UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Mineralogy, paragenesis, and mineralogic zonation of the Silver Queen vein system, Owen Lake, central… Hood, Christopher Thomas Saul 1991

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

Item Metadata

Download

Media
831-UBC_1991_A6_7 H66.pdf [ 24.11MB ]
Metadata
JSON: 831-1.0052415.json
JSON-LD: 831-1.0052415-ld.json
RDF/XML (Pretty): 831-1.0052415-rdf.xml
RDF/JSON: 831-1.0052415-rdf.json
Turtle: 831-1.0052415-turtle.txt
N-Triples: 831-1.0052415-rdf-ntriples.txt
Original Record: 831-1.0052415-source.json
Full Text
831-1.0052415-fulltext.txt
Citation
831-1.0052415.ris

Full Text

MINERALOGY, PARAGENESIS, AND MINERALOGIC ZONATION OF THE SILVER QUEEN VEIN SYSTEM OWEN LAKE, CENTRAL BRITISH COLUMBIA By C h r i s t o p h e r Thomas S a u l Hood B.Sc,  University of B r i t i s h  Vancouver, B r i t i s h  Columbia  C o l u m b i a , 1979  A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in  THE FACULTY OF GRADUATE STUDIES (Geological We  accept to  this  Sciences)  thesis  the required  as c o n f o r m i n g standard  THE UNIVERSITY OF BRITISH COLUMBIA SEPTEMBER, 1991 @  •H  • •„  C h r i s t o p h e r Thomas S a u l Hood, 1991  In  presenting this  thesis in partial  fulfilment  of the requirements  for an advanced  degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and study. I further agree that permission for extensive copying; of this thesis for scholarly purposes may be granted department  or by his or her representatives.  It  by the head of my  is understood  that  copying or  publication of this thesis for financial gain shall not be allowed without my written permission.  Department of  Cr?e~o[e>ai\  The University of British Columbia Vancouver, Canada  (2/88)  ii ABSTRACT  The S i l v e r Queen mine, southeast of Houston, c o n s i s t s of a s e r i e s of e p i t h e r m a l base- and bearing  veins  the T i p Top  B.C.,  precious-metal  hosted by Late Cretaceous v o l c a n i c rocks of  Hill  formation. M i n e r a l o g i c a l l y , the v e i n s  complex, d i s p l a y i n g s e v e r a l d i s c r e t e m i n e r a l i z i n g  stages  c h a r a c t e r i z e d by the presence of c e r t a i n s u l f i d e and s p e c i e s . The  c o m p l e x i t y of the v e i n mineralogy has  a problem i n a s s e s s i n g  the systemic e v o l u t i o n of  are  gangue  presented the  hydrothermal system. This study describes  i n d e t a i l the nature of  mineralogy, d i v i d i n g the assemblages p r e s e n t i n t o d i s t i n c t p a r a g e n e t i c stages.  four  P a r t i c u l a r a t t e n t i o n was  t o the o c c u r r e n c e o f p o t e n t i a l l y economic phases electrum).  the  S u l f i d e phases which were  paid  (e.g.  compositionally  s e n s i t i v e t o t r a c e element v a r i a t i o n s were examined by e l e c t r o n microprobe t o determine v a r i a t i o n s on s i n g l e g r a i n and d e p o s i t  s c a l e s . Microbeam a n a l y s i s a l s o a s s i s t e d i n the  i d e n t i f i c a t i o n of several s u l f o s a l t species. Evaluation the m i n e r a l o g y and  paragenesis allowed f o r the assessment of  the e v o l u t i o n of the Paragenetically, four d i s t i n c t stages. fine grained  deposit. the m i n e r a l i z a t i o n i s d i v i d e d i n t o The  p y r i t e and  f i r s t stage i s c h a r a c t e r i z e d  by  quartz m i n e r a l i z a t i o n , w i t h hematite  abundant i n the assemblage i n the c e n t r a l segment of most e x t e n s i v e  of  the  (Number Three) v e i n . B a r i t e , s v a n b e r g i t e ,  h i n s d a l i t e become abundant towards the south end  of  the  and  Number Three v e i n , w i t h m a r c a s i t e more abundant towards the n o r t h . Stage I I i s dominated by the presence o f massive s p h a l e r i t e and l a y e r e d carbonate manganoan carbonates  ( c a l c i t e i n the south,  i n the n o r t h ) . Stage I I I , however, i s  more complex. M i n e r a l i z a t i o n c o n s i s t s of c h a l c o p y r i t e , galena, f a h l o r e s  ( t e t r a h e d r i t e - t e n n a n t i t e ) , electrum,  q u a r t z , and s u l f o s a l t s . Included i n the s u l f o s a l t assemblage are the unusual Pb-Bi-Cu-Ag s p e c i e s b e r r y i t e , m a t i l d i t e , g u s t a v i t e , and a i k i n i t e . The  f i n a l stage of m i n e r a l i z a t i o n  i s v o l u m e t r i c a l l y minor and i s dominated by q u a r t z , pyrobitumen, and  fine-grained  calcite.  Minor element t r e n d s i n t e t r a h e d r i t e s and  sphalerites  r e v e a l a m i n e r a l i z i n g f l u i d w i t h a h i g h degree o f compositional v a r i a b i l i t y . Tetrahedrite  g r a i n s show w e l l  developed o s c i l l a t o r y c o m p o s i t i o n a l zoning i n Sb, As, B i , Ag, and Cu, w h i l e s p h a l e r i t e s are commonly v i s u a l l y w e l l l a y e r e d . The  l a t t e r was  found t o be the main r e p o s i t o r y f o r  the unusual metals Ga, Ge,  and In, which are found i n  anomalous l e v e l s i n S i l v e r Queen o r e . The S i l v e r Queen v e i n s are proposed  t o have e v o l v e d  from f l u i d s o r i g i n a t i n g a t depth t o the south o f the Number Three v e i n . P u l s e s of m e t a l - b e a r i n g f l u i d s i n t e r a c t e d w i t h c o o l e r groundwaters, producing the observed d i s t r i b u t i o n of assemblages. The presence of Ga, Ge,  and In may  have been  sourced i n an o r g a n i c - r i c h l a y e r exposed i n s e v e r a l l o c a l e s i n the S i l v e r Queen mine a r e a .  iv TABLE OF CONTENTS Page ABSTRACT  i i  TABLE OF CONTENTS  iv  LIST OF TABLES  viii  LIST OF FIGURES  X  LIST OF PLATES  xiii  ACKNOWLEDGEMENTS  xviii  CHAPTER 1.0  INTRODUCTION  1  1.1 1.2 1.3  1 1  1.4 CHAPTER 2.0  G e n e r a l Statement L o c a t i o n and Access H i s t o r y o f Deposits and P r e v i o u s Work Purpose and Scope  3 6  GEOLOGIC SETTING OF THE SILVER QUEEN MINE 2.1 2.2  I n t r o d u c t i o n and T e c t o n i c Setting R e g i o n a l Geology 2.2.1 2.2.2  2.3  8  Geologic S e t t i n g Geology o f the Owen Lake Area  8 9 9 14  Geology o f the Mine Area  15  2.3.1 2.3.2  Introduction Geology and Petrography  15 18  (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11)  18 19 20 22 23 23 24 25 26 28 29  Unit Unit Unit Unit Unit Unit Unit Unit Unit Unit Unit  1 2 3 4 4a 5 5a 5b 6 7 8  V TABLE OF CONTENTS  cont'd page  2.4 CHAPTER 3.0  2.3.3  Geochronology  30  2.3.4  Structure  35  Character  o f Veins  36  MINERALOGY AND PARAGENESIS  42  3.1 3.2 3.3 3.4  42 43 45  I n t r o d u c t i o n and Scope Character o f V e i n i n g Sampling and A n a l y s i s Number Three v e i n and associated veining 3.4.1 I n t r o d u c t i o n 3.4.2 V e i n M i n e r a l o g y (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24)  48 48 49  Pyrite 49 Sphalerite 52 Chalcopyrite 54 Galena 54 Tetrahedrite 55 Aikinite 60 Berryite 60 Matildite 64 SeligmanniteBournonite 64 Polybasite, F r e i b e r g i t e , and Pyrargyr i t e 66 B i s m u t h i n i t e and associated sulfosalts.66 P r o u s t i t e and Geocronite 66 Arsenopyrite 71 Marcasite 71 Electrum 71 Bornite, Chalcocite and C o v e l l i t e 72 Pyrrhotite 72 Hematite and Magnetite 73 Titanium Oxides 73 Quartz 73 Carbonates 75 Barite 76 Svanbergite and Hinsdalite 77 Pyrobitumen 77  vi TABLE OF CONTENTS  cont'd page  3.4.3 3.5  CHAPTER 4 . 0  M i n e r a l i z a t i o n i n Other Veins  85  3.5.1 3.5.2 3.5.3 3.5.4 3.5.5  85 98 101 109 117  Camp V e i n System Chisholm V e i n s . P o r t a l Veins Cole Lake V e i n s George Lake Veins  COMPOSITIONAL VARIATION IN  SULFIDES  120  4.1 4.2 4.3 4.4  I n t r o d u c t i o n and O b j e c t i v e s 120 Sampling Techniques 122 A n a l y t i c a l Methodology 122 T e t r a h e d r i t e Zonation 124 4.4.1 Introduction 124 4.4.2 S i n g l e G r a i n Zonation i n Tetrahedrites 125 4.4.3 Deposit-scale variations i n T e t r a h e d r i t e Composition.... 139 4.4.4 T e t r a h e d r i t e s from other veins 141 4.4.5 Bismuthian T e t r a h e d r i t e s An unusual occurrence 142 4.4.6 Discussion 144  4.5  S p h a l e r i t e Zonation  4.6  Introduction.. Systematic Trends i n S p h a l e r i t e Zonation  153  4.5.3  Discussion  155  S u l f o s a l t and E l e c t r u m  DISCUSSION  5.1 5.2 5.3  ....153  4.5.1 4.5.2  4.6.1 4.6.2 4.6.3 CHAPTER 5 . 0  Paragenesis and M i n e r a l o g i c Variation 77  153  Chemistry...160  Introduction S u l f o s a l t Compositions Electrum Compositions  160 161 164 172  Introduction 172 C o n d i t i o n s o f M i n e r a l Deposition...172 E v o l u t i o n o f t h e Hydrothermal System 187  vii TABLE OF CONTENTS  cont'd page  5.4 CHAPTER 6 . 0  Comparison w i t h o t h e r v e i n deposits  P R A C T I C A L ASPECTS OF MINERALOGIC STUDIES  6.1 6.2 6.3  Introduction Occurrence and B e n e f i c i a t i o n of Economic M i n e r a l s Recommendations f o r F u t u r e Exploration  196 199  199 200 206  CHAPTER 7 . 0  SUMMARY AND C O N C L U S I O N S  215  CHAPTER 8 . 0  REFERENCES  218  APPENDIX A  SAMPLE S I T E LOCATIONS  225  APPENDIX  P A R A G E N E T I C DIAGRAMS F O R M I N E R A L I Z E D STRUCTURES A T QUEEN MINE  APPENDIX  B  C  MICROPROBE ANALYSES  SILVER 233 255  viii LIST OF TABLES page TABLE 2.1.1  S t r a t i g r a p h i c Units i n the Buck Creek A r e a  11  S t r a t i g r a p h i c Units of the S i l v e r Queen mine (Owen Lake) A r e a  17  Summary o f Whole-rock PotassiumArgon d a t a f o r rocks i n t h e v i c i n i t y of t h e S i l v e r Queen mine  31  M i n e r a l Species i d e n t i f i e d a t the S i l v e r Queen mine  47  Zonal A n a l y s i s o f T e t r a h e d r i t e sample 3CHN90-1  128  Zonal A n a l y s i s o f T e t r a h e d r i t e sample 3CHN89-46  130  Zonal A n a l y s i s o f T e t r a h e d r i t e sample 3CHN89-5  131  Zonal A n a l y s i s o f S p h a l e r i t e sample 3CHN89-5  156  Zonal A n a l y s i s o f S p h a l e r i t e sample 3CHN89-1  158  Zonal A n a l y s i s o f S p h a l e r i t e sample 3CHN90-1  158  Microprobe a n a l y s i s o f S u l f o s a l t Compositions  166  TABLE 4.6.2  Electrum  171  TABLE 5.2.1  S p e c i a t i o n o f Ore Metals i n Hydrothermal S o l u t i o n s  TABLE 2.3.1 TABLE 2.3.2  TABLE 3.3.1 TABLE 4.4.1 TABLE 4.4.2 TABLE 4.4.3 TABLE 4.5.1 TABLE 4.5.2 TABLE 4.5.3 TABLE 4.6.1  TABLE 5.4.1 TABLE 6.1.1 TABLE 6.1.2  Compositions  Comparative Anatomy o f V o l c a n i c - H o s t e d Epithermal  174 Deposits  197  Economic M i n e r a l o g y o f t h e S i l v e r Queen P r o p e r t y  208  Electrum Occurrence, S i l v e r Queen P r o p e r t y  213  ix LIST OF TABLES  cont'd page  TABLE A - l  Underground  Sample S i t e s  TABLE A-2  D r i l l Hole Sample S i t e s  TABLE C - l  Microprobe A n a l y s e s  226 229 .255  x LIST OF FIGURES page Figure  1.2.1  F i g u r e 2.1.1  F i g u r e 2.3.1  L o c a t i o n o f the S i l v e r Queen Gold-Silver-Copper-LeadZ i n c Mine  1  Geology o f the Buck Creek Area, W e s t - c e n t r a l B r i t i s h Columbia  10  Geology o f the S i l v e r Queen Mine Area  Figure  2.3.2  F i g u r e 3.4.22  F i g u r e 3.4.23  F i g u r e 3.4.24  F i g u r e 3.4.25  F i g u r e 3.4.26  F i g u r e 4.4.6  Figure  Figure  4.4.7  4.4.8  F i g u r e 4.4.9  Owen Lake S t r a t i g r a p h y  i n pocket 16  Paragenesis o f t h e Number Three System Longitudinal section of the Number Three v e i n ; P a r a g e n e t i c stage abundance  86  Longitudinal section of the Number Three v e i n ; Stage I m i n e r a l abundance  87  Longitudinal s e c t i o n of the Number Three v e i n ; Stage I I m i n e r a l abundance  88  Longitudinal section of the Number Three v e i n ; Stage I I I m i n e r a l abundance  89  Contour p l o t o f Zn/(Zn+Fe) f o r T e t r a h e d r i t e g r a i n "cores"; Number Three v e i n l o n g i t u d i n a l s e c t i o n  132  Contour p l o t o f Zn/(Zn+Fe) f o r T e t r a h e d r i t e g r a i n "rims"; Number Three v e i n l o n g i t u d i n a l s e c t i o n  133  Contour p l o t o f Ag/(Ag+Cu) f o r T e t r a h e d r i t e g r a i n "cores"; Number Three v e i n l o n g i t u d i n a l s e c t i o n  134  Contour p l o t o f Ag/(Ag+Cu) f o r T e t r a h e d r i t e g r a i n "rims"; Number Three v e i n l o n g i t u d i n a l s e c t i o n  135  82  xi LIST OF FIGURES  cont'd page  Contour p l o t o f As/(As+Sb+Bi) f o r T e t r a h e d r i t e g r a i n "cores"; Number Three v e i n l o n g i t u d i n a l s e c t i o n  136  Contour p l o t o f