ; S p r i n g e r - V e r l a g P u b l i s h i n g Company, New Y o r k . Byer s, F.M. J r . Page 125 1961: P e t r o l o g y of V o l c a n i c S u i t e s , A l e u t i a n I s l a n d s ; G e o l o g i c a l S o c i e t y of Am e r i c a B u l l e t i n , V. 72, p. 93-128. C a m p b e l l , R.B. 1973: S t r u c t u r a l C r o s s - S e c t i o n and T e c t o n i c Model f o r the S o u t h e a s t e r n C a n a d i a n C o r d i l l e r a ; C a n a d i a n J o u r n a l of E a r t h S c i e n c e s , v. 10, no. 11, p. 1607 - 1620. Cann, J.R. 1970: Rb, S r , Y, Z r , and Nb i n Some Ocean F l o o r B a s a l t s ; E a r t h and P l a n e t a r y S c i e n c e L e t t e r s , v. 10, p. 7 - 11. C a r m i c h a e l , I . S . E . 1964: The P e t r o l o g y of T h i n g m u l i , a T e r t i a r y V o l c a n o i n E a s t e r n I c e l a n d ; J o u r n a l of P e t r o l e u m , v. 5, p. 435 - 460. C a r m i c h a e l , I .S.E., T u r n e r , F . J . , and Verhoogen, J . 1974: Igneous P e t r o l o g y ; McGraw H i l l Book Company, 739 pp. Chayes, F. 1975: T i t a n i a and Al u m i n a C o n t e n t of O c e a n i c and C i r c u m O c e a n i c B a s a l t ; M i n e r a l M a g a z ine, v. 34, p. 126 - 131. Page 126 Chayes, F. 1966: A l k a l i n e and S u b a l k a l i n e B a s a l t s ; American J o u r n a l of S c i e n c e , v. 264, p. 128 - 145. C h u r k i n , M. J r . 1974: P a l e o z o i c M a r g i n a l Ocean B a s i n V o l c a n i c Arc Systems i n the C o r d i l l e r a C o r r e l a t i o n and M i c r o p l a t e T e c t o n i c s ; G e o l o g i c a l S o c i e t y of A m e r i c a B u l l e t i n , v. 88, p. 769 - 786. C o a t s , R.R. 1968: B a s a l t i c A n d e s i t e s ±n_ Hess, H.H., and P o l d e r v a a t , A. ( e d s . ) , The P o l d e r v a a r t T r e a t i s e on Rocks of B a s a l t i c C o m p o s i t i o n , I n t e r s c i e n c e 2; John W i l e y and Sons P u b l i c a t i o n , New Y o r k , p. 689 - 736. 1962: Magma Type and C r u s t a l S t r u c t u r e i n the A l e u t i a n Arc i n MacDonald, G.A. and Kuno, H. ( e d s . ) , American G e o p h y s i c a l U n i o n Monograph 6 "The C r u s t of the P a c i f i c " , p. 92 - 109. Coleman, P . J . (ed) 1973: The Western P a c i f i c ; I s l a n d A r c s , M a r g i n a l Seas, G e o c h e m i s t r y ; C r a n e , Russak and Co. I n c . , N.Y., Page 127 U n i v e r s i t y of Western A u s t r a l i a P r e s s , p. 107 - 364, 455 - 532 and 543 - 598. C o n d i e , K . C. 1976: T r a c e Element G e o c h e m i s t r y of Ar c h e a n G r e e n s t o n e B e l t E a r t h S c i e n c e Review, v. 12, p.393 - 417. C o n d i e , K.C., and Moore, J.M. 1977: G e o c h e m i s t r y of P r o t e r o z o i c V o l c a n i c Rocks from the G r e n v i l l e P r o v i n c e , E a s t e r n O n t a r i o ; i n B a r a g a r , W.R.A., Coleman, L.C., and H a l l , J.M. ( e d s . ) , " V o l c a n i c Regimes i n Canada", G e o l o g i c a l A s s o c i a t i o n Canada, S p e c i a l Paper 16, p. 149 - 168. Coney, P . J . 1972: C o r d i l l e r a n T e c t o n i c s and N o r t h American P l a t e M o t i o n American J o u r n a l of S c i e n c e , v. 272, no.7, p. 603 - 628. D a v i e s , J . F . , G r a n t , R.W.E., and Whi t e h e a d , R.E.S. 1979: Immobile T r a c e E l e m e n t s and Archean V o l c a n i c S t r a t i g r a p h y i n the Timmins M i n i n g A r e a , O n t a r i o ; C a n a d i a n J o u r n a l of E a r t h S c i e n c e , 16, no . 2, p. 305 - 311. Page 128 Deer, W.A., Howie, R.A., and Zussman, J . 1966: An I n t r o d u c t i o n to Rock. Forming M i n e r a l s , Longmans, Green and Company, London, 538 p. D e n n i s , J.G. 1972: S t r u c t u r a l G e o l o g y , The R o n a l d P r e s s Company, New York, 532 p. Dewey, J . F . , and B i r d , J.M. 1970: L i t h o s p h e r e , P l a t e , C o n t i n e n t a l M a r g i n T e c t o n i c s and the E v o l u t i o n of the A p p a l a c h i a n Orogen; G e o l o g i c a l S o c i e t y of Am e r i c a B u l l e t i n v.81, p. 1031-1060. 1970b: M o u n t a i n B e l t s and G l o b a l T e c t o n i c s , J o u r n a l of G e o p h y s i c s , v. 75, no.4, p. 2615 - 2647. Dewey, J . F . and H o r s f i e l , B. 1970: P l a t e T e c t o n i c s , Orogeny and C o n t i n e n t a l Growth, N a t u r e , v. 225, no. 5232, p. 521 - 525. 1969: C o n t i n e n t a l M a r g i n s : A t l a n t i c v e r s u s Andean; E a r t h and P l a n e t a r y and S c i e n c e L e t t e r s , v. 6. no.3, p. 189 - 197. Page 129 D i c k i n s o n , W.R. 1974: S e d i m e n t a t i o n W i t h i n and B e s i d e A n c i e n t Magmatic A r c s ; S o c i e t y Economic and P e t r o l e u m M i n e r a l o g y S p e c i a l P u b l i c a t i o n , no.19, p. 230 - 239. 1974: P l a t e T e c t o n i c s and S e d i m e n t a t i o n ; S o c i e t y of Economic and P e t r o l e u m M i n e r a l o g y S p e c i a l P u b l i c a t i o n , Number 22, pp. 1 - 27. 1972: E v i d e n c e f o r P l a t e T e c t o n i c Regimes i n the Rock R e c o r d ; American J o u r n a l of S c i e n c e , v. 272, p. 551 - 576. 1970: R e l a t i o n s of A n d e s i t e s , G r a n i t e s and D e r i v a t i v e S a n d s t o n e s to Arc T r e n c h T e c t o n i c s ; Review of G e o p h y s i c and Space P h y s i c , v. 8, p. 813 - 860. 1968: C i r c u m P a c i f i c A n d e s i t e T y p e s ; J o u r n a l of G e o p h y s i c a l R e s o u r c e s , v. 75, p. 2261 - 2269. D i c k i n s o n , W.R. and H a t h e r t o n , T. 1967: A n d e s i t e V o l c a n i s m and S e i s m i c i t y Around the P a c i f i c ; S c i e n c e , v. 157, p. 801 - 803. D i c k i n s o n , W.R. and R i c h Page 130 1972: P e t r o l o g i c I n t e r v a l s and P e t r o f a c i e s i n the G r e a t V a l l e y Sequence, Sacramento, C a l i f o r n i a ; G e o l o g i c a l A s s o c i a t i o n of Ame r i c a B u l l e t i n , v. 83, no.10, p. 3007 - 3024. D o u g l a s , R.J.W., G a b r i e l s e , H., Wheeler, J.O., S t o t t , D.F., and B e l y e a r , H.R. 1970: Geology of Western Canada, in_ D o u g l a s , R.J.W. ( e d ) , "Geology and Economic M i n e r a l s of Canada"; G e o l o g i c a l S urvey of Canada, Economic G e o l o g y R e p o r t 1, p. 367 - 488. E i s b a c h e r , G .H . 1977a: M e s o z o i c - T e r t i a r y B a s i n Models f o r the C a n a d i a n C o r d i l l e r a and T h e i r G e o l o g i c C o n s t r a i n t s , C a n a d i a n J o u r n a l of E a r t h S c i e n c e , v. 14, p. 2414 - 2421. 1974: E v o l u t i o n of S u c c e s s o r B a s i n s i n the C a n a d i a n C o r d i l l e r a ; S o c i e t y of Economic and P e t r o l e u m M i n e r a l o g y S p e c i a l P u b l i c a t i o n , no.19, p. 274 - 291. Ewart, A. 1976: M i n e r a l o g y and C h e m i s t r y of Modern O r o g e n i c Lavas -Page 131 Some S t a t i s t i c s and S c i e n c e L e t t e r s , v. I m p l i c a t i o n s , E a r t h 31, p. 417 - 432. and P l a n e t a r y Ewart, A., Mateen, A. and Ross, J.A. 1976: Review of the M i n e r a l o g y and C h e m i s t r y of T e r t i a r y C e n t r a l V o l c a n i c Complexes i n the S o u t h e a s t Q u e e n s l a n d and N o r t h e a s t New Sout h Wales; Ln J o h n s o n , R.W. ( e d ) , " V o l c a n i s m i n A u s t r a l i a " ; E l s e v i e r P r e s s L i m i t e d , A r n s t , O x f o r d , New Y o r k . F i s h e r , R.V. 1960: C l a s s i f i c a t i o n of V o l c a n i c B r e c c i a s ; G e o l o g i c a l S o c i e t y of A m e r i c a B u l l e t i n , v. 71, p. 973-982. F l o y d , B.A. and W i n c h e s t e r , J.A. 1978: I d e n t i f i c a t i o n and D i s c r i m i n a t i o n of A l t e r e d and Metamorphosed V o l c a n i c Rocks u s i n g Immobile E l e m e n t s ; Chem. G e o l . , v. 21, p. 291 - 306. 1976: G e o c h e m i c a l D i s c r i m i n a t i o n of D i f f e r e n t Magma S e r i e s and T h e i r D i f f e r e n t i a t i o n P r o d u c t s U s i n g Immobile E l e m e n t s ; Chem. G e o l . , v. 20, p. 325 - 343. 1975: Magma Type and T e c t o n i c S e t t i n g D i s c r i m i n a t i o n U s i n g Page 132 Immobile E l e m e n t s ; E a r t h and P l a n e t a r y S c i e n c e L e t t e r s , v. 27, p. 211 - 218. G a b r i e l s e , H. 1977: P l a t e T e c t o n i c s and M i n e r a l D e p o s i t s i n the C a n a d i a n C o r d i l l e r a ; Western I n t e r - U n i v e r s i t y G e o l o g i c a l C o n f e r e n c e , V a n c o u v e r , B.C.,Program w i t h A b s t r a c t s . 1978: O p e r a t i o n Dease; G e o l o g i c a l S u r v e y of Canada, Paper 78 - IA, R e p o r t of A c t i v i t y , p. 1 - 4. 1976: E n v i r o n m e n t s of C a n a d i a n C o r d i l l e r a D e p o s i t i o n a l B a s i n s , C i r c u m - P a c i f i c Energy and M i n e r a l R e s o u r c e s Memoir 25, p. 492 - 502. 1967: T e c t o n i c E v o l u t i o n of the N o r t h e r n C o r d i l l e r a , C a n a d i a n J o u r n a l of E a r t h S c i e n c e , v. 5., p. 272 - 298. G a b r i e l s e , H. and Wheeler, J.O. 1960: T e c t o n i c Framework of S o u t h e r n Yukon and N o r t h w e s t e r n B r i t i s h C o l u m b i a ; G e o l o g i c a l Survey of Canada, Paper 60 - 24. G e l i n a s , L., Brook, C., P e r r a u l t , G., C a r r i g n a n , J , . T r u d e l , P., Page 133 and Gras so , F . 1977: C h e m o - S t r a t i g r a p h i c D i v i s i o n s W i t h i n t h e A b i t i b i V o l c a n i c B e l t , Rouyn-Noranda D i s t r i c t , Quebec; _in B a r a g a r , W.R.A., Coleman, L.C., H a l l , J . M . ( e d s ) , " V o l c a n i c Regimes i n Canada", G e o l o g i c a l A s s o c i a t i o n of Canada, S p e c i a l Paper 16, p. 276 - 277. G e l i n a s , L., and B r o o k s , C. 1974: A r c h e a n Quench T e x t u r e T h o l e i i t e s ; C a n a d i a n J o u r n a l of E a r t h S c i e n c e , v. 11, p. 324 - 341. Goodwin, A.M. 1977: A r c h e a n V o l c a n i s m i n S u p e r i o r P r o v i n c e , C a n a d i a n S h i e l d ; _in_ B a r a g a r , W.R.A., Coleman, L.C., H a l l , J.M. (e d s ) " V o l c a n i c Regimes i n Canada", G e o l o g i c a l A s s o c i a t i o n of Canada, S p e c i a l Paper 16, p. 205 - 241. 1974: The Most A n c i e n t C o n t i n e n t a l M a r g i n s ; in_ Burk, C.A., and Drake, C.L. ( e d s ) , "The Geology of C o n t i n e n t a l M a r g i n s " , S p r i n g e r - V e r l a g , New Y o r k . Gordon, T.M. and Greenwood, H.J. 1970: D o l o m i t e + Q u a r t z + Water = T a l c + C a l c i t e + C02; American J o u r n a l of S c i e n c e , v. 268, no.3, p. 225 -Page 134 242 . G o r s h k o v , G.S. 1962: P e t r o c h e m i c a l F e a t u r e s of V o l c a n i s m i n R e l a t i o n to the Types of E a r t h ' s C r u s t ; _in MacDonald, G.A., and Kuno , H., "The C r u s t of the P a c i f i c B a s i n " ; G e o p h y s i c s Monograph 6, American G e o p h y s i c a l U n i o n , W a s h i n g t o n , D.C. Green, N.L. 1977: M u l t i S tage A n d e s i t e G e n e s i s i n the G a r a b a l d i Lake A r e a , S o u t h w e s t e r n B r i t i s h C o l u m b i a , unpub. PhD T h e s i s , U n i v e r s i t y of B r i t i s h C o l u m b i a . G r i f f i t h s , J.R. 1977: M e s o z o i c - E a r l y C e n o z o i c V o l c a n i s m , P l u t o n i s m and M i n e r a l i z a t i o n i n S o u t h e r n B r i t i s h C o l u m b i a ; A P l a t e T e c t o n i c S y n t h e s i s ; C a n a d i a n J o u r n a l of E a r t h S c i e n c e , v. 14, no.7, p. 1611 - 1624. 1977: Geology and M e t a l l o g e n y of the L a c h l a n Orogen, A u s t r a l i a , A Time - Space A n a l y s i s and P r e l i m i n a r y T e c t o n i c S y n t h e s i s ; CSIRO I n v e s t i g a t i o n R e p o r t 123. p. 1 - 42. Page 135 Gunning, H.C., White, W.H., L i t t l e , H.W., A r m s t r o n g , J . E . , Y a t e s , R.G., Ney, C.S. and H o l l a n d , S.S. 1966 T e c t o n i c H i s t o r y and M i n e r a l D e p o s i t s of the Western C o r d i l l e r a ; C a n a d i a n I n s t i t u t e of M i n i n g M e t a l l u r y , S p e c i a l Volume 8, 353 p. H a l b e r g , J . A . 1972: G e o c h e m i s t r y of A r c h e a n V o l c a n i c B e l t s i n the E a s t e r n G o l d f i e l d s R e g i o n of Western A u s t r a l i a ; J o u r n a l of P e t r o l e u m , v. 12, p. 45 - 56. H a l b e r g , J.A. and W i l l i a m s , D.A.C. 1972: A r c h ean M a f i c and U l t r a m a f i c Rock A s s o c i a t i o n i n the E a s t e r n G o l d f i e l d s R e g i o n , Western A u s t r a l i a ; E a r t h P l a n e t a r y and S c i e n c e L e t t e r , v. 15, p. 191. H a m i l t o n , W. 1966: O r i g i n of V o l c a n i c Rocks of E u g e o s y n c l i n e s and I s l a n d A r c s Ln P o o l e , W.H., (ed) " C o n t i n e n t a l M a r g i n s and I s l a n d s A r c s " , C a n a d i a n G e o l o g i c a l S u r v e y Paper 66 -15, 486 p. Page 136 H a r k e r , A. 1939: Metamorphism; D u t t o n and Company I n c . , New York, 362 pp . H a r t , S.R., B r o o k s , C., Krogh, T.E., D a v i s , S.L., and Nava, D. 1970: A n c i e n t and Modern V o l c a n i c Rocks: A T r a c e Element Model, E a r t h and P l a n e t a r y S c i e n c e L e t t e r s , v. 10. pp. 17 - 28. Hess, H.H. and P o l d e r v a a r t , A. ( e d s ) 1967: B a s a l t s - the P o l d e r v a a r t T r e a t i s e on Rocks of B a s a l t i c C o m p o s i t i o n ; I n t e r s c i e n c e P u b l i s h e r s , New York, London, Sydney. Hubbard, N.J. 1969: A C h e m i c a l Comparison of Ocean Ridge H a w a i i a n T h o l e i i t i c and H a w a i i a n A l k a l i B a s a l t ; E a r t h and P l a n e t a r y S c i e n c e L e t t e r s , v. 15, p. 346 - 352. H u t c h i n s o n , R.W. 1973: V o l c a n o g e n i c S u l f i d e D e p o s i t s and T h e i r M e t a l l o g e n i c S i g n i f i c a n c e , Economic G e o l o g y , v. 68, no.8, p. 1223 - 1245. Page 137 Hyndman, D.W. 1972: P e t r o l o g y of Igneous and M e t a m o r p h i c Rocks; McGraw-H i l l Book Company, New York, London, T o r o n t o . 533 P. I r v i n e , T.N. and B a r a g a r , W.R.A. 1971: A Guide to C h e m i c a l C l a s s i f i c a t i o n of the Common V o l c a n i c Rocks; C a n a d i a n J o u r n a l of E a r t h S c i e n c e , v. 8 p. 523 - 548. I s h i h a r a 1974 Ge o l o g y of Kuroko D e p o s i t s , M i n i n g G e o l o g i c a l S p e c i a l I s s u e Number 6, p. 1 - 9. J a k e s , P. and G i l l , J . 1970: Rare E a r t h E l e m e n t s and the I s l a n d Arc T h o l e i i t e S e r i e s ; E a r t h and P l a n e t a r y S c i e n c e L e t t e r s , v. 9, p. 17 - 28. J a k e s , P. and White, A.R. 1972: Major and T r a c e E l e m e n t s Abundance i n V o l c a n i c Rocks of O r o g e n i c A r e a s ; G e o l o g i c a l S o c i e t y of America B u l l e t i n , v. 83, p. 29 - 40. Page 138 1969: S t r u c t u r e of D i s t r i b u t i o n 223 - 236. the M e L a n e s i a n Arc and C o r r e l a t i o n of Magma T y p e s , T e c t o n o p h y s i c s , v. w i t h 8, p. K a r i g , D.E. 1973: C o m p o s i t i o n of I s l a n d Arc - M a r g i n a l B a s i n Complexes i n the N o r t h w e s t and Southwest P a c i f i c ; ±u_ Coleman, P . J . (ed.) "The Western P a c i f i c - I s l a n d A r c s , M a r g i n a l Seas, G e o c h e m i s t r y " , p. 355 - 364. 1972: Remnant A r c s ; G e o l o g y S o c i e t y of A m e r i c a B u l l e t i n , v. 83, p. 1057 - 1068. 1970: R i d g e s and B a s i n s of the Tonga - Kermadec I s l a n d Arc System; J o u r n a l of G e o p h y s i c a l R e s e a r c h , v. 75, p. 239 - 254. K e r r , P. F. 1959: O p t i c a l M i n e r a l o g y ; McGraw - H i l l Book Company I n c . , New York, T o r o n t o , 442 p. Kuno, H . 1969: A n d e s i t e i n Time and Space; ±n_ M c B i r n e y , A.R., Page 139 " P r o c e e d i n g s of the A n d e s i t e C o n f e r e n c e " , Department of Geology and M i n e r a l R e s e a r c h , Oregon B u l l e t i n , v. 65, p. 13 - 20. 1967: O r i g i n of A n d e s i t e and I t s B e a r i n g on the I s l a n d Arc S t r u c t u r e ; B u l l e t i n of V o l c a n o l o g y , v. 32, p. 144 -176 . 1966: L a t e r a l V a r i a t i o n of B a s a l t Magma Type A c r o s s C o n t i n e n t a l M a r g i n I s l a n d A r c s , B u l l e t i n of V o l c a n o l o g y v. 29, p. 195. 1959: O r i g i n of C e n o z o i c P e t r o g r a p h i c P r o v i n c e s of Japan and S u r r o u n d i n g A r e a s , B u l l e t i n of V o l c a n o l o g y , v. 20, p. 37. L a n g f o r d , F . J . and M o r i n , J.A. 1976: Development of the S u p e r i o r P r o v i n c e of Northwest O n t a r i o by M e r g i n g of I s l a n d A r c s ; G e o l o g i c a l S o c i e t y of A m e r i c a B u l l e t i n , v. 83, p. 1057 - 1068. M c B i r n e y , A.R. 1969: C o m p o s i t i o n a l V a r i a t i o n s i n C e n o z o i c C a l c - A l k a l i n e S u i t e s of C e n t r a l A m e r i c a , ijn " P r o c e e d i n g s of the Page 140 A n d e s i t e C o n f e r e n c e " , Department of M i n e r a l R e s e a r c h , Oregon, B u l l e t i n 65, p. 185 - 189. 1969: A n d e s i t e and R h y o l i t i c V o l c a n i s m of O r o g e n i c B e l t s ; A merican G e o p h y s i c a l Monograph 13, p. 501 - 507. MacDonald, G.A. 1960: D i s s i m i l a r i t y of C o n t i n e n t a l and O c e a n i c Rock Types; J o u r n a l of P e t r o l e u m , v. 1, p. 172-177. Manson , V. 1967 : G e o c h e m i s t r y of B a s a l t i c Rocks 1. Major E l e m e n t s ; _in_ Hess, H.H. and P o l d e r v a a r t , A. ( e d s ) , "The P o l d e r v a a r t T r e a t i s e on Rocks of B a s a l t i c C o m p o s i t i o n " , I n t e r s c i e n c e New York, p. 215. M i d d l e m o s t , E.A.K. 1973: A S i m p l e C l a s s i f i c a t i o n of V o l c a n i c Rocks, B u l l e t i n of V o l c a n o l o g y , v. 36, p. 382 - 397. M i t c h e l l , A.H.G. 1970: F a c i e s of an E a r l y M i o c e n e , V o l c a n i c A r c , M a l e k u l a I s l a n d , New M c B r i d e s ; S e d i m e n t a r y G e o l o g y , v. IA, p. 201 - 2A3. Page 1A1 M i t c h e l l , 197 3: A.H.G., and B e l l , J.D. I s l a n d Arc E v o l u t i o n and R e l a t e d M i n e r a l D e p o s i t s ; J o u r n a l of G e o l o g y , v. 81, no. 4, p. 381 - 405. 1970: V o l c a n i c E p i s o d e s i n I s l a n d A r c s ; G e o l o g i c a l S o c i e t y of London P r o c e e d i n g s no. 1612, p. 9 - 12. M i t c h e l l , A.H.G., and G a r s o n , M.S. 1972: M i n e r a l i z a t i o n a t P l a t e B o u n d a r i e s , M i n e r a l s S c i e n c e E n g i n e e r i n g , v. 8, no. 2, p. 129 - 169. M i t c h e l l , A.H.G., and R e a d i n g , H.G. 1969: C o n t i n e n t a l M a r g i n s , G e o s y n c l i n e s and Ocean F l o o r S p r e a d i n g , J o u r n a l o f G e o l o g y , v. 77, p. 629 - 646. 1971: E v o l u t i o n of I s l a n d A r c s , J o u r n a l of G e o l o g y , v. 79, p. 253 - 284. Mi y a s h i r o , A. 1975: V o l c a n i c Rock S e r i e s and T e c t o n i c S e t t i n g ; Annual Review, E a r t h and P l a n e t a r y S c i e n c e , v. 3, p. 251 - 269. Page 142 1975: I s l a n d Arc V o l c a n i c Rock S e r i e s : A C r i t i c a l Review, P e t r o l o g i e , v. 1, p. 177 - 187. 1974: V o l c a n i c Rock S e r i e s i n I s l a n d A r c s and C o n t i n e n t a l M a r g i n s ; American J o u r n a l of S c i e n c e , v. 274, p. 321 -355 . 1973: The T r o o d o s O p h i o l i t i c Complex Was P r o b a b l y Formed i n An I s l a n d A r c ; E a r t h and P l a n e t a r y S c i e n c e L e t t e r s , v. 19, p. 318 - 424. 1973: Metamorphism and Metamorphic B e l t s ; George A l l e n and Unwin Company L i m i t e d , London, 492 p. 1972: Metamorphism and R e l a t e d Magmatism i n P l a t e T e c t o n i c s , A merican J o u r n a l of S c i e n c e , v. 272, p. 629 - 656. M i y a s h i r o , A. and Fumiko, S. 1975: T h o l e i i t i c and C a l c - A l k a l i c S e r i e s i n R e l a t i o n t o the B e h a v i o u r s of T i t a n i u m , Vanadium, Chromium and N i c k e l ; A merican J o u r n a l of S c i e n c e , v. 275, p. 265 - 277. Monger , J.W.H, Page 143 1978: E v o l u t i o n of the C a n a d i a n unpub. m a n u s c r i p t . C o r d i l l e r a : A R e e x a m i n a t i o n ; 1978: E v o l u t i o n of the C o r d i l l e r a , GEOS F a l l , E n e r g y , Mines and R e s o u r c e s P u b l i c a t i o n . 1977: Upper P a l e o z o i c Rocks of the Western C o r d i l l e r a and T h e i r B e a r i n g on C o r d i l l e r a E v o l u t i o n ; C a n a d i a n J o u r n a l of E a r t h S c i e n c e s , v. 14, p. 1832 - 1859. 1977: Upper P a l e o z o i c Rocks of N o r t h w e s t e r n B r i t i s h C o l u m b i a ; G e o l o g i c a l S u r v e y of Canada, Paper 77 - 1A, R e p o r t of A c t i v i t i e s , p. 255 - 262. 1977a: The T r i a s s i c T a k l a Group i n M c C o n n e l l Creek Map A r e a , N o r t h C e n t r a l B r i t i s h C o l u m b i a ; G e o l o g i c a l Survey of Canada, Paper 76 - 29, 45 p. 1975: C o r r e l a t i o n of E u g e o s y n c l i n a l T e c t o n o s t r a t i g r a p h i c B e l t s i n the N o r t h American C o r d i l l e r a ; G e o s c i e n c e of Canada, v. 2, p. 4 - 10. 1974: Upper P a l e o z o i c Rocks of t h e A t l i n T e r r a n e , N o r t h -w e s t e r n B r i t i s h C o l u m b i a and S o u t h - c e n t r a l Yukon; Page 144 G e o l o g i c a l S u r v e y of Canada, Paper 74 - 47, 63 p. 1972: O c e a n i c C r u s t i n the C a n a d i a n C o r d i l l e r a jLn I r v i n g , E. (ed) "The A n c i e n t O c e a n i c L i t h o s p h e r e " , Department of Ene r g y , Mines and R e s o u r c e s , E a r t h P h y s i c s B r a n c h , P u b l i c a t i o n , v. 42, p. 59 - 64. Monger, J.W.H., and C h u r c h , B.N. 1977: R e v i s e d S t r a t i g r a p h y of the T a k l a Group, N o r t h - C e n t r a l B r i t i s h C o l u m b i a ; C a n a d i a n J o u r n a l of E a r t h S c i e n c e , v. 14, no.2, p. 318 - 326. Monger, J.W.H., R i c h a r d s , T.A., and P a t e r s o n , I.A. 1978: The H i n t e r l a n d B e l t of the C a n a d i a n C o r d i l l e r a : New Data from N o r t h e r n and C e n t r a l B r i t i s h C o l u m b i a ; C a n a d i a n J o u r n a l of E a r t h S c i e n c e , v. 15, p. 823 -830 . / ; W.H., S o u t h e r , J.G. and G a b r i e l s e , H. E v o l u t i o n o f the C a n a d i a n C o r d i l l e r a : A P l a t e T e c t o n i c Model; American J o u r n a l of S c i e n c e , v. 272, p. 577 -602 . Monger, J.W.H., and T h o r s t a d , L. Page 145 Monger , J . 1972 : 1978: Lower Meso z o i c S t r a t i g r a p h y , Cry Lake (104 1) and S p a t s i z i (104 H) Map A r e a s , B r i t i s h C o l u m b i a ; G e o l o g i c a l S u r v e y of Canada, Paper 78 - IA, R e p o r t of A c t i v i t i e s , p. 21-24. Moore, J .M., J r . 1977 : O r o g e n i c V o l c a n i s m i n the P r o t e r o z o i c of Canada; ±n_ B a r a g a r , W.R.A., Coleman, L.C., and H a l l , J.M. ( e d s ) , " V o l c a n i c Regimes i n Canada", p. 127 - 148. Moorehouse, W.W. 1959: The Study of Rocks i n T h i n S e c t i o n ; Harper and B r o t h e r s , New York, 514 p. N e v i n , C M . 