As/(As+Sb+Bi) f o r T e t r a h e d r i t e g r a i n "rims"; Number Three v e i n l o n g i t u d i n a l s e c t i o n  137  Contour p l o t o f Weight Percent Bismuth i n T e t r a h e d r i t e s ; Number Three v e i n l o n g i t u d i n a l s e c t i o n  138  F i g u r e 4.4.13  Ag/(Ag+Cu) v s . As/(As+Sb+Bi) p l o t S i l v e r Queen T e t r a h e d r i t e s  145  F i g u r e 4.4.14  B i atoms v s . Sb atoms p l o t S i l v e r Queen T e t r a h e d r i t e s  146  F i g u r e 4.4.15  B i atoms v s . As atoms p l o t S i l v e r Queen T e t r a h e d r i t e s  147  F i g u r e 4.4.16  Schematic diagram o f environment of t e t r a h e d r i t e d e p o s i t i o n i n a vein breccia  152  Log ag2~Log aQ2 diagram showing the s t a b i l i t y f i e l d s o f common hydrothermal m i n e r a l s i n t h e presence o f quartz  177  Log aQ2 P diagram showing common hydrothermal m i n e r a l s t a b i l i t i e s a t 250° C and Log t o t a l s u l f u r o f -3  178  Log ao2~P diagram showing s t a b i l i t y f i e l d s o f common hydrothermal m i n e r a l s and a r s e n i c s p e c i e s a t a temperature o f 250° C and Log t o t a l s u l f u r o f -2  179  Log ag2-Temperature diagram for selected sulfosalt sulfidation curves  181  Textural properties i n d i c a t i v e of degree o f s a t u r a t i o n  188  F i g u r e 4.4.10  F i g u r e 4.4.11  F i g u r e 4.4.12  F i g u r e 5.2.1  -  F i g u r e 5.2.2  H  H  F i g u r e 5.2.3  F i g u r e 5.2.4  F i g u r e 5.3.1  xii LIST OF FIGURES  cont'd page  F i g u r e 5.3.2  Figure A - l F i g u r e A-2  Figure B - l  S o l u b i l i t y of b a r i t e contoured on a T e m p e r a t u r e - s a l i n i t y diagram, showing p r e d i c t e d t r a j e c t o r i e s f o r b o i l i n g and mixing S u r f a c e sample s i t e s , Queen mine area  189  Silver i n pocket  L o n g i t u d i n a l s e c t i o n of Number Three v e i n showing Sample s i t e pos i t i o n s .  232  P a r a g e n e t i c diagrams f o r m i n e r a l i z e d s t r u c t u r e s at S i l v e r Queen mine ( e x c l u d i n g Number Three v e i n )  233  xiii LIST OF PLATES page Figure  Figure  3.2.1  3.4.1  Surface exposure o f southern p a r t o f Number Three v e i n , a t "bend" near Alimak R a i s e  44  Interlayered Carbonate-Sphalerite v e i n , northernmost Number Three v e i n  50  Figure  3.4.2  M u l t i e p i s o d i c Quartz m i n e r a l i z a t i o n from the southern Number Three v e i n  51  Figure  3.4.3  B r e c c i a t e d c o l l i f o r m P y r i t e (py A ) , f o l l o w e d by f i n e g r a i n e d intergrown P y r i t e (py B) and Quartz (qz) mineralization  51  C o l l i f o r m low-Fe S p h a l e r i t e from the n o r t h - c e n t r a l p a r t o f t h e Number Three v e i n a t sample s i t e 3CHN89-87  53  "Chalcopyrite disease" i n S p h a l e r i t e from the deep n o r t h Number Three v e i n  53  Intergrown Galena (gn) and T e n n a n t i t e (tn) on margin o f l a r g e Sphalerite (si) grain  56  Backscattered e l e c t r o n photomicrograph o f Galena (gn) g r a i n from southern Number Three vein  57  B r e c c i a t e d P y r i t e (py) w i t h l a t e r i n f i l l i n g T e n n a n t i t e (tn) from south end o f Number Three v e i n  58  Fracture i n f i l l i n g s of Tennantite (tn) i n C h a l c o p y r i t e (cpy) from P o r t a l v e i n Three  59  Backscattered e l e c t r o n photomicrograph o f l a t h - s h a p e d B e r r y i t e (ber) g r a i n s t h a t have undergone p a r t i a l replacement by M a t i l d i t e (md)  61  Figure  Figure  Figure  Figure  Figure  3.4.4  3.4.5  3.4.6  3.4.7  3.4.8  F i g u r e 3.4.9  Figure  3.4.10  xiv LIST OF PLATES  cont'd page  F i g u r e 3.4.11  F i g u r e 3.4.12  F i g u r e 3.4.13  F i g u r e 3.4.14  Backscattered e l e c t r o n photomicrograph o f elongate B e r r y i t e (ber) g r a i n r e p l a c e d along cleavage d i r e c t i o n s by Galena (gn)  62  B e r r y i t e (ber) g r a i n undergoing replacement by T e n n a n t i t e (tn) along g r a i n margins  63  Backscattered e l e c t r o n photomicrograph o f e x s o l v e d Bournonite (bour) i n Galena (gn) from northernmost Number Three v e i n  65  I n c l u s i o n o f Cuprobismutite (cpb) and Cu-Pb-Bi s u l f o s a l t (ss) i n bismuthian T e n n a n t i t e (tn)  67  F i g u r e 3.4.15  Backscattered e l e c t r o n photomicrograph o f unmixing t e x t u r e s i n bismuthian Tennantite (tn) and B i s m u t h i n i t e ( b i s ) i n P y r i t e . . . . 6 8  F i g u r e 3.4.16  Backscattered e l e c t r o n photomicrograph o f e x s o l v e d Geocronite ( g c ) , P r o u s t i t e (pr) and an u n i d e n t i f i e d Ag-Sb-Pb s u l f o s a l t (ss) i n massive Galena (gn)  F i g u r e 3.4.17 F i g u r e 3.4.18  F i g u r e 3.4.19  F i g u r e 3.4.20  F i g u r e 3.4.21  .69  Euhedral M a r c a s i t e (mc) from deep n o r t h Number Three v e i n  70  Electrum ( e l ) i n intergrown Galena (gn) and M a t i l d i t e (md), along the margin o f P y r i t e (py) g r a i n s  74  Zoned and b r e c c i a t e d Carbonate (cb A, B, C) from c e n t r a l n o r t h e r n p a r t o f Number Three v e i n  78  Stage IV C a l c i t e (cc) v e i n i n g c u t t i n g e a r l i e r Quartz (qz) and Sphalerite (si)  79  Secondary e l e c t r o n image o f Svanbergite (sv) g r a i n i n t e r s t i t i a l t o P y r i t e (py)  80  XV  LIST OF PLATES  cont'd page  F i g u r e 3.5.1  F i g u r e 3.5.2  F i g u r e 3.5.3  F i g u r e 3.5.4  F i g u r e 3.5.5  F i g u r e 3.5.6 F i g u r e 3.5.7  F i g u r e 3.5.8  Figure 3 . 5 . 9  F i g u r e 3.5.10  Backscattered e l e c t r o n photomicrograph of s y m p l e c t i c intergrowths of P y r a r g y r i t e (pyg) and Galena (gn) from northernmost p a r t o f Camp v e i n s  91  Overgrowths o f A r s e n o p y r i t e (aspy) on bladed phase t h a t has been r e p l a c e d by P y r i t e (py)  92  Backscattered e l e c t r o n photomicrograph of P y r r h o t i t e (po) and P y r i t e (py) t h a t have r e p l a c e d bladed mineral  93  Bladed B a r i t e (ba) i n m a t r i x o f manganoan Carbonate (cb) and v u g - i n f i l l i n g Quartz (qz)  96  Broken Pyrobitumen ( p y b i t ) mass i n manganoan Carbonate (cb) and A r s e n o p y r i t e (aspy) from sample s i t e 3CHN89-15 (Appendix A) on Camp v e i n s  97  C r o s s - s e c t i o n a l s l a b o f Mae Three vein  99  A r g e n t i a n T e t r a h e d r i t e ( t t ) pods, w i t h S p h a l e r i t e ( s i ) and Galena (gn) i n a B a r i t e (ba) matrix  99  Backscattered e l e c t r o n photomicrograph of l a r g e E l e c t r u m ( e l ) g r a i n i n intergrown Galena (gn) and M a t i l d i t e (md) from sample s i t e 2CHN89-4 (Appendix A ) , P o r t a l v e i n Three  100  P o l i s h e d s e c t i o n o f t y p i c a l Number F i v e v e i n m a t e r i a l , showing inward growth o f S p h a l e r i t e ( s i ) , C h a l c o p y r i t e (cpy), and Q u a r t z + s u l f o s a l t s (qz, s s ) episodes  103  Intergrown Galena (gn) and M a t i l d i t e (md) exsolved from Pb-Bi s o l i d solution  104  xvi LIST OF PLATES  cont'd page  F i g u r e 3.5.11  F i g u r e 3.5.12  F i g u r e 3.5.13 F i g u r e 3.5.14  F i g u r e 3.5.15  F i g u r e 3.5.16  F i g u r e 3.5.17  F i g u r e 3.5.18  Backscattered electron photomicrograph o f B e r r y i t e (ber) l a t h s i n G u s t a v i t e (gs) m a t r i x , w i t h Galena (gn) r e p l a c i n g both phases a l o n g cleavage d i r e c t i o n s  105  Backscattered electron photomicrograph o f zoning i n P o r t a l v e i n Three Carbonate  106  L a t e stage (Stage IV) pyrobitumen ( p y b i t ) from P o r t a l v e i n Three  107  Cross-sectional slab of P o r t a l v e i n Four, showing " b r e c c i a " nature o f m i n e r a l i z a t i o n  110  W e l l l a y e r e d Carbonate ( c b ) , S p h a l e r i t e ( s i ) , and Galena (gn) from c e n r a l C o l e v e i n , sample s i t e 1CHN89-12 (Appendix A)  I l l  C r u s t i f o r m growth o f A r s e n o p y r i t e (aspy) over p r e - e x i s t i n g b l a d e d phase t h a t has been r e p l a c e d by aspy, P y r i t e (py), and Galena (gn)  112  Backscattered electron photomicrograph o f s y m p l e c t i c i n t e r g r o w t h s o f Galena (gn) and A i k i n i t e (aik) i n t e r s t i t i a l t o Hematite-Magnetite (he-mt)  115  I n c l u s i o n o f intergrown Galena (gn) M a t i l d i t e (md), and E l e c t r u m ( e l ) i n P y r i t e (py)  116  F i g u r e 3.5.19  Intergrown Galena (gn) and M a t i l d i t e (md) a l o n g margin o f P y r i t e (py) g r a i n , i n m a t r i x o f C h a l c o p y r i t e (cpy)...116  F i g u r e 3.5.20  Intergrown P e a r c e i t e (pc) and E l e c t r u m ( e l ) i n Carbonate v e i n l e t c u t t i n g C h a l c o p y r i t e (cpy)  119  xvii LIST OF PLATES  cont'd page  F i g u r e 4.4.1  F i g u r e 4.4.2  F i g u r e 4.4.3  F i g u r e 4.4.4  F i g u r e 4.4.5  F i g u r e 4.5.1  O s c i l l a t o r y zoned T e t r a h e d r i t e g r a i n from sample s i t e 2CHN89-19 (Appendix A) on the northern Number Three v e i n a t the i n t e r s e c t i o n of t h e B u l k l e y c r o s s c u t and the South End d r i f t  127  T e t r a h e d r i t e from sample s i t e 3CHN90-1 (Appendix A) on deep n o r t h Number Three v e i n  128  T e t r a h e d r i t e from sample s i t e 2CHN89-46 (Appendix A) on south c e n t r a l Number Three v e i n  130  T e t r a h e d r i t e from sample s i t e 3CHN89-5 (Appendix A) on south Number Three v e i n  131  Backscattered e l e c t r o n photomicrograph o f zonation i n Bismuth c o n t e n t s i n T e t r a h e d r i t e from t h e Number F i v e v e i n , sample s i t e 1CHN89-117 (Appendix A)  149  Layered S p h a l e r i t e from sample s i t e 3CHN89-5 (Appendix A ) , south Number Three v e i n  156  xviii ACKNOWLEDGEMENTS In t h e course o f completing my t h e s i s , s e v e r a l i n d i v i d u a l s and agencies have p r o v i d e d much a p p r e c i a t e d a s s i s t a n c e , without which t h e t h e s i s would have been an impossibility. I am e s p e c i a l l y indebted t o Dr. A l a s t a i r J . S i n c l a i r f o r o f f e r i n g me t h e o p p o r t u n i t y t o work on t h e Owen Lake P r o j e c t , and f o r h i s c o n s t r u c t i v e c r i t i c i s m , i n s i g h t s , and e x t r a o r d i n a r y p a t i e n c e t h a t allowed me t o complete t h i s work. Dr. C r a i g L e i t c h and Dr. Margaret (Peggy) Thomson p r o v i d e d much needed a s s i s t a n c e i n d e c i p h e r i n g t h e m i n e r a l o g i c s t o r y behind t h e S i l v e r Queen v e i n s and g r e a t l y supplemented t h e e v o l u t i o n o f t h i s t h e s i s w i t h t h e i r own work. My thanks a l s o go out t o my coworkers X i a o l i n Cheng, Marek Nowak, and Zophia Radlowski f o r t h e i r suggestions on geology, a l t e r a t i o n , and metal d i s t r i b u t i o n s a t S i l v e r Queen. An a d d i t i o n a l note o f thanks f o r a l l o w i n g me use o f the computing equipment on s h o r t n o t i c e . P a c i f i c Houston Resources Inc. and New Nadina E x p l o r a t i o n s L t d . a r e thanked f o r a l l o w i n g access t o t h e S i l v e r Queen workings and f o r f i n a n c i a l a s s i s t a n c e i n and out o f t h e f i e l d . J . Hutter and W.W. Cummings p r o v i d e d h e l p f u l d i s c u s s i o n s on t h e mine area d u r i n g my s t a y a t S i l v e r Queen mine. Dr. Gerry C a r l s o n i s thanked f o r h i s c o n t i n u i n g i n t e r e s t and support o f t h e Owen Lake P r o j e c t , and f o r h e l p f u l reviews o f t h i s r e p o r t . Dr. Lee Groat i s a l s o thanked f o r h e l p f u l l a s t - m i n u t e e d i t i n g o f t h i s paper. J . Knight and Yvonne Douma p r o v i d e d much-needed t e c h n i c a l a s s i s t a n c e i n r e l a t i o n t o t h e e l e c t r o n microprobe and scanning e l e c t r o n microscopy work. The mineralogy s e c t i o n o f t h e Owen Lake P r o j e c t was made p o s s i b l e through a c o o p e r a t i v e r e s e a r c h grant between the N a t u r a l Sciences and E n g i n e e r i n g Research C o u n c i l and New Nadina E x p l o r a t i o n s L t d . ( e a r l i e r w i t h P a c i f i c Houston Resources I n c . ) .  1  1.0  1.1  INTRODUCTION  GENERAL STATEMENT The S i l v e r Queen d e p o s i t p r o v i d e s an e x c e l l e n t  o p p o r t u n i t y t o examine a wide v a r i e t y of processes t o the development of an e p i t h e r m a l base- and  related  precious-metal  v e i n system. D e s p i t e ongoing e x p l o r a t i o n and development of the d e p o s i t s i n c e 1912 bismuthian  (and the occurrence of r a r e  s u l f o s a l t s p e c i e s : eg. H a r r i s and Owens, 1973),  no p r e v i o u s attempt has been made t o s y s t e m a t i c a l l y i d e n t i f y and c a t e g o r i z e the v e i n mineralogy  of the e n t i r e d e p o s i t .  The aim of t h i s study i s thus t o d e s c r i b e i n d e t a i l the v e i n mineralogy  i n o r d e r t o develop a mine s c a l e p a r a g e n e t i c  sequence. An i n t e r n a l l y c o n s i s t e n t model of composition 1.2  and m i n e r a l d e p o s i t i o n i s then  LOCATION AND  fluid presented.  ACCESS  The S i l v e r Queen (Nadina, Bradina) mine area i s l o c a t e d 35 k i l o m e t e r s southeast of Houston, c l o s e t o the e a s t  shore  of Owen Lake i n the B u l k l e y V a l l e y r e g i o n of w e s t - c e n t r a l B r i t i s h Columbia ( F i g . 1.2.1; l a t i t u d e 54.2 and l o n g i t u d e 126.4  degrees north  degrees west). An e x c e l l e n t a l l - w e a t h e r  f o r e s t r y road p r o v i d e s access from Houston, and s e v e r a l four-wheel  d r i v e a c c e s s i b l e roads c r o s s the p r o p e r t y .  g a t e - c o n t r o l l e d d i r t roads a l s o access the n o r t h e r n e a s t e r n s i d e s of the map  area ( F i g 1.2.1).  Two  and  2 FIGURE 1.2.1:  LOCATION OF THE SILVER QUEEN GOLD-SILVERLEAD-ZINC-COPPER MINE  3  1.3  HISTORY OF DEPOSITS AND  PREVIOUS WORK  The h i s t o r y of development of the S i l v e r Queen mine a r e a i s paraphrased  from Marsden (1984), and from subsequent  company r e p o r t s . The p r o p e r t y , r e c e n t l y o p t i o n e d t o P a c i f i c Houston Resources L t d . (at the b e g i n n i n g of t h i s study) now  100%  c o n t r o l l e d by New  and  Nadina E x p l o r a t i o n s L t d . , i s  dormant a t p r e s e n t . M i n e r a l i z a t i o n a t the S i l v e r Queen mine was d u r i n g a l a n d survey by Jim H o l l a n d i n 1912.  The  discovered area  s u r r o u n d i n g the w e l l exposed v e i n m i n e r a l i z a t i o n i n the w a l l s of Wrinch canyon subsequently was Wrinch and p a r t n e r s of H a z e l t o n , B.C.. claims  (to the south) was  staked f o r Dr. The Chisholm  Group of  staked soon a f t e r , w i t h the  Diamond B e l l e Group of c l a i m s staked t h r e e years  later.  The F e d e r a l Mining and Smelting group o p t i o n e d p r o p e r t y i n 1923,  H.C.  completing  500  the  f e e t of d r i f t i n g on  two  a d i t s i n the w a l l s of Wrinch canyon. The p r o p e r t y then l a y idle until  1928,  when F.H.  T a y l o r conceived the Owen Lake  Mining and Development Company and combined the t h r e e c l a i m groups. Development of the p r o p e r t y proceded  until  1930,  w i t h the f o l l o w i n g work completed d u r i n g t h a t p e r i o d : 1. ) C o n s t r u c t i o n of roads and camp 2. ) S i n k i n g of the C o l e s h a f t i n order t o d e l i n e a t e the c o n t i n u i t y of the v e i n . 3. ) C o n s t r u c t i o n of the 2600' l e v e l E a r l A d i t t o i n t e r s e c t both the Wrinch (Number Three) and Cole v e i n systems  4  4.)  1000'  of c r o s s - d r i f t i n g t o d e l i n e a t e the extent  of  the P o r t a l v e i n s d i s c o v e r e d d u r i n g c r e a t i o n of  the  Earl Adit. The  S i l v e r Queen area was  i n a c t i v e u n t i l 1941,  Canadian E x p l o r a t i o n L t d . l e a s e d the crown grants p r o v i n c i a l government. L i m i t e d work was p e r i o d from 1941  t o 1963,  the p r o p e r t y i n 1963  from the  completed i n the  w i t h Nadina E x p l o r a t i o n s a q u i r i n g  by s t a k i n g open ground and an agreement  w i t h Canex. A p a r a l l e l program of t r e n c h i n g and d r i l l i n g was  when  surface  a l s o c a r r i e d out on the neighbouring  claim  group near Cole Lake, f o l l o w i n g i t s a q u i s i t i o n by F r o n t i e r E x p l o r a t i o n s L t d . i n 1960.  The program continued on  the  s e r i e s o f v e i n s at Cole Lake u n t i l F r o n t i e r E x p l o r a t i o n s Ltd.  was  succeeded by New  F r o n t i e r Petroleum L t d . i n  1977.  Nadina r e h a b i l i t a t e d the S i l v e r Queen workings and by had completed the f o l l o w i n g work on the  1967  property:  1. ) 3500' of t r e n c h i n g 2. ) 1400'  of c r o s s c u t t i n g and d r i f t i n g on  the  2880' l e v e l 3. ) 16 d r i l l  holes t o t a l i n g  1600'  Kennco optioned the p r o p e r t y i n 1967,  concentrating  a p o t e n t i a l porphyry copper t a r g e t a s s o c i a t e d w i t h e x t e n s i v e a l t e r a t i o n zone i n the southern p r o p e r t y . F i v e d r i l l holes p e n e t r a t e d  the  p o r t i o n of the  the t h i c k cover  overburden, but f a i l e d t o i n t e r s e c t any  had completed the f o l l o w i n g :  of  significant  m i n e r a l i z a t i o n . Nadina continued work on the p r o p e r t y , by 1971  on  and  5  1. ) 5000' o f t r e n c h i n g 2. ) 5060' o f underground d r i l l i n g on t h e Number Three structure. 3. ) 24137' o f s u r f a c e d r i l l i n g on t h e Number Three and a s s o c i a t e d systems. 4. ) underground s t r i p p i n g and stope p r e p a r a t i o n . 5. ) 4000' o f d r i f t i n g 6. ) s o i l geochemistry, electromagnetic In 1971, P a c i f i c  a e r i a l magnetometer, and  surveys.  Petroleum  Resources,  Nadina  E x p l o r a t i o n s , and B r a l o r n e Mines formed t h e Bradina venture. The mine was subsequently f o r 1972, m i l l i n g per day. M i l l i n g  Joint  hurried into production  192,000 tons o f o r e a t a r a t e o f 350 tons problems and i n e f f i c i e n t p r o c e s s i n g methods  f o r c e d c l o s u r e o f t h e o p e r a t i o n i n 1973. Work was s p o r a d i c from 1973 u n t i l  1980, when Nadina r e o r g a n i z e d t o form New  Nadina E x p l o r a t i o n s L t d . 8250' o f t r e n c h i n g was completed, w i t h d r i l l h o l e s completed on the Number Three and NG3 v e i n s . I n 1981, B u l k l e y S i l v e r  Resources c o n t i n u e d work on  the p r o p e r t y , and i n the 1983-84 season, totalling  s i x s u r f a c e holes  3405' were completed. L i m i t e d s u r f a c e d r i l l i n g  work on t h e Number Three and t a i l i n g s continued u n t i l  pond v i c i n i t i e s  1986, when B u l k l e y S i l v e r  reorganized t o  form Houston Metals C o r p o r a t i o n . Houston Metals r e h a b i l i t a t e d t h e workings and c a r r i e d o u t an e x t e n s i v e s u r f a c e and underground d r i l l i n g program i n t h e p e r i o d from 1987 t o 1989. T a r g e t s i n c l u d e d :  6  1. ) Expansion o f confirmed r e s e r v e s  i n t h e south  p o r t i o n o f t h e Number Three system. 2. ) D r i l l t e s t i n g o f t h e George Lake v e i n from the newly extended B u l k l e y 3. ) Surface d r i l l i n g  crosscut.  on the Cole Lake  system.  4. ) D i s c o v e r y and d e l i n e a t i o n o f t h e Camp v e i n E x t e n s i o n o f the South End d r i f t ,  system.  construction of a decline  t o i n t e r s e c t the v e i n below the 2600' l e v e l , and c r o s s c u t t i n g t o i n t e r s e c t the Number One and Number Two v e i n s , was a l s o completed i n t h i s p e r i o d .  In 1989, Houston  Metals (now P a c i f i c Houston Ltd.) c o n t i n u e d d e l i n e a t i o n o f reserves  i n the h i g h grade p o r t i o n o f t h e southern Number  Three v e i n . By 1991, f u l l c o n t r o l o f the p r o p e r t y had r e v e r t e d t o New Nadina E x p l o r a t i o n s L t d . . 1.4 PURPOSE AND SCOPE The purpose o f t h i s study i s t o d e s c r i b e  and i n t e r p r e t  the mineralogy o f t h e v e i n systems exposed a t t h e S i l v e r Queen mine and e s t a b l i s h a p a r a g e n e t i c sequence f o r t h e major v e i n systems  ( F i g u r e 1.4.1). D e t a i l e d g e o l o g i c  of the mine area o f s u r f a c e and underground was  mapping  first  undertaken t o c h a r a c t e r i z e the s e t t i n g o f t h e v e i n system and p r o v i d e comparisons w i t h o t h e r d e p o s i t s s c a l e . Petrographic geologic  on a r e g i o n a l  descriptions further characterized  each  u n i t ( L e i t c h e t a l . , 1990) and K-Ar i s o t o p i c  analyses (provided  by t h e U n i v e r s i t y o f B r i t i s h  Columbia  Geochronology L a b o r a t o r y ) produced approximate ages f o r the l i t h o l o g i e s exposed a t S i l v e r Queen.  7  To examine the v e i n system i n d e t a i l , a t o t a l of s u r f a c e , 62 underground, and  117  134  d r i l l hole samples were  taken, i n c l u d i n g 50 v e i n c r o s s s e c t i o n s of the Number Three/NG3 s t r u c t u r e and  a number of s e c t i o n s across  v e i n s . A t o t a l of about 150  smaller  p o l i s h e d t h i n s e c t i o n s and  110  p o l i s h e d s e c t i o n s were examined through r e f l e c t e d and transmitted  l i g h t microscopy i n order to c h a r a c t e r i z e  the  mineralogy and paragenesis of the v a r i o u s v e i n systems  (here  d e f i n e d as v e i n s o c c u r r i n g i n c l o s e s p a t i a l a s s o c i a t i o n w i t h each o t h e r - eg. the Number Three, F o o t w a l l , Number One Number Two  veins) present  e l e c t r o n microscope and  and  a t S i l v e r Queen mine. Scanning  e l e c t r o n microprobe analyses  of  s e v e r a l s u l f i d e phases ( t e t r a h e d r i t e , s p h a l e r i t e , and s u l f o s a l t s ) was  undertaken i n o r d e r t o i d e n t i f y  phases of u n c e r t a i n i d e n t i t y and  f u r t h e r e s t a b l i s h the  p a r a g e n e s i s and environment of ore The  deposition.  r e s u l t s of the m i n e r a l o g i c  broader study concerning  geologic  sulfide  s t u d i e s are p a r t of a  s e t t i n g , mineralogy,  a l t e r a t i o n , and d e p o s i t e v o l u t i o n of the S i l v e r Queen area. Examples of p a r a l l e l r e s e a r c h c a r r i e d out by the Owen Lake P r o j e c t are i n c l u d e d i n Cheng et a l . (1991) and Thomson and Sinclair  (1991).  8  2.0 2.1  GEOLOGIC SETTING OF THE  INTRODUCTION AND  SILVER QUEEN MINE  TECTONIC SETTING  S i l v e r Queen mine occurs w i t h i n a b l o c k of L a t e Cretaceous 1970;  rocks of the T i p Top H i l l v o l c a n i c s (Church,  L e i t c h et a l . , 1990)) south of Houston, c e n t r a l  B r i t i s h Columbia. The rocks are p a r t of the Buck Creek Tertiary outlier  (Church, 1973), a broad,  f a u l t bounded  b a s i n c o n t a i n i n g a number of L a t e Cretaceous  and Eocene  v o l c a n i c c e n t e r s ( F i g u r e 2.1.1). The e n t i r e b a s i n belongs  to  the S t i k i n e Terrane, which i n c l u d e s : c a l c a l k a l i n e t o a l k a l i n e immature v o l c a n i c i s l a n d a r c rocks of the L a t e T r i a s s i c T a k l a Group; s u b a e r i a l t o submarine c a l c a l k a l i n e v o l c a n i c , v o l c a n i c l a s t i c and sedimentary  rocks of the E a r l y  t o Middle J u r a s s i c Hazelton Group; L a t e J u r a s s i c and Cretaceous  s u c c e s s o r b a s i n sedimentary  Lake, Skeena and Sustut groups;  Early  rocks of the Bowser  and l a t e E a r l y Cretaceous  to  T e r t i a r y c a l c a l k a l i n e c o n t i n e n t a l v o l c a n i c - a r c r o c k s of the K a s a l k a , Ootsa Lake, and Goosly Lake groups (Maclntyre  and  D e s j a r d i n s , 1988). P r e s e r v a t i o n of many of the younger v o l c a n i c sequences occurs w i t h i n grabens,  h a l f grabens,  and  p o s s i b l e c a u l d r o n subsidence complexes generated by b l o c k f a u l t i n g t h a t was these rocks  c l o s e l y a s s o c i a t e d w i t h the e r u p t i o n o f  (Souther, 1977). W e l l d e f i n e d i n t r u s i v e b e l t s of  J u r a s s i c , Cretaceous, and T e r t i a r y age are a l s o p r e s e n t , w i t h s e v e r a l of the p l u t o n s (eg. G l a c i e r Gulch, Smithers)  a s s o c i a t e d w i t h porphyry copper,  near  stockwork  9  molybdenum, and mesothermal  and e p i t h e r m a l base- and  precious-metal v e i n m i n e r a l i z a t i o n  ( C a r t e r , 1981). Armstrong  (1988) suggests t h a t the T e r t i a r y p l u t o n i c episode spans a t e m p o r a l l y narrow p e r i o d (at most, 45-55 Ma), r e s u l t i n g from a wide s u b d u c t i o n - r e l a t e d magmatic a r c . 