1931: P r i n c i p l e s of S t r u c t u r a l G e o l o g y ; W i l e y and Sons I n c o r p o r a t e d , London, 303 p. N i c h o l l s , I.A., and W h i t f o r d , D.J. 1976: P r i m a r y Magmas A s s o c i a t e d With Q u a t e r n a r y V o l c a n i s m i n the Western Sunda A r c , I n d o n e s i a ; Ln J o h n s o n , R.W., ( e d ) , V o l c a n i s m i n A u s t r a l a s i a , E l s e v i e r P u b l i s h i n g , New Y o r k , p. 77 - 90. Page 146 N o c k o l d s , S.R. 1954: Average C h e m i c a l C o m p o s i t i o n s of Some Igneous Rocks: G e o l o g i c a l S o c i e t y of A m e r i c a B u l l e t i n , v. 65, p. 1007 - 1032. P a r s o n s , W.H. 1968: C r i t e r i a f o r R e c o g n i t i o n of V o l c a n i c B r e c c i a s : Review; G e o l o g i c a l S o c i e t y of A m e r i c a , Memoir 115, p. 263 -304 . P a t e r son , I.A. 1975: G e o l o g y of the Cache Creek Group and M e s o z o i c Rocks at the N o r t h e r n End of the S t u a r t Lake B e l t , C e n t r a l B r i t i s h C o l u m b i a ; G e o l o g i c a l S u r v e y of Canada, Paper 75 - IA, R e p o r t of A c t i v i t i e s , p. 31 - 41. 1973: The Geology of the P i n c h i Lake A r e a , C e n t r a l B r i t i s h C o l u m b i a ; u n p u b l i s h e d PhD T h e s i s , 260 p. P e a r c e , J.A. 1975: B a s a l t G e o c h e m i s t r y Used to I n v e s t i g a t e P a s t T e c t o n i c E n v i r o n m e n t s on C y p r e s s ; T e c t o n o p h y s i c s , v. 25, p. 41 - 67. Page 147 P e a r c e , J.A., and Cann, J.R. 1973: T e c t o n i c S e t t i n g of B a s i c V o l c a n i c Rocks D e t e r m i n e d U s i n g T r a c e E l e m e n t s A n a l y s i s ; E a r t h P l a n e t a r y and S c i e n c e L e t t e r s , v. 19, p. 290. P e a r c e , T.H., Gorman, B.E., and B i r k e t t , T.C. 1977: The R e l a t i o n s h i p Between Major Element C h e m i s t r y and T e c t o n i c E n v i r o n m e n t of B a s i c and I n t e r m e d i a t e V o l c a n i c Rocks; E a r t h P l a n e t a r y and S c i e n c e L e t t e r s , v. 36, p. 121 - 132. 1976: T e c t o n i c S e t t i n g I n f e r r e d From C h e m i s t r y of C e n o z o i c and A r c h e a n v o l c a n i c s ; E.O.S. T r a n s a c t i o n s of the American G e o p h y s i c a l Union 57, pp. 343 - 344. 1975: The T i 0 2 - K20 - P205 Diagram: A Method of D i s c r i m -i n a t i n g Between O c e a n i c and N o n o c e a n i c B a s a l t s ; E a r t h and P l a n e t a r y S c i e n c e L e t t e r s , v. 24, p. 419 - 426. P e a r s o n , D.E. and P a n e l e y e v , A. 1976: Kutcho Creek Map Area (104 1/1W), G e o l o g i c a l F i e l d Work, B r i t i s h C olumbia M i n i s t r y of Mines and P e t r o l e u m R e s o u r c e s , p. 74 - 76. Page 148 1975: C u p i f e r o u s I r o n S u l f i d e D e p o s i t s , Kutcho Creek Map Area (104 1/1W), G e o l o g i c a l F i e l d Work, B r i t i s h C olumbia M i n i s t r y of Mines and P e t r o l e u m R e s o u r c e s , G.E.M. R e p o r t , p. 86 - 93. 1974: Kutcho Creek M a s s i v e S u l p h i d e D e p o s i t ; G e o l o g y E x p l o r a t i o n and M i n i n g i n B r i t i s h C o l u m b i a M i n i s t r y of Mines and P e t r o l e u m R e s o u r c e s , p. 343 - 347. P i c h l e r , H., and Z e i l , W. 1969: A n d e s i t e s of the C h i l e a n Andes; in M c B i r n e y , A.R. ( e d ) , P r o c e d i n g s of the A n d e s i t e C o n f e r e n c e , Department of M i n e r a l R e s e a r c h Oregen B u l l e t i n 65, p. 165. P r e t o , V.A. 1977: The N i c o l a Group: M e s o z o i c V o l c a n i s m R e l a t e d to R i f t i n g i n S o u t h e r n B r i t i s h C o l u m b i a ; in_ B a r a g a r , W.R .A • » C o l eman, L.C., H a l l , J . M . ( e d s ) , " V o l c a n i c Regimes i n Canada G e o l o g i c a l A s s o c i a t i o n of Canada, S p e c i a l Paper 16, p 39 - 60. Ramber g, H. 1952: The O r i g i n of Metamorphic and M e t a s o m a t i c Rocks; U n i v e r s i t y of C h i c a g o P r e s s , C h i c a g o . Page 149 Ramsay, J .G. 1967: F o l d i n g and F r a c t u r i n g of Rocks; McGraw - H i l l P u b l i c a t i o n , New York, 568 p. R i t t m a n , A. 1962: V o l c a n o e s and T h e i r A c t i v i t y , I n t e r s c i e n c e P u b l i c a t i o n , New York, 305 p. S a n g s t e r , D.F. 1972: P r e c a m b r i a n V o l c a n o g e n i c M a s s i v e S u l p h i d e D e p o s i t s i n Canada: A Review; G e o l o g i c a l S u r v e y of Canada, Paper 72 - 22, 42 p. 1971: G e o l o g i c a l S i g n i f i c a n c e of S t r a t a b o u n d S u l f i d e D e p o s i t s , P r o c e e d i n g s G e o l o g i c a l A s s o c i a t i o n of Canada, v. 23, p. 69 - 72. S a t o , T. 1974: D i s t r i b u t i o n and G e o l o g i c S e t t i n g of Kuroko D e p o s i t s i n N o r t h e a s t Honshu, J a p a n ; ±n_ I s h i h a r a , A. ( e d ) , "Geology of Kuroko D e p o s i t s " , M i n i n g G e o l o g i c a l S p e c i a l I s s u e Number 6, p. 1 - 9. Page 150 Sawkins , F . J . . 1976: M a s s i v e S u l p h i d e D e p o s i t s i n R e l a t i o n to G e o t e c t o n i c s ; G e o l o g i c a l A s s o c i a t i o n of Canada, S p e c i a l Paper 14, p. 221 - 240. 1978: S u l f i d e Ore D e p o s i t s i n R e l a t i o n to P l a t e T e c t o n i c s ; J o u r n a l of G e o l o g y , v. 80, no.4, p. 377 - 397. Schau, M.P. 1968: G e o l o g y of the Upper T r i a s s i c N i c o l a Group i n S o u t h -C e n t r a l B r i t i s h C o l u m b i a ; u n p u b l i s h e d PhD T h e s i s , U n i v e r s i t y of B r i t i s h C o l u m b i a , 211 p. 1970: S t r a t i g r a p h y and S t r u c t u r e of the Type Area of the Upper T r i a s s i c N i c o l a Group i n S o u t h - C e n t r a l B r i t i s h C o l u m b i a ; G e o l o g i c a l A s s o c i a t i o n of Canada, S p e c i a l Paper Number 6, p. 123 - 135. S m i t h , R.E. 1968: R e d i s t r i b u t i o n of Major E l e m e n t s i n the A l t e r a t i o n of Some B a s i c Lavas D u r i n g B u r i a l Metamorphism; J o u r n a l of P e t r o l e u m , v. 9, p. 191 - 219. Page 151 S o u t h e r , J.G. 1977: V o l c a n i s m and T e c t o n i c E n v i r o n m e n t s i n the C a n a d i a n C o r d i l l e r a - A Second Look in_ B a r a g a r , W.R.A., Coleman, L.C., H a l l , J.M. ( e d s ) , " V o l c a n i c Regimes i n Canada"; G e o l o g i c a l A s s o c i a t i o n of Canada, S p e c i a l Paper 16, p. 3 - 24. 1971: Geology and M i n e r a l D e p o s i t s of the T u l s e q u a h Map A r e a , B r i t i s h C o l u m b i a ; G e o l o g i c a l S u r v e y of Canada, Memoir 362, 84 p. 1971: T e l e g r a p h Creek Map A r e a ; G e o l o g i c a l S u r v e y of Canada, 71 - 44, 38 p. 1970: V o l c a n i s m and I t s R e l a t i o n s h i p to Recent C r u s t a l Movements i n the C a n a d i a n C o r d i l l e r a ; C a n a d i a n J o u r n a l of E a r t h S c i e n c e s , v. 7, p. 553 - 563. S o u t h e r , J.G. and A r m s t r o n g , J . E . 1966: N o r t h C e n t r a l B e l t of the C o r d i l l e r a of B r i t i s h C o l u m b i a ; C a n a d i a n I n s t i t u t e of M i n i n g M e t a l l u r g y , S p e c i a l Volume 8, p. 171. S t a n t o n , R.L. Page 152 1972 : Ore P e t r o l o g y ; M c G r a w - H i l l P u b l i c a t i o n , London and M o n t r e a l , 713 p. New York, S t r o n g , D.F. 1977: V o l c a n i c Regimes of the Newfoundland A p p a l a c h i a n s ; _in_ B a r a g a r , W.R.A., Coleman, L.C., H i l l , J.M. ( e d s ) , " V o l c a n i c Regimes i n Canada"; G e o l o g i c a l A s s o c i a t i o n of Canada, S p e c i a l Paper 16, p. 61 - 90. Sugimura, A. 1968: S p a t i a l R e l a t i o n s of B a s a l t i c Magmas i n I s l a n d A r c s , i n Hess, H.H. and P o l d e r v a a r t , A . ( e d s ) , "The P o l d e r v a a r t T r e a t i s e , Rocks of B a s a l t i c C o m p o s i t i o n " , I n t e r -s c i e n c e P u b l i c a t i o n , New York, p. 537 - 571. S u t h e r l a n d - B r o w n , A., C a t h r o , R.J., P a n t e l e y e v , . R . J . , and Ney, C.S. 1971: . M e t a l l o g e n y of the C a n a d i a n C o r d i l l e r a ; C a n a d i a n I n s t i t u t e of M i n i n g M e t a l l . T r a n s , v. 74,- p. 121 - 145. T a t s u m i , T. (ed) 1970: V o l c a n i s m and Ore G e n e s i s ; U n i v e r s i t y of Tokyo P r e s s , Tokyo, p. 153 - 180 and p. 197 - 206. T a y l o r , S.R. Page 153 1969: T r a c e Element C h e m i s t r y of A n d e s i t e s and A s s o c i a t e d C a l c - A l k a l i n e Rocks, ±n_ M c B i r n e y , A.R., " P r o c e e d i n g s of the A n d e s i t e C o n f e r e n c e " , Department of Ge o l o g y and M i n e r a l R e s e a r c h , Oregon, B u l l e t i n , v. 65, p. 43 - 64. T a y l o r , S.R., Kaye, M., White, A.R., Duncan, A.R., and Ewart, A. 1969: G e n e t i c S i g n i f i c a n c e of Co, C r , N and V C o n t e n t ; G e o c h i m i c a Cosmochimica A c t a , v. 33, p. 275 - 286. Thompson, R.I. and P a n t e l e y e v , A. 1976: S t r a t a b o u n d M i n e r a l D e p o s i t s of the C a n a d i a n C o r d i l l e r a ; i_n Wolfe K.H. ( e d ) , Handbook of S t r a t a -bound and S t r a t i f o r m Ore D e p o s i t s , p. 37 - 108. T i p p e r , H.W. 1978: J u r a s s i c B i o s t r a t i g r a p h y , Cry Lake Map C o l u m b i a ; G e o l o g i c a l S u r v e y of Canada, R e p o r t of A c t i v i t i e s , p. 25 - 27. T i p p e r , H.W. and R i c h a r d s , T.A. 1976: J u r a s s i c S t r a t i g r a p h y and H i s t o r y of N o r t h - C e n t r a l B r i t i s h C o l u m b i a ; G e o l o g i c a l Survey of Canada, B u l l e t i n 270, 73 p. Area , B r i t i s h Paper 78 - 1A, Page 154 T o z e r , E.T . 1958: S t r a t i g r a p h y of the Lewes R i v e r Group ( T r i a s s i c ) , C e n t r a l L a b e r g e A r e a , Yukon T e r r i t o r y ; G e o l o g i c a l S u r v e y of Canada, B u l l e t i n 43. T r e t t i n , H.P. 1954: Geology of the L i l l o e t A r e a ; G e o l o g i c a l S u r v e y of of Canada; B u l l e t i n 44, 105 p. T u r n e r , F . J . and W e i s s , L.E. 1963: S t r u c t u r a l A n a l y s i s of Metamorphic T e c t o n i t e s ; McGraw - H i l l , T o r o n t o , 545 p. V a l l i e r , T.L. and B a t i z a , R. 1978: P e t r o g e n e s i s of S p i l i t e and K e r a t o p h y r e From a Permian and T r i a s s i c V o l c a n i c Arc T e r r a n e , E a s t e r n Oregon and Western Idaho, U.S.A.; C a n a d i a n J o u r n a l of E a r t h S c i e n c e s , v. 25, p. 1356 - 1369. Watson, K. D. and Mathews, W.H. 1944: The Tuya T e s l i n A r e a , B r i t i s h C o l u m b i a ' Department of M i n e s , B u l l e t i n 19, 52 p. Weber, M. Page 155 1977: The G e o l o g y and M i n e r a l o g y of the Cu - Zn - Fe M a s s i v e S u l f i d e D e p o s i t a t Kutcho C r e e k , B r i t i s h C o l u m b i a ; u n p u b l i s h e d BSc T h e s i s , U n i v e r s i t y of B r i t i s h C o l u m b i a , 61 p. Wheeler, J.O. 1966: E a s t e r n T e c t o n i c B e l t of the Western C o r d i l l e r a i n B r i t i s h C o l u m b i a , i_n C a n a d i a n I n s t i t u t e o f M i n i n g M e t a l l u r g y , S p e c i a l Volume 8, p. 27 - 45. 1961: W h i t e h o r s e Map A r e a , Yukon T e r r i t o r y ; G e o l o g i c a l S u r v e y of Canada, Memoir 312, 156 p. Wheeler, J.O. and G a b r i e l s e , H. 1972: The C o r d i l l e r a n S t r u c t u r e P r o v i n c e ±n_ P r i c e , R.A. and D o u g l a s , J . W . ( e d s ) , " V a r i a t i o n s i n T e c t o n i c S t y l e s i n Canada"; G e o l o g i c a l A s s o c i a t i o n of Canada, S p e c i a l Paper Number 11, p. 1 - 81. White, W.H. 1966: Problems of M e t a l l o g e n y i n the Western C o r d i l l e r a i n C a n a d i a n I n s t i t u t e of M i n i n g M e t a l l u r g y , S p e c i a l Volume 8, p. 349. Page 156 1959: T e c t o n i c s i n B r i t i s h C o l u m b i a ; American A s s o c i a t i o n of P e t r o l e u m G e o l o g y , B u l l e t i n , v. 43, p. 60 - 100. W h i t f o r d , D.J. 1977: G e o c h e m i s t r y of L a t e C e n o z o i c Lavas From E a s t e r n I n d o n e s i a , R o l e of S u b d u c t e d Sediments i n P e d o -g e n e s i s ; G e o l o g y , v. 5, p. 571 - 575. J.F.G. The P e t r o g r a p h y of B a s a l t i c Rocks; i_n Hess, H.H. and P o l d e r v a a r t , A. ( e d s ) , "The P o l d e r v a a r t T r e a t i s e on Rocks of B a s a l t i c C o m p o s i t i o n " , I n t e r s c i e n c e , New York, p. 163 - 214. W i l l i a m s , H., T u r n e r , F . J . and G i l b e r t , C M . P e t r o g r a p h y - An I n t r o d u c t i o n to the Study of Rocks i n T h i n S e c t i o n , Freeman and Company, San F r a n s i s c o , 384 p. W i l k i n s o n , 1967 : W i l s o n , H.D.B., Andrews, P., Maxham, R.L., and R a m l a l , K. 1965: A r c h e a n V o l c a n i s m i n the C a n a d i a n S h i e l d ; C a n a d i a n J o u r n a l of E a r t h S c i e n c e , v. 2, p. 161 - 175. W i n c h e s t e r , J.A., and F l o y d , P.A. Page 157 1977 : G e o c h e m i c a l D i s c r i m i n a t i o n of D i f f e r e n t Magma S e r i e s and T h e i r D i f f e r e n t a t i o n P r o d u c t s U s i n g Immobile E l e m e n t s ; C h e m i c a l G e o l o g y , v. 20, p. 325 - 343. 1976: G e o c h e m i c a l Magma Type D i s c r i m i n a t i o n - A p p l i c a t i o n to A l t e r e d and Metamorphosed B a s i c Igneous Rocks; E a r t h and P l a n e t a r y S c i e n c e L e t t e r s , v. 28, p. 459 - 469. W i n k l e r , H.G.F. 1974: P e t r o g e n e s i s of Metamorphic Rocks; S p r i n g e r - V e r l a g , 334 p. Y e l l u r , D.D. 1977: G e o c h e m i c a l C l u e s i n the I n v e s t i g a t i o n of the T e c t o n i c E n v i r o n m e n t of the Dalma G r e e n s t o n e s , B i h a r I n d i a , C h e m i c a l G e o l o g y , v. 20, p. 345 - 363. Yoder, H.S., and T i l l e y , C.E. 1962: O r i g i n of B a s a l t Magmas: An E x p e r i m e n t a l Study of the N a t u r a l and S y n t h e t i c Rock Systems; J o u r n a l of P e t r o l e u m , v. 3, p. 342 - 532. York, D. Page 158 1967: The B e s t I s o c h r o n ; E a r t h and P l a n e t a r y S c i e n c e L e t t e r s , v. 2, p. 479 - 482. Page 159 APPENDIX I PETROLOGY Page 160 PETROLOGY Rocks of the Kutcho F o r m a t i o n encompass a wide range of c o m p o s i t i o n s r a n g i n g from a l k a l i n e and c a l c a l k a l i n e b a s a l t to c a l c a l k a l i n e r h y o l i t e . Most r o c k s a r e v o l c a n i c l a s t i c a l t h o u g h some f l o w r o c k s may e x i s t . T e x t u r e s a r e masked by d e f o r m a t i o n . Over two hundred t h i n s e c t i o n s of r o c k s of the Kutcho F o r m a t i o n and a few r e p r e s e n t a t i v e s e c t i o n s from the I n k l i n and T a k l a F o r m a t i o n s , Sinwa L i m e s t o n e and Cache Creek Group were examined by the a u t h o r . D e s p i t e minor v a r i a t i o n s most r o c k s of the Kutcho F o r m a t i o n f a l l i n t o one of the u n i t s d i s c u s s e d i n the t e x t - "STRATIGRAPHY AND PETROLOGY OF THE KUTCHO FORMATION" and summarized i n l i s t form below. 1. C o n g l o m e r a t e 2. T u f f and A r g i l l i t e 3 . B a s i c S c h i s t 4. B r e c c i a 5. C h l o r i t e S c h i s t 6. F e l d s p a r , q u a r t z - e y e , s e r i c i t e s c h i s t 7. B a s a l t i c t o d a c i t i c t u f f and b r e c c i a Rocks of the Kutcho F o r m a t i o n have been v a r i a b l y Page 161 metamorphosed, deformed and l o c a l l y m e t a s o m a t i z e d . These p r o c e s s e s have o v e r p r i n t e d and i n p a r t d e s t r o y e d o r i g i n a l t e x t u r e s . Common metamorphic m i n e r a l a s s e m b l a g e s have been d i s c u s s e d i n C h a p t e r 4, "METAMORPHISM". I n c l u d e d i n t h i s a p p e n d i x a r e summary d e s c r i p t i o n s of each of the s t r a t i g r a p h i c u n i t s w i t h e x e m p l e t o r y d e s c r i p t i o n s of s p e c i f i c s a m p l e s . For b r e v i t y the f o l l o w i n g m i n e r a l a b b r e v i a t i o n s have been u s e d : CB -- c a r b o n a t e CL -- c h l o r i t e EP -- e p i d o t e HB -- h o r n b l e n d e HE -- h e m a t i t e KF -- p o t a s s i u m f e l d s p a r OP -- opaques PF -- p l a g i o c l a s e PY -- p y r i t e QZ -- q u a r t z SE -- s e r i c i t e TA -- t e m o l i t e - a c t i n o l i t e Page 162 BASALTIC TO DACITIC TUFF AND BRECCIA B a s a l t i c to d a c i t i c t u f f and b r e c c i a i s the o l d e s t known u n i t of the Kutcho s u i t e . Up to 215 m of t h i c k n e s s has been o b s e r v e d ( B r i d g e , 1978, p e r s . comm.) assuming no s t r u c t u r a l t h i c k e n i n g . L i t h o l o g i e s i n c l u d e m a s s i v e t u f f , f e l d s p a r ( w i t h or w i t h o u t r e l i c t h o r n b l e n d e or a u g i t e ) c r y s t a l t u f f and c h a o t i c b r e c c i a s w i t h f r a g m e n t s from 1 to 35 cm. i n s i z e . Rocks a r e now d o m i n a n t l y c h l o r i t i c s c h i s t s w i t h r e l i c t f r a g m e n t a l t e x t u r e s . E p i d o t e i s u b i q u i t o u s and i n some h o r i z o n s l a r g e b r e c c i a f r a g m e n t s a r e p r e f e r r e n t i a l l y e p i d o t i z e d . E p i d o t e a l s o o c c u r s as c l o t s of r a d i a t i n g c r y s t a l s . In t h i n s e c t i o n r o c k s a r e w e l l - f o l i a t e d c h l o r i t e , e p i d o t e , p l a g i o c l a s e s c h i s t s w i t h r e l i c t p h e n o c r y s t s and comminuted f r a g m e n t s of p l a g i o c l a s e and h o r n b l e n d e or a u g i t e . P l a g i o c l a s e , t h e dominant c r y s t a l , commonly makes up 50 p e r c e n t of the r o c k , and i s e x t e n s i v e l y a l t e r e d to e p i d o t e , c a r b o n a t e and l e s s e r s e r i c i t e . In t o t a l , e p i d o t e c o n s t i t u t e s between 5 and 25 p e r c e n t of the r o c k , c h l o r i t e g e n e r a l l y between 20 and 30 p e r c e n t , t r e m o l i t e - a c t i n o l i t e up to 20 p e r c e n t and c a r b o n a t e 1 to 2 p e r c e n t . D e t a i l e d sample d e s c r i p t i o n s f o l l o w . Page 163 77-88B (A.8) M a c r o s c o p i c D e s c r i p t i o n - W e l l - f o l i a t e d f e l d s p a r c h l o r i t e e p i d o t e s c h i s t i s i n t e r l a y e r e d w i t h a u g i t e p o r p h y r y . The s c h i s t i s p a l e g r e e n on w e a t h e r e d s u r f a c e s and m o t t l e d by r e s i s t a n t , 2 to 6 mm s i z e d e p i d o t e c l o t s . M i c r o s c o p i c D e s c r i p t i o n -M i n e r a l o gy 40 - 45% PF - f i n e - g r a i n e d , comminuted, a l t e r e d to SL, CL and EP. 30 - 35% CL - c l o t s p a r a l l e l i n g the f o l i a t i o n 15 - 16% EP - as i r r e g u l a r c l o t s , 2 to 6 cm i n s i z e , r e p l a c e s PF 6 - 7% TA - commonly w i t h CL, p a r a l l e l s f o l i a t i o n 1% CB - r e p l a c e s PF and o c c u r s w i t h CB D i s c u s s i o n E p i d o t e a p p e a r s to r e p l a c e PF a g g r e g a t e s or o r i g i n a l m a f i c g r a i n s . 78 - 358B (A.35) Page 164 M a c r o s c o p i c D e s c r i p t i o n - W e l l - f o l i a t e d c h l o r i t e t r e m o l i t e e p i d o t e s c h i s t . The r o c k has abundant e l o n g a t e l e n s e s and s e g r e g a t i o n s of e p i d o t e and i s dark g r e e n on w e a t h e r e d s u r f a c e s . M i c r o s c o p i c D e s c r i p t i o n -M i n e r a l o g y 25 - 30% CL - as f i n e f o l i a t e d masses 20 - 25% TA - as s h e a t h - l i k e a g g r e g a t e s t h a t wrap around EP . 20 - 25% EP - s u b h e d r a l b l e b s and l a r g e r masses; f o l i a t i o n wraps around 15 - 20% PF - r e l i c t g r a i n s , a l b i t i c i n c o m p o s i t i o n , f i n e g r a i n s 4 - 5% OP - d o m i n a n t l y p y r i t e D i s c u s s i o n - M i n e r a l s show a v e r y s t r o n g a l i g n m e n t p a r a l l e l the f o l i a t i o n . F o l i a t i o n w r a p p i n g around e p i d o t e s u g g e s t e p i d o t e was p r e k i n e m a t i c or may have r e p l a c e d an e x i s t i n g m i n e r a l . ( p o s t k i n e m a t i c a l l y ) 78 - 360 (A.36) Page 165 M a c r o s c o p i c D e s c r i p t i o n f o l i a t e d and c o n t a i n s 2 - C h l o r i t e , e p i d o t e s c h i s t i s to 4 mm s i z e d e p i d o t e b l e b s . v e r y w e l l M i c r o s c o p i c D e s c r i p t i o n -50 - 55% PF - as f i n e g r a i n s , i n m a t r i x , and as g r a n u l a r a g g r e g a t e s 20 - 25% CL - t h r o u g h o u t r o c k w i t h f i n e EP b l e b s 12 - 15% EP - as i r r e g u l a r masses 1 - 2% OP D i s c u s s i o n - Rock i s t e x t u r a l l y inhomogeneous w i t h c o a r s e f e l d s p a r a g g r e g a t e s i n a f i n e a n n e a l e d m a t r i x . I n t e r g r a i n a n g l e s of 120 d e g r e e s s u g g e s t r e c r y s t a l l i z a t i o n . E p i d o t e c l o t s appear to be r e p l a c i n g PF a g g r e g a t e s . 78 - 360C M a c r o s c o p i c D e s c r i p t i o n - M o d e r a t e l y w e l l - f o l i a t e d c h l o r i t e s c h i s t has s u b c i r c u l a r to e l l i p t i c a l e p i d o t e b l e b s . E p i d o t e b l e b s appear to have a r a d i a l p a t t e r n . The r o c k w e a t h e r s dark green w i t h r e s i s t a n t e p i d o t e knobs. Page 166 M i c r o s c o p i c D e s c r i p t i o n -M i n e r a l o g y 40 - 45% EP - as r a d i a l a g g r e g a t e s and i r r e g u l a r b l e b s r e p l a c i n g PF 30 - 35% PF - f i n e c r y s t a l l i n e m o s a i c s r e p l a c e d by i r r e g u l a r EP b l e b s 25 - 30% CL - r e p l a c e s and c o n s t i t u t e s most of m a t r i x 5 - 6% QZ - as p a t c h y c r y s t a l l i n e m o s a i c s a l o n g f r a c t u r e s ; a l s o n o t e d between and i n c o r e of r a d i a t i n g EP masses 1 - 2% OP - d o m i n a n t l y p y r i t e D i s c u s s i o n - E p i d o t e a p p e a r s to r e p l a c e PF t h r o u g h o u t the r o c k . Q u a r t z i s c o n s i d e r e d to have a s e c o n d a r y o r i g i n as a r e s u l t of PF r e p l a c e m e n t . 