2.2  REGIONAL GEOLOGY  2.2.1  Geologic  Setting  The S i l v e r Queen mine l i e s on the western margin of the Buck Creek b a s i n , as d e f i n e d by Church (1973). Church  (1973)  suggested t h a t the arrangement o f known L a t e Cretaceous and Eocene v o l c a n i c c e n t e r s r e p r e s e n t e d a s e m i - c i r c u l a r c a l d e r a generated s t r u c t u r e , w i t h the r e s u r g e n t c e n t e r l o c a t e d near the  E q u i t y S i l v e r mine (Figure 2.1.1). Church and Barakso  (1990) r e c o g n i z e d e i g h t e e n major g e o l o g i c u n i t s w i t h i n the b a s i n , r a n g i n g i n age from E a r l y J u r a s s i c  (Sinemurian) t o  Miocene. The s t r a t i g r a p h y , i n c l u d i n g age dates f o r component u n i t s of the Buck Creek b a s i n , i s summarized  i n Table  2.2.1  ( c f . Church and Barakso, 1990). O l d e s t r o c k s i n the Buck Creek b a s i n are a f f i l i a t e d w i t h the H a z e l t o n Group and i n c l u d e an assemblage of g e n t l y d i p p i n g r e s i s t a n t  lavas,  p y r o c l a s t i c s and interbedded (and b a s a l ) sedimentary r o c k s . The group i s exposed on the n o r t h e r n , northwestern, and e a s t e r n margins o f the Buck Creek area and i n s e v e r a l s m a l l e r windows eroded i n t o the o v e r l y i n g T e r t i a r y sequences (Church and Barakso, 1990). In t h e a r e a near Burns Lake, the H a z e l t o n Group i s i n t r u d e d by the g r a n i t i c T o p l e y I n t r u s i o n s over an a r e a o f about f i f t y square k i l o m e t e r s .  FIGURE 2.1.1: GEOLOGY OF THE BUCK CREEK AREA*  11 TABLE 2.1.1:  STRATIGRAPHIC UNITS IN THE  BUCK CREEK AREA  Age/Epoch  Formation  Lithology  MIOCENE 21.4 Ma  Poplar (Tpb)  Olivine Basalts  EOCENE to 48.2 Ma  Buck Creek (KTo)  48.7 54.3  Goosly Lake (KTo)  Bladed f e l d s p a r p o r p h y r i t i c andesite to t r a c h y a n d e s i t e lavas  Goosly Intrusions (KTo)  Syenomonzonite-gabbro b o d i e s . Bladed f e l d s p a r and amygdular dykes i n S i l v e r Queen area.  Burns Lake (KTo)  Conglomerates,sandstone and s h a l e s  Nanika I n t r u s i o n s (Kg)  G r a n i t i c stocks, i n c l u d i n g Nadina  to Ma  51-52 Ma  53  Ma  Buttes  UPPER CRETACEOUS 75.5 t o T i p Top 84.6 Ma (KTo)  78.7  Ma  Hill  Bulkley Intrusions (Kg)  LOWER CRETACEOUS Skeena Group (KB)  JURASSIC  Hazelton (Jh)  Group  Telkwa Formation  Fine-grained andesitic b a s a l t i c lavas breccias  and  Mtn.  Feldspar-biotite p o r p h y r i t i c andesites and fragmental r o c k s . Lesser a c i d volcanics M i c r o d i o r i t e s i l l s and stocks. Basic to i n t e r m e d i a t e stocks Conglomerates,sandstone and i n t e r m i x e d f e l s i c fragmental v o l c a n i c s . L o c a l l y shale or massive r h y o l i t e s Fine-grained andesitic, r h y o l i t i c , and b a s a l t i c l a v a s and v o l c a n i clastics maroon t u f f and breccia  G r a n i t i c bodies Topley Intrusions Burns Lake (Jg) • M o d i f i e d from Church and Barakso (1990) ** " ( ) " correspond t o symbols i n F i g u r e 2.1.1.  tuffnear  12  Lower Cretaceous  nonmarine and marine sedimentary  and  v o l c a n i c rocks of the Skeena Group unconformably o v e r l i e the H a z e l t o n Group i n the Buck Creek area and Richards, 1976)  and are exposed i n a s e r i e s of s m a l l  windows i n the Late Cretaceous and Barakso,  (Table 2.2.1)(Tipper  and T e r t i a r y cover  (Church  1990). Exposures of the Skeena Group rocks  extend from the v i c i n i t y of Goosly Lake southeast t o F r a n c o i s Lake. The Skeena Group rocks are i n t u r n unconformably o v e r l a i n by Late Cretaceous sedimentary  t o Eocene v o l c a n i c and  r o c k s , i n f o r m a l l y named the F r a n c o i s Lake group  (Church and Barakso,  1990)  (Table 2.2.1). The o l d e s t of the  s i x major u n i t s and t h r e e i n t r u s i v e episodes d e f i n e d by Church and Barakso (1990) c o n s i s t s of u n d i v i d e d r h y o l i t i c l a v a s , t u f f s , b r e c c i a s and r e l a t e d i n t r u s i o n s exposed on the northwest  shore of F r a n c o i s Lake and i n the v i c i n i t y of the  S i l v e r Queen mine. The s l i g h t l y younger T i p Top  Hill  v o l c a n i c rocks o v e r l i e the r h y o l i t e s , w i t h the major exposure o c c u r r i n g on the e a s t s i d e of Owen Lake. Church (1970) c o n s i d e r e d the body of m i c r o d i o r i t e a t Mine H i l l r e p r e s e n t the e r u p t i v e c e n t e r of the T i p Top H i l l  to  volcanics,  w i t h nearby b r e c c i a bodies s u g g e s t i n g p r o x i m i t y t o a v o l c a n i c vent. The r h y o l i t i c rocks and T i p Top  Hill  formation are i n t u r n i n t r u d e d by s m a l l d i o r i t i c , gabbroic and f e l s i c porphyry i n t r u s i o n s of the B u l k l e y i n t r u s i v e event  (Table 2.2.1). Church and Barakso (1990) a l s o i n c l u d e d  the Mine H i l l m i c r o d i o r i t e w i t h t h i s event and noted  the  13  apparent  comagmatic r e l a t i o n s h i p between the m i c r o d i o r i t e  and a s s o c i a t e d a n d e s i t i c l a v a s of the T i p T o p ' H i l l f o r m a t i o n . The Nanika I n t r u s i o n s were emplaced about twenty m i l l i o n years l a t e r  (Table 2.2.1) and are r e p r e s e n t e d by  two  s m a l l stocks southeast of the town of Houston, and by the l a r g e r Nadina Mountain s t o c k on the west s i d e of Owen Lake. P o o r l y exposed conglomerates of the Burns Lake formation o v e r l i e the T i p Top H i l l  f o r m a t i o n , w i t h the p r i n c i p a l  exposure o c c u r r i n g n o r t h and e a s t of the town of Burns Lake. A s e r i e s of younger t r a c h y a n d e s i t i c , t r a c h y t i c and  basaltic  l a v a s and a s s o c i a t e d i n t r u s i v e s of the Goosly Lake formation are exposed i n the v i c i n t y of Goosly Lake. Church (1985) suggests  t h a t a s e t of t h r e e syenomonzonite stocks w i t h  a s s o c i a t e d dykes, o c c u r r i n g i n w e s t e r l y alignment  between  the E q u i t y S i l v e r and the S i l v e r Queen areas, r e p r e s e n t an e r u p t i v e a x i s f o r the Goosly Lake formation. The Buck Creek f o r m a t i o n o v e r l i e s the Goosly Lake l a v a s i n s e v e r a l l o c a t i o n s and c o n s i s t s p r i n c i p a l l y of g r a i n e d amygdaloidal  fine-  l a v a s and l e s s e r p o r p h y r i t i c l a v a s  and  b r e c c i a s , forming the most w i d e l y d i s t r i b u t e d u n i t i n the Buck Creek area (Table 2.2.1). The u n i t i s best exposed as t h i n l y l a y e r e d l a v a flows on the r i d g e s southeast of town of Houston (Church and Barakso, 1990). Uppermost of the F r a n c o i s Lake group rocks are r h y o l i t i c and t r a c h y t i c rocks of the Fenton Creek f o r m a t i o n , exposed i n a s m a l l area south of the Morice R i v e r and west of the Buck Creek map  area.  14  Miocene columnar b a s a l t s o f t h e P o p l a r Buttes  formation  cap t h e T e r t i a r y sequence on P o p l a r B u t t e s , near t h e west end o f F r a n c o i s Lake (Church and Barakso,  2.2.2  Geology  1990).  of the Owen Lake Area  The Owen Lake area i s on t h e western margin o f t h e Buck Creek b a s i n i n rocks belonging p r i n c i p a l l y t o t h e Late Cretaceous  T i p Top H i l l  formation. A n d e s i t i c l a v a s , t u f f s ,  and b r e c c i a s o f t h e u n i t form a g e n t l y n o r t h - t o n o r t h w e s t e r l y - d i p p i n g homocline,  with the oldest units  exposed i n t h e south. S l i g h t l y o l d e r a c i d i n t r u s i v e s a r e r e v e a l e d t o t h e n o r t h e a s t o f Owen Lake on Okusyelda  Hill,  although Church (1973) c o n s i d e r e d much o f t h e q u a r t z s e r i c i t e - p y r i t e a l t e r e d rocks immediately  southeast o f t h e  m i n e s i t e t o be o f s i m i l a r composition. T i p Top H i l l l i t h o l o g i e s a l s o cover much of t h e southwestern  margin o f  Owen Lake, w i t h a l a r g e quartz monzonite s t o c k (dated a t 53 Ma by C a r t e r [1981]) and nearby p l a n t f o s s i l - b e a r i n g greywackes and a r g i l l i t e s  (Lang, 1929) o c c u r r i n g d i r e c t l y  west o f t h e S i l v e r Queen mine a t Mount Nadina. Church (1984) a l s o notes l a r g e exposures  o f t r a c h y a n d e s i t i c Goosly Lake  l a v a s o c c u r r i n g t o t h e south o f , and exposed i n t h e w a l l s of,  Riddeck  Creek ( F i g u r e 2.3.1, i n p o c k e t ) . The occurrences  of  Goosly Lake l a v a s a r e i n t u r n o v e r l a i n by amygdular l a v a s  of  t h e Buck Creek formation, which forms a s e r i e s o f  prominent c l i f f s bounding the s o u t h e a s t e r n p o r t i o n o f t h e Owen Lake v a l l e y . More a r g i l l a c e o u s r o c k s , i n t r u d e d by  15  r h y o l i t e dykes ( p o s s i b l y r e l a t e d t o those on Okusyelda H i l l ) and a s m a l l quartz monzonite stock, occur i n the n o r t h e a s t e r n p o r t i o n o f the Owen Lake a r e a . Ages o f u n i t s i n the Owen Lake area and a s s o c i a t e d s t r u c t u r e and f a u l t i n g w i l l be d i s c u s s e d i n s e c t i o n s  2.3.2  and 2.3.3. 2.3  GEOLOGY OF THE MINE AREA  2.3.1  Introduction M i n e r a l i z a t i o n a s s o c i a t e d w i t h the S i l v e r Queen mine i s  hosted by rocks o f the T i p Top H i l l f o r m a t i o n and i s roughly d e l i n e a t e d by E m i l Creek on the n o r t h and Riddeck Creek on the south  ( F i g u r e 2.3.1). The s u c c e s s i o n d i s p l a y s a g e n t l e  n o r t h w e s t e r l y d i p , w i t h the o l d e s t u n i t s exposed i n the south and becoming p r o g r e s s i v e l y younger t o the n o r t h . L e i t c h e t a l . (1990) d i v i d e d the sequence i n t o f i v e major u n i t s and t h r e e dyke types, and compared t h e sequence t o rocks d e s c r i b e d as Kasalka Group o c c u r r i n g w i t h i n the Tahtsa Lake  (Maclntyre, 1985) and Mount C r o n i n  D e s j a r d i n s , 1988) map  (Maclntyre and  areas. Armstrong (1988) c l a s s i f i e d the  Kasalka type s e c t i o n as l a t e E a r l y Cretaceous  age, an age  which does not agree w i t h the much younger ages o b t a i n e d f o r v o l c a n i c u n i t s i n the S i l v e r Queen mine a r e a . As a r e s u l t , the i n f o r m a l c l a s s i f i c a t i o n o f Church (1984) has been used here when c o n s i d e r i n g the proper s t r a t i g r a p h i c nomenclature f o r the S i l v e r Queen r o c k s . F i g u r e 2.3.2  and Table 2.3.1  summarize t h e  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 present i n the s u c c e s s i o n a t  FIGURE 2.3.2: OWEN LAKE STRATIGRAPHY  EBV  •Refer t o T a b l e 2.3.1 f o r u n i t  identifications  17 TABLE 2.3.1:  STRATIGRAPHIC UNITS OF THE SILVER QUEEN (OWEN LAKE) AREA  Formation  Epoch  Age (Ma)  Miocene  21.4  Poplar Buttes  Eocene  50.4  F r a n c o i s Lake  51.9  Symbol/Unit MPBv/  Lithology Olivine Basalt  EBv/8  Basalt,diabase dykes  EOv/7a  Trachyandes i t e basalt  /7  Bladed f e l d s p . porphyry dykes  -MINERALIZATION 51.3  78.7 70.3  78.3  /6  Amygdule dykes  uKqp/5b  Quartz-eye porph. stocks and dykes  uKKp/5a  Intrusive porph. s t o c k s and s i l l s  uKKud/5 /4a  uKKfp/4  Microdiorite Feldsparbiotite porphyry dykes Feldspar porphyritic andesite  uKKb/3  Medium t o coarse t u f f breccia  uKKt/2  Ash, c r y s t a l , and l a p i l l i tuff  uKKc/1  Polymictic b a s a l conglomerate, shale and sandstone interbeds  18  S i l v e r Queen mine. A b a s a l r e d d i s h p u r p l e  polymictic  conglomerate (Unit 1) i s o v e r l a i n by a fragmental u n i t r a n g i n g from c r y s t a l t u f f and b r e c c i a  (Unit 2) t o coarse l a p i l l i  (Unit 3). T h i s i n t u r n i s succeeded by a t h i c k  feldspar p o r p h y r i t i c andesite  flow ( U n i t 4) and i n t r u d e d by  several small microdiorite s i l l s et  tuff  a l . , 1990). The s u c c e s s i o n  and stocks  (Unit 5) ( L e i t c h  i s i n t r u d e d by a s e r i e s o f  Eocene age b l a d e d f e l d s p a r p o r p h y r i t i c t r a c h y a n d e s i t e  dykes  (Unit 6), f i n e - g r a i n e d amygdular dykes (Unit 7), and diabase dykes ( U n i t 8). L i t h o l o g i e s t h a t a r e p o t e n t i a l l y c o r r e l a t i v e w i t h t h e Goosly Lake formation o f Church (1973) unconformably o v e r l i e t h e S i l v e r Queen sequence i n the southern p o r t i o n o f t h e map area.  2.3.2  Geology The  and  Petrography  s t r a t i g r a p h i c succession  d e f i n e d w i t h i n the S i l v e r  Queen a r e a i s i n c l u d e d w i t h i n t h e L a t e Cretaceous T i p Top H i l l Formation, as d e f i n e d by Church (1984). A more complete d e s c r i p t i o n of the units recognized Unit  a t Owen Lake f o l l o w s .  