78 - 368A (A.39) M a c r o s c o p i c D e s c r i p t i o n - L i g h t g r e e n to b u f f w e a t h e r i n g w e l l -• f o l i a t e d , f e l d s p a t h i c , c h l o r i t e s c h i s t . E l o n g a t e c a r b o n a t e b l e b s Page 167 o c c u r t h r o u g h o u t the r o c k and te n d to weather r e c e s s i v e l y . S p l o t c h y l i m o n i t e s t a i n i n g i s e v i d e n t . M i c r o s c o p i c D e s c r i p t i o n -M i n e r a l o g y 50 -- 55% PF - as f i n e g r a n u l a r m o s a i c s , a l s o i n g r a n u l a r a g g r e g a t e s 16 -- 16% TA - g e n e r a l l y p a r a l l e l the f o l i a t i o n , minor g r a i n s p e r p e n d i c u l a r to i t 10 -- 12% EP - as s u b h e d r a l (.4 mm) b l e b s 6 -- 7% OP - d o m i n a n t l y p y r i t e 3 -- 4% CL - f i n e e l o n g a t e g r a i n s p a r a l l e l the f o l i a t i o n a s s o c i a t e d w i t h TA 2% Vug s t AP D i s c u s s i o n - Metamorphism has. d e s t r o y e d most of the p r i m a r y t e x t u r e s but g e n e r a l r o c k c o m p o s i t i o n s u g g e s t s a v o l c a n i c o r i g i n . Page 168 FELDSPAR-QUARTZ-EYE SERICITE SCHIST F e l d s p a r q u a r t z - e y e s e r i c i t e s c h i s t a r e metamorphic e q u i v a l e n t s of d a c i t i c to r h y o l i t i c t u f f s and b r e c c i a s . The s c h i s t s c o n s t i t u t e b o t h f o o t w a l l and h a n g i n g w a l l to m a s s i v e s u l p h i d e m i n e r a l i z a t i o n i n t h e t y p e a r e a . T o t a l t h i c k n e s s of f o o t w a l l and h a n g i n g w a l l a r e 320 m and 245 m, r e s p e c t i v e l y . A l e n s of f e r r u g i n o u s c h e r t i s found i n t h e s e r o c k s a t the same g e n e r a l h o r i z o n as m a s s i v e s u l p h i d e m i n e r a l i z a t i o n . F r a g m e n t a l l i t h o l o g i e s dominate the sequence w i t h o r i g i n a l r o c k s r a n g i n g from f i n e t u f f to c o a r s e b r e c c i a w i t h f r a g m e n t s up to 20 cm i n l e n g t h e v i d e n t . F r a g m e n t a l r o c k s a r e g e n e r a l l y m o n o l i t h o l o g i c . In t h i n s e c t i o n q u a r t z , f e l d s p a r and s e r i c i t e a r e the dominant m i n e r a l s . Q u a r t z and f e l d s p a r o c c u r as i n d i v i d u a l g r a i n s or a g g r e g a t e s of v a r y i n g s i z e and abundance. Q u a r t z o c c u r s as " e y e s " or augen and some l e s s deformed g r a i n s have s u b h e d r a l forms; a h a b i t u n i q u e to v o l c a n i c r o c k s ( G a b r i e l s e , 1978, p e r s . comm.). Q u a r t z g e n e r a l l y c o n s t i t u t e s between 18 and 40 p e r c e n t of the e n t i r e r o c k and i s r e p l a c e d by c a r b o n a t e and s e r i c i t e a l o n g f r a c t u r e s . A l b i t i c p l a g i o c l a s e , the dominant f e l d s p a r o c c u r s as Page 169 l a r g e s u b h e d r a l g r a i n s t h a t a r e commonly augen-shaped as c o a r s e g r a n u l a r a g g r e g a t e s , and as f i n e m a t r i x g r a i n s i n amounts between 20 and 45 p e r c e n t . Both zoned and unzoned p h e n o c r y s t s a r e e v i d e n t ; the l a t t e r b e i n g dominant. P l a g i o c l a s e i s a l t e r e d to s e r i c i t e and c a r b o n a t e w i t h l e s s e r c h l o r i t e and e p i d o t e i n t h e s e s i l i c i c r o c k s . Both q u a r t z and f e l d s p a r g r a i n s a r e f r a c t u r e d w i t h g r a i n o f f s e t s p a r a l l e l l i n g the f o l i a t i o n and f i n e l y comminuted f r a g m e n t s a r e common i n s t r a i n or p r e s s u r e shadows (Ramberg, 1952). The m a t r i x i s d o m i n a n t l y f i n e g r a i n e d s e r i c i t e w i t h minor amounts of c h l o r i t e , e p i d o t e and r e l i c t q u a r t z and f e l d s p a r . A w e l l d e v e l o p e d f o l i a t i o n i s e v i d e n t t h r o u g h o u t . Rocks i n t h i s h o r i z o n a r e m i n e r a l o g i c a l l y homogeneous. S l i g h t c o m p o s i t i o n a l and t e x t u r a l v a r i a t i o n s d i f f e r e n t i a t e l i t h o l o g i e s . 77 - 86C (A.7) M a c r o s c o p i c D e s c r i p t i o n - Medium q u a r t z - e y e s and f e l d s p a r g r a i n s o c c u r i n a m a t r i x of c h l o r i t e and s e r i c i t e s c h i s t . The m a t r i x to g r a i n r a t i o v a r i e s r a d i c a l l y i n s u c c e s s i v e h o r i z o n s . F o l i a t i o n i s p o o r l y to m o d e r a t e l y w e l l - d e v e l o p e d as a f u n c t i o n of the amount of m a t r i x . F r a g m e n t a l t e x t u r e s a r e e v i d e n t on c u t s u r f a c e s . Page 170 D i s s e m i n a t e d p r y i t e i s u b i q u i t o u s . M i s c r o s c o p i c D e s c r i p t i o n -M i n e r a l o g y 40 - 45% PF - c o m p o s i t i o n i s a l b i t i c , abundant SE a l t e r a t i o n 30 - 35% QZ - comminuted and a n n e a l e d g r a n u l a r a g g r e g a t e s form c o a r s e " e y e s " , a l s o f i n e m a t r i x g r a i n s . 8 - 9% CL - p a r a l l e l s the f o l i a t i o n 5 - 6% SE - commonly p e r i p h e r a l to PF and QZ g r a i n s , p a r a l l e l and randomly o r i e n t e d to t h e f o l i a t i o n 1 - 2% EP - augen- shaped; p o s s i b l y pseudomorphing h o r n b l e n d e D i s c u s s i o n - The inhomogeneous c h a r a c t e r o f the r o c k and p r e s e n c e of f r a g m e n t s s u g g e s t s i t i s t u f f a c e o u s i n n a t u r e . 77 - 186C (A.12) M a c r o s c o p i c D e s c r i p t i o n - F e l d s p a r , q u a r t z - e y e , c h l o r i t e , s e r i c i t e , c r y s t a l t u f f has abundant, l a r g e (3 to 8 mm) q u a r t z -Page 171 e y e s , f i n e (1 to 1.5 ram) f e l d s p a r c r y s t a l s and c h l o r i t i c c l o t s pseudomorphing o r i g i n a l m a f i c g r a i n s i n a f i n e g r een m a t r i x . The r o c k i s o n l y m o d e r a t e l y w e l l - f o l i a t e d . M i c r o s c o p i c D e s c r i p t i o n -M i n e r o l o g y 25 - 30% QZ - g r a i n s a r e commonly f r a c t u r e d and a n n e a l e d and have u n d u l o s e e x t i n c t i o n 20 - 25% PF - r e l i c t g r a i n s a r e a l b i t i c i n c o m p o s i t i o n 20 - 25% EP - commonly pseudomorphs PF w i t h EP; some z o n i n g e v i d e n t 6 - 8% SE - p a r a l l e l and a t 45 a n g l e s to the f o l i a t i o n , commonly r e c r y s t a l l i z e d to p o l y g o n a l a r c s 5 - 6% CL - as b l e b s and masses s u b p a r a l l e l the f o l i a t i o n 1 - 2% OP - d o m i n a n t l y p y r i t e D i s c u s s i o n - F o l i a t i o n i s more e v i d e n t i n t h i n s e c t i o n . F o l d s and p o l y g o n a l a r c s i n CL and SE s u g g e s t a syn and p o s t k i n e m a t i c o r i g i n f o r t h e s e m i n e r a l s . Page 172 77 - 1861 (A.14) M a c r o s c o p i c D e s c r i p t i o n - F i n e - g r a i n e d q u a r t z - e y e , s e r i c i t e s c h i s t , grey to w h i t e or w e a t h e r e d s u r f a c e and b u f f on f r e s h s u r f a c e , c o n t a i n s abundant c a r b o n a t e l e n s e s . D i s s e m i n a t e d s u l p h i d e s , i n p a r t i c u l a r h e m a t i t e , a r e common around the c a r b o n a t e l e n s e s . M i c r o s c o p i c D e s c r i p t i o n -M i n e r a l o g y 20 - 22% CB - p o i k i l o b l a s t i c g r a i n s r e p l a c i n g QZ, PF, KF and m a t r i x . 20 - 22% SE - bent and r e c r y s t a l l i z e d g r a i n s g e n e r a l l y p a r a l l e l 18 - 22% QZ - c o a r s e , h i g h l y f r a c t u r e d g r a i n s , CB and SE r e p l a c e s 10 - 12% PF - some r e l i c t t w i n n i n g , e x t e n s i v e l y r e p l a c e d by CB and SE 4 - 5% KF - v e r y f i n e - g r a i n e d , r e p l a c e d by SE and CB 3 - 4% OP - o f t e n w i t h CL r e p l a c i n g m a f i c m i n e r a l Page 173 1 - 2% CL - as augen- shaped b l e b s , a s s o c i a t e d OP t Z i r c o n D i s c u s s i o n - CB, CL a g g r e g a t e s , PF, and QZ a l l e x h i b i t augen forms i n a w e l l - f o l i a t e d m a t r i x . CB d e f l e c t s f o l i a t i o n and i s M a c r o s c o p i c D e s c r i p t i o n - H e m a t i t i c q u a r t z - e y e , f e l d s p a r , s e r i c i t e s c h i s t has l a r g e , 3 to 8 mm q u a r t z - e y e s i n a w e l l -f o l i a t e d m a t r i x of f e l d s p a r , s e r i c i t e and s h l o r i t e . H e m a t i t e i s g e n e r a l l y a s s o c i a t e d w i t h q u a r t z - e y e s . A f r a g m e n t a l t e x t u r e i s e v i d e n t . M i c r o s c o p i c D e s c r i p t i o n -M i n e r a l o g y 35 - 40% QZ - f r a c t u r e d , u n d u l o s e e x t i n c t i o n p r e k i n e m a t i c or i s a l a t e r r e p l a c e m e n t of t e c t o n i z e d m i n e r a l g r a i n s 77 - 186E (A.13) 20 - 25% PF - g e n e r a l l y a l b i t i c i n c o m p o s i t i o n , f i n e a l t e r a t i o n to SE and EP i s u b i q u i t o u s 12 - 15% CL - g e n e r a l l y p a r a l l e l s the f o l i a t i o n Page 174 12 - 15% SE - r e p l a c e s PF and m a t r i x 3 - 4% EP - as v e r y f i n e a l t e r a t i o n of PF 2 - 3% CB - o f t e n a s s o c i a t e d w i t h OP 1 - 2% OP M i c r o s c o p i c D e s c r i p t i o n -M i n e r a l o g y 30 - 35% PF - many a l b i t e t w i n s a r e b e n t , f r a c t u r e d and o f f s e t , c o m p o s i t i o n i s a l b i t i c , CB r e p l a c e m e n t i s common 15 - 18% QZ - g r a n u l a r a g g r e g a t e s , u n d u l o s e e x t i n c t i o n and r e p l a c e m e n t by CB a l o n g f r a c t u r e s common 10 - 12% SE - r e p l a c i n g PF and f i n e m a t r i x , p a r a l l e l and a t 45 a n g l e s to the f o l i a t i o n 8 - 10% CB - r e p l a c e s PF a l o n g f r a c t u r e s , 8 - 10% KF - f i n e , d i s s e m i n a t e d g r a i n s i n m a t r i x 6 - 7% EP - as f i n e b l e b s i n m a t r i x 2 - 3% OP - g e n e r a l y w i t h CL D i s c u s s i o n - C o a r s e g r a i n s a r e h i g h l y c a t a c l a s t i z e d and c a r b o n a t e r e p l a c e m e n t i s abundant. Page 175 FERRUGINOUS CHERT 78 - 243 (A.23) M a c r o s c o p i c D e s c r i p t i o n - Rock i s h i g h l y f r a c t u r e d , red,, w h i t e and grey w e a t h e r i n g , f e r r u g i n o u s c h e r t . P y r i t e i s common a l o n g f r a c t u r e s . M i c r o s c o p i c D e s c r i p t i o n -M i n e r a l o g y 80 - 85% QZ - g r a i n s a r e a f i n e c r y s t a l l i n e m o s a i c , a r e f l a t t e n e d i n the f o l i a t i o n and show u n d u l o s e e x t i n c t i o n ; a l s o as c o a r s e r f l a t t e n e d g r a i n s i n v e i n s . 6 - 8% OP - i r r e g u l a r h e m a t i t i c b l e b s and PY 3 - 4% CL - i s found a l o n g f r a c t u r e s a s s o c i a t e d w i t h opaques 1% CB - a s s o c i a t e d w i t h opaques D i s c u s s i o n - A w e l l - d e v e l o p e d f o s e c t i o n . C h l o r i t e g r a i n s growing may be a d i f f u s i o n r e a c t i o n to f o ( W i n k l e r , 1974) l i a t i o n i s e v i d e n t i n t h i n outward from opaque f i l l e d v e i n s rm an iron-magnesium s i l i c a t e . Page 176 MASSIVE SULPHIDE M a s s i v e s u l p h i d e m i n e r a l i z a t i o n i s found as t h r e e main l e n s e s i n a c i d i c s c h i s t s . A d e t a i l e d d i s c u s s i o n of t h e m a s s i v e s u l p h i d e l e n s e s i s p r e s e n t e d i n Appendix IV. ECONOMIC GEOLOGY. Page 177 CHLORITE SCHIST C h l o r i t e s c h i s t o c c u r s as t h i n l a y e r s and l e n s e s t h r o u g h o u t b a s a l t i c to d a c i t i c t u f f and b r e c c i a and to a l e s s e r e x t e n t i n f e l d s p a r , q u a r t z eye s c h i s t . The u n i t i s a c h l o r i t e s c h i s t c h a r a c t e r i z e d by low s i l i c a (50 to 52% S i 0 2 ) , d o l o m i t e rhombs, i r r e g u l a r e p i d o t e b l e b s and d i s s e m i n a t e d p y r i t e . In t h i n s e c t i o n , c h l o r i t e s c h i s t i s d o m i n a n t l y a mass of c h l o r i t e (45 - 50%) and f i n e f e l d s p a r g r a i n s and g r a n u l a r a g g r e g a t e s w i t h minor amounts of s e r i c i t e (8 - 10%) and t r e m o l i t e -a c t i n o l i t e (1 - 2 % ) . D o l o m i t e rhombs a r e s e c o n d a r y and d e f l e c t the f o l i a t i o n . P y r i t e o c c u r s as i r r e g u l a r f l a t t e n e d masses and as s u b i d i o m o r p h i c g r a i n s . F i n e q u a r t z v e i n l e t s p a r a l l e l the f o l i a t i o n . 78 - 351 (A.31) M a c r o s c o p i c D e s c r i p t i o n - W e l l - f o l i a t e d , d ark green c h l o r i t e s c h i s t has d o l o m i t e rhombs and i r r e g u l a r b l e b s c o n c e n t r a t e d i n s p e c i f i c h o r i z o n s or l a y e r s . D o l o m i t i c rhombs a r e c h a r a c t e r i s t i c . Abundant p y r i t e i s d i s s e m i n a t e d i n the f o l i a t i o n . Page 178 M i c r o s c o p i c D e s c r i p t i o n -M i n e r a l o g y 45 - 50% CL - s h e a t h - l i k e masses 30 - 35% PF - v e r y f i n e g r a i n e d , 1 to 2 mm g r a n u l a r a g g r e g a t e s common 8 - 10% SE - v e r y f i n e n e e d l e - l i k e g r a i n s a r e i n t e r g r o w n w i t h CL 5 - 7% Opaques - PY - as i r r e g u l a r masses arid s u b i d i o m o r p h i c g r a i n s 1 - 2% TA - f i n e a g g r e g a t e s w i t h CL 1 - 2% DOL D i s c u s s i o n - P l a g i o c l a s e g r a i n s a r e h i g h l y f l a t t e n e d and have d i f f u s e g r a i n b o u n d a r i e s . T r e m o l i t e - a c t i n o l i t e s u r r o u n d s p y r i t e i n q u a r t z v e i n s . Page 179 BRECCIA A m o n o l i t h o g i c b r e c c i a , of l i m i t e d a r e a l e x t e n t , i s found w i t h i n and near the top of f e l d s p a r , q u a r t z - e y e , s e r i c i t e s c h i s t . Both f r a g m e n t s and m a t g r i x a r e q u a r t z - e y e , f e l d s p a r s e r i c i t e s s h i s t . Fragments range i n s i z e from 2 to 25 cm and c l a s t p e r c e n t a g e s range from 30 to 70 p e r c e n t . C l a s t s a r e g e n e r a l l y l e s s w e l l - f o l i a t e d t h an the m a t r i x . In t h i n s e c t i o n c l a s t d e s c r i p t i o n s a r e s i m i l a r to t h o s e of f e l d s p a r , q u a r t z - e y e , s e r i c i t e s c h i s t . The m a t r i x i s composed of 20 - 25% p l a g i o c l a s e , 20 - 25% c h l o r i t e , 18 - 20% e p i d o t e , 10 -12% c a r b o n a t e and a 8 - 10% s e r i c i t e . E p i d o t e , c a r b o n a t e , c h l o r i t e and s e r i c i t e r e p l a c e o r i g i n a l f e l d s p a r and m a f i c g r a i n s . F i n e d i s s e m i n a t e d p y r i t e i s U b i q u i t o u s . 77 - 192D (A.16) M a c r o s c o p i c D e s c r i p t i o n - The b r e c c i a i s m o n o l i t h o l i g i c and c o n t a i n s c l a s t s of b u f F w e a t h e r i n g q u a r t z - e y e , f e l d s p a r p o r p h y r y or c r y s t a l t u f f . C l a s t s a r e l e s s f o l i a t e d t h an the m a t r i x which i s composed of f i n e , 1 to 1.5 mm f e l d s p a r g r a i n s i n c h l o r i t e , s e r i c i t e s c h i s t . F e l d s p a r s commonly have e p i d o t i z e d c o r e s and f i n e c h l o r i t e c l o t s a r e e v i d e n t . Page 180 M i c r o s c o p i c D e s c r i p t i o n -M a t r i x M i n e r a l o g y 20 - 25% PF - u n d u l o s e e x t i n c t i o n , r e p l a c e d by SE, l i t t l e t w i n n i n g e v i d e n t 20 - 25% CL - as f e l t e d masses and as c l o t s p seudomorphing m a f i c g r a i n s ; g r a i n s a r e commonly b e n t . 18 - 20% EP - pseudomorphing or p a r t i a l l y r e p l a c i n g PF; zoned; f o l i a t i o n i s d e f l e c t e d and wrapped around g r a i n s . i ' 8 - 10% SE - r e p l a c e s PF 5 - 7 % - opaques 1% - r o c k f r a g m e n t s - h i g h l y e p i d o t i z e d f i n e g r a n u l a r masses of KF and PF D i s c u s s i o n - G r a i n s a r e f l a t t e n e d and a n n e a l e d (have 120 degree i n t e r g r a i n a n g l e s ) . C h l o r i t e i s g e n e r a l l y bent s u g g e s t i n g a pre to syn k i n e m a t i c o r i g i n ; s e r i c i t e commonly forms p o l y g o n a l a r c s and i s s y n k i n e m a t i c . The m a t r i x a p p e a r s to be a c a l c a r e o u s t u f f . Page 181 BASIC SCHIST W e l l - f o l i a t e d b a s i c t u f f i s i n t e r c a l a t e d w i t h f e l d s p a r , q u a r t z - e y e , s e r i c i t e s c h i s t , t u f f and a r g i l l i t e and c o n g l o m e r a t e as l e n s e s and l a y e r s . G e n e r a l l y l e n s e s a r e from 1 to 3m t h i c k but one l a r g e l e n s has a maximum t h i c k n e s s of 450 m t h i c k . L i t h o l o g i e s a r e somewhat v a r i a b l e and i n c l u d e f e l d s p a r , c h l o r i t e s c h i s t s ; c o a r s e b l a d e d f e l d s p a r , c h l o r i t e s c h i s t ; f e l d s p a r , a u g i t e , c h l o r i t e s c h i s t s and a u g i t e c h l o r i t e s c h i s t s . L i t t l e change i n b u l k c o m p o s i t i o n i s e v i d e n t . Rare f r a g m e n t a l t e x t u r e s a r e o b s e r v e d and i n t e r n a l l a y e r i n g i s e v i d e n t by v a r i a t i o n i n s i z e , shape and c o n c e n t r a t i o n of c r y s t a l s . In t h i n s e c t i o n p l a g i o c l a s e f e l d s p a r i s the dominant r e l i c t p h e n o c r y s t and o c c u r s as 0.1 to 1.5 cm s u b h e d r a l g r a i n s , augen-shaped g r a i n s and as c o a r s e g r a n u l a r s t a r - s h a p e d a g g r e g a t e s . Some z o n i n g i s e v i d e n t i n g r a i n s but i s not common and may be masked by a l t e r a t i o n . P l a g i o c l a s e i s a l b i t i c i n c o m p o s i t i o n and g r a i n s a r e v a r i a b l y s a u s s u r i t i z e d , s e r i c i t i z e d and c a r b o n i t i z e d . E p i d o t e i s a more common a l t e r a t i o n m i n e r a l than i n a c i d i c r o c k s . The degree of a l t e r a t i o n f o r g r a i n s i s h i g h l y v a r i a b l e even on the t h i n s e c t i o n s c a l e . P l a g i o c l a s e g r a i n s a r e be n t , f r a c t u r e d and p a r t i a l l y or e n t i r e l y r o t a t e d i n t o the p l a n e of the f o l i a t i o n . P a t c h y , c r y s t a l l i n e m o s a i c s a r e s u g g e s t i v e of Page 182 r e c r y s t a l l i z a t i o n . O r i g i n a l m a f i c p h e n o c r y s t s or g r a i n s have been r e p l a c e d by c l o t s of c h l o r i t e and b i o t i t e w i t h l e s s e r amounts of t r e m o l i t e - a c t i n o l i t e and minor c a r b o n a t e . The m a t r i x i s a f e l t e d mass of f i n e c h l o r i t e , s e r i c i t e , p l a g i o c l a s e , o r t h o c l a s e , c a r b o n a t e and minor q u a r t z . Due to i t s v e r y f i n e g r a i n e d n a t u r e , the p r e s e n c e of p o t a s s i u m f e l d s p a r was d e t e r m i n e d by sodium c o b a l t i n i t r i t e s t a i n i n g . C h e m i c a l l y the u n i t i s c h a r a c t e r i z e d by low s i l i c a v a l u e s (48 to 54 p e r c e n t S i 0 2 ) , g e n e r a l l y h i g h K20 (4 to 6 p e r c e n t ) and h i g h P205, (0.6 to 1.1 p e r c e n t ) . The b a s i c t u f f i s c h a r a c t e r i z e d by abundant o r t h o c l a s e , p l a g i o c l a s e , c h l o r i t e and b i o t i t e . I t i s c o m p o s i t i o n a l l y q u i t e homogeneous but l i t h o l o g i c a l l y and t e x t u r a l l y v a r i a b l e as i l l u s t r a t e d by f o l l o w i n g d e s c r i p t i o n s . 77-85E M a c r o s c o p i c D e s c r i p t i o n - Very f i n e - g r a i n e d , w e l l - f o l i a t e d f e l d s p a r , c h l o r i t e , e p i d o t e s c h i s t i s d ark g r e e n on f r e s h s u r f a c e and i s g r e y to g r e e n on w e a t h e r e d s u r f a c e . Page 183 M i c r o s c o p i c D e s c r i p t i o n -M i n e r a l o g y 30 - 40% PF - as f i n e i r r e g u l a r g r a i n s and f r a c t u r e d and a n n e a l e d a g g r e g a t e s 20 - 25% EP - i r r e g u l a r , e l o n g a t e d masses p a r a l l e l i n g the f o l i a t i o n , r e p l a c e PF and m a t r i x 12 - 15% CL - p a r a l l e l s the f o l i a t i o n , o c c u r s w i t h and r e p l a c e s TA 4 - 5% TA - has a s s o c i a t e d opaques, p a r a l l e l s the f o l i a t i o n , forms p o l y g o n a l a r c s 3 - 4% CB - as p o i k i l o b l a s t i c b l e b s r e p l a c i n g PF and m a t r i x 2 - 3% QZ - f i n e a n n e a l e d a g g r e g a t e s w i t h u n d u l o s e e x t i n c t i o n 2% OP 1% B l - a s s o c i a t e d w i t h CL D i s c u s s i o n - The v e r y f i n e - g r a i n e d n a t u r e of the. r o c k and l a c k r e l i c t c r y s t a l s s u g g e s t s a t u f f a c e o u s o r i g i n . 77 - 18 Page 184 M a c r o s c o p i c D e s c r i p t i o n - W e l l - f o l i a t e d c h l o r i t e , f e l d s p a r s c h i s t w i t h l a r g e (2 to 3 mm) f l a t t e n e d c h l o r i t e c l o t s and f i n e f e l d s p a r p h e n o c r y s t s i n a f i n e dark m a t r i x . P y r i t e i s abundant as cubes and f l a t t e n e d b l e b s . M i c r o s c o p i c D e s c r i p t i o n -M i n e r a l o g y 40 - 45% PF - s u b i d i o m o r p h i c g r a i n s a r e both p a r a l l e l and p e r p e n d i c u l a r the f o l i a t i o n ; bent and f r a c t u r e d t w i n s a r e common; r e p l a c e d by SE and CB 10 - 12% CB - r e p l a c e s PF; f l a t t e n e d i n the f o l i a t i o n 8 - 10% CL - p a r a l l e l s the f o l i a t i o n ; i n t e r g r o w n w i t h B l 6 - 8% B l - w i t h CL i n augen-shaped c l o t s ; a l s o w i t h f i n e SE 8 - 10% SE - p a r a l l e l s the f o l i a t i o n and forms p o l y g o n a l a r c s 6 - 8% KF - f i n e g r a i n e d m a t r i x 4 - 5% EP - f i n e , 1-2 mm, augen-shaped b o d i e s s u r r o u n d e d by CL 1 - 2% OP Page 185 D i s c u s s i o n - P o s s i b l e , c r u d e l a y e r i n g i s e v i d e n t . Augen-shaped masses of CL, BI and EP p r o b a b l y pseudomorph a m a f i c m i n e r a l . 77-185E M a c r o s c o p i c D e s c r i p t i o n - Rock i s a c o a r s e - b l a d e d f e l d s p a r , s e r i c i t e s c h i s t w i t h 10 to 12 mm l o n g s u b i d i o m o r p h i c p l a g i o c l a s e l a t h e s i n a w e l l f o l i a t e d CL, SE, KF and PF m a t r i x . Sodium c o b a l t i n i t r i t e s t a i n i n g i n d i c a t e s the p r e s e n c e of K - f e l d s p a r . The r o c k i s grey to g r e e n w i t h abundant l i m o n i t i c s t a i n i n g on f r e s h and w e a t h e r e d s u r f a c e . M i c r o s c o p i c D e s c r i p t i o n -M i n e r a l o g y 25 - 30% PF - a l b i t i c i n c o m p o s i t i o n and r e p l a c e d by s e r i c i t e and c a r b o n a t e . A l b i t e t w i n s a r e bent and f r a c t u r e d . 20 - 22% SE - p a r a l l e l s the f o l i a t i o n ; g r a i n s a r e bent and r e c r y s t a l l i z e d as p o l y g o n a l a r c s 15 - 20% KF - v e r y f i n e comminuted g r a i n s , SE a l t e r a t i o n common Page 186 10 - 11% CL - i n t e r g r o w n w i t h B l 7 - 8% B l - g e n e r a l l y p a r a l l e l the f o l i a t i o n ; o c c u r s w i t h or r e p l a c e s CL; CL and pseudoraorph m a f i c m i n e r a l 5 - 6% CB - r e p l a c i n g PF and f i n e m a t r i x 1 - 2% OP - g e n e r a l l y w i t h BI-CL c l o t s 1 - 2% EP - f i n e b l e b s i n PF D i s c u s s i o n - CL and B l appear to r e p l a c e o r i g i n a l m a f i c g r a i n s T e x t u r e s s u g g e s t CL and B l a r e s y n k i n e m a t i c . 7 - 183C (B.4) M a c r o s c o p i c D e s c r i p t i o n - W e l l - l a y e r e d , w e l l - f o l i a t e d , f e l d s p a c h l o r i t e s c h i s t w i t h augen-shaped f e l d s p a r s or f e l d s p a r a g g r e g a t e s i n a f i n e c h l o r i t i c m a t r i x . L i m o n i t i c s t a i n i n g i s comon . M i c r o s c o p i c D e s c r i p t i o n -M i n e r a l o g y 45 - 50% PF - augen-shaped g r a n u l a r a g g r e g a t e s a r e r e p l a c e d by CB and SE, c o m p o s i t i o n i s a l b i t i c Page 187 15 - 18% CL - p a r a l l e l s the f o l i a t i o n ; i n the m a t r i x 10 - 12% SE - r e p l a c e s PF and m a t r i x , p a r a l l e l s the f o l i a t i o n 2 - 3% CB - i r r e g u l a r p o i k i l o b l a s t i c b l e b s i n PF and m a t r i x 2 - 3% CL - o c c u r s w i t h BI 1 - 2% OP D i s c u s s i o n ' - The r o c k i s p r o b a b l y a c r y s t a l t u f f . I t i s w e l l -f o l i a t e d w i t h many PF g r a i n s r o t a t e d i n t o the p l a n e of the f o l i a t i o n . C l o t s of TA, CL, BI EP OP p r o b a b l y pseudomorph o r i g i n a l m a f i c m i n e r a l s . 78-345 M a c r o s c o p i c D e s c r i p t i o n - C o a r s e - b l a d e d f e l d s p a r w i t h 1 to 7 mm s u b h e d r a l f e l d s p a r l a t h e s and f i n e dark g r e e n c l o t s i n a f i n e c h l o r i t e m a t r i x . P l a g i o c l a s e i s e x t e n s i v e l y r e p l a c e d by e p i d o t e . M i c r o s c o p i c D e s c r i p t i o n -Page 188 M i n e r a l o g y - 30 - 35% SE - v e r y f i n e g r a i n s p a r a l l e l the f o l i a t i o n 25 - 30% PF - f i n e to c o a r s e s u b h e d r a l l a t h e s r e p l a c e d by SE and EP; bent and f r a c t u r e d a l b i t e t w i n s common 15 - 18% TA - o c c u r s w i t h BI and CL as i r r e g u l a r masses 10 - 12% EP - r e p l a c e s PF and m a t r i x as i r r e g u l a r b l e b s 5 - 6% CL - w i t h BI and TA i n masses 5 - 6% BI - w i t h TA and BI pseudomorphing o r i g i n a l m a f i c s 3 - 4% CB - p o i k i l o b l a s t i c b l e b r e p l a c i n g PF , m a t r i x and m a f i c s 1 - 2% OP D i s c u s s i o n - Rock i s p r o b a b l e o r i g i n a l f l o w or t u f f . Most PF g r a i n s are r o t a t e d i n t o the f o l i a t i o n . TA may be syn to p o s t - k i n e m a t i c as i t both p a r a l l e l s and c r o s s c u t s the f o l i a t i o n 77-345A M a c r o s c o p i c D e s c r i p t i o n - C o a r s e - b l a d e d f e l d s p a r , h o r n b l e n d e Page 189 c r y s t a l t u f f w i t h 1 to 10 f i n e c h l o r i t i c m a t r i x . mm r e l i c t PF and f i n e dark c l o t s i n a M i c r o s c o p i c D e s c r i p t i o n -M i n e r a l o g y - 30 - 35% PF -25 - 30% SE -18 - 20% EP -15 - 20% HB -8 - 10% B l -2 - 3% CL -1 - 2% OP a l m o s t c o m p l e t e l y r e p l a c e d by SE and EP r e p l a c e s f i n e m a t r i x and PF w i t h EP, HB and CL i r r e g u l a r and f l a t t e n e d b l e b s d e f l e c t i n g the f o l i a t i o n p seudomorphing o r i g i n a l m a f i c s w i t h o c c u r s w i t h and f r i n g i n g HB o c c u r s w i t h B l D i s c u s s i o n - Rock i s w e l l - f o l i a t e d w i t h no a p p a r e n t l a y e r i n g O r i g i n a l m a f i c g r a i n s a r e pseudomorphed by HB, CL, B l and EP 78-345D M a c r o s c o p i c D e s c r i p t i o n - A u g i t e , f e l d s p a r p o r p h y r y or c r y s t a l Page 190 t u f f w i t h 1 to 3 mm dark c l o t s and f i n e (1 mm) PF g r a i n s i n a l i g h t g r e y to g r e e n m a t r i x . F i n e c a r b o n a t e b l e b s o c c u r s t h r o u g h o u t . M i c r o s c o p i c D e s c r i p t i o n -M i n e r a l o g y - 30 - 35% PF - f i n e g r a i n s i n m a t r i x r e p l a c e d by SE, CB and CL 30 - 35% SE - r e p l a c e s PF and m a t r i x 10 - 12% CB - p o i k i l o b l a s t i c b l e b s r e p l a c i n g PF and m a t r i x has a s s o c i a t e d OP, CL and BI 8 - 10% CL - o c c u r s w i t h BI pseudomorphing m a f i c g r a i n s 8 - 10% BI - w i t h CL as e l o n g a t e d c l o t s 2 - 3% OP - i r r e g u l a r b l e b s and w i t h CB p a r a l l e l the f o l i a t i o n D i s c u s s i o n - The r o c k i s w e l l - f o l i a t e d , n o n - l a y e r e d . O r i g i n a l g r a i n s e x h i b i t a h i g h degree of r e p l a c e m e n t . Page 191 TUFF AND ARGILLITE HORIZON T u f f and a r g i l l i t e i s l i t h o l o g i c a l l y v a r i e d sequence c h a r a c t e r i z e d by w e l l - d e v e l o p e d l a y e r i n g . L i t h o l o g i e s i n c l u d e v e r y f i n e q u a r t z , f e l d s p a r , s e r i c i t e s c h i s t ; f i n e c h l o r i t e , f e l d s p a r s c h i s t ; b l a c k to g r e e n s h a l e and s i l t s t o n e w i t h or w i t h o u t f i n e to c o a r s e i n t e r l a y e r e d q u a r t z i t e , c a l c a r e o u s l e n s e s s e r i c i t e s c h i s t and greywacke. D i s s e m i n a t e d p y r i t e and l i m o n i t i c box work a f t e r p y r i t e a r e common. In t h i n s e c t i o n a l l r o c k s a r e f o l i a t e d . C h l o r i t e and s e r i c i t e w i t h l e s s e r c a r b o n a t e and e p i d o t e a r e common s e c o n d a r y m i n e r a l s r e p l a c i n g q u a r t z , f e l d s p a r and f i n e m a f i c g r a i n s . Sample d e s c r i p t i o n s f o l l o w . S-77-56-7598 M a c r o s c o p i c D e s c r i p t i o n - W e l l - f o l i a t e d , b l a c k a r g i l l i t e i s i n t e r l a m i n a t e d w i t h .5 to 1.5 mm w h i t e q u a r t z o - f e l d s p a t h i c l a m i n a e . C o a r s e r l a y e r s a r e commonly l e n s o i d . P y r i t e and p y r r h o t i t e o c c u r a l o n g the f o l i a t i o n . Page 192 M i c r o s c o p i c D e s c r i p t i o n -M i n e r a l o g y - 1 2% up t o 15% - Opaques i n some l a y e r s 6 8% SE 75 85% QA, PF, KF ( d e p e n d i n g on o t h e r m i n e r a l p e r c e n t a g e s w i t h i n l a y e r s ) 2 3% CB D i s c u s s i o n - A l l g r a i n s show e x t r e m e f l a t t e n i n g and 120 d e g r e e i n t e r g r a i n a n g l e s s u g g e s t i v e o f a n n e a l i n g . The a v e r a g e g r a i n s i z e i s .05 mm. S e r i c i t e p a r a l l e l s t h e f o l i a t i o n and f o r m s p o l y g o n a l a r c s where f o l d e d . The c o n c e n t r a t i o n o f opaque m i n e r a l s v a r i e s m a r k e d l y i n d i f f e r e n t l a y e r s . C a r b o n a t e o c c u r s as p o i k i l o b l a s t i c rhombs and as v e i n s b o t h p a r a l l e l and p e r p e n d i c u l a r t o t h e f o l i a t i o n . 77-195A (A. 17) M a c r o s c o p i c D e s c r i p t i o n - V e r y f i n e , w e l l - f o l i a t e d c h l o r i t e , c a r b o n a t e , s e r i c i t e s c h i s t i s i n t e r l a y e r e d w i t h b a s i c t u f f . The r o c k i s brown t o m o t t l e d g r e e n w i t h l i m o n i t i c b l e b s on f r e s h and w e a t h e r e d s u r f a c e s . E l o n g a t e b l e b s o f c a r b o n a t e p a r a l l e l t h e f o l i a t i o n . Page 193 M i c r o s c o p i c D e s c r i p t i o n -M i n e r a l o g y - 15 - 20% CL - as t h i n l e n s e - l i k e s h e e t s 20 - 22% SE - as f e l t e d masses w i t h c h l o r i t e and r e p l a c i n g PF; g r a i n s a r e g e n e r a l l y bent 20 - 22% CB - as e l o n g a t e d b l e b s commonly w i t h L I , some g r a i n s a r e bent 15 - 20% QZ - shows u n d u l o s e e x t i n c t i o n w i t h l i t t l e a p p a r e n t a l t e r a t i o n 10 - 15% PF and KF d i f f i c u l t to d i s t i n g u i s h due to f i n e g r a i n e d n a t u r e 2 - 3% Opaques - g e n e r a l l y s u b h e d r a l p y r i t e D i s c u s s i o n - The t e x t u r e and m i n e r a l o g y s u g g e s t r o c k i s a f i n e g r a i n e d , c a l c a r e o u s t u f f . Q u a r t z and f e l d s p a r g r a i n s a r e o f t e n p a r t i a l l y a n n e a l e d . Some c a r b o n a t e i s a l m o s t c e r t a i n l y p r i m a r y w h i l e o t h e r b l e b s a r e p o r p h y r o b l a s t i c and s e c o n d a r y . 77-185G (A. 11) M a c r o s c o p i c D e s c r i p t i o n - W e l l - l a y e r e d , w e l l - f o l i a t e d , f i n e q u a r t z , f e l d s p a r , c h l o r i t e , s e r i c i t e s c h i s t i s i n t e r l a y e r e d w i t h Page 194 v e r y f i n e t u f f or mudstone. F i n e c h l o r i t e and c a r b o n a t e p a r t i n g s p a r a l l e l the f o l i a t i o n . D i s s e m i n a t e d p y r i t e i s f l a t t e n e d i n the f o l i a t i o n . M i c r o s c o p i c D e s c r i p t i o n -M i n e r a l o g y - 25% QZ u n d u l o s e e x t i n c t i o n , f r a c t u r e d and g e n e r a l l y i n f i n e m a t r i x 25 - 30% PF "- some r e l i c t t w i n n i n g , g e n e r a l l y r e p l a c e d by SE, v e r y low r e l i e f s u g g e s t PF i s a l b i t i c i n c o m p o s i t i o n 15 - 20% SE - r e p l a c e s FP and f i n e m a t r i x , o c c u r s s u b p a r a l l e l and a t 45. degree a n g l e s to the f o l i a t i o n 10 - 12% KF - some u n d u l o s e e x t i n c t i o n , l i t t l e s e r i c i t i z a t i o n 7 - 8% CB - p o i k i l o b l a s t i c r e p l a c i n g QZ, PF, KF and m a t r i x 1% EP - as f i n e a l t e r a t i o n of m a t r i x 1% r o c k f r a g m e n t s 1% opaques D i s c u s s i o n - G r a i n s a r e g e n e r a l l y comminuted, a n n e a l e d g r a n u l a r a g g r e g a t e s . L a r g e r g r a i n s have augen s h a p e s . Page 195 CONGLOMERATE Co n g l o m e r a t e i s i n t e r c a l a t e d w i t h and i n p a r t a f a c i e s e q u i v a l e n t of t u f f and a r g i l l i t e , and caps the Kutcho F o r m a t i o n . I t i s l a r g e l y composed of c l a s t s d e r i v e d from i m m e d i a t e l y u n d e r l y i n g v o l c a n i c r o c k s and t h e m a t r i x c o m p o s i t i o n does not d i f f e r m a r k e d l y from i n t e r m e d i a t e to a c i d i c t u f f s . L e n s e s of l i m e s t o n e , b a s i c s c h i s t , t u f f , a r g i l l i t e and sand a r e i n t e r c a l a t e d t h r o u g h o u t . C l a s t s range from 0.5 t o 12 cm i n d i a m e t e r and i n c l u d e w h i t e to gr e e n q u a r t z - e y e , s e r i c i t e s c h i s t ; s e r c i c i t e s c h i s t ; q u a r t z - e y e , f e l d s p a r , s e r i c i t e s c h i s t ; l e s s e r c h l o r i t e s c h i s t ; c a r b o n a t e and q u a r t z i t e . A m a t r i x of q u a r t z , f e l d s p a r , s e r i c i t e and c h l o r i t e c o m p o s i t i o n c l o s e l y a p p r o x i m a t e s t h a t of a c i d i c c r y s t a l t u f f s . C l a s t s a r e h i g h l y a t t e n u a t e d and e l o n g a t e d i n the p l a n e of the f o l i a t i o n and a l t h o u g h c r u d e l a y e r i n g i s o b s e r v e d i t i s o f t e n o b s c u r e d by the w e l l - d e v e l o p e d f o l i a t i o n . In w e s t e r n e x t e n t s of the b e l t much of the c o n g l o m e r a t e and i n t e r l a y e r e d t u f f and s a n d s t o n e have a c h a r a c t e r i s t i c r e d to p u r p l e c o l o u r to t h e i r m a t r i c e s . P e t r o g r a p h i c d e s c r i p t i o n s of e x e m p l e t o r y samples f o l l o w . Page 196 77-99E (A. 9) M a c r o s c o p i c D e s c r i p t i o n - C o n g l o m e r a t e of the Kutcho F o r m a t i o n i s i n t e r l a y e r e d w i t h r e d t u f f a c e o u s r o c k s i n the w e s t e r n p a r t of the map a r e a . C l a s t s a r e e l o n g a t e d p a r a l l e l the f o l i a t i o n and commonly f r a c t u r e d p e r p e n d i c u l a r to i t . C l a s t l i t h o l o g i e s i n c l u d e q u a r t z - e y e , s e r i c i t e s c h i s t ; a r g i l l i t e ; l a r g e q u a r t z g r a i n s ; c h l o r i t e s c h i s t and range i n s i z e from 3 to 30 cm. The m a t r i x i s composed of f i n e , e p i d o t i z e d f e l d s p a r , c a r b o n a t e and t u f f a c e o u s m a t e r i a l . M i c r o s c o p i c D e s c r i p t i o n - In t h i n s e c t i o n many c l a s t s a r e e x t e n s i v e l y r e p l a c e d by e p i d o t e . C h l o r i t i c c l a s t s commonly have f i n e e p i d o t i z e d f e l d s p a r g r a i n s and opaques. E p i d o t e , c h l o r i t e and s e r i c i t e r e p l a c e much of the f i n e m a t r i x . M i n e r a l o g y - 4% CB - r e p l a c e s QZ and PF. 2 - 3% CL - r e p l a c e s m a t r i x 6 - 8% OP - g e n e r a l l y c o n c e n t r a t e d a l o n g g r a i n b o u n d a r i e s D i s c u s s i o n - C o a r s e q u a r t z and f e l d s p a r g r a i n s a r e f r a c t u r e d p a r a l l e l and p e r p e n d i c u l a r to the f o l i a t i o n . Many of t h e s e g r a i n s a r e p o l y c r y s t a l l i n e , a n n e a l e d a g g r e g a t e s . Page 197 \ / 77-151E M a c r o s c o p i c D e s c r i p t i o n - F i n e - g r a i n e d a r e n i t e i s o n l y p o o r l y f o l i a t e d , w e a thers w h i t e to grey and i s h i g h l y f r a c t u r e d and v e i n e d by q u a r t z . Rock i s h i g h l y l i m o n i t i c and s t a i n i n g w i t h sodium c o b a l t i n i t r i t e s u g g e s t s minor amounts of K - f e l d s p a r a r e p r e s e n t a l o n g f r a c t u r e s . M i c r o s c o p i c D e s c r i p t i o n -65 - 70% QZ - as v e r y f i n e e x t i n c t i o n 20 - 25% PF - KF 5 - 6% OP 1 - 2% SE - no p r e f e r r e d g r a i n i n t e r f a c e s D i s c u s s i o n - Q u a r t z and f e l d s p a r g r a i n s are w e l l - f o l i a t e d and f l a t t e n e d , g e n e r a l l y e x h i b i t 120 degree i n t e r g r a i n a n g l e s w i t h r a g g e d g r a i n b o u n d a r i e s . The a v e r a g e g r a i n s i z e i s from 0.1 to 0.2mm. Page 198 77-104 M a c r o s c o p i c D e s c r i p t i o n - S t r e t c h e d p e b b l e s and c o b b l e s l i e i n a w e l l - f o l i a t e d m a t r i x of l i m o n i t i c , s e r i c i t e s c h i s t . C l a s t s i n c l u d e c h l o r i t e s c h i s t , q u a r t z - e y e s c h i s t , q u a r t z i t e , c a r b o n a t e , q u a r t z " e y e s " and rounded e p i d o t e f r a g m e n t s . . M i c r o s c o p i c D e s c r i p t i o n - Both m a t r i x and c l a s t s a r e e x t e n s i v e l y r e p l a c e d by s e r i c i t e t h a t i s o r i e n t e d both p a r a l l e l and a t 45 degree a n g l e s to the f o l i a t i o n . Q u a r t z - f e l d s p a r f r a g m e n t s e x h i b i t some g r a p h i c t e x t u r e and q u a r t z shows e v i d e n c e of c omminution, s m e a r i n g of g r a i n s i n the f o l i a t i o n and a n n e a l i n g of comminuted g r a i n s . M a t r i x and c l a s t s a r e v e r y p y r i t i c . C h l o r i t i c f r a g m e n t s may c o n t a i n up to 10% d i s s e m i n a t e d p y r i t e . 77-100C (A. 9) M a c r o s c o p i c D e s c r i p t i o n - Q u a r t z - e y e s e r i c i t e s c h i s t f r a gment from c o n g l o m e r a t e . S c h i s t o s i t y i s w e l l - d e v e l o p e d and i s warped around 1-4 mm s u b r o u n d e d q u a r t z eyes and l e s s e r p l a g i o c l a s e c r y s t a l s . The r o c k w e a t h e r s w h i t e to b u f f and i s m o t t l e d g r e y on the f r e s h s u r f a c e . P o t a s s i u m s t a i n i n g i n d i c a t e s minor amounts of K - f e l d s p a r . Page 199 M i c r o s c o p i c D e s c r i p t i o n -M i n e r a l o g y - 35 - 40% QZ - f r a c t u r e d to a n n e a l e d g r a i n s w i t h u n d u l o s e e x t i n c t i o n 30% PF - a l b i t i c , r e p l a c e d by SE, EP +- CB, bent t w i n l a m e l l a e 12 - 14% SE - r e p l a c e s FP and QZ, gen p a r a l l e l s f o l i a t i o n 3 - 4% KF - h i g h l y f r a c t u r e d 77-196D M a c r o s c o p i c D e s c r i p t i o n - I n t e r l a y e r e d c o n g l o m e r a t e and c a r b o n a t e has f l a t t e n e d and e l o n g a t e d 1 to 10 cm s i z e s c l a s t s of q u a r t z - e y e , s e r i c i t e s c h i s t ; c h l o r i t e , s e r i c i t e s c h i s t and s e r i c i t e s c h i s t i n f i n e m a t r i x of same. C a r b o n a t e i s common as m a t r i x and l e n s e s . M i c r o s c o p i c D e s c r i p t i o n -M i n e r a l o g y - 40 - 45% CB - as c r y s t a l l i n e masses, g r a i n s a r e commonly bent 15 - 20% PF - as c r y s t a l l i n e a g g r e g a t e s and Page 200 i n d i v i d u a l g r a i n s commonly a l t e r e d by CB 12 - 15% QZ - as f i n e 1 mm g r a i n s , a l s o minor m i c r o g r a p h i c i n t e r g r o w t h s w i t h FP 10 - 12% SE - commonly as a l t e r a t i o n of QZ and FP, l e s s e r amounts i n CB m a t r i x 1 - 2% OP - g e n e r a l l y i n CB m a t r i x , o f t e n r i m c l a s t s D i s c u s s i o n - Most f r a c t u r e d g r a i n s a r e a n n e a l e d . Page 201 INKLIN FORMATION The I n k l i n F o r m a t i o n i s c h a r a c t e r i z e d by a sequence of i n t e r c a l a t e d greywacke, gre y to b l a c k s h a l e and s i l t s t o n e and b l a c k p h y l l i t e w i t h some i n t e r c a l a t e d c o n g l o m e r a t e l e n s e s . A b a s a l c o n g l o m e r a t e i s common. D i s s e m i n a t e d p y r i t e i s u b i q u i t o u s . In the Cry Lake map a r e a i t i s d i f f i c u l t to d i s t i n g u i s h b a s a l I n k l i n c o n g l o m e r a t e from upper Kutcho c o n g l o m e r a t e where Sinwa l i m e s t o n e i s a b s e n t . 77-001 ( E . 2) M a c r o s c o p i c D e s c r i p t i o n - W e l l - f o l i a t e d , p o o r l y l a y e r e d , grey to dark g r e e n greywacke w i t h c o a r s e (2-3 mm) q u a r t z and f e l d s p a r g r a i n s and mud c h i p s common. S t a i n i n g w i t h sodium c o b a l t i n i t r i t e i n d i c a t e s the p r e s e n c e of moderate amounts of o r t h o c l a s e . M i c r o s c o p i c D e s c r i p t i o n -M i n e r a l o g y - 30% QZ - comminuted and f r a c t u r e d g r a i n s show u n d u l o s e e x t i n c t i o n and some e v i d e n c e of r e c r y s t a l l i z a t i o n 20% SE - v e r y f i n e g r a i n s p a r a l l e l the Page 202 f o l i a t i o n 15% PF - g r a i n s a r e comminuted and r e p l a c e d by s e r i c i t e , low e x t i n c t i o n a n g l e s and r e l i e f s u g g e s t an a l b i t i c c o m p o s i t i o n 8 - 10% EP - f i n e ( g r e a t e r than .01 mm) g r a i n s d i s s e m i n a t e d t h r o u g h o u t r o c k 1 - 2% CB - f i n e f l a t t e n e d g r a i n s 1 - 2% CL - as t h i n l a y e r s and l e n s e s r e p l a c i n g mud c h i p s l e s s t h a n 1% B l - w i t h CL D i s c u s s i o n - Q u a r t z and f e l d s p a r g r a i n s a r e commonly augen- shaped and a l l m i n e r a l s show a s t r o n g a l i g n m e n t p a r a l l e l the f o l i a t i o n . 78-329A M a c r o s c o p i c D e s c r i p t i o n - Green to b u f f or t a n w e a t h e r i n g , p o o r l y f o l i a t e d I n k l i n c o n g l o m e r a t e c o n t a i n s c l a s t s of f i n e q u a r t z - e y e , s e r i c i t e s c h i s t ; a u g i t e p o r p h y r y and f e l d s p a t h i c c h l o r i t e s c h i s t i n a t u f f a c e o u s m a t r i x of f e l d s p a r , c h l o r i t e , q u a r t z and s e r i c i t e . C l a s t s a r e s u b a n g u l a r , range i n s i z e from 1 to 8 cm and a r e s l i g h t l y f l a t t e n e d i n the f o l i a t i o n . Page 203 M i c r o s c o p i c D e s c r i p t i o n - Both c l a s t s and m a t r i x a r e c o m p o s i t i o n a l l y s i m i l a r . The m a t i x c o m p o s i t i o n i s a u g i t e , f e l d s p a r , d e v i t r i f i e d g l a s s , e p i d o t e and minor c h l o r i t e and c a r b o n a t e . 77-152 M a c r o s c o p i c D e s c r i p t i o n - C o n g l o m e r a t e of the I n k l i n F o r m a t i o n w e athers grey-brown c o n t a i n s 1 to 4 cm l o n g c l a s t s of q u a r t z - e y e , s e r i c i t e s c h i s t ; c o a r s e f e l d s p a r , s e r i c i t e s c h i s t ; f i n e p l a g i o c l a s e s c h i s t ; b l a c k a r g i l l i t e ; e p i d o t i z e d q u a r t z , f e l d s p a r p o r p h y r y ; a u g i t e p o r p h y r y and b l ded f e l d s p a r p o r p h y r y i n a f i n e greywacke m a t r i x . C l a s t s a r e e l o n g a t e d p a r a l l e l to the f o l i a t i o n and f r a c t u r e d p e r p e n d i c u l a r to i t . Page 204 INTRUSIVE ROCKS B l a i r V o l c a n i c Dykes M a c r o s c o p i c D e s c r i p t i o n - Dyke r o c k s a r e h o r n b l e n d e , q u a r t z , p l a g i o c l a s e p o r p h y r i e s . Rocks v a r y from m a s s i v e to p o o r l y f o l i a t e d . When f o l i a t e d , f o l i a t i o n p a r a l l e l s t h a t of the Kutcho c o u n t r y r o c k s . Q u a r t z i s g e n e r a l l y a m e t h y s t i n e . Page 205 SINWA FORMATION L i m e s t o n e of the Sinwa F o r m a t i o n v a r i e s from 0 to 250 i n t h i c k n e s s . I t g e n e r a l l y caps and i s i n t e r c a l a t e d w i t h upper p a r t of the c o n g l o m e r a t e and t u f f and a r g i l l i t e of the Kutcho s e q u e n c e . I t i s a f e t i d , p o o r l y to n o n - f o s s i l i f e r o u s g r e y l i m e s t o n e to m a r b l e . B e d d i n g i s r a r e l y o b s e r v e d and i s t h o u g h t be masked by the w e l l d e v e l o p e d f o l i a t i o n . Page 206 CACHE CREEK GROUP The Cache Creek Group i s a v a r i e d assemblage of o c e a n i c r o c k s i n c l u d i n g b a s i c to i n t e r m e d i a t e v o l c a n i c f l o w s and t u f f s , c h e r t and a r g i l l i t e , c a r b o n a t e and u l t r a m a f i c r o c k s (Monger, 1975). In o u t c r o p v o l c a n i c r o c k s of the Cache Cr e e k Group c l o s e l y r e s e m b l e more b a s i c r o c k s of the Kutcho s u i t e but can be d i s t i n g u i s h e d by the p r e s e n c e of two d i s t i n c t c l e a v a g e s . P e t r o g r a p h i c a l l y i t i s d i f f i c u l t to s e p a r a t e the two v o l c a n i c s u i t e s . V o l c a n i c r o c k s of the Cache Creek Group appear to be more e x t e n s i v e l y a l t e r e d but v a r y i n g d e g r e e s of a l t e r a t i o n a r e p r e s e n t i n both r o c k s . Sample d e s c r i p t i o n s of v o l c a n i c r o c k s f o l l o w . 77-159B (G. 5) M a c r o s c o p i c D e s c r i p t i o n - W e l l - f o l i a t e d , p a l e g r e e n w e a t h e r i n g , f e l d s p a t h i c , c h l o r i t e , s e r i c i t e s c h i s t . S m a l l c h l o r i t i c b l e b s a r e common. Sodium c o b a l t i n i t r i t e s t a i n i n g i n d i c a t e s v e r y minor amounts of K - f e l d s p a r . The r o c k i s h i g h l y f r a g m e n t a l w i t h 3-6 cm Page 207 f r a g m e n t s i n m a t r i x of the same c o m p o s i t i o n . M i c r o s c o p i c D e s c r i p t i o n -M i n e r a l o g y - 60 - 65% PF - g e n e r a l l y h i g h l y a l t e r e d to'EP + SE; a l b i t i c ; r e l i c t t w i n n i n g e v i d e n t ; some " f r e s h " f e l d s p a r s may be p o r p h y r o b l a s t i c 12 - 15% CL - as i r r e g u l a r b l e b s p a r a l l e l the f o l i a t i o n 10 - 12% EP - r e p l a c i n g FP and m a f i c m i n e r a l s 8 - 10% TA - as r a d i a t i n g s h e a t h s w i t h CL r e p l a c i n g m a f i c m i n e r a l s 1 - 2% SE - r e p l a c i n g FP 1 - 2% OP D i s c u s s i o n - T e x t u r e s s u g g e s t r o c k i s a f i n e t u f f or b r e c c i a w i t h r e l i c t f r a g m e n t s of PF, CL and TA i n f i n e m a t r i x of TA, CL and EP. 77-159E (G. 4) M a c r o s c o p i c D e s c r i p t i o n - A l t e r e d and b l e a c h e d , t a n to green w e a t h e r i n g , e p i d o t i z e d f i n e g r a i n e d v o l c a n i c . Very f i n e ( l e s s Page 2Q8 than 1 mm ) FP c r y s t a l s and c h l o r i t e " b l e b s " are e v i d e n t . The r o c k i s c u t by numerous q u a r t z v e i n l e t s . M i c r o s c o p i c D e s c r i p t i o n -M i n e r a l o g y - 30 - 35% EP - as i r r e g u l a r b l e b s 25 - 30% CL - o c c u r s w i t h EP i n i r r e g u l a r shaped c l o t s 10 - 12% TA - as randomly o r i e n t e d f e l t e d masses 10 - 25% FP - v e r y f i n e g r a i n e d m i c r o l i t e s 3 - 4% OP 2 - 3% D e v i t r i f i e d g l a s s 1 - 2% Rock f r a g m e n t s - FP and EP g r a n u l a r a g g r e g a t e s D i s c u s s i o n - No f o l i a t i o n i s e v i d e n t . The r o c k i s h i g h l y a l t e r so o r i g i n a l t e x t u r e s have been d e s t r o y e d . 