1  A p o o r l y s o r t e d p o l y m i c t i c conglomerate u n i t forms t h e b a s a l member o f t h e T i p Top H i l l s u c c e s s i o n , i d e n t i f i c a t i o n of the u n i t i n d r i l l hole,  with  underground  workings, and i n a roadcut near t h e southern end o f Owen Lake. The u n i t i s reddish-brown t o p u r p l e  i n c o l o u r and  h e t e r o l i t h i c , c o n t a i n i n g predominantly rounded t o subangular white q u a r t z and grey-brown t o maroon t u f f and porphyry  19  c l a s t s . C l a s t s are up t o one meter i n diameter and little  display  evidence of s i z e grading. The m a t r i x i s predominantly  f i n e sand, cemented by q u a r t z , s e r i c i t e , and i r o n oxides. The lower c o n t a c t of the u n i t i s not exposed and i s assumed to  be i n f a u l t c o n t a c t w i t h younger Ootsa Lake Group rocks  o c c u r r i n g f a r t h e r t o the south. The upper c o n t a c t has been intersected i n d r i l l  h o l e and i n underground workings near  the c e n t e r of the p r o p e r t y . The c o n t a c t i s t y p i c a l l y occupied by the i n t r u s i v e porphyry u n i t than the c r y s t a l - l i t h i c t u f f u n i t conformable,  (Unit 2) and  appears  although the former u n i t i s c o n s i d e r e d t o occur  as s t o c k s and s i l l s al.,  ( U n i t 5A) r a t h e r  r a t h e r than d i s c r e t e flows ( L e i t c h et  1990).  Unit 2 A sequence of f i n e c r y s t a l t u f f s w i t h interbedded laminated t u f f s , ash t u f f s , l a p i l l i t u f f s , and s t r a t i g r a p h i c a l l y o v e r l i e s the conglomerate  tuff-breccias  u n i t i n the  S i l v e r Queen a r e a . The u n i t i s present predominantly  i n the  southern p a r t of the p r o p e r t y (Figure 2.3.1) and has been a l t e r e d h y d r o t h e r m a l l y t o q u a r t z , s e r i c i t e , and p y r i t e .  An  e s t i m a t e d t h i c k n e s s of up t o 100 m has been measured. A massive, is  grey t o white, s t r o n g l y a l t e r e d f i n e c r y s t a l  the most widespread  l i t h o l o g y , g r a d i n g i n t o a porphyry of  s i m i l a r appearance and composition Broken phenocrysts  tuff  ( L e i t c h e t a l . , 1990).  and i n t e r b e d s c o a r s e l y fragmental o r  laminated m a t e r i a l suggest t h a t the m a j o r i t y o f the u n i t i s t u f f a c e o u s . Outcrops  on the east s i d e of the George Lake  20  f a u l t a l s o d i s p l a y i n t e r b e d s of a v e r y f i n e g r a i n e d , uniform "ash t u f f "  ("Unit 2A" on F i g u r e 2.3.1). The  f i n e t u f f beds  are dark grey and s i l i c e o u s i n appearance, w i t h angular b l o c k s of e i t h e r mixed ( h e t e r o l i t h i c ) m a t e r i a l o r l a r g e r c l a s t s t h a t are b a r e l y d i s t i n g u i s h a b l e from the m a t r i x . In the Chisholm v e i n area ( F i g u r e 2.3.1), U n i t 2 commonly c o n t a i n s t h i n  (10 cm.  t h i c k ) i n t e r b e d s of laminated  t u f f , d i s p l a y i n g near v e r t i c a l d i p s and  soft-sediment  deformation f e a t u r e s . In the c o a r s e r g r a i n e d l e n s e s up t o one meter t h i c k , g e n t l e n o r t h e r l y d i p s are r e t a i n e d . T h i n ' s e c t i o n s of U n i t 2 m a t e r i a l r e v e a l a l i t h o l o g y c o n s i s t i n g of broken (1-2 mm.  wide), a l t e r e d p l a g i o c l a s e r e l i c s ,  abundant, probably secondary  with  anhedral q u a r t z g r a i n s (0.5  wide) i n a m a t r i x of f i n e - g r a i n e d secondary  mm.  sericite,  carbonate, p y r i t e , and q u a r t z . The o r i g i n a l mafic component i s unknown due t o e x t e n s i v e a l t e r a t i o n of the u n i t . Unit  3  U n i t 3 c o n s i s t s of a d i s t i n c t i v e c o a r s e fragmental  unit  t h a t o v e r l i e s or p o s s i b l y i s i n t e r l a y e r e d w i t h the upper p a r t of U n i t 2. Large bodies of the u n i t are exposed t o the south of the t a i l i n g s pond area and i n the v i c i n i t y of the C o l e v e i n ( F i g u r e 2.3.1). In d r i l l c o r e , the u n i t d i s p l a y s s u b v e r t i c a l c o n t a c t s w i t h U n i t 4 and U n i t 5, s u g g e s t i n g a p o s s i b l e i n t r u s i v e r e l a t i o n s h i p w i t h the s u r r o u n d i n g u n i t s . T h i s concept i s supported by an apparent  decrease i n  fragment s i z e and d e n s i t y towards the c e n t e r o f the b r e c c i a b o d i e s . Since the s u b v e r t i c a l c o n t a c t s occur w i t h the  21  microdiorite 4)  f  there  contacts  (Unit 5) o r f e l d s p a r p o r p h y r i t i c a n d e s i t e  (Unit  i s a l s o a p o s s i b i l i t y t h a t the o r i e n t a t i o n of  the  i s c o n t r o l l e d by the i n t r u s i o n of U n i t 4 and/or  U n i t 5 i n t o a p r e - e x i s t i n g conformable b r e c c i a u n i t .  Drill  h o l e i n t e r s e c t i o n s from the southern end of the Number Three v e i n system show conformable c o n t a c t s U n i t 4,  between U n i t 3  and  s u g g e s t i n g t h a t the U n i t 3 b r e c c i a i s o l d e r than the  feldspar p o r p h y r i t i c andesite  u n i t (Unit 4). L e i t c h et a l .  (1990) suggested t h a t U n i t 3 may  represent  the u n s o r t e d nature of the c l a s t s and  a lahar,  citing  locally variable clast  l i t h o l o g y . Macintyre (1985) a l s o noted a s i m i l a r u n i t w i t h i n rocks i n the Kasalka Range near Tahtsa Lake. In outcrop, the u n i t commonly forms  discontinuous  l e n s e s w i t h some s u g g e s t i o n of a g e n t l e n o r t h e r l y d i p apparent c o n f o r m i t y w i t h the u n d e r l y i n g  tuffaceous  and  unit.  Fragments are g e n e r a l l y angular t o subangular and up t o h a l f a meter across cm.).  (though g e n e r a l l y i n the range from 2 t o 5  For the most p a r t , the  fragments are composed of  m a t e r i a l t h a t i s t e x t u r a l l y s i m i l a r t o the p o r p h y r i t i c l i t h o l o g i e s ( U n i t s 4 and t u f f or cherty material  feldspar  5A), w i t h c l a s t s of  l o c a l l y p r e s e n t . The m a t r i x i s  h i g h l y v a r i a b l e , forming anywhere from almost zero t o p e r c e n t of the rock. In t h i n s e c t i o n , the fragments  ninety  are  found t o be composed of s t r o n g l y a l t e r e d f e l d s p a r porphyry, f i n e t u f f , and  quartz o r q u a r t z o f e l d s p a t h i c  i n a f i n e tuffaceous  rocks,  enclosed  m a t r i x ( L e i t c h et a l . , 1990).  I d e n t i f i c a t i o n of the o r i g i n a l mineralogy i s d i f f i c u l t ,  due  22  t o i n t e n s e q u a r t z - s e r i c i t e - p y r i t e + carbonate  alteration  t h a t i s a s s o c i a t e d w i t h many o f t h e b r e c c i a b o d i e s . In some l o c a l e s , such as i n the v i c i n i t y o f t h e Cole v e i n s , hydrothermal b r e c c i a s i n U n i t s 3, 4, and 5 a r e a l s o present near t h e major v e i n s . Unit 4 A t h i c k succession of feldspar p o r p h y r i t i c andesite flows forms the most e x t e n s i v e u n i t i n t h e S i l v e r Queen mine area, o v e r l y i n g t h e o l d e r fragmental u n i t s and forming much of the o u t c r o p i n the n o r t h e r n p o r t i o n o f t h e map area. Large exposures  o c c u r t o the n o r t h o f Wrinch Canyon, w i t h  the e n t i r e u n i t a p p a r e n t l y d i p p i n g g e n t l y t o the northwest. L e i t c h e t al. (1990) c o r r e l a t e d the f e l d s p a r porphyry w i t h t h e T i p Top H i l l v o l c a n i c s o f Church  (1970),  unit  although  minor d i f f e r e n c e s i n the s i z e and d e n s i t y o f the phenocrysts are noted. In outcrop, U n i t 4 i s g e n e r a l l y w e l l j o i n t e d and weathers t o a g r e y i s h c o l o u r , w i t h w e l l d e f i n e d f e l d s p a r phenocrysts v i s i b l e . The phenocrysts n o r m a l l y d i s p l a y t r a c h y t i c t e x t u r e d flow l a m i n a t i o n most e a s i l y v i s i b l e on weathered s u r f a c e s . Coarser g r a i n e d exposures may r e p r e s e n t s i l l s and s t o c k s , s i m i l a r t o those d e s c r i b e d i n the type s e c t i o n s o f M a c l n t y r e (1985) and M a c l n t y r e and D e s j a r d i n s (1988). Contacts w i t h the m i c r o d i o r i t e u n i t  (Unit 5) tended  t o be g r a d a t i o n a l over d i s t a n c e s o f a few meters, i n some underground exposures sharp.  although  c o n t a c t s were found t o be  23  Chemically/ the f e l d s p a r p o r p h y r i t i c u n i t i s between andesite  and  dacite  (Church, 1973), w i t h the  s i m i l a r t o t h a t of the m i c r o d i o r i t e u n i t s e c t i o n , U n i t 4 i s dominated (up t o 40 t o three m i l l i m e t e r - l o n g  Unit  ( U n i t 5 ) . In t h i n  %) by euhedral,  two  andesine c r y s t a l s w i t h l e s s e r  amounts of c l i n o p y r o x e n e and mm.)  composition  hornblende phenocrysts  (1-2  . 4A Narrow (up t o two  meters t h i c k ) b i o t i t e  feldspar  p o r p h y r i t i c dykes o c c u r i n s c a t t e r e d l o c a l i t i e s around the S i l v e r Queen mine, the most n o t a b l e c u t t i n g the lower p a r t of the U n i t 4 flow s e c t i o n on the n o r t h s i d e of Cole Lake (Figure 2.3.1). L e i t c h et al. represent  feeders  (1990) c o n s i d e r e d  the dykes t o  t o the o v e r l y i n g U n i t 4 flows,  commenting  on the r e l a t i v e t e x t u r a l s i m i l a r i t y between the two The  dykes are p u r p l i s h - g r e y  of b l a c k b i o t i t e  units.  i n outcrop, w i t h s c a t t e r e d books  (up t o 3 mm.  across) and  p l a g i o c l a s e phenocrysts (1-2 mm.  abundant  a c r o s s ) i n an  aphanitic  groundmass. Unit 5 U n i t 5, a l s o termed the  "Mine H i l l m i c r o d i o r i t e " crops  out i n the v i c i n i t y of the Number Three and systems ( F i g u r e 2.3.1) and the c e n t e r subvolcanic  i n several smaller  of the S i l v e r Queen area. The stocks,  s i m i l a r t o the  sills,  C o l e Lake v e i n  and dykes and  localities in  u n i t occurs as is  chemically  f e l d s p a r porphyry flow u n i t , the  being e l e v a t e d potassium contents w i t h i n the  difference  microdiorite  24  (Church, 1970,  1971). Contacts w i t h the f e l d s p a r  porphyry  u n i t are g e n e r a l l y g r a d a t i o n a l , but dykes c r o s s - c u t t i n g o l d e r u n i t s have been noted. In outcrop, the m i c r o d i o r i t e i s e q u i g r a n u l a r , l a c k s flow banding, and d i s p l a y s a f i n e r g r a i n s i z e than the f e l d s p a r porphyry. P l a g i o c l a s e phenocrysts mm.)  and r e l i c mafic m i n e r a l s (<0.5  mm.)  occur w i t h i n a p i n k  f e l d s p a t h i c groundmass, w i t h primary magnetite w i t h i n the l e s s a l t e r e d specimens.  (<1  present  L e i t c h et al.  (1990)  noted the s i m i l a r i t y of the m i c r o d i o r i t e - f e l d s p a r  porphyry  assemblage t o rocks observed i n the Kasalka Range (Maclntyre, 1985)  near Tahtsa Lake, c l a s s i f y i n g them as  l a t i t e - a n d e s i t e s o r d a c i t e a c c o r d i n g t o the c l a s s i f i c a t i o n of Streckeisen  (1967; c f . Maclntyre, 1985).  In t h i n s e c t i o n , U n i t 5 i s q u i t e s i m i l a r t o the f e l d s p a r porphyry u n i t . O s c i l l a t o r y zoned andesine  (^45-30  from p e t r o g r a p h i c a n a l y s i s ) i s most abundant, w i t h l e s s e r amounts of euhedral c l i n o p y r o x e n e ( p a r t i a l l y a l t e r e d t o c h l o r i t e ) and hornblende Scattered  relics  q u a r t z phenocrysts  l a t e - s t a g e overgrowths  (altered to c h l o r i t e ) .  (up t o 1 mm.),  many d i s p l a y i n g  of q u a r t z , are a l s o p r e s e n t , although  not v i s i b l e i n hand sample. The groundmass c o n s i s t s of f i n e g r a i n e d q u a r t z , p l a g i o c l a s e , and potassium f e l d s p a r  (Leitch  et a l . , 1990). Unit  5A A coarse f e l d s p a r porphyry u n i t i s exposed near the  southern e x t e n t of known m i n e r a l i z a t i o n , o c c u r r i n g as bodies up t o one k i l o m e t e r a c r o s s (Figure 2.3.1) i n the v i c i n i t y of  25  C o l e Creek. I n t e r s e c t i o n s w i t h i n d r i l l h o l e commonly encounter porphyry  the u n i t between U n i t s 1 and 3, although  the  i s a p p a r e n t l y i n t r u s i v e t o both. Much of the u n i t  has been i n t e n s e l y a l t e r e d t o q u a r t z - s e r i c i t e - p y r i t e , r e s u l t i n g i n d i f f i c u l t i e s i d e n t i f y i n g the o r i g i n a l mineralogy.  In outcrop, the u n i t i s massive and p a l e brown  in  c o l o u r , w i t h a l t e r e d phenocrysts  to  c r e a t e a "honeycomb" p a t t e r n . The rock i s composed of  approximately  commonly weathered out  f i f t y p e r c e n t s e r i c i t i z e d or s a u s s u r i t i z e d  p l a g i o c l a s e phenocrysts  up t o f i v e m i l l i m e t e r s a c r o s s  and  o f t e n g l o m e r o p o r p h y r i t i c , w i t h l e s s e r amounts of s m a l l e r a l t e r e d mafic r e l i c s i n a f i n e f e l d s p a t h i c groundmass ( L e i t c h e t a l . , 1990). The c o a r s e g r a i n e d nature and l a c k o f f l o w banding  d i s t i n g u i s h U n i t 5A from U n i t s 4 and  5,  although a l l three are a p p a r e n t l y r e l a t e d t o the same magmatic event. L e i t c h et al.  (1990) noted the s i m i l a r i t y t o  rocks near Tahtsa Lake (Macintyre, 1985)  and c o n s i d e r e d U n i t  5A t o r e p r e s e n t a s u b v o l c a n i c or i n t r u s i v e body t h a t emplaced below o r postdates the f e l d s p a r porphyry Unit  was  unit.  5B Q u a r t z - f e l d s p a r p o r p h y r i t i c rocks c l a s s i f i e d  as  "Okusyelda" d a c i t e ( r h y o l i t e ) by Church (1970) o c c u r i n s c a t t e r e d l o c a l i t i e s near the S i l v e r Queen mine. The  largest  body outcrops on the h i l l s i d e n o r t h of E m i l Creek ( F i g u r e 2.3.1) and i s a p p a r e n t l y p a r t of a l a r g e r s u b v o l c a n i c s t o c k . D y k e - l i k e bodies were a l s o found near Cole Creek and i n d r i l l holes l o c a t e d near the southern p o r t i o n s o f the Number  26  Three and uncertain,  George Lake v e i n s . Contacts w i t h U n i t s  4 and  5  although i t appears t o be i n t r u s i v e i n t o U n i t  are 4.  Church (1984) suggested a p o s s i b l e c o r r e l a t i o n between the quartz porphyry u n i t and  a c i d v o l c a n i c rocks i n the  p a r t of the Buck Creek area; however, L e i t c h et al.  eastern (1990)  noted a s i m i l a r i t y t o i n t r u s i v e rocks i n the Kasalka Range dated a t 76 Ma  and  thus c o n s i d e r e d the quartz porphyry u n i t  a t Owen Lake t o be younger than the microdiorite  (Unit 5) and  encapsulating  f e l d s p a r p o r p h y r i t i c andesite  (Unit 4 ) . U n i t 5B i s b e l i e v e d t o be p r e - m i n e r a l i z a t i o n it  i s c u t by a t h i c k c a l c i t e v e i n i s the bed  and  has  since  of E m i l Creek  undergone q u a r t z - s e r i c i t e - p y r i t e a l t e r a t i o n i n the  southern p o r t i o n of the S i l v e r Queen a r e a . T h i n s e c t i o n a n a l y s i s by L e i t c h et al.  (1990) found  t h a t the q u a r t z porphyry u n i t i s d i s t i n g u i s h a b l e by  the  presence of t e n t o f i f t e e n p e r c e n t quartz phenocrysts (up 2 mm.  a c r o s s ) . Euhedral andesine p l a g i o c l a s e c r y s t a l s  smaller  r e l i c mafic g r a i n s  and  are a l s o p r e s e n t , s e t i n a  groundmass c o n s i s t i n g of equal amounts of p l a g i o c l a s e , and  to  quartz,  potash f e l d s p a r . Quartz and  lesser  p l a g i o c l a s e were a l s o noted as angular fragments and/or shards. Unit  6 Unit  6 c o n s i s t s of s e r i e s of v a r i a b l y amygdaloidal  dykes t h a t are c l o s e l y a s s o c i a t e d mineralization.  w i t h the major areas of  I n d i v i d u a l dykes are up t o 15 meters a c r o s s  and most f r e q u e n t l y p a r a l l e l the northwest t r e n d i n g  vein  27  systems (eg. Number Three system), although e a s t , and n o r t h - t r e n d i n g  northeast,  dykes were a l s o found. The dykes may a l s o  be h i g h l y i r r e g u l a r and anastomosing i n form, w i t h d i p s ranging  from s u b v e r t i c a l t o n e a r l y f l a t l y i n g . The l a t t e r  example i s p a r t i c u l a r i l y evident  i n dyke exposures on the  h i l l s i d e above t h e S i l v e r Queen camp, where s e v e r a l dykes up t o t e n meters i n t h i c k n e s s d i s p l a y n o r t h e a s t e r l y dips i n the 20° t o 40° range ( F i g u r e 2.3.1). Workers a t both the S i l v e r Queen mine and t h e E q u i t y S i l v e r mine have i n past r e f e r r e d t o the amygdular dykes as " p u l a s k i t e " , although t h i s term i s i n a c c u r a t e due t o i t s compositional  implications.  Amygdular dykes may be h i g h l y weathered i n s u r f a c e exposure, r e s u l t i n g i n d i f f i c u l t i e s i n i d e n t i f i c a t i o n . Weathered s u r f a c e s  a r e g e n e r a l l y p u r p l i s h t o greyish-brown  in; c o l o u r , w i t h t h e s o f t e r , c a r b o n a t e - b e a r i n g amygdales o f t e n weathered out on s u r f a c e . Fresh dyke m a t e r i a l  from  underground exposures i s dark g r e y i s h i n c o l o u r i n the c e n t e r o f t h e dykes, p a l i n g t o l i g h t brown o r creamy c o l o u r towards t h e c h i l l e d dyke margins. In some cases, the narrowness ( l e s s than two meters) o f t h e dyke r e s u l t s i n the e n t i r e dyke l a c k i n g amygdales and the d a r k e r grey c o l o u r . H i g h l y a l t e r e d examples were noted where a s s o c i a t e d w i t h v e i n m i n e r a l i z a t i o n , and s u l f i d e - b e a r i n g v e i n l e t s were f r e q u e n t l y noted t o c u t the dykes. Amygdules a r e most f r e q u e n t l y c a l c i t e , w i t h i r o n oxide m i n e r a l o g i e s i n d i v i d u a l amygdules may be up t o two centimeters  a l s o noted,; across.  L e i t c h e t al. (1990) noted t h a t the l o n g axes o f amygdales  28  commonly p a r a l l e l e d the dyke w a l l s , thus a s s i s t i n g i n d e t e r m i n a t i o n of the dyke o r i e n t a t i o n . However, i n the l a r g e r dykes, amygdale o r i e n t a t i o n s were found t o be random. In t h i n s e c t i o n , U n i t 6 c o n s i s t s predominantly of f i n e grained  (0.25  mm.  or l e s s ) , t r a c h y t i c textured  feldspar  m i c r o l i t e s w i t h i n an a p h a n i t i c m a t r i x t h a t i s commonly a l t e r e d t o s e r i c i t e and  carbonate. These dykes appear t o  t r a n s i t i o n a l t o b l a d e d f e l d s p a r t r a c h y a n d e s i t i c dykes 7) both t e x t u r a l l y and Unit  be  (Unit  geochemically.  7 Bladed f e l d s p a r t r a c h y a n d e s i t e  dykes o f U n i t 7 are  s p a t i a l l y c l o s e l y a s s o c i a t e d w i t h amygdular dykes m i n e r a l i z a t i o n . The  and  dykes g e n e r a l l y s t r i k e n o r t h w e s t e r l y  and  have steep t o s u b v e r t i c a l d i p s , w i t h rough o r i e n t a t i o n s commonly maintained f o r d i s t a n c e s  of one  kilometer  o r more.  Thicknesses range from l e s s than one meter t o f i v e meters. In outcrop, U n i t 7 i s d i s t i n g u i s h a b l e by the of t r a c h y t i c t e x t u r e d  presence  p l a g i o c l a s e l a t h s up t o one  centimeter  i n l e n g t h s e t i n a dark greyish-brown groundmass. Less abundant c l i n o p y r o x e n e phenocrysts up t o s i x m i l l i m e t e r s across  are a l s o p r e s e n t  (eg. Bear v e i n l o c a l e - s e e  Figure  2.3.1). Underground exposures of the dykes d i s p l a y brownish c h i l l e d margins s i m i l a r t o those o f the  pale  amygdular  dykes, but u n l i k e the U n i t 6 dykes, appear t o p o s t - d a t e m i n e r a l i z a t i o n and  cut the major m i n e r a l i z e d  structures.  No  s i g n i f i c a n t a l t e r a t i o n o r c r o s s - c u t t i n g v e i n l e t s were noted w i t h i n the U n i t 7 dykes.  29  T h i n s e c t i o n a n a l y s i s r e v e a l s a groundmass composed of feathery, i n t e r l o c k i n g p l a g i o c l a s e m i c r o l i t e s with i n t e r s t i t i a l q u a r t z , a l k a l i f e l d s p a r , opaques, and rutile  skeletal  (?) ( L e i t c h et a l . , 1990). P l a g i o c l a s e phenocrysts  are s t r o n g l y o s c i l l a t o r y zoned i n t h i n s e c t i o n , r a n g i n g andesine (Ansg) cores t o o l i g o c l a s e ( A n ^ ) clinopyroxene  phenocrysts are probably  rims.  from  The  iron-rich,  as  i n d i c a t e d by t h e i r s t r o n g green c o l o u r . Church (1971, 1973)  determined t r a c h y a n d e s i t i c  compositions f o r the U n i t 7 dykes a t S i l v e r Queen mine  and  s i m i l a r rocks a s s o c i a t e d w i t h the Goosly I n t r u s i o n s near the E q u i t y S i l v e r mine. Both U n i t 6 and U n i t 7 appear t o  be  r e l a t e d t o i n t r u s i o n of the Goosly s t o c k s , a concept t h a t i s supported by age dates from the S i l v e r Queen dykes as d e s c r i b e d i n S e c t i o n 2.3.3. Unit 8 A s e r i e s of diabase dykes forms the youngest u n i t w i t h i n the immediate v i c i n i t y of the S i l v e r Queen mine, w i t h perhaps the best example exposed i n the w a l l s of Wrinch canyon ( F i g u r e 2.3.1). The  dykes are l e s s abundant than U n i t  6 o r U n i t 7, but tend t o c o n c e n t r a t e  i n the v i c i n i t y of  major m i n e r a l i z e d s t r u c t u r e s and d i s p l a y northwest o r west s t r i k e s and thicknesses  subvertical dips. Orientations  east-  and  (up t o f i v e meters) tended to d i s p l a y a  greater  degree of c o n s i s t a n c y a l o n g s t r i k e than dykes of U n i t s 6 7. In outcrop,  the dykes are g e n e r a l l y t o p o g r a p h i c a l l y  and  30  r a i s e d r e l a t i v e t o the surrounding rock, and are dark brown to b l a c k i s h i n colour. T h i n s e c t i o n a n a l y s i s confirmed t h e presence of d i a b a s i c - t e x t u r e d p l a g i o c l a s e i n a clinopyroxene matrix, w i t h a c c e s s o r y opaque m i n e r a l s  ( L e i t c h e t a l . , 1990). The  dykes d i s p l a y no evidence o f a l t e r a t i o n o r c r o s s - c u t t i n g by m i n e r a l i z a t i o n . Although t h e diabase dykes appear t o be much younger and f r e s h e r than the amygdular and bladed f e l d s p a r dykes, age dates o b t a i n e d f o r the t h r e e u n i t s suggest a c l o s e temporal 2.3.3  r e l a t i o n s h i p ( S e c t i o n 2.3.3).  Geochronology  S e v e r a l o f t h e u n i t s present a t the S i l v e r Queen mine were a n a l y z e d by whole rock K-Ar i n o r d e r t o determine  potential  c o r r e l a t i o n s with r e g i o n a l l y described s t r a t i g r a p h i e s . A n a l y s e s were completed  by J . Harakal and D. Runkle o f t h e  U n i v e r s i t y o f B r i t i s h Columbia; rocks were analyzed f o r potassium by atomic a b s o r p t i o n u s i n g a Techtron AA4 spectrophotometer  and argon by i s o t o p e d i l u t i o n u s i n g an AEI  MS-10 mass spectrometer and h i g h p u r i t y ^ A r s p i k e . Samples were chosen on the b a s i s o f l a c k of v i s i b l e  alteration  ( i n c l u d i n g r e t e n t i o n of magnetic c h a r a c t e r ) and r e p r e s e n t a t i o n of t h e i n d i v i d u a l u n i t s . R e s u l t s a r e summarized i n Table 2.3.1.  31  TABLE 2.3.2 Summary of whole rock potassium-argon data f o r rocks i n the v i c i n i t y of the S i l v e r Queen mine, central B r i t i s h Columbia. Date Obtained  Unit/Lithology  Sample Site 2CHN89-16 Ma 1CHN89-47 Ma  1CHN89-15 Ma  Unit  5  78. 7 ±  2.7  78. 3 +  2.7  70. 3 +  2.5  microdiorite Unit  4  feldspar-porphyritic a n d e s i t e (minor b i o t i t e ) Unit  4A  feldspar-biotite p o r p h y r i t i c dyke  1CHN89-110  Unit 7 feldspar-porphyritic t r a c h y a n d e s i t e dyke  51. 9 ±  1.8Ma  2CHN89-14  Unit 6 amygdular t r a c h y a n d e s i t e dyke  51. 3 +  1.8Ma  50. 