77-166E (G. 6) M a c r o s c o p i c D e s c r i p t i o n - F e l d s p a t h i c , c h l o r i t e s c h i s t has f i n e ( 1 mm) e p i d o t i z e d f e l d s p a r p h e n o c r y s t s i n a f i n e groundmass of c h l o r i t e and s e r i c i t e . Poor l a y e r i n g i s e v i d e n t . Page 209 M i c r o s c o p i c D e s c r i p t i o n -M i n e r a l o g y - 30 - 35% PF - f r a c t u r e d and a n n e a l e d g r a i n s 25 - 30% EP - 1-1.5 mm c l o t s pseudomorphing m i n e r a l g r a i n s ; some f l a t t e n i n g i n the f o l i a t i o n , but a l s o grows a c r o s s the f o l i a t i o n 20 - 22% CL 6 - 7% TA - forms p o l y g o n a l a r c s , grows i n f i r s t f o l i a t i o n and i n s e c o n d a r y c r e n u l a t i o n c l e a v a g e 6 - 7% CB - a s s o c i a t e d w i t h e p i d o t e , overgrows f o l i a t i o n 2 - 3% QZ - p a r t i a l l y r e p l a c e d by CB D i s c u s s i o n - Two w e l l - d e v e l o p e d c l e a v a g e s a r e e v i d e n t - a p r i m a r y f o l i a t i o n and a s e c o n d a r y c r e n u l a t i o n c l e a v a g e . R e l i c t l a y e r i n g i s a l s o e v i d e n t . E p i d o t e may be syn to p o s t - k i n e m a t i c as i t both p a r a l l e l s and grows over the f o l i a t i o n . Page 210 77-167D (G. 7) M a c r o s c o p i c D e s c r i p t i o n - F i n e (l-2mm) p a r t l y e p i d o t i z e d f e l d s p a r and c h l o r i t e c l o t s o c c u r i n a f i n e g r e y g r e e n m a t r i x . M i c r o s c o p i c D e s c r i p t i o n -M i n e r a l o g y - 45 - 50% PF - r e c r y s t a l l i z e d g r a n u l a r m o s a i c s ; some bent and f r a c t u r e d r e l i c t t w i n s ; a l b i t i c i n c o m p o s i t i o n 15 - 18% EP - r e p l a c e PF and may pseudomorph an amp h i b o l e 8 - 10% CL - i n masses w i t h T A m a y r e p l a c e TA a l o n g c l e a v a g e 10 - 11% TA - c r y s t a l s o f t e n p e r p e n d i c u l a r to the f o l i a t i o n 3 - 4% CB - as i r r e g u l a r b l e b s and s t r i n g e r s ; may s u r r o u n d OP 2 - 3% Op D i s c u s s i o n - Rock has a g e n e r a l f r a g m e n t a l a p p e a r a n c e . I t i s w e l l f o l i a t e d and most o r i g i n a l g r a i n s a r e h i g h l y r e p l a c e d . Page 211 77-172A M a c r o s c o p i c D e s c r i p t i o n - W e l l - l a y e r e d , w e l l - f o l i a t e d f e l d s p a r c r y s t a l t u f f w i t h f i n e 1 to 1.5 mm s u b h e d r a l p l a g i o c l a s e g r a i n s and c h l o r i t i c c l o t s i n f i n e g r e y - g r e e n m a t r i x . Numerous c a r b o n a t e v e i n s c u t t h e r o c k p a r a l l e l i n g the f o l i a t i o n . M i c r o s c o p i c D e s c r i p t i o n -M i n e r a l o g y - 50 - 55% FP - v e r y f i n e a n n e a l e d g r a n u l a r a g g r e g a t e s 18 - 20% CL 16 - 18% TA - commonly r a d i a t i n g masses 5 - 6% EP - c l o u d e d h i g h r e l i e f masses r e p l a c i n g FP 2 — 3% OP - a s s o c i a t e d w i t h CL 1 - 2% CB - o c c u r s w i t h CL i n QZ v e i n s D i s c u s s i o n - W e l l - d e f i n e d , which may be metamorphic i n o r i g i n l a y e r i n g i s e v i d e n t . Many v e i n s a r e f i n e g r a i n e d q u a r t z and f e l d s p a r . Page 212 77-195A (A. 17) M a c r o s c o p i c D e s c r i p t i o n - v e r y f i n e , w e l l - f o l i a t e d c h l o r i t e , c a r b o n a t e , s e r i c i t e s c h i s t i s i n t e r l a y e r e d w i t h b a s i c t u f f . The r o c k i s brown to m o t t l e d g r e e n w i t h l i m o n i t i c b l e b s on f r e s h and weathered s u r f a c e s . E l o n g a t e b l e b s of c a r b o n a t e p a r a l l e l the f o l i a t i o n . M i c r o s c o p i c D e s c r i p t i o n -M i n e r a l o g y - 15 - 20% CL - as t h i n l e n s - l i k e s h e e t s 20 - 22% SE - as f e l t e d masses w i t h c h l o r i t e and r e p l a c i n g PF; g r a i n s g e n e r a l l y bent 20 - 22% CB - as e l o n g a t e d b l e b s commonly w i t h L I 15 - 20% QZ - shows u n d u l o s e e x t i n c t i o n w i t h l i t t l e a p p a r e n t a l t e r a t i o n 10 - 15% PF and KF - d i f f i c u l t to d i s t i n g u i s h due to f i n e g r a i n e d n a t u r e 2 - 3% Opaques - g e n e r a l l y s u b h e d r a l p y r i t e D i s c u s s i o n - The t e x t u r e and m i n e r a l o g y s u g g e s t r o c k i s a f i n e g r a i n e d , c a l c a r e o u s t u f f . Q u a r t z and f e l d s p a r g r a i n s a r e o f t e n p a r t i a l l y a n n e a l e d . C a r b o n a t e a p p e a r s p r i m a r y and s e c o n d a r y . Page 213 I APPENDIX I I ROCK SAMPLE DESCRIPTIONS Page 214 TABLE II . 1 LOCATION, STRATIGRAPHIC UNIT, FIELD NAME ANO [RVINE-BARAGAR NAME FOR ROCKS OF THE KUTCHO FORMATION, CRY LAKE MAP-AREA Sample dumber Lat.(N.}/Lorrg.(W.) Stratigraphic Rock Unit Field Name Irvine-Baragar Name A.1 58° 137129° 07' Tuff and Argi l -l i te Chlorite -feldspar schist Calc-alkaline Basalt, High Al A.2 58° 147129° 00' S i l ic Schist Quartz-eye- sericitR Calc-alkaline Rhyolite, schist K-poor A.3 53° 11 7128° 50' Tuff and Argi l -l i te Chlorite - fe ldspar-epidote schist Calc-alkaline Basalt, K-rich, High Al A.4 58° 117128° 50' Tuff and Argi l -l i te Chlorite - fe ldspar-epidote schist Tholeiitic Basalt, K-poor A.5 58° 077128° 20' Tuff and Argi l -l i te Calcareous tuff Tholei i t i c Andesite, K-poor A.6 58° 097128° 23' Basic to Inter-mediate Tuff-8reccia Chlorite - feldspar-epidote schist Tholeiitic Basalt A. 7 S8° 077128° 20' S i l i c ic Schist Quartz-eye - fe ld -spar-chlorite-sericite schist Calc-alkaline -Rhyo 1 i te, K-poor A.8 58° 147129° 00' S i l i c ic Schist Chlorite-feldspar Calc-alkaline Basalt, schist with epidote K-poor, High Al clots A.9 58° 237129° 30' Conglomerate Matrix of conglom-erate quart?-feldsoar-st ,cite schist Calc-alkaline Rhyolite, K-poor A.10 ' 58° 127128° 24' S i l i c i c Schist Quartz-eye-sericite Calc-alkaline Rhyolite, schist K-rich A.11 68° 127128° 24' S i l i c ic Schist Quartz- feldspar -chlorite - sericite schist Calc-alka1ine Rhyolite, K-poor A.12 58° 117128° 20' S i l i c ic Schist Feldspai— quartz-eye-serici te-chlorite schist Tholeiitic Andesite, K-rich A.13 58° 127128° 24' S i l i c ic Schist Quartz-eye - feld-spar -sericite schist Calc-alkaline Rhyolite, K-poor A.14 58° 11 7128° 20' S i l i c ic Schist Quartz-eye-sericite Calc-alkaline Rhyolite schi st A.lb 58° 11 7128° 20' S i l i c i c Schist Quartz-eye-sericite Calc-alkaline Rhyolite schist K-rich A.16 68° 117128° 20' Breccia Feldspar -chlorite -sericite schist .Calc-alkaline Andesite, K-poor, H i g h Al . A.17 68° 117128° 20' Tuff and Argil -1 i te S i l ic ic tuff Tholeiitic Rhyolite A.18 58° 11 7128° 20' Tuff and Argi l -l i te Chlorite Schist Calc-alkaline 3asalt, K-poor, H i g h A l . A.19 68° 127129° 03' Tuff and Argi l -l i te Feldspar -chlori te -sericite schist •Tholei i t ic Basalt C i ' ^ s n i P I C A T I O M AFTER IRVINE AND BARAGAR ( 1976) Page 215 TABLE I I . 1 ( c o n t ' d . ) Sample plumber Lat.(N.)/long.(W.) Stratigraphic Rock Unit Field Name Irvine-Baragar Name A.20 58° H 7 1 2 9 0 02' A.21 53° 087128° 27' A.22 58° 25 7129° 44' A.23 58° 117128° 30' A.24 58° 247129° 49' A.25 58° 247129° 49' A.26 58° 24 7 129° 49' A.27 58° 107128° 15' A.28 58° 107128° 15' A.29 58° 117128° 20' A.30 58° 09 7128° 32' A.31 58° 137128° 24' A.32 53° 137128° 24' Tuff and A r g i l -l i t e Basic to inter-mediate Tuff-Breccia Tuff and A r g i l -l i t e S i l i c i c Schist Tuff and A r g i l -l i t e Tuff and A r g i l -l i t e Tuff and A r g i l -l i t e Tuff and A r g i l -l i t e S i l i c i c Schist Basic to Inter-mediate Tuff-Breccia Tuff-Argil l i t e Chlorite Schist S i l i c i c Schist Feldspar - c h l o r i t e Calc-alkaline Andesite, schist High A l . Chlorite -feldspar- Calc-alkaline 8asalt, epidote schist K-poor, High A l , Calc-alkaline Rhyolite, K-poor A.33 58° 117128° 22' S i l i c i c Schist A.34 58° 117128° 21' Basic to Inter-mediate Tuff-Breccia A.35 58° 117128° 21' Basic to Inter-mediate Tuff-Breccia A.36 58° 117128° 21' S i l i c i c Schist A.37 58° 127128° 21' Chlorite Schist A.38 58° 107 128° 35' S i l i c i c Schist Calcareous sand-stone Ferruginous Chert Poorly banded chert Feldspar-augite - T h o l e i i t i c Basalt chlorite schist C h l o r i t e - feldspar—Tholeiitic Basalt, epidote schist K-rich Quartz -feldspar - Calc-alkaline Dacite, chlorite-epidote K-poor schist Quartz- feldspar - Calc-alkaline Rhyolite s e r i c i t e schist K-poor Chlorite-feldspar Calc-alkaline -Andesite, schist S i l i c i c t u ff Chlorite -Seriate Schist Quartz-eye - f e l d -spar -chlorite -se r i c i t e schist Quartz-eye - f e l d -spar-sericite schist Chlorite - feldspar epidote schist K-poor, High A l . Calc-alkaline Dacite, K-poor T h o l e i i t i c Andesite, K-rich Calc-alkaline Dacite, K-poor Calc-alkaline Rhyolite, K-poor •Tholeiitic Basalt, K-poor Chlorite - epidote- Calc-alkaline Basalt, feldspar schist K-poor, High A l . Quartz-eye - f e l d - Calc-alkaline Rhyolite, spar—sericite K-poor schist Chlorite - feldspar T h o l e i i t i c Basalt, schist K-rich Epidote~ chloriteT Calc-alkaline Dacite, feldspar>- s e r i c i t e K-poor schist Page 216 TABLE I I . 1 (cont'd.) Sample Number la t . (N. ) / tong. (W.) Strat igraphic Rock Unit F i e l d Name Irvine-8aragflr Name A. 39 A. 40 A.41 A.42 A.43 A. 44 A. 43 A. 46 A.47 A.48 A.49 A.50 A.51 A.52 A.53 A.54 A.a5 A.56 58 u 107128" 58° 097128° 58° 117128° 58° 117128° 58° 10' 307 128° 18' 58° 10' 207 128° 13' 38° 10' 1U7 128° 18' 58° 10' 05"/ 128° 18' 58° 107128° 58° 10' 057 128° 2T 58° 127128° 58° 127128° 58° 127128° 58° 127128° 58° 12' 30"/ 128° 23" 58° 117128° 35' 8asic to In ter-mediate Tuff-Breccia 35' Basic to Inter-mediate Tuff-Breccia 23' S i l i c i c Schist 18' Basic to Inter-mediate Tuff-Breccta Basic to I n t e r -mediate Tuff-8reccia Tuff A r g i l l i t e Basic to Inter-mediate t u f f S i l i c i c Schist 21' S i l i c i c Schist Basic to In ter -mediate Tuff-Breccia S i l i c i c Schist S i l i c i c Schist S i l i c i c Schist S i l i c i c Schist S i l i c i c Schist Basic to In ter-mediate Tuff-8reccia Basic to Inter-mediate Tuff-Breccia 20' 20' 20' 20' 23" 24" 58° 117123° 58° 117128° 16" S i l i c i c Schist Feldspar -ch lo r i te -Ca lc -a lka l ine basalt , epidote schist k-poor, High Al . Chlori te -ep ido te - Tho le i i t i c Basalt t remol i te- K-rich ac t ino l i t e schist Quartz-eye - f e l d s p a r -se r i c i t e schist Hanging Wall Unit* Chlori te - s e r i c i t e schist Feldspathic chlor-i t e schist Siliceous t u f f Chlorite-epidote schist Rhyolite dike or * s i l l Quartz - feldspar "trondhjemite"* ch lo r i te - se r ic i te schist Rare quartz and fe ld-spar, carbonate* metacrysts Very f ine feldspar crysta ls* Layered* Altered basalt* Chlorite Schist Basalt flow* Quartz-eye - se r i - * c i te schist Quartz-eye-feldspar * ser ic i te schist Quartz-eye - ser i-c i te schist Oolomi t i c , Hanging wal Siliceous ser ic i te no quartz eyes* schist Quartz-feldspar-ser ic i te schist Chlorite schist Feldspathic chlo-r i t e schist c last from hanging wall fragmental* Quartz - feldspar ser ic i te schist *) DATA FROM A. PANTELEYEV (pers. comm., 1977 very coarse grained* Page 217 TA8LE I I . 2 LOCATION, FIELD NAME AND IRVINE-BARAGAR NAME FOR ROCKS OF THE BASIC SCHIST-KUTCHO FORMATION, CRY LAKE MAP-AREA Sample Number L a t . ( N . ) / Long . (W. ) F i e l d Name I r v i n e - B a r a g a r Name Comments 8 .1 58° 1 2 7 128° 2 4 ' F e l d s p a r - c h l o r i t e -s e r i c i t e s c h i s t C a l c - a l k a l i n e D a c i t e * Abundant c a r b o n -a t e p a r t i n g s B.2 53° 1 1 7 128° 2 0 ' Coarse b laded p l a g i o -c l a s e - c h l o r i t e - b i o -t i t e - e p i d o t e s c h i s t C a l c - a l k a l i n e A n d e s i t e , High Al B.3 58° 1 1 7 128° 2 0 ' C h l o r i t e - s e r i c i t e s c h i s t C a l c - a l k a l i n e D a c i t e * c a r b o n a t e rhombs abundant B.4 .58° 1 2 7 128° 2 4 ' F e l d s p a r - c h l o r i t e s c h i s t C a l c - a l k a l i n e Ande-s i t e , K - p o o r , High Al Wel l l a y e r e d B.5 58° 1 1 7 128° 2 1 ' F e l d s p a r - c h l o r i t e , s e r i c i t e s c h i s t C a l c - a l k a l i n e D a c i t e * B.6 58° 1 3 7 128° 2 3 ' Medium g r a i n e d , b l a d e d f e l d s p a r - c h l o r i t e s c h i s t C a l c - a l k a l i n e D a c i t e * B.7 58° 1 3 7 128° 2 3 ' Coarse b laded p l a g i o -c l a s e - c h l o r i t e . s c h i s t T h o l e i i t i c B a s a l t 3 .8 580 I T ; 128° 2 0 ' Coarse b laded p l a g i o -c l a s e - c h l o r i t e s e r i c i t e s c h i s t C a l c - a l k a l i n e Rhyo-l i t e * B.9 58° 1 1 7 128° 2 4 ' Coarse b laded p l a g i o -c l a s e - c h l o r i t e b i o t i t e s c h i s t C a l c - a l k a l i n e Ande-s i t e , K - r i c h , High Al B.IO 58° 1 0 7 128° 13 ' Coarse b laded p l a g i o -c l a s e - c h l o r i t e -b i o t i t e s c h i s t C a l c - a l k a l i n e O a c i t e , average B . l l 58° 1 3 7 128° 2 4 ' P l a g i o c l a s e - c h l o r i t e b i o t i t e - t r e m o l i t e -a c t i n o l i t e s c h i s t C a l c - a l k a l i n e D a c i t e , average B.12 58° 1 3 7 128° 2 4 ' P l a g i o c l a s e - c h l o r i t e b i o t i t e s c h i s t C a l c - a l k a l i n e A n d e s i t e , High Al Very f i n e graine< B.13 58° 1 2 7 128° 2 4 ' P l a g i o c l a s e - b i o t i t e e p i d o t e s c h i s t C a l c - a l k a l i n e Ande-s i t e , K - r i c h , H i g h Al •8.14 58° 1 3 7 128° 2 4 ' P l a g i o c l a s e - t r e m o l i t e -a c t i n o l i t e - b i o t i t e s c h i s t T h o l e i i t i c B a s a l t , K - r i c h a.15 58° 1 3 7 128° 2 3 ' C h l o r i t e - b i o t i t e t r e m o l i t e - a c t i n o l i t e s c h i s t Not A v a i l a b l e H o r n b l e n d i t e * B.16 58° 1 3 7 128° 2 3 ' C h l o r i t e - b i o t i t e t r e m o l i t e - a c t i n o l i t e Not A v a i l a b l e H o r n b l e n d i t e * s c h i s t B.17 53° 1 1 7 C h l o r i t e - s e r i c i t e 128° 2 0 ' c a r b o n a t e s c h i s t B.18 58° 1 3 7 S e r i c i t e - b i o t i t e -128° 2 4 ' f e l d s p a r s c h i s t C a l c - a l k a l i n e R h y o l i t e , K - r i c h C a l c - a l k a l i n e Rhyo1 ite Very f i n e g r a i n e d ( * ) I n d i c a t e s d a t a f rom A. Pan te leyev ( P e r s . comm., 1977) Page 218 TABLE II . 3 LOCATION, FIELD NAME ANO IRVINE-BARAGAR NAME FOR ROCKS OF THE EAGLEHEAD AREA (C.l TO C.6), FOR ROCKS OF THE TAKLA FORMATION (F.l TO F.6) ANO FOR ROCKS OF THE CACHE CREEK GROUP (G.l TO G.8), CRY LAKE MAP-AREA AND DEASE LAKE MAP-AREA Sample Number Lat.(N.)/Long.(W.) Field Name Irvine-Baragor Name C.l 58° 29 7129° 08' Quartz - feldspar - s e r i c i t e schist Calc alkaline Rhyolite, K-poor C.2 C.3 58° 58° 30 7129° 09' 30 7 129° 10' Feldspar - quartz - se{^{j}|£ Feldspar- augite -epidote schist Calc alkaline Dacite Calc-alkaline Basalt, High Al C.4 58° 307129° 10' Fine feldspar epidote-chlorite schist Calc-alkaline Andesite, K-poor, High Al C.5 58° 287129° 44' Quartz-eye - feldspar s e r i c i t e schist Calc alkaline Rhyolite, K-poor C.6 58° 30 7129° 09' Quartz- feldspar - s e r i c i t e schist Calc alkaline Rhyolite, K-rich F.l 58° 247128° 32" Augite-Feldspar Crystal tuff T h o l e i i t i c Basalt, K-rich F.2 58° 117128° 45' Feldspar- epidote ch l o r i t e tuff T h o l e i i t i c Andesite, K-poor F.3 58° 24 7 128° 44' Well layered intermediate tuff T h o l e i i t i c Andesite, K-poor F.4 58° 247128° 42' Augite-feldspar crystal tuff Calc-alkaline, Basalt, K-rich, High Al F.5 58° 24 7 130° 05' Augite - Plagioclase crystal tuff and breccia Calc-alkaline Basalt, K-rich, High Al F.6 58° 117129° 52' Sheared Augite porphyry T h o l e i i t i c P i c r i t e 8asalt, K-rich G.l 58° 20 7 128° 43' Greenstone T h o l e i i t i c Basalt, K-poor G.2 58° 157128° 26' Feldspar- chlorite - epidote schist T h o l e i i t i c Basalt, K-rich G.3 58° 20 7 128° 30' Greenstone T h o l e i i t i c Basalt, K-poor G.4 58° 20 7128° 26' Greenstone with chlorite clots T h o l e i i t i c Basalt, K-rich G.5 58° 247129° 02' Feldspar - chlorite - s e r i c i t e schist Calc-alkaline, Andesite K-poor, High Al G.6 58° 207128° 45' Feldspar - chlo r i t e - epidote schist T h o l e i i t i c Basalt, K-rich G.7 58° 207128° 45' Epidotized feldspar- chlor-it e schist Calc alkaline Andesite, K-poor G.8 58° 087128° 25' Chlorite - feldspar schist T h o l e i i t i c Basalt, K-rich Page 219 TABLE II . 4 LOCATION, FIELD NAME AND IRVINE-BARAGAR NAME FOR ROCKS NORTH OF THE . KUTCHO FAULT (D.l to D.IO) AND ROCKS OF THE INKLIN FORMATION ( E . l , E.2) CRY LAKE MAP-AREA Sample Number Lat.(N.)/Long.(W.) Field Name Irvine-Barager Name 0.1 58° 15 7128° 26' Banded Chert or fine-grained sandstone T h o l e i i t i c Rhyolite D.2 58° 247128° 42' Quartz-eye - plagioclase crystal tuff Calc-alkaline, Andesite K-poor, High Al D.3 58° 247128° 24' Interlayered c h l o r i t e and feldspar - c h l o r i t e -carbonate schist Not applicable 0.4 58° 25 7128° 45' Coarse quartz-eye - fel d -spar - s e r i c i t e - s c n i s t Calc-alkaline Rhyolite, K-poor D.5 58° 247128° 44' Feldspar- quartz-eye-c h l o r i t t - s e r i c i t e schist Calc-alkaline Rhyolite 0.6 58° 25 7128° 45' Quartz-eye rhyolite Calc-alkaline Rhyolite, K-poor D.7 58° 257128° 45' Quartz Arenite to Quartz Wacke Not applicable O.d 53° 237128° 35' Quartz -feldspar porphyry Calc-alkaline Dacite; K-poor D.9 53° 267128° 44' Quartz-eye - feldspar c h l o r i t e - s e r i c i t e schist T h o l e i i t i c Rhyolite, K-poor 0.10 58° 25 7 128° 43' Fine q u a r t z i t i c sandstone Not applicable E.l 53° 137129° 10' Arkose Calc alkaline Rhyolite E.2 58° 137129° 10' Greywacke Calc-alkaline Andesite: K-rich, High Al Page 2 2 0 APPENDIX I I I ROCK GEOCHEMICAL DATA Page 221 T A B L E I I I . l CHEMICAL ANALYSES ANO NORMATIVE MINERALS FOR ROCKS OF THE KUTCHO FORMATION, CRY LAKE MAP-AREA, 8RITISH COLUMBIA Sample Number A.l A.2 A.3 A.4 A.5 A.6 A.7 A.8 A.9 A. 10 A. .11 A. .12 A. .13 SJ02 50.60 78.90 50.00 45.60 47.60 51.40 74.10 48.80 72.10 64.00 63. .30 69, .00 68.40 AI263 18.60 11.60 19.70 12.40 14.90 13.80 12.60 16.40 10.00 13.00 14. ,90 13. .50 12. .90 Fe203 3.30 .80 5.40 2.20 2.30 4.90 - 2.70 .70 .10 .60 1.50 1, .00 FeO 4.10 .10 3.00 8.10 7.40 5.60 3.30 6.70 .60 5.10 3! .90 2 .20 3. .30 MgO 3.42 .14 3.96 13.60 6.56 4.03 2.13 9.30 .44 2.63 2. .69 2, .37 3, .15 CaO 9.31 .06 8.81 8.35 7.2S 10.70 .33 6.62 5.00 2.13 4. ,06 4 .61 1, .54 Na20 3.60 6.00 3.10- 1.90 3.30 2.40 4.30 3.20 3.40 .80 2. ,40 1, .90 2.40 K20 .54 .10 1.89 - .03 .10 .33 .01 1.51 3.42 2. .10 1, .01 .79 Ti02 1.08 .12 .74 1.17 1.66 1.62 .47 1.03 .18 .48 .57 .32 .39 P205 .28 - .11 .10 .12 .18 .05 .08 .01 .03 .07 .02 .03 MnO .21 .01 .19 .21 .25 .18 .07 .24 .03 .07 .08 .04 .04 C02 1.80 .10 .90 1.80 3.00 1.60 - .50 3.80 5.50 3! .10 .30 1, .40 H20 2.90 .70 2.90 3.80 4.70 2.50 2.40 4.60 1.00 2.30 2. .70 2 .20 3 .90 Total 99.9 98.7 100.8 99.6 99.5 99. 100.2 100.2 98.9 100.5 99. .6 100.7 99 .2 Ba 354 39.8 673 12.1: 216 29.5 99.9 16.7 940 848 705 292 128 Co 13.1 <10 23.6 45.5 23.4 31.1 <10 39.8 <10 <10 11, .8 24 .2 <10 Cr <5 <5 34 734 115 <5.1 <5 235 <5 <5 15. .4 127 <5 Ni <10 <10 <10 28.fi 39.5 20.4 <10 89.2 <10 <10 10. .1 427 <10 Cu 23.7 21.9 22.4 30.4 50.9 39.3 <7 <7 13 18.1 26. .3 264 12. .2 Zn 40 40 40 40 8Q 50 - 50 - 110 60 50 30 Rb - - 20 - - - - 30 20 40 Sr 576 51.2 532 63.4 128 264 50.7 122 205 13.9 139 273 24. ,8 V 147 <20 310 190 324 347 32.3 331 26.4 59.7 121 231 33. ,9 Y 45 40.2 <40 <40 43.1 51.8 56.8 43 <40 <40 42. .8 <40 <40 Zr 117 204 86.9 60.2 64.4 89.2 114 ' 69.8 46.5 1000 157 68, .7 130 F 400 200 400 300 300 300 300 600 200 400 600 900 400 CI 200 20Q 100 200 IQO IQO 200 100 100 100 100 500 100 S - - - - 4100 - - - - 7500 500 QZ 6.09 44.40 _ _ 7.65 12.99 42.61 _ 46.48 44.90 35. .36 41. ,83 47, ,07 C .01 1.66 - - 3.71 - 4.80 .46 2.57 8.20 8. .84 1. .70 8. ,49 Or 3.30 .60 11.47 - .19 .61 2.00 .06 9.14 20.80 12. ,71 6. .17 4, .90 Ab 31.48 51.83 26.91 16.85 29.59 21. Q8 37.25 28.33 29.43 6.96 20. ,77 16. .61 21. ,30 An 34.08 - 35.51 26.52 17.18 27.61 1.34 30.51 .73 ,09 21. .54 Dl - - 1.51 2.65 - 7.55 - - _ _ He - - .95 .78 - 5.43 _ - -En 8.80 .23 9.82 26.54 17.31 6.92 5.43 22.86 1.12 2.21 6. ,85 6. ,10 7. ,86 Fs 5.35 - 6.03 9.02 9.97 5.71 5.54 9.12 .29 2.91 5. ,01 2. ,73 4. ,74 Fo - - .44 5.42 - - - .96 - -Fa - - .27 2.03 - - - .42 -Wo - - - - - - _ _ _ Mt 3.87 .01 3.33 3.34 3.53 4.70 _ 3.84 1.04 .15 89 2. ,25 1. 52 II Hm 2.12 .23 1.44 2.33 3.34 3.19 .91 2.05 .35 .94 l ! ,11 63 ,70 Ap .67 _ .26 .24 .30 .43 .12 .19 .02 .07 16 05 07 Cc 4.23 .23 2.10 4.29 7.23 3.78 - 1.19 8.84 12.86 21 71 2. 34 Page 222 TABLE I I I . l ( cont'd.) CHEMICAL ANALYSES ANO NORMATIVE MINERALS FOR ROCKS OF THE KUTCHO FORMATION, CRY LAKE MAP-AREA, BRITISH COLUMBIA cont'd Sample (A.23) (A.26) Number A.14 A.15 A.16 A.17 A.18 A.19 A. 20 A.21 A. 22 A.24 A.25 A. .27 SiO? 52.90 59.50 52.10 74.00 46.90 49.10 53.60 41.30 58.60 87.10 92.30 48.50 42.90 72 .20 A I 2 O 3 15.00 16.10 14.30 13.10 16.40 13.80 18.80 17.30 12.00 .70 3.00 14.70 14.50 13 .50 Fe203 1.30 .50 1.30 2.90 1.50 1.20 5.10 3.20 .50 10.30 - 2.00 1.30 1 .40 FeO 3.90 2.60 4.50 .30 7.90 11.50 3.00 12.90 1.10 1.30 - 6.30 9.50 1 .40 MgO 2.01 2.94 4.62 .14 8.55 6.80 3.20 6.04 .87 .30 - 7.25 6.79 1 .13 CaO 6.89 3.37 9.91 .03 10.20 4.39 7.62 5.49 11.60 .05 3.39 8.04 7.59 Z .33 NaoO 1.90 .50 2.90 7.20 2.80 1.30 4.00 3.20 4.60 - - 3.00 3.10 L .10 K;)5 2.63 3.46 .44 .10 - .45 1.14 .02 1.08 - - 1.15 1.36 .47 Ti0 2 .33 .41 .47 .50 1.13 2.23 .86 3.17 .24 - - 1.41 3.14 .41 P2O5 .03 .OS .11 .05 .07 .24 .17 .26 .07 .01 .01 .13 .44 .05 MnO .32 .10 .45 .07 .14 .22 .16 .25 .05 .01 - .22 .21 .12 CO2 10.40 6.60 5.70 .10 .10 1.50 - - 9.00 - 2.70 1.60 3.50 .40 H?0± 2.40 2.70 3.40 .40 3.20 6.70 3.00 5.70 .30 .10 2.50 4.40 5.40 1 .30 Total 100.2 99.1 100.2 99.4 99.0 100.6 100.8 99.9 100.2 100.0 99.1 98.7 99.9 99 .3 Ba 713 23D 115 31.2 29.3 269 43 40 190 190 137 379 90 .2 Co <10 <10 17.3 <10 27.8 47.3 47.9 <10 <10 <10 30.2 26.4 <10 Cr 140 <5 43 14.4 230 93.3 13.1 <5 <5 <5 66 79.4 <5 Ni <10 <10 <10 <10 78.3 75 40.1 < i r <10 <10 72.7 12.4 <10 Cu <7 <7 38.7 8.1 53.7 287 25.2 7 . 8 16.3 <7 75.2 IS <7 Zn 50 120 30 30 30 70 110 - - <200 60 90 10 Rb 20 20 - 97 - - - • . - - 20 10 Sr 85.7 215 110 35.8 29 37.8 163 48.9 - <10 151 359 167 V 78.5 100 160 <20 247 429 582 34.8 <20 <20 260 250 35 .6 Y <40 51.2 <40 <40 <40 56.9 54.2 <40 <40 <40 <40 <40 <40 Zr 84.9 140 66.3 180 53.8 115 181 109 46.5 <20 30.5 125 26 .1 F 500 900 700 300 400 300 400 400 100 400 200 400 300 CI 300 400 100 200 300 200 300 300 500 100 400 600 100 S - 700 - - - - 300 - - - - -QZ 33.62 44.10 18.59 31.74 18.73 3.75 _ 25.81 80.46 91.11 .99 35 .38 c 9.24 11.92 4.65 1.16 - 7.81 - 3.35 3.20 .64 2.96 - 1 .43 Or 15.93 21.16 2.69 .60 - 2.87 6.93 .13 6.41 - - 7.21 22.50 .82 Ab 16.46 4.37 25.25 61.58 24.76 11.86 34.76 28.76 39.03 - - 26.92 9.59 43 .80 An - - 12.82 - 33.63 11.57 30.79 27.13 .20 .19 - 24.65 16.01 D .34 Di -2.04 - - - 9.95 - 3.23 - - - 3.50 12.80 He -2.18 - - - 4.75 - 2.19 - - - -.28 1.35 5.15 En - .83 11.89 .25 5.11 18.26 6.69 7.55 2.17 , .76 - 17.52 .48 'I .86 Fs - .44 7.49 .43 2.80 18.17 5.80 8.16 1.31 5.73 - 7.76 .22 .98 Fo - - - - 8.78 - - 5.91 - - 18.71 Fa - - - - 5.30 - 7.05 - 9.51 Mo 2.12 - - - . . _ Mt 1.93 .75 1.95 2.93 2.72 1.38 3.52 1.93 .73 2.20 3.08 2.84 \l .06 Ii .64 .31 .92 .96 2.24 3.43 1.68 6.40 .46 - 2.84 1.02 .79 Hm - - - - - - - - - .02 . _ Ap .07 .12 .26 .12 .17 .60 .41 .64 .16 .02 .32 1.17 .12 Cc 24.22 15.52 13.39 .23 .24 3.68 - - 20.53 - 6.06 3.86 - .92 Page 223 TABLE I I I . l ( c o n t ' d . ) CHEMICAL ANALYSES AND NORMATIVE MINERALS FOR ROCKS OF THE KUTCHO FORMATION, CRY LAKE MAP-AREA, BRITISH COLUMBIA Sample Number A.28 (A.29) A.30 A.31 A.32 A.33 A.34 A.35 A.36 A.37 A.38 A.39 A.40 Si 02 61.10 36.80 71.60 47.20 68.50 82.50 50.10 45.50 78.00 53.30 71.20 49.80 45.20 Al 203 15.70 14.80 14.20 15.50 13.50 10.10 14.80 18.50 11.70 14.50 12.30 15.70 12.30 Fe?03 1.50 1.30 .90 1.30 1.20 - 5.20 2.40 .20 4.60 1.10 2.30 1.50 FeO 2.50 7.70 2.30 9.90 3.80 .20 3.60 7.60 .70 8.50 3.00 6.50 8.40 MgO 1.97 6.90 .94 16.20 2.88 .34 5.51 9.26 .52 6.55 2.15 7.95 14.70 CaO 4.29 14.00 2.51 - 1.66 .01 12.80 7.45 - 5.89 1.05 8.77 8.59 Na20 4.00 3.50 5.70 - 3.90 5.20 1.80 3.00 6.30 .30 4.00 3.80 1.60 K20 1.69 .06 .10 - .28 .08 .02 .22 .03 .04 .66 .04 .58 Ti0 2 .56 1.12 .42 1.10 .64 .17 .90 .90 .17 .59 .56 1.15 1.05 P2O5 .16 .10 .06 .08 .12 .01 .11 .08 .01 .02 .09 .06 .07 MnO .09 .23 .03 .20 .19 - .25 .20 .01 .17 .13 .15 .20 C02 3.20 9.10 - .50 .60 - 2.20 - - - .10 .10 .30 H20± 2.90 4.60 1.10 8.40 2.60 .50 3.40 5.20 .70 4.40 2.00 3.50 5.80 Total 99.9 100.3 100.1 100.4 99.9 99.1 100.8 100.3 98.3 98.8 98.2 99.8 99.8 Ba 1690 316 316 8.4 343 38.8 30.4 18.8 24.5 60.7 40.1 42.7 Co 12.8 <10 <10 43.8 <10 <10 40.4 <10 52.5 <10 35.2 43.9 Cr 14.8 <5 <5 32.9 <S <5 146 <5 19.2 <5 186 217 N1 <10 <10 <10 117 <10 <10 69.7 <10 28.6 <10 66 74.7 Cu 8.2 7.7 7.7 326 55.7 <7 178 <7 10.5 17.6 89.2 102 Zn 40 - _ 371 40 - 130 30 80 50 50 Rb 50 - _ - _ - - - - - - 10 Sr 353 132 132 185 54.1 14.5 87.8 33.6 226 59.3 101 108 V 94.8 43.9 43.9 283 42.7 <20 353 <20 348 26.5 276 307 Y <40 <40 <40 <40 <40 <40 <40 <40 63 <40 <40 <40 Zr 135 <20 <20 385 498 <20 <20 49.7 <20 54.8 <20 29.2 F 400 200 200 200 300 200 300 200 300 200 400 300 CI 200 100 100 800 300 200 200 200 200 200 200 100 S - 900 900 400 - - - - - - -Qz 28.15 30.54 18.01 37.49 52.13 10.41 41.04 22.49 _ _ C 7.53 5.07 .30 16.81 5.59 1.48 - - 1.34 3.51 - -Or 10.33 .37 .60 - 1.70 .48 .12 1.37 .18 .25 .25 3.53 Ab 34.98 30.97 48.83 - 33.92 44.62 15.70 26.69 54.58 2.70 33.38 14.32 An .01 11.79 12.21 - 3.76 - 33.25 38.23 - 30.89 26.65 26.11 Oi - - - - - - 9.18 .04 - - 10.27 10.14 He - - _ - _ - 4.77 .02 - - 3.81 3 . 