4 +  1.8Ma  1CHN89-89  Unit 8 diabase dyke  A sample of U n i t analysis  5B was  from an exposure  a l s o r e c o v e r e d f o r U- Pb  i n Cole Creek ( F i g u r e  z i r c o n s e p a r a t e was made, w i t h p o s s i b l e  2. 3.1). A  contamination  induced by the presence of t i t a n i t e ( ? ) i n the heavy m i n e r a l f r a c t i o n . Chemical d i s s o l u t i o n and mass spectrometry procedures  (see Krogh, 1973)  were c a r r i e d out by Janet  Gabites of the U n i v e r s i t y of B r i t i s h Columbia, i s o t o p i c c o m p o s i t i o n of common Pb f o l l o w i n g  w i t h the  S t a c y and  Kramers (1975). Decay constants used were those recommended  32  by the IUGS Subcommision on Geochronology ( S t e i g e r Jager,  1977).  A 206PJ3/238TJ date y i e l d e d by the f i n e z i r c o n was  and  84.6+0.4 Ma,  l e a s t squares  w i t h an upper l i m i t  a n a l y s i s ) of 95+26 Ma.  (determined  fraction through  207/235 and 207/206  dates were found t o be more a f f e c t e d by the presence common Pb,  of  and are thus l e s s p r e c i s e than the 206/238 date.  Ages o b t a i n e d f o r the f e l d s p a r p o r p h y r i t i c flow ( U n i t 4) and  andesite  f o r the m i c r o d i o r i t e ( U n i t 5) agree  c l o s e l y w i t h v a l u e s of 77.1  + 2.7  t o 75.5  by Church (1973) f o r the T i p Top H i l l  + 2.0  Ma  fairly  obtained  f o r m a t i o n between the  E q u i t y S i l v e r mine and the Owen Lake a r e a . More i m p o r t a n t l y , the s i m i l a r i t y i n ages and compositions m i c r o d i o r i t e and the former may  f e l d s p a r porphyry  between the  support the n o t i o n t h a t  r e p r e s e n t a s u b v o l c a n i c e q u i v a l e n t t o the  a n d e s i t e f l o w s . Church (1984) i n c l u d e d s t r o n g l y a l t e r e d rocks i n the southern p o r t i o n of the S i l v e r Queen area w i t h i n a lower a c i d v o l c a n i c u n i t s t r a t i g r a p h i c a l l y below the T i p Top H i l l suggested  f o r m a t i o n , but L e i t c h et a l . (1990) have  t h a t these may,  the T i p Top H i l l  i n p a r t , be a l t e r e d e q u i v a l e n t s of  a n d e s i t e s , w i t h the q u a r t z  porphyry  i n t r u s i o n on Okusyelda H i l l b e l o n g i n g t o a l a t e r p e r i o d of plutonism  (see below).  dykes ( U n i t 4A)  Rare b i o t i t e - f e l d s p a r  porphyritic  from the Owen Lake area produced a  younger whole r o c k K-Ar  age  (70.3  the T i p Top H i l l y o l c a n i c s (78 Ma)  + 2.5  Ma)  slightly  than t h a t f o r  i n the same a r e a ,  although the appearence of these dykes i s s u g g e s t i v e of a  33  p o s s i b l e comagmatic r e l a t i o n s h i p w i t h the T i p Top  Hill  f o r m a t i o n . However, the p o s s i b i l i t y t h a t the dykes r e p r e s e n t a minor i n t r u s i v e episode undocumented i n the Buck Creek area can not be r u l e d out. The U-Pb  date o f 84.6  + 0.4  Ma o b t a i n e d f o r z i r c o n s  from a dyke of U n i t 5B c u t t i n g U n i t 2 fragmental rocks i n C o l e Creek c o n s t r a i n s the age o f the fragmental rocks a t the base of the T i p Top H i l l  sequence. I n t r u s i o n of the quartz  porphyry u n i t i s p r o b a b l y a s s o c i a t e d w i t h the same magmatic event t h a t produced  the more voluminous f e l d s p a r p o r p h y r i t i c  a n d e s i t e s and m i c r o d i o r i t e . The g r e a t e r degree of u n c e r t a i n t y a s s o c i a t e d w i t h the K-Ar K-Ar  dates and the f a c t t h a t  dates are commonly s l i g h t l y l e s s than the t r u e age,  r a i s e s the p o s s i b i l i t y of an even g r e a t e r age  f o r Units 4  and 5, w i t h U n i t 5B p o s t - d a t i n g the v o l c a n i c s e r i e s . T h i s p o s s i b i l i t y might e x p l a i n the apparent  intrusive  r e l a t i o n s h i p between U n i t s 4 and 5A i n the n o r t h e r n p a r t of the S i l v e r Queen map  area ( F i g u r e 2.3.1).  The t r a c h y a n d e s i t i c dykes of U n i t s 6 and 7 c l o s e l y b r a c k e t the p e r i o d of m i n e r a l i z a t i o n i n the S i l v e r Queen mine; a l t e r e d K-Ar  (near v e i n s ) amygdular dykes g i v e a whole rock  age of 51.3  dykes produced  + 1.8 Ma,  while unaltered bladed f e l d s p a r  an age of 51.9  + 1.8  Ma.  Consequently,  m i n e r a l i z a t i o n p r o b a b l y o c c u r r e d between 51 and 52 Ma may  and  have been d r i v e n by i n t r u s i v e a c t i v i t y a s s o c i a t e d w i t h  e i t h e r the Goosly o r the Nanika i n t r u s i o n s . The c l o s e l y resembles  former  the dyke u n i t s a t S i l v e r Queen mine,  34  t e x t u r a l l y , c h e m i c a l l y and g e o c h r o n o l o g i c a l l y . Church (1973) o b t a i n e d b i o t i t e separate K-Ar ages o f 49.7 + 3.0 and 50.3 + 1.5 Ma f o r s i m i l a r rocks i n t h e Goosly and P a r r o t t Lakes a r e a s . A date o f 50.4 + 1.8 Ma f o r a diabase dyke i n t h e S i l v e r Queen area suggests t h a t U n i t 8 may a l s o c o r r e l a t e w i t h t h e Goosly i n t r u s i o n s . Church and Barakso (1990) note the presence o f minor amounts o f b a s a l t s w i t h i n the Goosly v o l c a n i c s t h a t may r e p r e s e n t e x t r u s i v e e q u i v a l e n t s t o t h e diabase dykes. The Nanika i n t r u s i o n s , r e p r e s e n t e d by t h e 53 Ma s t o c k a t Mount Nadina ( C a r t e r , 1981) may a l s o have c o n t r i b u t e d t o p r o v i d i n g t h e "heat engine" f o r m i n e r a l i z i n g s o l u t i o n s a t S i l v e r Queen. No e q u i v a l e n t s t o t h e Buck Creek formation, dated by whole r o c k K-Ar a t 48.2 + 1.6 Ma (Church,  1973), t h e Fenton  Creek f o r m a t i o n , dated by whole rock K-Ar a t 48.9 + 1.7 Ma (Church,  1973b), o r t h e P o p l a r Buttes v o l c a n i c s , dated by  whole r o c k K-Ar a t 21.4 ± 1.1 Ma (Church,  1973), have been  r e c o g n i z e d a t S i l v e r Queen. A p o s s i b i l i t y e x i s t s t h a t t h e diabase dyke u n i t  (Unit 8) may i n f a c t be c o r r e l a t i v e w i t h  the Buck Creek formation, although t h e age date more c l o s e l y matches t h a t o f t h e Goosly  available  intrusions.  The v o l c a n i c s u c c e s s i o n a t t h e S i l v e r Queen mine has been compared t o s i m i l a r r o c k s o c c u r r i n g w i t h i n t h e Tahtsa Lake area ( L e i t c h e t al. (1990). However, whole rock K-Ar ages o f d a c i t i c l a p i l l i t u f f s o f 108 t o 107 + 5 Ma, and l a t e r i n t r u s i o n s a t 8 7 + 4 t o 83.8 + 2.8 Ma (Maclntyre, 1985), a r e much o l d e r than rocks from t h e Owen Lake a r e a . As  35  a r e s u l t , t h e l i t h o l o g i e s a t S i l v e r Queen w i l l be termed "Tip Top H i l l  formation" according  t o the c l a s s i f i c a t i o n of  Church (1984).  2.3.4  Structure The  s t r a t i g r a p h y i n the S i l v e r Queen mine area forms a  g e n t l y n o r t h w e s t - d i p p i n g homocline, w i t h l i t t l e evidence o f f o l d i n g a t t h e s c a l e mapped. U p l i f t i s a p p a r e n t l y of b l o c k trending,  the r e s u l t  f a u l t i n g , l o c a l l i z e d on a s e r i e s o f northwest easterly-dipping f a u l t s that apparently  pre-date  m i n e r a l i z a t i o n . S l i c k e n s i d e s i n underground exposures o f t h e f a u l t a s s o c i a t e d w i t h the Number Three v e i n i n d i c a t e t h a t uplift  (reverse  f a u l t i n g ) of the e a s t e r n  of t h e f a u l t s has occurred.  (hangingwall) s i d e s  Furthermore, t h e hangingwall  l i t h o l o g i e s t h a t a r e exposed on s u r f a c e  seem t o occupy  s t r a t i g r a p h i c a l l y lower p o s i t i o n s than t h e f o o t w a l l  rocks.  L i t t l e o r no h o r i z o n t a l movement a l o n g t h e northwesttrending  faults i s indicated.  A second s e t o f f a u l t s , t r e n d i n g  i n a northeasterly  d i r e c t i o n w i t h p o s s i b l e moderate n o r t h e r l y t o s u b v e r t i c a l d i p s , i s a l s o p r e s e n t i n the Owen Lake area. The f a u l t s , r e p r e s e n t e d by t h e Wrinch Creek and Cole Creek s t r u c t u r e s . ( F i g u r e 2.3.1), d i s p l a y predominantly h o r i z o n t a l movement t h a t p o s t - d a t e s m i n e r a l i z a t i o n . M. Thomson (pers. comm., 1991) has suggested t h a t movement a l o n g these f a u l t s may have been i n i t i a t e d along a p r e - e x i s t i n g s t r u c t u r e , a j o i n t plane, since veins  interpreted to f i l l  possibly  joints i n  36  Wrinch Canyon are  s u b p a r a l l e l t o the i n f e r r e d f a u l t plane.  S l i c k e n s i d e s and o f f s e t dykes i n d i c a t e t h a t both  right-  l a t e r a l and l e f t - l a t e r a l s t r i k e - s l i p motion has taken p l a c e along the Wrinch Creek f a u l t , w i t h no a s s o c i a t e d v e r t i c a l movement. L e f t - l a t e r a l s l i p , r e s u l t i n g i n o f f s e t of the Number Three v e i n i n the south, i s i n f e r r e d t o have occurred along the C o l e Creek f a u l t . Church and Barakso (1990) noted t h a t s l i c k e n s i d e s a l o n g n o r t h - and n o r t h w e s t e r l y s t r i k i n g f r a c t u r e s i n the v i c i n i t y of Mine H i l l d i s p l a y e d evidence of l a t e r a l motion, although the amount of movement i s g e n e r a l l y i n f e r r e d t o be 2.4  slight.  CHARACTER OF VEINS M i n e r a l i z a t i o n a t the S i l v e r Queen mine occurs as  fissure-fill,  base- and p r e c i o u s - m e t a l v e i n s t h a t  dominantly  f o l l o w n o r t h w e s t - t r e n d i n g f a u l t zones. Less commonly, v e i n s are o r i e n t e d approximately east-west.  The Number Three v e i n  (Figure 2.3.1) i s the l a r g e s t and most e c o n o m i c a l l y important of the known s t r u c t u r e s a t S i l v e r Queen mine, w i t h a s t r i k e l e n g t h of over 1,500  meters and a p r o b a b l e  c o n t i n u a t i o n i n the d r i l l - h o l e - d e l i n e a t e d NG3  v e i n south of  Cole Creek. The v e i n i s h i g h l y v a r i a b l e i n t h i c k n e s s , grade, and t e x t u r e s ; i n some s i t e s the v e i n c o n s i s t s of a s i n g l e m i n e r a l i z e d s t r u c t u r e w i t h inward c r u s t i f o r m m i n e r a l growth, while i n o t h e r s i t e s the v e i n may  anastomose and  a s s o c i a t e d w i t h both b r e c c i a t i o n of the host r o c k  be and  i n t e r n a l b r e c c i a t i o n of the v e i n m a t e r i a l . The g r e a t e s t widths of the s t r u c t u r e are present w i t h i n t h e c e n t a l  37  segment o f the v e i n , around and t o the south o f t h e B u l k l e y crosscut. due  In t h i s segment, v e i n margins a r e o f t e n  t o extensive  b r e c c i a t i o n o f the w a l l r o c k  indistinct  accompanied by  q u a r t z - s e r i c i t e - p y r i t e a l t e r a t i o n o f the fragments. M u l t i p l e v e i n i n g i s p r e s e n t throughout; i n the southern s e c t i o n o f the Number Three v e i n , s e v e r a l m i n e r a l i z e d  s t r u c t u r e s have  been-defined i n t h e hangingwall and f o o t w a l l The  rocks.  Number Three v e i n a l s o d i s p l a y s s u b s t a n t i a l  deviations  from t h e n o r t h w e s t e r l y s t r i k e . Near t h e Alimak  r a i s e on t h e southern p a r t o f t h e v e i n , the s t r u c t u r e bends a b r u p t l y towards t h e e a s t f o r a d i s t a n c e o f s e v e r a l hundred meters b e f o r e e n c o u n t e r i n g t h e Cole Creek f a u l t  (Figure  2.3.1). The v e i n i s i n t e r p r e t e d t o have been l e f t offset  laterally  (with an unknown v e r t i c a l component) by t h e f a u l t ,  w i t h the c o n t i n u a t i o n  r e p r e s e n t e d by the NG3 v e i n . L e i t c h et  al.  t h a t t h e change i n d i r e c t i o n on t h e  (1991) c o n s i d e r e d  v e i n may be due t o o f f s e t by a s p l a y from t h e C o l e Creek f a u l t , but re-examination o f s u r f a c e exposures suggest t h a t the change may simply be due t o the m i n e r a l i z a t i o n  switching  from one j o i n t s e t t o another. L e i t c h et al. (1991) a l s o noted a p o s s i b l e en e c h e l o n c h a r a c t e r  f o r t h e Number Three  system and f o r o t h e r v e i n s , r e s u l t i n g i n v a r i a b l e thicknesses  indrill  i n t e r s e c t i o n s along s t r i k e and down  d i p . Thomson and S i n c l a i r  (1991) propose an o r i g i n f o r t h e  Number Three v e i n as a primary f a u l t plane, w i t h  associated  s m a l l e r v e i n s o c c u r r i n g a l o n g conjugate shear and e x t e n s i o n p l a n e s . Movement a l o n g t h e j o i n t planes i s i n t e r p r e t e d t o  38  have been governed by i n f l a t i o n mass a s magmas were i n t r u d e d . wallrock  and o r e b r e c c i a s  and d e f l a t i o n o f t h e r o c k  The m u l t i - e p i s o d i c  i n t h e Number T h r e e v e i n was  g e n e r a t e d b y t h i s movement, a n d c o n t r i b u t e d openning o f f r a c t u r e s during A  number o f s m a l l e r  associated The  to the r e -  mineralization.  