1 0 En 5.07 8.19 2.37 42.81 7.37 .86 9.89 5.44 1.33 19.32 8.31 11.42 Fs 2.68 5.55 2.88 16.62 5.43 ' .09 5.89 2.56 .88 18.40 3.53 4 . 0 0 Fo - 6.87 - - _ - - 13.16 - - 5.25 15.85 Fa - 5.12 - - - - - 6.83 - - 2.46 6 . 1 2 Wo - _ _ _ _ _ _ - _ Mt 2.23 1.97 1.32 2.05 1.79 - 3.59 3.66 .30 3 . 2 2 3.46 2.30 11 1 . 1 0 2.23 .81 2.27 1.25 .33 1.76 1.80 .33 1.19 2.27 2 . 1 1 rim Ap .38 .24 .14 .20 .29 .02 .26 . 2 0 .02 .05 .14 .17 Cc 7.52 21.65 - 1.23 1.40 - 5.16 - - - .24 .72 Page 224 TABLE I I I . l (cont'd.) MAJOR ELEMENT CONCENTRATIONS AND NORMATIVE MINERALS FOR ROCKS OF THE KUTCHO FORMATION, CRY LAKE MAP-AREA, BRITISH COLUMBIA (*) DATA FROM PANTELEYEV (PERS. COMM. 1977); TRACE ELEMENT DATA NOT AVAILABLE Sample * # * * * * * * „* , , * Number A.41 A.42 A.43 A.44 A.45 A.46 A.47 A.48 A.49 A.SO A.SI A.52 A.53 A.54 A.55 A.55 S1O2 A l o O , Fe|03 FeO MgO CaO NaoO K20 TiO? P 20 5 MnO C02 H20± Total 69.22 68.79 70.96 76.54 52.08 79.86 73.64 50.87 73.90 73.85 72.57 67.38 75.70 65.28 61.38 65.12 13.33 12.56 12.36 12.47 15.69 11.41 13.33 14.02 12.26 11.40 12.20 11.30 12.05 14.75 15.88 14.80 1.65 1.78 1.02 .16 6.02 .25 .60 3.79 1.42 1.03 1.64 2.02 2.01 1.30 1.42 2.06 2.40 2.70 3.34 .97 5.50 .63 2.39 8.73 .15 1.62 .86 1.31 .87 4.27 4.89 2.99 2.15 2.18 2.42 1.41 3.98 .31 1.23 5.79 .22 1.47 1.05 4.42 .83 2.41 3.72 2.97 2.33 1.99 .91 .16 9.16 .11 .52 6.83 2.53 1.48 2.26 1.57 4.59 2.85 4.32 3.76 2.83 3.19 3.78 6.37 .32 6.20 5.79 4.00 4.25 2.90 3.13 1.25 3.26 5.56 1.89 4.29 1.S7 2.28 1.07 .13 .36 .09 .21 .09 1.42 1.52 1.45 .76 .39 .14 1.53 .11 .38 .60 .58 .33 .66 .19 .56 1.61 .31 .29 .33 .26 .25 .63 .65 .40 .32 .34 .15 .27 .57 .21 .25 .30 .25 .15 .15 .15 .17 .16 .15 .15 .05 .15 .14 .03 .18 .01 .06 .22 .03 .05 .05 .09 .04 .10 .10 .21 .23 .90 .06 .06 .16 .06 .19 .26 2.37 1.42 3.21 6.37 .40 .70 .40 .22 2.42 2.00 1.67 .82 3.00 .64 1.58 .88 .55 1.91 1.93 2.09 .32 2.31 3.82 2.57 99.8 99.64 99.04 99.72 98.18 99.97 100.35 97.03 99.66 99.09 100.46 98.97 101.38 100.40 KiO.15 99.65 Qz 38.81 34.71 38.83 36.74 22.04 42.95 36.30 3.33 43.77 49.54 47.74 51.63 45.92 23.16 <9.16 27.48 3.76 5.13 5.54 8.63 - 2.42 4.72 1.71 .55 8.46 9.24 8.56 4.60 2.29 .84 9.39 .67 35.17 36.26 25.24 26.76 10.84 29.43 47.15 16.60 37.39 20.82 . . . . 17.00 8.84 18.61 16.77 6.96 - - - 1.58 -1.74 12.47 .55 3.77 2.64 11.28 1.32 6.12 9.62 7.62 8.64 - 1.79 - .49 - 6.03 7.18 3.62 5.71 -3.18 .38 c 3.72 4.68 4.44 1.87 _ 1.12 3.62 Or 9.51 13.99 6.49 .78 2.23 .54 1.25 Ab 24.55 29.75 32.85 54.48 7.29 52.78 49.51 An 10.76 2.04 3.24 39.97 Oi - - - - 1.91 -He - - _ .33 _ En 5.49 6.25 6.19 3.55 9.66 .78 3.10 Fs 2.57 2.43 4.72 1.17 4.26 .56 3.11 Fo _ _ _ _ _ Fa - - _ _ Wo - _ _ _ Mt 2.45 1.93 1.52 .23 9.16 .36 .88 11 .74 .37 1.13 .63 1.32 .36 1.07 Hm - - _ . .. _ Ap .76 .74 .36 .64 1.40 .49 .59 Cc .54 2.36 .14 .14 .38 .14 .44 .73 .59 .61 5.43 1.54 2.06 3.00 2.20 1.92 2.14 3.08 .57 .63 .51 .47 1.22 1.28 .78 - - - .48 - _ . .36 .35 .36 .39 .38 .36 .36 3.32 7.38 14.84 .90 1.62 .94 .52 Page 225 TABLE I I I . 2 CHEMICAL ANALYSES AND NORMATIVE MINERALS FOR ROCKS OF THE BASIC SCHIST-KUTCHO FORMATION, CRY LAKE MAP-AREA, BRITISH COLUMBIA Sample # Number B.l 8.2 B.3 8.4 B.5 8.6 8.7 B.8 8.9 Si02 49.20 51.20 48.30 47.20 51.60 46.00 48.50 53.50 50.60 A1 2 0 3 13.70 14.70 16.40 14.80 17.60 15.20 13.70 17.80 16.30 Fe203 2.10 3.70 3.50 2.50 1.80 1.50 .90 2.00 3.50 FeO 5.80 4.80 5.10 6.40 6.10 7.20 6.80 4.20 4.60 MgO 5.23 5.15 5.49 6.50 3.50 5.45 4.77 2.34 3.09 CaO 7.50 7.83 4.22 6.65 4.78 7.31 7.01 3.79 8.04 Na20 2.80 3.00 2.40 2.60 3.60 1.20 2.50 2.60 3.40 K20 2.72 1.96 3.54 1.48 3.51 3.57 3.51 5.32 3.00 T i0 2 .60 .62 .71 .72 .69 .71 .64 .59 .61 P 2 0 5 .79 .82 .36 .90 .64 .55 .79 .69 .82 MnO .17 .17 .12 .19 .22 .18 .18 .08 .18 C02 5.00 3.10 3.30 4.30 2.40 7.40 8.80 2.60 2.40 H20± 3.70 3.50 4.30 5.30 4.00 4.20 2.50 3.10 2.20 Total 99.4 99.1 99.1 . 99.5 100.6 100.3 100.8 99.3 99.0 Ba 700 170 560 241 875 608 559 893 556 Co 28 <10 16.7 24.9 18.7 28.1 19.3 <10 22.4 Cr 98.8 <5 78.4 96.3 <5 56.9 82.7 <5 13.9 Ni 40.6 <10 27.2 90.3 <I0 17.1 16.8 <10 10.5 Cu 159 16.5 307 268 206 318 282 15.7 273 Zn 70 10 70 90 80 60 n o 80 50 Rb 50 0 70 - 60 - 100 50 40 Sr 312 228 195 321 292 341 445 368 1160 V 209 37.9 234 229 179 264 164 116 197 Y <40 51.8 <40 <40 <40 <40 <40 <40 <40 Zr 82.3 136 66.4 81.4 96.3 <20 <20 60.9 104 F 500 600 800 900 600 400 600 700 600 CI 200 400 300 200 400 200 100 200 100 S - - - - - 300 300 - 1300 Qz 11.26 8.78 13.16 10.51 6.25 15.88 10.41 12.33 2.68 C 6.27 2.64 9.47 8.94 6.51 9.69 - 8.08 .38 Or 16.83 11.97 9.29 22.14 21.53 21.87 .21 32.76 18.41 Ab 24.78 14.33 23.35 22.37 31.58 10.51 15.70 22.90 29.41 An .45 - - - 4.51 - 33.25 - 20.07 Di - - - - - - 9.18 - -He - - - - - - 4.77 - -En 13.62 13.24 17.16 12.22 9.04 10.66 9.89 6.85 7.98 Fs 3.62 9.23 10.11 7.77 9.32 8.75 5.90 5.07 8.61 Fo - - - - - - - - -Fa - - - - - - - - -Wo - - - - - - - - -Mt 3.18 3.17 3.42 3.39 2.71 2.25 3.59 3.02 3.17 n 1.19 1.22 1.45 1.43 1.36 1.40 1.76 1.17 1.20 Hm - . . _ _ - _ -Ap 1.92 1.96 2.22 2.11 1.54 1.56 .26 1.67 1 .97 Cc 11.89 7.28 10.38 9.14 5.66 17.43 5.16 6.16 5.66 Page 226 TABLE I I I . 2 ( c o n t ' d . ) CHEMICAL ANALYSES AND NORMATIVE MINERALS FOR ROCKS OF THE 8ASIC SCHIST, KUTCHO FORMATION, CRY LAKE MAP-AREA, BRITISH COLUMBIA (*) DATA FROM A. PANTELEYEV (PERS. COMM., 1977), TRACE ELEMENT OATA NOT AVAILABLE Sample * * * Number B.IO 8.11 B.12 8.13 B.14 B.15 B.16 8.17 B.18 Si02 53.00 50.20 50.80 51.10 48.50 50.95 52.03 46.10 54.50 A1 2 0 3 17.30 16.30 15.60 17.50 14.00 13.16 13.58 14.10 16.20 Fe203 2.80 3.20 2.10 3.80 2.80 3.17 3.58 5.40 .40 FeO 4.50 6.70 6.00 4.40 7.50 6.21 5.22 4.70 5.70 MgO 3.56 5.04 4.78 3.31 6.44 6.30 5.93 5.41 4.17 CaO 5.55 8.05 6.67 6.81 7.97 5.12 7.05 1.20 2.70 Na?0 4.50 2.20 2.90 2.80 1.60 3.23 3.52 - 2.50 K20* 2.96 3.58 3.80 3.91 4.30 3.25 3.83 4.05 5.34 T i0 2 .62 .69 .64 ..64 .73 .73 .73 .78 .64 P 2 0 5 .79 .68 .64 .87 .87 .87 .85 .98 .69 MnO .17 .16 .16 .15 .19 .18 .21 .17 .07 C02 2.40 .60 3.40 1.20 2.00 3.33 .06 6.50 4.20 H20± 2.30 2.90 3.00 2.30 2.90 2.43 1.81 4.80 2.50 Total 100.6 100.5 100.6 98.9 99.3 98.93 98.40 100.4 100.1 Ba 536 491 462 890 679 1230 723 Co 11.9 29.1 27.2 25.2 28.6 46.3 11.7 Cr 9.5 48 38.9 23 92.7 232 41.7 Ni <10 24.9 14.6 12.8 16 808 23.9 Cu 346 157 175 400 171 238 95.6 Zn 70 80 60 120 70 80 120 Rb 50 90 n o 100 90 30 140 Sr 727 618 620 757 469 291 139 V 117 246 209 205 267 305 206 Y <40 <40 <40 <40 <40 54.1 <40 Zr 61.5 224 24.1 46 <20 85.1 34.7 F 300 800 700 700 200 100 900 CI 700 100 300 200 600 300 200 S - - - - - - 370 Qz 3.85 5.30 2.38 _ 6.96 _ 13.27 C 4.13 - 4.10 1.19 - 4.48 - 6.48 Or 17.83 21.77 23.06 24.01 26.26 19.88 23.38 32.46 Ab 38.78 19.13 25.17 24.60 13.98 28.29 30.77 21.74 An 7.32 24.69 7.60 21.29 18.91 - 10.27 -01 - 3.64 - - 1.48 - 8.24 -He - 2.86 - - .97 - 7.64 -En 9.28 9.17 12.21 8.56 13.94 16.24 1.78 6.76 Fs 7.04 8.25 8.74 8.56 10.44 8.19 .70 5.99 Fo - 1.43 - - 1.36 - 5.61 -Fa - 1.42 - - 1.12 - 2.43 -Wo - - - - - - - -Mt 3.13 3.26 3.12 3.22 3.34 4.76 5.36 .60 n 1.20 1.35 1.25 1.26 1.43 1.44 1.43 1.25 Hm - - - - - - - -Ap 1.87 1.62 1.52 2.10 2.08 2.10 2.05 1.65 Cc 5.56 1.40 7.93 2.83 4.70 7.84 .14 9.82 Page 227 TABLE III .3 CHEMICAL ANALYSES ANO NORMATIVE MINERALS FOR ROCKS OF THE EAGLEHEAD AREA (C.I TO C.5) ANO FOR ROCKS OF THE TAKLA FORMATION (F.l TO F.5) CRY LAKE MAP-AREA AND DEASE LAKE MAP-AREA, BRITISH COLUMBIA Sample F . 5 Number C.l C . 2 C.3 C.4 C .5 C.6 F.l F . 2 F.3 F.4 F.6 Si0 2 70.30 61.60 50.20 51.60 65.10 66.10 47.80 49.80 55.80 53.00 49.50 47.40 Al20 3 16.50 16.50 16.40 16.30 13.90 15.50 12.50 17.80 17.40 15.00 18.00 11.50 Fe20 1.00 1.30 1.70 1.60 .30 .30 1.30 1.70 1.10 1.00 3.80 1.90 ;FeO .30 .20 6.00 6.30 1.10 1.50 6.80 6.40 5.50 6.90 6.30 9.20 MgO .37 .46 6.85 4.50 .73 .76 13.30 3.90 .38 5.00 4.34 12.90 CaO 2.39 12.30 7.62 4.90 6.12 2 . 5 5 12.00 1.34 6.60 5.00 8.50 8.12 Na20 5.90 2.30 3.20 4.70 5.70 .41 .80 1.80 5.40 3.00 2.80 1.10 K20 1.35 .45 1.33 .82 1.09 2.70 .74 .17 .76 .60 1.16 3.69 Ti0 2 .15 .16 1.53 1.89 .26 .27 .61 .98 .83 .90 1.17 .52 P 2 O 5 .03 .05 .38 .45 .09 .08 .08 .14 .13 .10 .26 .49 MnO .06 .05 .14 .13 .03 .04 .15 .19 .14 .20 .19 .19 C02 .90 7.00 1.00 2.10 4.10 2.80 - - - .50 - -H20t 1.00 2.30 2.90 4.00 .90 1.60 4.00 3..00 2.40 3.40 3.00 2.60 Total 100.5 99.1 99.4 99 .5 99 .5 99.0 100.4 99 .2 99.7 94.64 99.1 99.8 Ba 2020 1570 475 424 654 1800 357 112 254 337 347 622 Co <10 <10 22.8 24.8 <10 <10 436 13.1 13.6 <10 21.9 70 .2 Cr <5 <5 17 .5 23.4 <S <S 1110 130 <5 170 5 . 5 9.7 Ni <10 <10 73.4 41.9 <10 <10 246 42.7 <10 80.7 <10 25.6 Cu 9.0 <7 30.7 36.2 9 . 2 19.9 61.7 8.6 38.7 <7 54.1 17.1 Zn 10 _ 60 60 - 20 20 60 30 0 90 110 Rb 30 - 40 20 - 90 - - - - - 80 Sr 903 306 374 359 459 383 267 228 504 460 518 236 V <20 44 . 2 138 153 313 40.1 254 328 240 173 256 241 Y <40 <40 <40 <40 <40 <40 <40 <40 <40 <40 <40 <40 Zr 67.7 <20 104 187 109 39 72.9 86.1 75.7 93 . 2 <20 <20 F 300 400 600 700 200 400 400 300 300 200 300 1300 CI 200 200 300 200 100 400 200 100 200 200 400 300 S 100 - 200 400 - - - - 1500 - - 100 Qz 27.39 38.64 1.00 7.94 24.75 56.28 31.17 6.18 2.11 _ C 3.17 6.03 . 4.95 1.96 12.72 - 14.91 - - -Or 8.05 2.59 8.16 5.09 6.54 17.07 4.56 1.19 4.78 7.16 22.50 Ab 50.30 18.92 28.10 41.73 48.95 3.71 7.05 18.08 48.58 24.71 9.59 An 6.02 16.00 27.46 8.49 3.91 29.49 6.08 22.33 34.56 16.01 Di - 1.54 - 19.96 - ,1.20 3.56 12.80 He - .58 - - 5.61 - 8.96 2.76 5.15 En .93 1.23 17.00 11.76 1.85 .75 16.17 11.53 .45 9.62 • .48 Fs 7.32 7.70 1.42 .69 5 . 2 2 10.79 3.83 8.57 . 2 2 Fo _ _ _ - - 6.34 - - - 18.71 Fa - - - - - - 2.25 - - - 9.51 Wo - - - - - - - - -Mt .73 .73 2.56 2.43 .44 1.24 1.96 2.93 1.70 4.Q4 2.84 n .29 . 2 2 3.01 3.77 .50 . 5 5 1.21 2.21 1.68 2.32 1.02 Hm .50 1.14 . _ - - - - - - -Ap .07 .11 .92 1.10 .21 .20 .19 .39 .32 .63 1.17 Cc 2.06 17.48 1.89 5.01 9.46 6.81 - - - - -Page 228 TABLE III.4 CHEMICAL ANALYSES AND NORMATIVE MINERALS FOR ROCKS NORTH OF THE KUTCHO FAULT (D.l TO 0.10) AND FOR ROCKS OF THE INKLIN FORMATION ( E . l , E.2), CRY LAKE MAP-AREA, BRITISH COLUMBIA Sample # Number D.l D.2 0.3 D.4 0.5 D.6 0.7 0.8 D.9 D.10 Thk]i n Formation E.l E.2 S1O2 81.00 65.00 81.20 69.30 64.20 74.40 81.50 68.50 70.10 76.70 78.20 60.30 A1 20 3 2.40 13.00 1.90 16.50 15.20 14.90 4.30 16.50 16.30 13.20 12.90 16.40 Fe 20 3 .80 2.00 .60 1.00 1.60 .60 .60 1.40 1.60 .60 .30 4.10 FeO 2.68 2.00 .10 .90 1.50 .20 1.00 1.00 2.00 - - 2.60 MgO 2.68 2.00 .84 .75 1.18 .15 .38 .10 .30 .03 .43 2.73 CaO 5.77 2.00 7.25 .61 3.95 .52 5.01 2.48 1.09 - .02 5.49 Na20 - 2.00 - 4.00 2.90 4.20 .10 5.00 5.80 5.50 5.00 2.80 K20 .13 .20 .51 3.43 3.56 3.13 1.20 1.27 1.67 1.14 1.52 1.95 Tl0 2 .10 .50 .08 .26 .39 .03 .47 .30 .25 .02 .06 .74 P205 - .10 - .07 .11 - .08 .09 .05 - - .19 MnO .23 .10 .19 .03 .05 .08 .04 .16 .05 .05 .01 .14 co2 4.70 - 6.40 .50 2.60 .30 4.40 .20 .70 - - .10 H 20i 1.40 2.40 1.00 1.50 2.00 .80 1.10 1.20 1.20 .09 1.60 2.50 Total 99.6 91.3 100.1 99.0 99.4 99.3 100.5 99.3 99.5 98.2 100.3 100.1 8a 577 1150 1310 1250 1490 262 311 1470 1260 172 682 742 Co <10 <10 <10 <in <10 <10 <10 <10 <10 <10 <10 <10 Cr <5 <5 <5 <5 <5 <5 11.5 <5 <5 <5 <5 <5 Ni <10 <10 10.7 <10 <10 <10 <10 <10 <10 <10 <10 <10 Cu 119 50.3 41.9 9.0 7.8 12.1 11.2 20.4 <7 <7 <7 34 Zn 10 - - 30 60 20 0 50 20 60 - 50 Rb - - - 130 130 250 200 20 20 90 - 30 Sr 187 134 183 310 563 92.1 282 807 608 132 457 521 V <20 121 <20 38.9 91.8 <20 <20 43.1 29.8 <20 24.5 143 Y <40 <40 <40 <40 <40 <40 <40 <40 <40 <40 <40 <40 Zr 56 166 51.1 146 212 46.6 150 90 92.7 <20 48.7 114 F 200 300 300 600 600 500 300 400 400 200 200 700 CI 100 100 200 200 100 100 200 100 200 200 400 200 S - - - - - - 600 - - 200 - -Qz 74.30 50.61 79.50 32.55 31.34 38.03 76.37 30.59 28.34 41.44 43.29 19.77 C 2.25 6.86 1.36 6.37 5.84 4.42 2.86 3.17 4.72 3.00 3.04 .40 Or .77 1.33 3.04 20.84 21.66 18.79 7.16 7.74 9.89 6.93 9.13 11.85 Ab - 19.03 - 34.75 25.23 36.07 .85 43.61 49.12 47.86 42.97 24.34 An - 10.43 - - 2.51 .69 - 10.77 .66 - .10 26.06 Di - - - - - - - - - - - -He - - _ - - - _ _ _ _ En 6.38 5.60 .47 1.73 3.02 .38 .12 .26 .75 .08 1.09 6.99 Fs 4.35 1.55 - .42 .91 - .08 .50 2.03 - 5.14 Fo - - _ - _ _ -Fa - - _ - _ _ _ _ _ Wo - - _ _ _ - - _ Mt 1.15 3.26 .72 1.49 2.39 .33 .88 2.09 2.32 .11 _ 3.34 11 .19 1.07 .15 .51 .76 .06 .90 .59 .48 .04 .02 1.44 Hm - - .11 - - .04 _ _ - .54 .31 -Ap - .26 - .17 .26 - .19 .22 .12 - - .45 Cc 10.63 10.00 14.65 1.17 6.08 .69 10.09 .47 1.59 .23 Page 229 TABLE I I I . S CHEMICAL ANALYSES AND NORMATIVE MINERALS FOR ROCKS OF THE CACHE CREEK GROUP, CRY LAKE MAP-AREA, 8RITISH COLUMBIA Sample # Number G.1 G.2 G.3 G.4 G.5 G.6 G.7 G.8 Si Go 51.00 49.30 57.10 55.40 54.30 53.50 54.20 48.60 A1 20 3 13.00 15.80 14.90 13.00 12.80 13.50 16.60 14.90 Fe 2 0 3 2.00 4.50 3.50 1.60 .80 3.30 1.50 1.70 FeO 7.90 5.90 5.50 5.20 6.90 4.40 5.10 7.90 MgO 12.00 5.72 5.47 8.83 8.92 5.22 6.40 9.06 CaO 4.00 10.60 7.39 10.80 6.39 10.90 5.07 9.76 Na20 2.00 1.50 2.60 .90 4.70 1.40 5.90 1.60 K20 _ .32 .04 .06 .02 .40 .03 1.67 TiO, .30 2.19 .49 .48 1.40 .38 .50 .38 D205 .05 .25 .02 .01 .08 .04 .02 -MnO .02 .13 .09 .11 .18 .12 .15 .18 C02 _ _ - - - 4.20 .40 .90 H20± 5.60 3.80 2.30 3.40 2.60 3.40 3.30 4.20 Total 98.03 100.1 99.5 99.9 99.1 100.9 99.3 100.9 Ba 14.7 118 292 241 13.3 198 6.9 304 Co 37.3 374 30.8 17.3 36.9 18.5 23.4 53.3 Cr 726 708 70.4 210 115 286 51 272 ' Ni 282 90.3 52.9 98.8 30 75.5 5.9 111 Cu 461 43 15.6 21.5 60.4 43.2 7;3 110 Zn 90 - - 70 26 - 50 Rb - - - - - - - 50 Sr 41.3 321 56.1 35 25.5 246 41.6 791 V 276 251 339 205 233 189 181 234 Y <40 55.2 <40 <40 <40 <40 <40 <40 Zr 54 159 64.6 34 141 44.3 41.8 <20 F 200 300 100 100 300 200 200 200 CI S 100 200 200 200 200 500 200 100 Qz 7.79 9.94 15.34 15.55 21.01 C 2.77 . . - - .80 - -Or - 1.97 .24 .37 .12 2.43 .19 10.22 Ab 18.34 13.20 22.69 7.90 41.21 12.19 52.07 14.01 An 21.16 36.87 29.73 32.43 14.28 28.05 19.54 29.53 Oi _ 9.62 3.91 14.22 10.45 - 2.25 7.98 He - 3.38 2.57 4.31 4.12 - .93 3.95 En 32.40 10.36 12.24 16.22 16.41 13.37 10.15 15.22 Fs 13.97 4.17 9.24 5.64 7.41 8.69 4.83 8.64 Fo - - - 1 .24 - 3.31 3.10 Fa - - - - .62 - 2.00 1.94 Wo - - - - - - - -Mt 2.33 5.57 2.98 2.31 1.20 2.80 2.27 2.55 11 .62 4.33 .96 .95 2.76 .74 .99 .75 Hm - - - - - - - -Ap .13 .60 .05 .02 1.96 .10 .05 -Cr 9.33 .95 2.12 Pa ge 230 APPENDIX IV CIPW NORMATIVE VALUES Page 231 ROCK FORMATION GROUP Qz 9 I A C 3 I KUTCHO FORMATION AVERAGE MAXIMUM MINIMUM Or S I A AD 9 I A An 9 I I A Fj S Nt 9 I 11 3 I Ap 3 I A Cc 9 I A 01 9 I HE 9 I 7.09(1)' 33.: (2)" 4O.05((3|* 2.38(1)* 6.68(2)' 3.95(3)* 3.70(1)* 9.98(2)* 5.65(3)* 22.1(1)* 28.5(2)* 33.96(3) 23.7(1)* 6.96(2)* 3.86(3)* 12.6(1)* 3.78(2)* 3.53(3)* 7.20(1)* 2.32(2)* 2.12(3)* 3.38(1)* 1.32(2) 1.27(31 2.34(1)* .774(2)* 0.69(3) 0(1)" .228(2)" 0.04(3)* .442(1)* .226(2)* .28(3)" 4.13(1)" 12.4(2)" 33.62 44.10 56.23 16.81 11.92 12.72 22.5 21.16 20.80 35.17 39.03 61.58 39.97 18.61 21.54 42.81 9.62 11.28 18.17 7.18 16.03 9.16 2.23 3.08 6.40 1.28 1.25 0 1.14 1.0 1.4 .38 .76 24.22 20.55 3.24(3)* 14.84 0 25.81 23.16 0 3.20 0 0 2.59 .18 0 4.37 3.71 0 0 0 0 0.83 0.23 3ASIC SCHIST AVERAGE MAXIMUM MINIMUM 7.24(4)* 15.88 0 4.26(4)" 9.69 0 TAKLA N. KUTCHO AVERAGE MAXIMUM MINIMUM AVERAGE MAXIMUM MINIMUM 7.89(5)* 31.17 0 2.98(51* 14.91 0 0 0 1.38 0.73 0 .64 .22 .23 0 0 0 0(4) " 0 0 3040(6)* 79.5 0 20.2 32.76 .21 8.04(5)* 22.S 1.19 23.4(4)* 38.78 10.51 21.6(5)* 48.58 7.05 2. ,9(6)* 6.86 0 4,73(6)* 21.66 0 25.3(6)* 49.12 0 8.73(4)* 33.2S 0 21.7(5)* 34.56 6.0i 13.1(6)* 36.87 0 10.5(4)* 17.16 1.78 7.64(5)* 16..17 0.45 7.72(4)* 10.44 .70 5.72(51* 10.79 0.2 3.03(4)* 5.36 0.60 2.69(5)" 4.04 1.70 1.20(4)* 1.76 1.19 1.69(5) 2.32 1.02 0(51" 0 0 1.55(4)" 2.22 1.52 U V I 0 . 1 9 5.88(4)" 17.43 0.14 0 ( 5 ) " 0 0 CACHE CREEK AVERAGE MAXIMUM MINIMUM 7.75(7)" 21.01 0 15.34(8)" 1.62(7)" 2.77 0 0 (8)" 0 0 2.5(7)" 10.22 0 .24(8)" 22.70(7)* 52.07 7.90 22.69(8)* 25.98(7)* 36.87 14.28 29.78(8)" 16.30(7)* 32.40 10.15 12.24(8)" 7.66(6)" 32.4 a i 2 3.88(6)" 13.97 0 2.05(6)" 5.57 0 .0055(6)" .11 0 .229(6)" 1.96 0 3.38(6)" 14.65 0 7.62(7)" 13.97 4.17 9.24(8)* 2.79(7)* 4.04 1.70 1.59(7)" 2.76 .62 0(7) 0(7)" .41(7)" 1.96 0 1.84(7)" 9.83 0 6.36(7)" 10.45 0 3.91(8)" 2.38(7)* 4.31 0 2.57(8)" ••SAMPLE NUMBERS (1) N " 25 (2) » • 5 (3) N • 28 (4) N • 17 (5) N . 5 (6) N • 20 (7) N • 7 (8) N • 1 Page 232 APPENDIX V GEOLOGY AND SULPHIDE MINERALOGY OF THE KUTCHO CREEK MASSIVE SULPHIDE DEPOSIT Page 233 INTRODUCTION The Kutcho Creek m a s s i v e s u l p h i d e (Cu - Zn) d e p o s i t i s l o c a t e d i n n o r t h - c e n t r a l B r i t i s h C o l u m b i a i n the C a s s i a r M o u n t a i n Range, 10 km e a s t of the Kutcho Creek and 24 km n o r t h of the Pitman R i v e r ( F i g . 2 . 2 ). The d e p o s i t i s a v o l c a n o g e n i c , s t r a t a b o u n d body w i t h Cu, Zn, Fe and minor amounts of Ag as the p r e d o m i n a n t c o m m o d i t i e s . M i n e r a l s p r e s e n t i n c l u d e ( i n a p p r o x i m a t e o r d e r of abundance) p y r i t e , s p h a l e r i t e , c h a l c o p y r i t e , c h a l c o c i t e and minor amounts of g a l e n a , d i g e n i t e , t e t r a h e d r i t e - t e n n a n i t e , and c o v e l l i t e . Host r o c k s ( t h e Kutcho F o r m a t i o n ) a r e b a s i c to a c i d i c , v o l c a n i c and v o l c a n i c l a s t i c r o c k s o v e r l a i n by a r g i l l i t e s , t u f f a c e o u s a r g i l l i t e s , and c o n g l o m e r a t e and a r e b e l i e v e d to be Upper T r i a s s i c i n age (Monger and T h o r s t a d , 1978). The Kutcho F o r m a t i o n and o v e r l y i n g Sinwa L i m e s t o n e and I n k l i n F o r m a t i o n c o n s t i t u t e the K i n g Salmon A l l o c h t h o n . R e g i o n a l metamorphism, to lower g r e e n s c h i s t f a c i e s , t h o u g h t to be contemporaneous w i t h a major s o u t h w e s t e r l y t h r u s t i n g e v e n t t h a t j u x a p o s e s the K i n g Salmon A l l o c h t h o n a g a i n s t P a l e o z o i c Page 234 and Lower J u r a s s i c r o c k s , has a f f e c t e d the h o s t r o c k s and s u l p h i d e T e c t o n i s m has r e s u l t e d i n i s o c l i n a l f o l d i n g and development of an a x i a l p l a n e s c h i s t o s i t y . Metamorphism and a s s o c i a t e d t e c t o n i s m have l e a d to d e f o r m a t i o n and p a r t i a l r e m o b i l i z a t i o n of the s u l p h i d e body. A v o l c a n o g e n i c e x h a l a t i v e o r i g i n i s p r o p o s e d f o r the d e p o s i t , which i s s i m i l a r to K u r o k o - t y p e d e p o s i t s of J a p a n . Acknowledgements The w r i t e r w i s h e s to acknowledge Sumac Mines L i m i t e d f o r t h e i r a s s i s t a n c e i n p r o v i d i n g i n f o r m a t i o n and d r i l l c o r e samples; Esso M i n e r a l s Canada f o r e x t e n d i n g i n f o r m a t i o n and the G e o l o g i c a l Survey of Canada f o r t h e i r l o g i s t i c a l s u p p o r t d u r i n g the 1977 , 1978 and 1979 summer f i e l d s e a s o n s . P r e v i o u s Work - E x p l o r a t i o n and Development The Kutcho Creek m a s s i v e s u l p h i d e d e p o s i t was f i r s t d e t e c t e d by a r e g i o n a l g e o c h e m i c a l program showing anomalous Cu and Zn v a l u e s . T h i s l e a d to i t s i n i t i a l s t a k i n g by Sumac Mines i n 1972, f o l l o w e d s h o r t l y a f t e r by Esso M i n e r a l s Canada. A ma s s i v e Page 235 s u l p h i d e f l o a t b o u l d e r was l o c a t e d i n 1973, p r o v i d i n g the f i r s t v i s u a l e v i d e n c e of a m a s s i v e body of s u l p h i d e m i n e r a l i z a t i o n . Ground e l e c t r o m a g n e t i c s u r v e y s i n d i c a t e d the p r e s e n c e of a c o n d u c t o r . S i l t s a m p l i n g programs have i n d i c a t e d h i g h Cu and Zn v a l u e s and s o i l g e o c h e m i s t r y i n d i c a t e d anomolous r e s u l t s o n l y a t our near the m a s s i v e s u l p h i d e o u t c r o p a r e a . E x t e n s i v e d r i l l i n g and mapping programs have been c a r r i e d out by both companies to d e t e r m i n e the e x t e n t and grade of the ore body. S e v e r a l g e o p h y s i c a l t e c h n i q u e s have been u t i l i z e d . Ground e l e c t r o m a g n e t i c s , m e n t i o n e d p r e v i o u s l y , was f i r s t u s e d . Ground magnetometer work gave u n i n f o r m a t i v e r e s u l t s due to the l a c k of m a g n e t i c m i n e r a l s i n the d e p o s i t . A p o s i t i v e Bouguer g r a v i t y anomoly of .3 - .6 m i l l i g a l s (D. B r i d g e , unpub.) i s a s s o c i a t e d w i t h the m a s s i v e s u l p h i d e body. Both c h a r g e d p o t e n t i a l and i n d u c e d p o t e n t i a l have been used s u c c e s s f u l l y by Sumac Mines L i m i t e d . A. P a n t e l e y e v and D. P e a r s o n of the B.C. Department of Mines have worked i n t e r m i t t e n t l y on the r e g i o n a l and l o c a l g e o l o g y of the d e p o s i t s i n c e 1974. The r e g i o n a l g e o l o g y was examined by the G e o l o g i c a l Survey of Canada i n t h e 1977 to 1979 summer f i e l d s e a s o n s (Monger, Page 236 J . and T h o r s t a d , L. , 1978). G e o g r a p h i c S e t t i n g The d e p o s i t l i e s w i t h i n the C a s s i a r M o u n t a i n Range. E l e v a t i o n range from 1215 to 2300m i n the Cry Lake Map Area ( 1 0 4 1 ) . T r e e l i n e f o l l o w s the 1525 m c o n t o u r and a l a r g e p e r c e n t a g e of the d e p o s i t a r e a i s above i t . R e l i e f w i t h i n the d e p o s i t a r e a has a maximum of 1070 m. E x t e n s i v e g l a c i a t i o n has o c c u r r e d i n the a r e a l e a v i n g t i l l r a n g i n g i n t h i c k n e s s from 3 to 16 m, U-shaped v a l l e y s , m o r a i n e s and c i r q u e s . Poor d r a i n a g e , w i t h abundant swamps i n low l y i n g a r e a s , c h a r a c t e r i z e s the r e g i o n . A c c e s s At p r e s e n t the Kutcho a r e a i s a c c e s s e d by a i r t r a n s p o r t . There i s an a i r s t r i p on Kutcho Creek w i t h r o a d a c c e s s to the Kutcho zone. The C a s s i a r - S t e w a r t Highway runs a l o n g the w e s t e r n margin of the C r y Lake Map S h e e t . A w i n t e r c a t t r a i l c u r r e n t l y e x i s t s , r u n n i n g from Dease Lake to L e t a i n . Lake to H o t t a h Lake (32 km from the d e p o s i t ) . Page 237 C a s u a l H e l i c o p t e r c h a r t e r i s a v a i l a b l e a t Dease Lake and E d d o n t e n a j o n Lake (20 km s o u t h w e s t of the map s h e e t ) . F i x e d wing c h a r t e r s a r e a v a i l a b l e a t Dease Lake or Watson Lake (150 km to the n o r t h ) . There a r e no l a k e s w i t h i n the a r e a f o r f l o a t c r a f t to u t i l i z e , but 6-7 km from the showings an a i r s t r i p has been c o n s t r u c t e d ( a d j a c e n t the Kutcho R i v e r ) . S c h e d u l e d f l i g h t s o c c u r on a r e g u l a r b a s i s from Dease and Watson L a k e s . L o g i s t i c s S u p p l i e s and a c c o m o d a t i o n a r e a v a i l a b l e a t Watson Lake and l i m i t e d s u p p l i e s a r e a v a i l a b l e at Dease and E d d o n t e n a j o n L a k e s . The work s e a s o n i s from mid June to l a t e September. Summer weather i s g e n e r a l l y poor to m o d e r a t e l y good w i t h f r e q u e n t r a i n f a l l and snow above p e r s i s t i n g 1525 m. Geol o g y The Kutcho Creek d e p o s i t o c c u r s w i t h i n a sequence of b a s a l t i c t o a c i d i c f l o w and v o l c a n i c l a s t i c r o c k s of Upper T r i a s s i c age. An upper sequence of d o m i n a n t l y a c i d i c f r a g m e n t a l u n i t s and f l o w s h o s t t h e s u l p h i d e m i n e r a l i z a t i o n and the d e p o s i t s i t s s t r a t i g r a p h i c a l l y h i g h i n t h i s f r a g m e n t a l package c l o s e to the Page 238 c o n t a c t w i t h an o v e r l y i n g t u f f and a r g i l l i t e s e q u e n c e . F i g u r e 3.1 ( i n t e x t ) i l l u s t r a t e s s t r a t i g r a p h i c r e l a t i o n s h i p s of u n i t s w i t h i n the Kutcho Assemblage. The r o c k s a r e t h r u s t on T r i a s s i c to J u r a s s i c s t r a t a . The base of the s e c t i o n i s not exposed w i t h i n the a r e a of the d e p o s i t , but may be exposed f u r t h e r n o r t h (Monger and T h o r s t a d , 1978). W i t h i n the map a r e a the l o w e s t r o c k s a r e a t h i c k sequence of b a s i c to i n t e r m e d i a t e l i t h i c t u f f s , ash t u f f s , b r e c c i a s and f l o w s , which ar e o v e r l a i n by a d a c i t i c to r h y o l i t i c sequence of f i n e , grey s e r i c i t e to c o a r s e f r a g m e n t a l s e r i c i t e s c h i s t s . These r o c k s form the f o o t w a l l of the d e p o s i t and c o n t a i n d i s s e m i n a t e d p y r i t e f o r t h i c k n e s s e s i n e x c e s s of 150 m. below the a c t u a l m a s s i v e s u l p h i d e h o r i z o n . The m a s s i v e s u l p h i d e h o r i z o n o v e r l i e s f o o t w a l l r o c k s w i t h a g r a d a t i o n a l c o n t a c t as d i s s e m i n a t e d s u l p h i d e s become i n c r e a s i n g l y m a s s i v e and minor amounts of b o r n i t e and c h a l c o p y r i t e b e g i n to o c c u r w i t h p y r i t e . Both d i s s e m i n a t e d s u l p h i d e s and m a s s i v e s u l p h i d e l e n s e s o c c u r i n the h a n g i n g w a l l . Hanging w a l l r o c k s a r e f e l d s p a r , q u a r t z - e y e , s e r i c i t e s c h i s t s t h a t g r ade i n t o s i l i c e o u s q u a r t z - e y e s c h i s t . O v e r l y i n g t h i s i s a h o r i z o n of t u f f and a r g i l l i t e t h a t i s i n p a r t a f a c i e s Page 239 e q u i v a l e n t of the h a n g i n g w a l l a c i d v o l c a n i c s . A l e n s of b a s i c s c h i s t o c c u r s i n the t u f f and a r g i l l i t e u n i t and i s l o c a l l y the h a n g i n g w a l l h o r i z o n . T h i s u n i t i s somewhat e n i g m a t i c . P a n t e l e y e v (1975) has c a l l e d i t a "metagabbro" s u g g e s t i n g t h a t i t i s i n t r u s i v e i n n a t u r e . Mapping by the G e o l o g i c a l S u r v e y of Canada i n the 1977 and 1978 f i e l d s e a s o n s s u g g e s t i t may be a l e n t i c u l a r body of b a s i c f l o w s and v o l c a n i c l a s t i c r o c k s . A c o n g l o m e r a t e - a r g i l l i t e h o r i z o n caps the package, and a p p e a r s to r e p r e s e n t no major u n c o n f o r m i t y . The Sinwa L i m e s t o n e (Upper T r i a s s i c ) r e s t s on and i s g r a d a t i o n a l w i t h the upper c o n g l o m e r a t e . A l l r o c k s w i t h i n the a r e a have been i s o c l i n a l l y f o l d e d . In the p r o p e r t y a r e a a l a r g e a n t i c l i n a l s t r u c t u r e t h a t i s s l i g h t l y o v e r t u r n e d to the s o u t h c o n t r o l s o u t c r o p p a t t e r n s . M a s s i v e S u l p h i d e Body Morphology The s t r a t a b o u n d , m a s s i v e s u l p h i d e body i n a c i d f r a g m e n t a l r o c k s i s s e m i c o n t i n u o u s f o r a s t r i k e l e n g t h of- a p p r o x i m a t e l y t h r e e and one h a l f k i l o m e t r e s t r e n d i n g g e n e r a l l y e a s t - w e s t and d i p p i n g a p p r o x i m a t e l y 45 d e g r e e s to the n o r t h . Four main zones have been i d e n t i f i e d ( B r i d g e , 1979, unpub.) and t h e s e a r e : the Kutcho zone Page 240 which i s ore grade; the Sumac West zone, a f i n e g r a i n e d p y r i t i c zone and two Esso West z o n e s , which a r e t e x t u r a l l y s i m i l a r to the Kutcho zone. The s u l p h i d e body i s t a b u l a r and l e n t i c u l a r , p i n c h i n g and s w e l l i n g a l o n g i t s l e n g t h ; main ore o c c u r r e n c e s a r e i n t e r p r e t e d to o c c u r at or near the top of r h y l o t i t e domes. T h i n , l e n t i c u l a r p y r i t i c zones o c c u r i n both f o o t w a l l and h a n g i n g w a l l s of the main s u l p h i d e h o r i z o n . C a r b o n a t e l a y e r s and l e n s e s o c c u r t h r o u g h o u t . M i n e r a l i z a t i o n The showing i s p r i m a r i l y a Cu - Zn - Fe d e p o s i t . The m i n e r a l o g y of the d e p o s i t w i l l be d i s c u s s e d i n d e t a i l i n the l a t t e r h a l f of t h i s r e p o r t . The main m i n e r a l i z e d zone (80 - 85% s u l p h i d e s ) c o n s i s t p r e d o m i n a n t l y of p y r i t e , c h a l c o p y r i t e , s p h a l e r i t e and l e s s e r amounts of b o r n i t e and c h a l c o c i t e w i t h t r a c e amounts of t e t r a h e d r i t e - t e n n a n i t e , d i g e n i t e , and g a l e n a . P y r r h o t i t e i s r e p o r t e d by D. B r i d g e (1978, pers.comm.) and by M. Weber (unpub. BSc t h e s i s ) , however no p y r r h o t i t e was o b s e r v e d i n p o l i s h e d s e c t i o n s examined by the w r i t e r . Ag v a l u e s tend to be a s s o c i a t e d w i t h copper m i n e r a l i z a t i o n ( B r i d g e , u n pub.). P o l i s h e d s e c t i o n work by the w r i t e r s u p p o r t s t h i s . T r i a n g u l a r p l o t s (PV - CP+BO+CC+DG+C V- SL Page 241 and GA - CP+BO+CC+DG+CV - SL) show the pred o m i n a n t m i n e r a l i z a t i o n . P y r i t e t e n d s to be the major m i n e r a l w h i l e b o r n i t e , c h a l c o p y r i t e , c h a l c o c i t e c o v e l l i t e (Cu Fe) show s l i g h t l y g r e a t e r c o n c e n t r a t i o n than s p h a l e r i t e ( Z n ) . T h e r e i s a marked d e f i c i e n c y i n g a l e n a (Pb) v a l u e s . Gangue Gangue, a s s o c i a t e d w i t h the s u l p h i d e s , i s p r e d o m i n a n t l y c a r b o n a t e , s e r i c i t e and q u a r t z ; a l l o f t e n i n t i m a t e l y mixed. Q u a r t z - eye, s e r i c i t e s c h i s t i s common w i t h d i s s e m i n a t e d s u l p h i d e s , w h i l e c a r b o n a t e and/or s e r i c i t e t e n d s to o c c u r w i t h more m a s s i v e o r e . M a s s i v e d o l o m i t e l e n s e s c o n t a i n i n g l a r g e amounts of d i s s e m i n a t e d s u l p h i d e s o c c u r commonly i n the m a s s i v e o r e . C a r b o n a t e o c c u r s as a d i s t i n c t l a y e r a t the top of m i n e r a l i z e d h o r i z o n s . The n a t u r e of the c a r b o n a t e gangue w i l l be d i s c u s s e d i n more d e t a i l i n the l a t t e r h a l f of t h i s r e p o r t . Hanging W a l l S u l p h i d e s S e v e r a l l e n s e s of m a s s i v e s u l p h i d e , c o n f o r m a b l e w i t h h o s t r o c k s c h i s t and c a r b o n a t e , o c c u r i n the h a n g i n g , w a l l of the d e p o s i t . T h r e e d e f i n i t e l e n s e s have been r e c o g n i z e d i n s u c c e s s i v e s t r a t i g r a p h i c h o r i z o n s and may p o i n t to t h r e e m i n e r a l i z i n g e v e n t s Page 242 ( S c o t t , p e r s . comm., 1977). B r i d g e ( p e r s . comm. 1977) s u g g e s t s t h a t the m i n e r a l o g y of the l e n s e s ( i . e . b o r n i t e , c h a l c o p y r i t e and c h a l c o c i t e ) p o i n t s to the p o s s i b i l i t y t h a t some l e n s e s are r e m o b i l i z e d s u l p h i d e s from the main ore zone and may i n f a c t be b a r r e n , p y r i t i c h o r i z o n s t h a t have been r e p l a c e d by cop p e r m i n e r a l i z a t i o n . F o o t w a l l S u l p h i d e s F o o t w a l l s u l p h i d e s , g e n e r a l l y as d i s s e m i n a t e d p y r i t e or v e r y s m a l l m a s s i v e s u l p h i d e l e n s e s a r e found i n q u a r t z , s e r i c i t e and c a r b o n a t e gangue below the main zone of m i n e r a l i z a t i o n . S m a l l m a s s i v e s u l p h i d e l e n s e s a r e found up to 39 metres below the ma s s i v e h o r i z o n and d i s s e m i n a t e d p y r i t e g e n e r a l l y i n c r e a s e s i n c o n c e n t r a t i o n u p s e c t i o n to the m a s s i v e s u l p h i d e h o r i z o n . M i n e r a l Z o n a t i o n No d e f i n i t e m i n e r a l z o n a t i o n has been found w i t h i n the ma s s i v e o r e a l t h o u g h B r i d g e (1979, unpub.) s u g g e s t s t h e r e may be an i n v e r s e z o n a t i o n from the c l a s s i c Kuroko d e p o s i t s , w i t h a copper r i c h t o p and s l i g h t l y more z i n c r i c h b a s e . B r i d g e (1979) does however r e c o g n i z e a w e l l d e v e l o p e d l a t e r a l z o n a t i o n as s u l p h i d e b o d i e s have a v e r a g e copper to z i n c r a t i o s of 0.5 w h i l e Page 243 l a t e r a l e x h a l i t e f a c i e s have co p p e r to z i n c r a t i o s of 0.1. D i s s e m i n a t e d s u l p h i d e f e e d e r zones a r e b a r r e n . I n t e r n a l S t r u c t u r e and Ore T e x t u r e s The o r e r a n g e s from m a s s i v e to w e l l - l a y e r e d . M a s s i v e ore i s g e n e r a l l y a v e r y dense, compact g r a n u l a r a g g r e g a t e t h a t g r a d e s i n t o d i s s e m i n a t e d a n h e d r a l to e u h e d r a l g r a i n s ( l a r g e l y p y r i t e ) . L a y e r e d s p e c i m e n s v a r y from v e r y p o o r l y l a y e r e d to w e l l l a y e r e d , w i t h l a m i n a t i o n s r a n g i n g from 1 - 2 0 mm. Graded b e d d i n g , i n d i c a t i n g t o p s r i g h t s i d e up, i s p r e s e n t but not common. D e f o r m a t i o n of the o r e makes i d e n t i f i c a t i o n of o t h e r p r i m a r y s t r u c t u r e s d i f f i c u l t as a p e n e t r a t i v e f o l i a t i o n o c c u r s t h r o u g h o u t most of the p r i m a r y m i n e r a l s . T h e r e a r e some p o s s i b l e p r i m a r y s t r u c t u r e s worthy of m e n t i o n . P o s s i b l e c o n v o l u t e d l a m i n a t i o n (due to s y n - d e p o s i t i o n a l d e f o r m a t i o n ? ) o c c u r s w i t h f o l d i n g d e v e l o p e d i n l a y e r s under and o v e r l a i n by what appear to be undeformed l a m i n a e . T h i s may be due to some l a y e r s b e h a v i n g i n a more d u c t i l e f a s h i o n than o t h e r s . P o s s i b l e l o a d s t r u c t u r e s a r e e v i d e n t under l a y e r s of b r e c c i a . They appear to be of a p r i m a r y n a t u r e ( i . e . due to sediment l o a d i n g ) but may be due to ' f l o w ' of f o l i a t i o n and Page 244 l a y e r i n g around f r a g m e n t s d u r i n g d e f o r m a t i o n or p r o p h y r o b l a s t i c growth of m i n e r a l a g g r e g a t e s d u r i n g d e f o r m a t i o n . B r e c c i a t e x t u r e s a r e r a r e and g e n e r a l l y appear to be of p r i m a r y o r i g i n due to the n a t u r e of the gangue and s u l p h i d e m a t r i x . S u l p h i d e s o f t e n appear r e m o b i l i z e d i n b r e c c i a t e d a r e a s . R e m o b i l i z a t i o n of some s u l p h i d e s ( i . e . c h a l c o p y r i t e , b o r n i t e - + s p h a l e r i t e ) o f t e n c r e a t e s s e c o n d a r y b r e c c i a t e x t u r e s . M i c r o f a u l t i n g i s e v i d e n t w i t h o f f s e t s on q u a r t z v e i n l e t s and s u l p h i d e b l e b s from 2 - 1 0 mm. A l t e r a t i o n I t i s d i f f i c u l t to e s t a b l i s h d e f i n i t e a l t e r a t i o n m i n e r a l a s s e m b l a g e s a s s o c i a t e d w i t h the m i n e r a l i z i n g event due to a r e g i o n a l metamorphic o v e r p r i n t , t h a t has l e d to e x t e n s i v e s e r i c i t i z a t i o n of the r o c k s . D o l o m i t i c a l t e r a t i o n of h a n g i n g w a l l r o c k s a p p e a r s to be r e l a t e d to m i n e r a l i z a t i o n and i s c h a r a c t e r i z e d by the p r e s e n c e of e u h e d r a l d o l o m i t e rhombs t h a t o f t e n d e f l e c t f o l i a t i o n . T h e r e does appear to be an a r e a of more i n t e n s e s e r i c i t i z a t i o n a s s o c i a t e d w i t h the d e p o s i t ( B r i d g e , 1978, p e r s . comm.). Rock c h e m i s t r y p e r f o r m e d f o r Esso M i n e r a l s Canada has l e d Page 245 D. B r i d g e ( p e r s . comm., 1978) to s u g g e s t an e l e m e n t a l z o n a t i o n a r ound the d e p o s i t , w i t h Na20 d e p l e t i o n and r e l a t i v e e n r i c h m e n t i n K20 and S i 0 2 as w e l l as MgO and CaO. Data from B r i d g e u n p u b l i s h e d r e p o r t shows a s t r o n g t r e n d f o r e n r i c h m e n t ( s e v e n t i m e s the a v e r a g e f o r r o c k s of the a r e a ) of MgO and CaO i n r o c k s a s s o c i a t e d w i t h the ore body. K20 i s e n r i c h e d by a f a c t o r of two i n c o m p a r i s o n to c o u n t r y r o c k s . S i 0 2 c o n t e n t i s h i g h . B r i d g e s s t a t e s t h a t t e x t u r a l e v i d e n c e g i v e s l i t t l e i n d i c a t i o n f o r s e c o n d a r y i n t r o d u c t i o n o f S i 0 2 so t h a t the h i g h s i l i c a c o n t e n t of the r o c k s i s a p r i m a r y f e a t u r e of t h e r o c k s . H e m a t i t e i s found i n the m a t r i x or groundmass and i s commonly a s s o c i a t e d w i t h q u a r t z eyes i n the f e l d s p a r , q u a r t z - e y e p r o p h y r y s c h i s t s . S t a n t o n (1972) has s u g g e s t e d t h a t i r o n s i l i c a t e s o f t e n a l t e r to q u a r t z and h e m a t i t e d u r i n g metamorphism and t h i s may be the o r i g i n f o r the h e m a t i t i c q u a r t z e y e s . Metamorphism Metamorphism, b e l i e v e d contemporaneous w i t h major t h r u s t i n g (Monger and T h o r s t a d , 1978) has a f f e c t e d a l l r o c k s i n c l u d i n g t h e m a s s i v e s u l p h i d e body w i t h i n the Kutcho F o r m a t i o n . Most r o c k s a r e metamorphosed to lower g r e e n s c h i s t f a c i e s and t h e r e i s abundant e v i d e n c e f o r r e c r y s t a l l i z a t i o n of c h a l c o p y r i t e , Page 246 b o r n i t e and s p h a l e r i t e w i t h i n the s u l p h i d e h o r i z o n . P y r i t e a l s o shows a n n e a l e d t e c t o n i c f r a c t u r e s and some e u h e d r a l r e c r y s t a l l i z e d f o r m s . M i n e r a l o g y of the Kutcho Creek D e p o s i t The m i n e r a l o g y of the d e p o s i t i s r e l a t i v e l y s i m p l e . Cu-Zn-Fe a r e the major c o m m o d i t i e s w i t h minor amounts of Ag. The major s u l p h i d e m i n e r a l s a r e p y r i t e , s p h a l e r i t e , c h a l c o p y r i t e , b o r n i t e , w i t h l e s s e r amounts of c h a l c o c i t e and t r a c e amounts of t e t r a h e d r i t e - t e n n a n i t e , g a l e n a , d i g e n i t e , c o v e l l i t e and The gangue i s c a r b o n a t e , q u a r t z and s e r i c i t e w i t h c a r b o n a t e as the p r e d o m i n a n t m i n e r a l . A d e t a i l e d d i s c u s s i o n of m i n e r a l s and m i n e r a l t e x t u r e s f o l l o w s . To f a c i l i t a t e d i s c u s s i o n the f o l l o w i n g a b b r e v i a t i o n s w i l l be used i n the t e x t : BO - B o r n i t e CC - C h a l c o c i t e CP - C h a l c o p y r i t e CV - C o v e l l i t e DG - D i g e n i t e GA - G a l e n a Page 247 PY - P y r i t e SL - S p h a l e r i t e TT-TN - T e t r a h e d r i t e - T e n n a n i t e C a r b o n a t e Gangue S t a i n i n g , u s i n g A l i z a r i n Red and P o t a s s i u m F e r r i c y a n i d e and HC1 s o l u t i o n i n d i c a t e d the p r e s e n c e of abundant c a r b o n a t e i n the form of d o l o m i t e , f e r r o a n d o l o m i t e and c a l c i t e . L i m o n i t i c c a r b o n a t e gangue, found as t h i n l a m i n a e both above and i n ore zones ( o r a n g e on f r e s h s u r f a c e ) i s p r e d o m i n a n t l y f e r r o a n d o l o m i t e as d e t e r m i n e d by X-ray d i f f r a c t i o n and A l i z a r i n Red. N o n - l i m o n i t i c d o l o m i t e and f e r r o a n d o l o m i t e (CaMg .67 Fe .33 ( C03)2) o c c u r t h r o u g h o u t the ore h o r i z o n as m a s s i v e l e n s e s and/or s u l p h i d e m a t r i x . X-ray d i f f r a c t i o n of the c a r b o n a t e i n d i c a t e d the p r e s e n c e of m a g n e s i t e (MgC03) w i t h i n the sample. Minor amounts of c a l c i t e o c c u r i n the o r e , as i n d i c a t e d by a p o s i t i v e A l i z a r i n Red t e s t , a l t h o u g h X-ray d i f f r a c t i o n d i d not show peaks f o r c a l c i t e . C a l c i t e t e n d s to be i r r e g u l a r b l e b s , g e n e r a l l y non- f o l i a t e d and a p p e a r s to p o s t d a t e or be contemporaneous w i t h t e c t o n i s m . Page 248 T h i n c a r b o n a t e l a y e r s w i t h i n the s e r i c i t e s c h i s t a r e d o l o m i t e and f e r r o a n d o l o m i t e and g e n e r a l l y p a r a l l e l the f o l i a t i o n . D o l o m i t e and f e r r o a n d o l o m i t e a l s o o c c u r as v e i n l e t s f i l l i n g f r a c t u r e s . Rhombic d o l o m i t e p o r p h y r o b l a s t s are common i n the h a n g i n g w a l l and b e l i v e d r e l a t e d to o r i g i n a l m i n e r a l i z i n g f l u i d s , but may have been p a r t i a l l y r e m o b i l i z e d d u r i n g metamorphism. Some d o l o m i t e rhombs show a p r e f e r e n t i a l a l i g n m e n t p a r a l l e l the f o l i a t i o n , which may have o c c u r r e d due to growth d u r i n g metamorphism - or t e c t o n i c a l i g n m e n t . C a r b o n a t e i s b e l i e v e d to be an e x h a l i t i v e p r o d u c t r e l a t e d to v o l c a n i s m contemporaneous w i t h s u l p h i d e d e p o s i t i o n . Q u a r t z Gangue Q u a r t z c o n s t i t u t e s a major p o r t i o n of the gangue and i s g e n e r a l l y a s s o c i a t e d w i t h a s e r i c i t e s c h i s t , but a l s o o c c u r s a l o n e or w i t h c a r b o n a t e . I t i s commonly m i l k y w h i t e to c l e a r i n c o l o u r and i s o b s e r v e d as f r a g m e n t s i n b r e c c i a s , as g r a n u l a r a g g r e g a t e s and q u a r t z eyes i n s e r i c i t e s c h i s t and v e i n s t h a t both pre and p o s t d a t e t e c t o n i s m . E a r l i e r q u a r t z v e i n s a r e o f t e n a l m o s t Page 249 c o m p l e t e l y o b l i t e r a t e d due to t e c t o n i s m , but a r e s t i l l e v i d e n t . These commonly c o n t a i n b o r n i t e and c h a l c o p y r i t e . L a t e r , post or s y n t e c t o n i c q u a r t z v e i n s a r e g e n e r a l l y b a r r e n , but o f t e n show a gossanous h a l o . P y r i t e P y r i t e i s u b i q u i t o u s t h r o u g h o u t the ore and o c c u r s as d i s s e m i n a t i o n s r a n g i n g from 10-50% i n the f o o t w a l l and h a n g i n g w a l l as w e l l as i n the m a s s i v e o r e . D i s s e m i n a t e d g r a i n s a r e g e n e r a l l y a n h e d r a l to s u b h e d r a l and ten d to be f l a t t e n e d i n the p l a n e of the f o l i a t i o n . G r a i n s i z e v a r i e s from v e r y f i n e to c o a r s e . M a s s i v e p y r i t e o c c u r s as dense, a n h e d r a l , g r a n u l a r a g g r e g a t e s ; s u b h e d r a l f r a m b o i d s ; and i d i o m o r p h i c to s u b i o d o m o r p h i c g r a i n s i n o t h e r s u l p h i d e s . P y r i t e g r a i n s t e n d to deform i n a b r i t t l e manner, a l t h o u g h t h e r e i s some e v i d e n c e of r e c r y s t a l l i z a t i o n . More d u c t i l e d e f o r m a t i o n of p y r i t e c a u s e s f l a t t e n i n g of g r a i n s p a r a l l e l the f o l i a t i o n . G r a i n s , however, do not appear to have ' f l o w e d ' i n t o t h i s c o n f i g u r a t i o n and may be p a r t i a l l y r e c r y s t a l l i z e d g r a n u l a t e d g r a i n s . F r a c t u r e s i n p y r i t e , both p a r a l l e l and p e r p e n d i c u l a r to the f o l i a t i o n o f t e n c r e a t e e l o n g a t e d g r a i n s . In one c a s e , f r a g m e n t s of p y r i t e c r e a t e d by a s e r i e s of f r a c t u r e s Page 250 p a r a l l e l the f o l i a t i o n o f t e n show an e c h e l o n d i s p l a c e m e n t s a l o n g the f o l i a t i o n . The degree of f o l i a t i o n a p p e a r s to have some r e l a t i o n to the p e r c e n t a g e of gangue and r e l a t i v e amounts of p y r i t e ; as d i s s e m i n a t e d p y r i t e t e n d s to show g r e a t e r d e g r e e s of f l a t t e n i n g t h an more m a s s i v e p y r i t e . In one i n s t a n c e n o n f o l i a t e d p y r i t e g r a i n s were o b s e r v e d i n q u a r t z i t i c l e n s e s a d j a c e n t to f o l i a t e d p y r i t e i n s e r i c i t e gangue. I d i o m o r p h i c p y r i t e i s common and i s b e l i e v e d to be the r e s u l t of r e c r y s t a l l i z a t i o n . F r a m b o i d a l a g g r e g a t e s may be of p r i m a r y or of metamorphic o r i g i n . L i m o n i t e pseudomorphs a f t e r p y r i t e a l s o o c c u r . C h a l c o p y r i t e , b o r n i t e and minor amounts of s p h a l e r i t e a l l r e p l a c e p y r i t e a l o n g f r a c t u r e s . A l l of t h e s e m i n e r a l s a r e o b s e r v e d to embay p y r i t e and o c c u r as i r r e g u l a r b l e b s w i t h i n i t . One sample e x h i b i t e d r i m s of s u b h e d r a l p y r i t e r i m s f i l l e d w i t h s p h a l e r i t e t h a t c o n t a i n e d i r r e g u l a r f r a g m e n t s of p y r i t e . B o r n i t e i s the most common r e p l a c e m e n t of p y r i t e and one o c c u r r e n c e of b o r n i t e psuedomorphing c u b i c p y r i t e was o b s e r v e d . Replacement of p y r i t e may a c t u a l l y have been s y n c h r o n e o u s w i t h o r e d e p o s i t i o n as l a t e r h y d r o t h e r m a l f l u i d s i n t r o d u c e d copper and z i n c to the syst e m . Page 251 I n t i m a t e i n t e r g r o w t h s w i t h gangue s u g g e s t p y r i t e i s s y n d e p o s i t i o n a l w i t h gangue. The g e n e r a l s u b h e d r a l to e u h e d r a l n a t u r e of p y r i t e s u p p o r t s e a r l y d e p o s i t i o n . S p h a l e r i t e S p h a l e r i t e (SL) i s i n t e r s t i t i a l w i t h r e s p e c t to p y r i t e and gangue, has mutual g r a i n b o u n d a r i e s w i t h b o r n i t e and c h a l c o p y r i t e and may c o n t a i n v e r y s m a l l , s u b r o u n d e d c h a l c o p y r i t e b o d i e s . T e x t u r a l e v i d e n c e s u g g e s t t h a t SL i s s y n d e p o s i t i o n a l w i t h BO and CP. S m a l l CP b o d i e s may be the r e s u l t of e x s o l u t i o n or metamorphism. The f o r m e r o r i g i n i s f a v o u r e d by t h e w r i t e r . S p h a l e r i t e commonly r e p l a c e s PY a l o n g f r a c t u r e s and g r a i n b o u n d a r i e s . I t a l s o o c c u r s as embayments i n PY. One sample s u g g e s t s p o s s i b l e r e p l a c e m e n t by CP. C h a l c o p y r i t e C h a l c o p y r i t e a p p e a r s i n t e r s t i t i a l to PY and gangue. I t o c c u r s b o t h as f o l i a t e d b l e b s e l o n g a t e p a r a l l e l to the f o l i a t i o n and as m a s s i v e randomly o r i e n t e d , i r r e g u l a r b l e b s h a v i n g random o r i e n t a t i o n s . I t has mutual g r a i n b o u n d a r i e s w i t h SL and BO s u g g e s t i n g s y n d e p o s i t i o n a l r e l a t i o n s . CP commonly o c c u r s i n BO as Page 252 t h i n l a m e l l a e ( c u b i c o r i e n t a t i o n more f r e q u e n t than rhombic o n e s ) , as s m a l l i r r e g u l a r b l e b s , as r i m s and as m y r m e k i t i c i n t e r growths . L a m e l l a e a r e o f t e n o f f s e t and t r u n c a t e d by f r a c t u r e s i n b o r n i t e . These t e x t u r e s s u g g e s t p o s s i b l e e u t e c t i c c r y s t a l l i z a t i o n of BO and CP, but may be the r e s u l t of metamorphism. S m a l l b e l b s of CP i n SL a r e n o t e d , but not common. These a r e most l i k e l y e x s o l u t i o n t e x t u r e s , but a g a i n may be metamorphic i n o r i g i n . CP commonly r e p l a c e s PY a l o n g f r a c t u r e s and a t g r a i n b o u n d a r i e s . C o v e l l i t e (CV) i s o b s e r v e d o c c u r r i n g between BO and CP and may be r e p l a c i n g b o t h m i n e r a l s . D i g e n i t e a l s o a p p e a r s to r e p l a c e CP . M a s s i v e CP b l e b s a r e b e l i e v e d to be the p r o d u c t of r e m o b i l i z a t i o n of s u l p h i d e s d u r i n g metamorphism. R e m o b i l i z e d CP a l s o o c c u r s a l o n g f r a c t u r e s and m i c r o v e i n l e t s p e r p e n d i c u l a r to the l a y e r i n g . B o r n i t e B o r n i t e a p p e a r s i n t e r s t i t i a l to gangue and p y r i t e and s h a r e s m utual g r a i n b o u n d a r i e s w i t h s p h a l e r i t e and c h a l c o p y r i t e . W e l l f o l i a t e d , d i s s e m i n a t e d b l e b s of BO a r e commonly t r u n c a t e d by m a s s i v e , n o n - f o l i a t e d b l e b s t h a t appear to be the r e s u l t of Page 253 r e m o b i l i z a t i o n . M a s s i v e BO b l e b s a r e commonly a s s o c i a t e d w i t h CC. BO a l s o o c c u r s a l o n g v e i n s and f r a c t u r e s and i n one sample, BO b l e b s a r e f o l i a t e d and o f f s e t i n an en e c h e l o n manner to the f o l i a t i o n . T h i s a p p e a r s to have been a p r e t e c t o n i c v e i n t h a t has been, i n p a r t , r e m o b i l i z e d and d e f o r m e d . B o r n i t e g e n e r a l l y c o n t a i n s l a m e l l a e and i r r e g u l a r b o d i e s of CP. I t i s a l s o rimmed by CP s u g g e s t i n g p o s s i b l e e x s o l u t i o n of CP i n BO. M y r m e k i t i c i n t e r g r o w t h s a l s o o c c u r and may r e p r e s e n t mutual e x s o l u t i o n . I t i s p o s s i b l e t h a t t h e s e t e x t u r e s a r e the r e s u l t of metamorphism. B o r n i t e - c h a l c o c i t e commonly o c c u r as m y r m e k i t i c to s u b g r a p h i c i n t e r g r o w t h s . In one sample l a m e l l a e of CC a r e e v i d e n t i n BO. Both a r e found rimming each o t h e r . The former t e x t u r e s may r e p r e s e n t mutual e x s o l u t i o n w h i l e the l a t t e r s u g g e s t c h a l c o c i t e e x s o l u t i o n i n b o r n i t e . A g a i n , metamorphism may be r e s p o n s i b l e f o r t h e s e t e x t u r e s . D i g e n i t e o c c u r s a l o n g f r a c t u r e s , g e n e r a l l y as t h i n v e i n - l i k e b o d i e s , but a l s o as i r r e g u l a r b l e b s i n BO. C o v e l l i t e o c c u r s a l o n g g r a i n b o u n d a r i e s and f r a c t u r e s between CP and BO. Page 254 Both DG and CV are i n t e r p r e t e d as l a t e r r e p l a c e m e n t m i n e r a l s . C h a l c o c i t e C h a l c o c i t e o c c u r s as m y r m e k i t i c to s u b - g r a p h i c i n t e r g r o w t h s and as t h i n l a m e l l a r b o d i e s i n BO. T e x t u r e s s u g g e s t a e u t e c t i c r e l a t i o n between CC and BO, but metamorphic r e c r y s t a l l i z a t i o n may a l s o be r e s p o n s i b l e . D i g e n i t e D i g e n i t e i s p r e s e n t i n o n l y s m a l l amounts r e p l a c i n g p r i m a r y m i n e r a l s . The r a r e p r e s e n c e of o r i e n t e d , t h i n l a m e l l a r b o d i e s of DG may s u p p o r t an e x s o l u t i o n o r i g i n but t h e r e i s a p o s s i b i l i t y t h a t t h e s e b o d i e s a r e s u l t of DG p r e f e r e n t i a l l y r e p l a c i n g CP l a m e l l a e or DG i s r e p l a c i n g BO a l o n g c l e a v a g e b o u n d a r i e s . DG g e n e r a l l y o c c u r s a l o n g f r a c t u r e s i n BO but i s a l s o o b s e r v e d c u t t i n g a c r o s s CP l a m e l l a e , s u p p o r t i n g the i d e a t h a t i t p o s t - d a t e s i n i t i a l c r y s t a l l i z a t i o n and c o o l i n g . I t a l s o o c c u r s a t g r a i n b o u n d a r i e s between CP and BO, p o s s i b l y as a r e a c t i o n zone between t h e two m i n e r a l s or a mutual e x s o l u t i o n p r o d u c t . Page 255 C o v e l l i t e C o v e l l i t e i s r a r e , but p r e s e n t , o c c u r r i n g on r i m s and o c c a s i o n a l l y a l o n g f r a c t u r e s i n BO. I t i s a l s o n o t e d between CP and BO. CV i s t h o u g h t to be s e c o n d a r y r e p l a c e m e n t . T e t r a h e d r i t e - T e n n a n i t e (TT-TN) TT - TN o c c u r s w i t h BO and CP as i r r e g u l a r g r a i n s . In one sample.TT - TN i s s u r r o u n d e d by a d i s c o n t i n u o u s r i m of CP, s u g g e s t i n g CP may be r e p l a c i n g TT. G a l e n a G a l e n a i s r a r e , but does o c c u r as i r r e g u l a r g r a i n s both i n and p e r i p h e r a l l y to BO. I t a p p e a r s to be the l a s t m i n e r a l d e p o s i t e d . Summary: T e x t u r e s P r i m a r y , metamorphic and r e p l a c e m e n t t e x t u r e s a r e a l l p r e s e n t w i t h i n the o r e . Many t e x t u r e s have more than one p o s s i b l e Page 256 i n t e r p r e t a t i o n and d e t a i l e d d i s c u s s i o n s of t h e s e t e x t u r e s have been i n c l u d e d i n the p r e v i o u s d i s c u s s i o n of the m i n e r a l o g y . A. summary of o b s e r v e d t e x t u r e s i s p r e s e n t e d i n p o i n t form below: 1. M y r m e k i t i c i n t e r g r o w t h s - BO and CP BO and CC 2. L a m e l l a r t e x t u r e s - CP l a t h e s i n BO minor DG l a t h e s i n BO 3. S u b g r a p h i c t e x t u r e s - BO and CC a l s o minor CP and BO 4. Rim t e x t u r e s - CP r i m s BO and TT BO r i m s CC CC r i m s BO CV r i m s BO and CP 5. Mutual g r a i n b o u n d a r i e s - SL, CP, BO 6. A n h e d r a l to i n t e r s t i t i a l g r a i n s - SL, CP, BO 7. G r a n u l a r t e x t u r e s - PY commonly as m a s s i v e , g r a n u l a r Page 257 a g g r e g a t e s 8. S u b i d i o m o r p h i c to i d i o m o r p h i c g r a i n s - PY 9. F r a m b o i d a l a g g r e g a t e s - PY 10. Growth between two m i n e r a l s - CV between CP and BO 11. F r a c t u r e r e p l a c e m e n t - BO, SL, CP a l o n g f r a c t u r e s i n PY DG and CV i n BO and/or CP 12. Embayments - SL, CP and BO embay PY 13. P o i k i l o b l a s t i c t e x t u r e - PY 14. V e i n f i l l i n g s - CP, BO and minor SL 15. F o l i a t e d - commonly BO, SL, CP PY may or may not be, f o l i a t i o n i s more pronounced w i t h abundant gangue 16. E n c l o s e d g r a i n s - TT i n BO, CP GA i n BO CP i n DG Page 258 17. C r o s s - c u t t i n g r e l a t i o n s - DG t r u n c a t e s CP l a m e l l a e CP l a m e l l a e t r u n c a t e d by f r a c t u r e s i n BO QZ v e i n c u t s the f o l i a t i o n CP, BO v e i n s c u t the f o l i a t i o n 18. E m u l s i o n t e x t u r e - CP i n BO CP i n SL 19. Comb s t r u c t u r e - CB gangue f i l l i n g v o i d s 20. M a s s i v e , r e m o b i l i z e d b l e b s - CC, BO, CP 21. Pseudomorphs - BO a f t e r PY LI a f t e r PY 22. B r e c c i a t e x t u r e - PY, SL, BO, CP f r a g m e n t s w i t h gangue 23. F r a c t u r e s - PY i s h i g h l y f r a c t u r e d b o t h p e r p e n d i c u l a r and p a r a l l e l the f o l i a t i o n - BO o f t e n a r e o f f s e t a l o n g f r a c t u r e s 24. D i s s e m i n a t e d i n gangue - PY, CP, BO and minor SL Page 259 25. Graded l a y e r i n g - PY, SL 26. Comminuted g r a i n s - PY 27. En e c h e l o n d i s p l a c e m e n t s - PY and DG M i c r o p r o b e A n a l y s i s M i c r o p r o b e a n a l y s e s of s e v e r a l o r e s p e c i m e n s were c a r r i e d out to d e t e r m i n e and c o n f i r m the p r e s e n c e of c e r t a i n m i n e r a l s . Only a v e r y b r i e f summary of r e s u l t s w i l l be p r e s e n t e d . As would be e x p e c t e d z i n c , c opper and i r o n peaks dominated s u l p h i d e s c a n s . Pb peaks were n o t e d i n samples where g a l e n a was found to be p r e s e n t i n p o l i s h e d s e c t i o n . A n a l y s e s i n d i c a t e d t h a t s p h a l e r i t e was g e n e r a l l y i r o n - r i c h . In s c a n s where s i l v e r peaks o c c u r r e d , r e l a t i v e abundance of z i n c were low compared to c o p p e r s u g g e s t i n g t h a t s i l v e r v a l u e s c o r r e l a t e w i t h c o p p e r v a l u e s s u p p o r t i n g of the c l o s e a f f i n i t y of t e t r a h e d r i t e to copper m i n e r a l s o b s e r v e d i n p o l i s h e d s e c t i o n . Page 260 X-Ray D i f f r a c t i o n X -ray d i f f r a c t i o n was u s e f u l i n i d e n t i f i c a t i o n of gangue m i n e r a l s . Q u a r t z , K - f e l d s p a r , c h l o r i t e and s e r i c i t e peaks ar e w e l l - d e f i n e d . Other peaks s u g g e s t e d the dominant c a r b o n a t e m i n e r a l s were c a l c i t e , d o l o m i t e and f e r r o a n d o l o m i t e . P a r a g e n e s i s Due to metamorphic e f f e c t s a c l e a r l y d e f i n e d p a r a g e n e t i c sequence c a n n o t be d e f i n e d and t e x t u r a l e v i d e n c e t h a t a p p e a r s to d e f i n e a p a r a g e n e t i c sequence may i n f a c t d e f i n e S t a n t o n ' s (1964) c r y s t a l l o b l a s t i c s e r i e s . S t a n t o n s u g g e s t s t h a t d u r i n g r e c r y s t a l l i z a t i o n of o r e s , m i n e r a l s t e n d to assume s p e c i f i c c o n f i g u r a t i o n s and d e g r e e s o f i d i o m o r p h i s m ; and t h a t "what a p p e a r s to be p a r a g e n e s i s i n many s t r a t i f o r m o r e s a r e i l l u s o r y , the t e x t u r e s r e f l e c t i n g r e l a t i v e t e n d e n c i e s to assume c r y s t a l f a c e s or convex b o u n d a r i e s . The r e s u l t of r e l a t i v e s u r f a c e e n e r g i e s r a t h e r than the sequence of d e p o s i t i o n , they a r e i n terms of metamorphic p e t r o l o g y a c r y s t a l l o b l a s t i c s e r i e s " . S t a n t o n ' s g e n e r a l i z e d c r y s t a l l o b l a s t i c s e r i e s c o r r e s p o n d s q u i t e c l o s e l y to s e q u e n c e s d e t e r m i n e d f o r the Kutcho Creek d e p o s i t . B r i e f l y the p a r a g e n e t i c ( c r y s t a l l o b l a s t i c ) sequence f o r the d e p o s i t i s p y r i t e f o l l o w e d by c h a l c o p y r i t e , b o r n i t e - c h a l c o c i t e and s p h a l e r i t e a l l of which Page 261 s h a r e mutual g r a i n b o u n d a r i e s and appear i n t e r s t i t i a l to p y r i t e . T e t r a h e d r i t e - t e n n a n t i t e and g a l e n a may be s l i g h t l y ( c r o s s c u t t i n g and i n t e r s t i t i a l t e x t u r e s a r e o b s e r v e d ) . D i g e n i t e and c o v e l l i t e appear as e x s o l u t i o n l a m e l l a e . Weber (1977 , unpub.BSc t h e s i s ) s u g g e s t s two phases of m i n e r a l i z a t i o n o c c u r r e d : i n i t i a l c a r b o n a t e , p y r i t e , s p h a l e r i t e , c h a l c o p y r i t e phase f o l l o w e d by q u a r t z , b o r n i t e , c h a l c o c i t e , c h a l c o p y r i t e , t e t r a h e d r i t e - t e n n a n t i t e , d i g e n i t e and g a l e n a phase d e p o s i t e d by a l a t e r h y d r o t h e r m a l e v e n t . The p r e s e n c e of b o r n i t e and c h a l c o p y r i t e a s s o c i a t e d w i t h q u a r t z v e i n s w i t h i n the m a s s i v e s u l p h i d e l e n d s some c r e d e n c e to t h i s but the a u t h o r f a v o u r s one m i n e r a l i z i n g e v e n t w i t h r e m o b i l i z a t i o n of s u l p h i d e m i n e r a l s by a c o n t i n u u m of h y d r o t h e r m a l e v e n t s . Geothermometry I t i s d i f f i c u l t w i t h a system of t h i s n a t u r e to e s t a b l i s h a b s o l u t e t e m p e r a t u r e s of d e p o s i t i o n due to a g e n e r a l l a c k of i n d i c a t i v e g e o t h e r m e t r i c m i n e r a l s and metamorphic r e c r y s t a 1 l i z i o n . C o u n t r y r o c k s a r e metamorphosed to lower g r e e n s c h i s t f a c i e s (350 d e g r e e s to 450 d e g r e e s C) so i t i s not u n r e a s o n a b l e to assume the same t e m p e r a t u r e s of the s u l p h i d e body. Only v e r y wide t e m p e r a t u r e r a n g e s can be d e r i v e d w i t h the p r e s e n t m i n e r a l o g y . Page 262 The r a n g e s w i l l be l i s t e d i n p o i n t form. 1. BO - PY s t a b i l i t y range i s from 228 d e g r e e s C to 568 d e g r e e s C ( K u l l e r u d , 1959). 2. CC and CV can n o t c o e x i s t a t t e m p e r a t u r e s > 400 d e g r e e s C (Rosenboom, 1966). 3. PY shows some e v i d e n c e of r e c r y s t a l l i z a t i o n s u g g e s t i n g t e m p e r a t u r e s o f at l e a s t 450 d e g r e e s C f o r n u c l e a t i o n and growth of PY ( G r a f f and S k i n n e r , 1970). 4. BO+PY = CP+DG at 228 d e g r e e s C, but slow r e a c t i o n a l l o w t h e s e m i n e r a l s to c o e x i s t m e t a s t a b l y ( K u l l e r u d , 1959). 5. BO - CC s o l i d s o l u t i o n can e x i s t a t t e m p e r a t u r e s as low as 430 d e g r e e s C w i t h u n l i m i t e d s o l i d s o l u t i o n a t t e m p e r a t u r e s g r e a t e r than 475 d e g r e e s C ( K u l l e r u d , 1959). 6. CV and DG a r e not s t a b l e a t t e m p e r a t u r e s g r e a t e r than 507 de g r e e s C ( K u l l e r u d , 1959). 7. A l t h o u g h P0 was not found i n p o l i s h e d s e c t i o n s i t does c o e x i s t w i t h PY (Weber, 1977). Page 263 8. The p r e s e n c e of c a r b o n a t e s u g g e s t r e l a t i v e l y low t e m p e r a t u r e s of d e p o s i t i o n . 9. A c t u a l t e m p e r a t u r e s c a n n o t be d e t e r m i n e d but Smirnov (1968) s u g g e s t s low t e m p e r a t u r e s i n the range of 200 d e g r e e s to 300 d e g r e e s C f o r p y r i t i c o r e s . I t i s b e l i e v e d t h a t the m i n e r a l s were d e p o s i t e d at r e l a t i v e l y low t e m p e r a t u r e s . Metamorphism has r e m o b i l i z e d many of the m i n e r a l s . T e m p e r a t u r e r a n g e s t a b u l a t e d above a r e c o n s i s t e n t w i t h t h o s e a s s i g n e d to the lower g r e e n s c h i s t f a c i e s of metamorphism. D i s c u s s i o n The Kutcho Creek d e p o s i t i s s i m i l a r to K u r o k o - t y p e d e p o s i t s of J a p a n . I t s a s s o c i a t i o n w i t h a c i d i c v o l c a n i c r o c k s , o c c u r r i n j near the end of t h e v o l c a n i c c y c l e , the l a r g e l y s t r a t i f o r m n a t u r e of the ore body, d i f f u s e f o o t w a l l c o n t a c t s , and p r o x i m i t y i n the s e c t i o n of o v e r l y i n g t u f f and a r g i l l i t e s u p p o r t the c o m p a r i s o n . The s t r a t i f o r m n a t u r e and the p r e s e n c e of abundant s e d i m e n t a r y f e a t u r e s such as l a y e r i n g , g r a d e d l a y e r i n g , p o s s i b l e l o a d s t r u c t u r e s , e t c . p o i n t to a s y n g e n e t i c o r i g i n . The s u l p h i d e l e n s e s o v e r l i e f e e d e r zones of d i s s e m i n a t e d p y r i t e t h a t c o i n c i d e Page 264 w i t h the most a r e a s of i n t e n s e sodium d e p l e t i o n and p o t a s s i u m e n r i c h m e n t . The Kutcho C r e e k d e p o s i t i s s i m i l a r i n n a t u r e to C a n a d i a n A r c h e a n m a s s i v e • s u l p h i d e d e p o s i t s ( S a n g s t e r , 1972). A s y n g e n e t i c , v o l c a n o g e n i c o r i g i n i s i n f e r r e d f o r the d e p o s i t . Page 265 REFERENCES FOR APPENDIX V A n d e r s o n , C.A. 1969: M a s s i v e S u l f i d e D e p o s i t s and V o l c a n i s m ; Ecomomic G e o l o g y , v. 64, p. 129 - 146. B a r t o n , J r . , P.B. 1970: S u l f i d e P e t r o l o g y ; M i n e r a l S o c i e t y of A m e r i c a , S p e c i a l Paper 3, p. 197 - 198. B a r t o n , J r . , P.B. and T o u l m i n , P. 1966: Phase r e l a t i o n s I n v o l v i n g S p h a l e r i t e i n the Fe- Zn- S System; Economic G e o l o g y , v. 61, p. 815 - 849. B a r t o n , J r . , P.B. and S k i n n e r , B . J . 1970: S u l f i d e M i n e r a l S t a b i l i t i e s i n B a r n e s , H.L. (ed) " G e o c h e m i s t r y of H y d r o t h e r m a l Ore D e p o s i t s " , p. 236 - 333. B a s t i n , E.S. 1950: I n t e r p r e t a t i o n of Ore t e x t u r e s ; G e o l o g i c a l S o c i e t y of America Memoir 45. Page 266 B r i d g e , D. 1978: G e o l o g y of the Kutcho Creek M a s s i v e S u l f i d e D e p o s i t , N o r t h e r n B r i t i s h C o l u m b i a ; unpub. i n t e r n a l r e p o r t f o r Esso M i n e r a l s L t d . B r e t t , R. 1964: E x p e r i m e n t a l Data from the Cu- Fe - S System and T h e i r B e a r i n g on E x s o l u t i o n T e x t u r e s ; Economic G e o l o g y , v. 59, p. 1241 - 1269. B r e t t , R. and K u l l e r u d , G. 1960: The Fe - Pb - S System; Economic G e o l o g y , V. 55, p. 354 - 369. G i l m o u r , P. 1971: S t r a t a b o u n d M a s s i v e P y r i t i c S u l f i d e D e p o s i t s - A Review; Economic G e o l o g y , v. 66, no. B, p. 1239 -1244. G r a f f , J . L . and S k i n n e r , B . J . 1970: S t r e n g t h and D e f o r m a t i o n of P y r i t e and P y r r h o t i t e ; Economic G e o l o g y , v 65, p. 206. Page 267 K u l l e r u d , G . 1959: S u l f i d e System as a G e o l o g i c a l Thermometer, in_ A b e l s o n ( e d ) , R e s e a r c h e s i n G e o c h e m i s t r y V I . M a r g o l i n , H. (ed) 1966: R e c r y s t a l l i z a t i o n , G r a i n Growth and T e x t u r e s ; American S o c i e t y f o r M e t a l s Seminar McDonald, J.A. 1967: Metamorphism and I t s E f f e c t s on S u l f i d e A s s e m b l a g e s ; M i n e r a l o g y v. 2, p. 200- 220. M c K i n s t r y , H. 1959: M i n e r a l a s s o c i a t i o n i n S u l f i d e O r e s : The Cu - Fe - S -0 System; economic g e o l o g y , v. 54, p. 975 - 1001. Merwin, H.E. and Lombard, R.H. 1937: The System, Cu- Fe- S; Economic G e o l o g y , V. 32, p. 203 - 284. Monger, J . and T h o r s t a d , L. 1978: Lower M e s o z o i c S t r a t i g r a p h y , Cry Lake (104 I ) and S p a t s i z i (104 H) Map A r e a s , B r i t i s h C o l u m b i a ; G e o l o g i c a l S u r v e y pf Canada paper 78 - 1A, R e p o r t of A c t i v i t i e s 21 - 24. Page 268 P e a r s o n D.E. and P a n t e l e y e v , A. 1976: Map Area (104 I/1W), G e o l o g i c a l F i e l d Work, B.C.D.M. G.E.M. R e p o r t , p. 74 1975: C u p r i f e r o u s I r o n S u l p h i d e D e p o s i t s , Kutcho Creek Map Area (104 1/ IW); G e o l o g i c a l F i e l d Work, B.C.D.M., p . 86 . 1974: Kutcho Creek M a s s i v e S u l p h i d e D e p o s i t , G.E.M. R e p o r t p. 344. Rosenboom, E.H. 1966: An I n v e s t i g a t i o n of the Sytem Cu - S and Some N a t u r a l Copper S u l f i d e s Between 25 and 700 d e g r e e s C.; Economic G e o l o g y , v. 61, p. 641 - 672. S a n g s t e r , D.F. 1972: P r e c a m b r i a n V o l c a n o g e n i c M a s s i v e S u l p h i d e D e p o s i t s i n Canada: A Review; G e o l o g i c a l Survey of Canada Paper 72 - 22, 42 p. S t a n t o n , R.L. 1972: Ore P e t r o l o g y ; McGraw - H i l l Pub., N.Y., London, M o n t r e a l , 713 p. Page 269 1964: M i n e r a l I n t e r f a c e s i n S t r a t i f o r m O r e s ; B u l l e t i n I n s t , of M i n i n g and M e t a l l u r g y , A u s t r a l i a , v. 696. 1958: Abundances of Cu, Zn, and Pb i n Some S u l p h i d e D e p o s i t s ; J o u r n a l of G e o l o g y , v. 66, p. 484 - 502. Smirnov , V.I . 1974: Temperature C o n d i t i o n s of the O r i g i n of S t r a t a b o u n d P y r i t i c V o l c a n o g e n i c Ore D e p o s i t s ; S o c i e t y of M i n i n g G e o l o g i s t s , Japan S p e c i a l I s s u e 3, p. 221. S u f f e l , G.G., H u t c h i n s o n , R.W., and R i d l e r , R.H. 1974: Metamorphism of M a s s i v e S u l f i d e s at Manitouwadge, O n t a r i o , S o c i e t y of M i n i n g G e o l o g i s t s S p e c i a l I s s u e 3, p. 235 - 240. S u l l i v a n , C . J . 1957: Heat and T e m p e r a t u r e s i n Ore D e p o s i t i o n ; Economic Geology v. 52, p. 5 - 24. T a t s u m i , T. (ed) 1970: V o l c a n i s m and Ore G e n e s i s ; U n i v e r s i t y of Tokyo P r e s s , Tokyo, p. 153 - 180 and p. 197 - 206. Page 270 T e m p e l m a n - K l u i t , D.J. 1970: The R e l a t i o n s h i p Between S u l p h i d e G r a i n S i z e and Metamorphic Grade of Host Rocks i n Some S t r a t a b o u n d P y r i t i c O r e s ; C a n a d i a n J o u r n a l of E a r t h S c i e n c e s , v. 7 p. 1339 - 1345. Vokes, F.M. 1971: A s p e c t s of the R e g i o n a l Metamorphic M o b i l i z a t i o n of P r e e x i s t i n g D e p o s i t s , M i n e r a l D e p o s i t s , V. 6, no.2, p. 122 - 129. 1969: A Review of the Metamorphism of S u l f i d e D e p o s i t s ; E a r t h S c i e n c e s Review, v. 5, p. 99. Weber, M. 1977 : The G e o l o g y and M i n e r a l o g y of the Cu -Zn - Fe M a s s i v e S u l f i d e D e p o s i t a t Kutcho C r e e k , B r i t i s h C o l u m b i a , Unpub. BSc T h e s i s , U n i v e r s i t y of B.C. Page 271 

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:
https://iiif.library.ubc.ca/presentation/dsp.831.1-0052826/manifest

Comment

Related Items