veins  and v e i n systems a r e  w i t h t h e m a i n Number T h r e e s y s t e m  (Figure  George Lake v e i n o c c u p i e s a prominent northwest  lineament t o the east of  nature of  a s e r i e s of veins  fault  2.3.1). trending  o f t h e Number T h r e e v e i n a n d c o n s i s t s hosted by a broad  z o n e . No s u r f a c e  (up t o 30 m.  wide)  outcrop of the vein i s a v a i l a b l e ,  a l t h o u g h t h e v e i n system has been i n t e r s e c t e d i n s e v e r a l scattered d r i l l  holes  f o r a distance  o f a b o u t 900 m e t e r s . A s  w i t h t h e Number T h r e e v e i n , m i n e r a l i z a t i o n i s d o m i n a t e d b y simple base metal s u l f i d e s i n a gajngue. C r u s t i f o r m  textures  guartz-carbonate-barite  a r e l e s s abundant i n t h e George  L a k e v e i n t h a n i n t h e Number T h r e e s y s t e m , a n d i n o n e s i t e , post-mineralization remobilized The  f a u l t movement a p p e a r s t o h a v e  the softer s u l f i d e  minerals.  C o l e Lake system i n c l u d e s  mineralogically disparate  veins  a number o f s m a l l ,  ( B e a r , NG6, B a r i t e ,  C o l e s h e a r , Lead and Copper) l o c a t e d e a s t 1  s y s t e m . The v e i n s of  been t r a c e d  f o r lengths  The C o l e v e i n i s a l s o n o t a b l e  developed layered  o f t h e George Lake  a r e up t o o n e m e t e r w i d e a n d i n t h e c a s e  t h e C o l e v e i n system extend  kilometer.  Cole,  o f up t o o n e  f o rthe well-  n a t u r e o f t h e m i n e r a l i z a t i o n , w h i c h has  t o an i n t e r s e c t i o n i n d r i l l  hole  NGF8  (Figure  39  2.3.1). Networks o f m i n e r a l i z e d s t r i n g e r s a r e a s s o c i a t e d w i t h a l l o f t h e v e i n s i n t h e Cole Lake a r e a . Three s m a l l , but important  v e i n systems occur i n t h e  western and southwestern p o r t i o n o f t h e S i l v e r Queen mine area. Each i s d i s t i n g u i s h e d by a r e l a t i v e abundance of carbonate and s i l v e r - b e a r i n g s u l f o s a l t s , and by t h e discontinuous  nature o f t h e v e i n i n g . The P o r t a l v e i n s a r e  perhaps t h e most numerous, c o n s i s t i n g o f t e n s m a l l e r v e i n s and one l a r g e system (the Switchback-Number F i v e system) l o c a t e d near t h e entrance  t o t h e 2600' l e v e l workings. The  v e i n s a r e h i g h l y v a r i a b l e i n mineralogy (e.g. see Chapter 3) and t h i c k n e s s , i n p l a c e s widening t o widths o f one meter and then p i n c h i n g out o r o f f s e t by f a u l t s a few tens o f meters along s t r i k e . O r i e n t a t i o n s v a r y from n o r t h w e s t e r l y  to east-  west, w i t h d i p s v a r y i n g from s u b v e r t i c a l t o 45°. The v e i n s are w e l l l a y e r e d and i n p l a c e s vuggy, w i t h l a t e  stage  s u l f o s a l t s and pyrobitumen i n f i l l i n g t h e vugs. The  Camp v e i n system occurs  the P o r t a l v e i n s  immediately t o t h e west o f  ( F i g u r e 2.3.1) and i s known s o l e l y from  d r i l l i n g due t o a t h i c k cover o f overburden i n t h e immediate v i c i n i t y o f t h e mine camp. The v e i n s a r e among t h e most s i l v e r - r i c h on t h e p r o p e r t y and c o n t a i n e a s i l y v i s i b l e c o n c e n t r a t i o n s o f s i l v e r s u l f o s a l t s . The v e i n s have been i n t e r p r e t e d t o have an en echelon  form ( L e i t c h e t a l . ,  1991), w i t h numerous open-space f i l l i n g t e x t u r e s , i n c l u d i n g a d e l i c a t e l a y e r i n g . A p o o r l y known group o f s t r u c t u r e s occurs t o t h e south o f t h e Camp v e i n s i n t h e t a i l i n g s pond  40  area, d i s p l a y i n g many o f the f e a t u r e s o f t h e Camp v e i n s , but substantially less  silver-rich.  A t h i r d major group o f v e i n s , the Chisholm  system,  occurs i n t h e southwest e x t r e m i t y o f t h e a r e a . The group c o n s i s t s o f f o u r h i g h l y i r r e g u l a r v e i n s d i s t i n g u i s h e d by t h e presence o f abundant galena and b a r i t e , w i t h l o c a l l y h i g h c o n c e n t r a t i o n s o f s u l f o s a l t s . V e i n widths  a r e up t o f o r t y  c e n t i m e t e r s , w i t h exposed s t r i k e lengths o f l e s s than 150 meters. The system i s o r i e n t e d roughly n o r t h w e s t e r l y , w i t h d i p s v a r y i n g from l e s s than 50° t o s u b v e r t i c a l . S e v e r a l o t h e r s t r u c t u r e s are a l s o p r e s e n t i n t h e S i l v e r Queen a r e a , e i t h e r a s s o c i a t e d w i t h l a r g e r systems (eg. Number One and Number Two v e i n s ) o r i n i s o l a t e d s t r u c t u r e s (eg. Church v e i n ) . As w i t h the l a r g e r systems, t e x t u r e s a r e dominated by c r u s t i f o r m ingrowth o f s u l f i d e and gangue m i n e r a l o g i e s , w i t h d e l i c a t e l a y e r i n g common. Large areas o f t h i c k overburden  may a l s o hide other important systems as  w e l l as e x t e n s i o n s t o t h e known s t r u c t u r e s . W a l l r o c k a l t e r a t i o n a s s o c i a t e d w i t h t h e v e i n s i s most e x t e n s i v e i n t h e southern p a r t o f t h e S i l v e r Queen area, where a broad zone o f q u a r t z - s e r i c i t e - p y r i t e a l t e r e d and porphyry  tuffs  i s exposed. Cheng et al. (1991) c h a r a c t e r i z e d  a l t e r a t i o n a s s o c i a t e d w i t h m i n e r a l i z a t i o n as weak, moderate, and s t r o n g . Weakly a l t e r e d rock i s abundant throughout the S i l v e r Queen a r e a and i s d i s t i n g u i s h e d by e x t e n s i v e a l t e r a t i o n o f mafic phenocrysts t o c h l o r i t e and p l a g i o c l a s e margins t o c l a y s . Moderately  a l t e r e d rock i s l o c a l l i z e d as  broad envelopes around v e i n s , w i t h almost  complete  c o n v e r s i o n of primary m i n e r a l s t o s e r i c i t e , chlorite,  illite,  quartz and carbonate. S t r o n g l y a l t e r e d m a t e r i a l  b e s t developed a d j a c e n t t o the v e i n , w i t h the primary mineralogy completely a l t e r e d t o q u a r t z , s e r i c i t e ,  pyrite,  and carbonate. Width of the zone of s t r o n g l y a l t e r e d rock g e n e r a l l y decreases towards the n o r t h end of the Number Three v e i n  (Cheng e t al.,  1991).  42 3.0 3•1  MINERALOGY AND  I n t r o d u c t i o n and  PARAGENESIS  Scope  M i n e r a l i z a t i o n a t the S i l v e r Queen mine occurs mainly i n a s e r i e s of base- and p r e c i o u s - m e t a l northwest-trending  v e i n s o r i e n t e d along  f a u l t s . In a d d i t i o n , s e v e r a l s m a l l e r  v e i n s t h a t s t r i k e i n an e a s t e r l y d i r e c t i o n are present i n the western p a r t of the p r o p e r t y . Surface exposure o f t h i s second group of v e i n s i s l i m i t e d , w i t h the Camp v e i n  and  Twinkle Zone systems ( F i g u r e 2.3.1) d e f i n e d o n l y from  drill  h o l e i n t e r s e c t i o n s . The Number Three v e i n , however, i s exposed underground and by e x t e n s i v e s u r f a c e t r e n c h i n g  and  i s the l a r g e s t known m i n e r a l i z e d s t r u c t u r e i n the a r e a . I t extends more than 1.5 southern  e x t e n s i o n o f f s e t by a l a t e r  f a u l t . The holes and  kilometers along s t r i k e , with  the  northeast-trending  o f f s e t p o r t i o n has been i n t e r c e p t e d i n d r i l l l a b e l l e d the NG3  v e i n , a f t e r the f i r s t d r i l l  t h a t i n t e r s e c t e d the s t r u c t u r e . The  hole  George Lake v e i n i s  e a s t of the Number Three v e i n , i n a prominent northwestt r e n d i n g lineament  and a s s o c i a t e d f a u l t zone. U n l i k e  the  Number Three v e i n , the George Lake v e i n i s not exposed on s u r f a c e due recessed  t o the great depth of overburden w i t h i n the  lineament  t r a c e . D r i l l h o l e i n t e r s e c t i o n s are  few  and w i d e l y spaced, d e s p i t e the p o t e n t i a l l y l a r g e r e s e r v e s t h a t may  be present w i t h i n the v e i n . The Cole Lake v e i n s  occur f u r t h e r t o the e a s t , c o n s i s t i n g of a s e r i e s of structures trending i n a northwesterly  smaller  to northerly  d i r e c t i o n . The main Cole Lake v e i n i s the most l a t e r a l l y  43  e x t e n s i v e and b e s t exposed of the v e i n s i n t h i s area, w i t h a probable  c o n t i n u a t i o n i n t e r s e c t i o n i n a d r i l l hole ("NGF8"-  see F i g u r e 2.3.1) t o the n o r t h of the Cole Lake area. The v e i n s a t S i l v e r Queen are h i g h l y v a r i a b l e m i n e r a l o g i c a l l y and d i s p l a y abundant c r u s t i f o r m and open-space f i l l i n g important  t e x t u r e s . The m i n e r a l o g i e s  other  a l s o show  d i f f e r e n c e s between v e i n s t h a t are c l o s e  s p a t i a l l y . Hence, the v e i n s must be e v a l u a t e d s y s t e m a t i c a l l y both m i n e r a l o g i c a l l y and p a r a g e n e t i c a l l y i n order t o b e t t e r understand the r e l a t i o n s h i p s among d i f f e r e n t v e i n systems on the p r o p e r t y and t o d e f i n e the e v o l u t i o n of the l a r g e m i n e r a l i z i n g system. An important  component o f the  m i n e r a l o g i c a l study has been the i d e n t i f i c a t i o n  and  c h a r a c t e r i z a t i o n of minerals w i t h economic p o t e n t i a l , aspect which may  a s s i s t i n d e f i n i n g p o t e n t i a l ore  an  processing  problems a s s o c i a t e d w i t h f u t u r e development. 3.2  Character The  two  of V e i n i n g  o r i e n t a t i o n s of v e i n s at S i l v e r Queen c l u s t e r i n t o  general d i r e c t i o n s : veins that trend i n a  d i r e c t i o n , and v e i n s t h a t t r e n d approximately  northwesterly east-west.  L e i t c h et al.(1991) noted t h a t v e i n s d i d not r e t a i n a t a b u l a r form, but r a t h e r anastomose and  simple  form m u l t i p l e v e i n s ,  s t r i n g e r s , and shear zones. I n d i v i d u a l v e i n s w i t h i n the major systems a l s o d i s p l a y an en e c h e l o n - l i k e c h a r a c t e r , both a l o n g s t r i k e and down d i p . The d i s c o n t i n u o u s  nature  of  the v e i n s r e s u l t s i n u n c e r t a i n t y w i t h c o r r e l a t i o n between drill  s e c t i o n s and,  thus, problems i n ore r e s e r v e  estimation  44  F i g u r e 3 . 2 . 1 : S u r f a c e exposure of s o u t h e r n p a r t of Number Three v e i n a t "bend" near A l i m a k R a i s e . Note s m a l l e r splayf i l l i n g c o n j u g a t e f r a c t u r e o f f o f main s t r u c t u r e .  45  ( L e i t c h et al.,  1991;  Nowak, 1991). B r e c c i a t i o n of  adjacent t o the v e i n s  i s a l s o widespread and makes  d e t e r m i n a t i o n of the exact borders of the v e i n s  wallrock  difficult.  Furthermore, v e i n s  l o c a l l y were s e a l e d d u r i n g one  stage of  m i n e r a l i z a t i o n and  then r e f r a c t u r e d and m i n e r a l i z e d  during  a  subsequent stage, l e a d i n g t o asymmetric m i n e r a l d i s t r i b u t i o n patterns  with concentrations  of s u l f i d e s near  the  hangingwall or f o o t w a l l of the v e i n s r a t h e r than i n the  vein  cores. The  r e g i o n a l j o i n t i n g p a t t e r n has  been noted t o e x h i b i t  a s t r o n g c o n t r o l on v e i n o r i e n t a t i o n , e s p e c i a l l y i n the Number Three system (Thomson and  Sinclair,  1991). In  p a r t i c u l a r , the abrupt change i n o r i e n t a t i o n of the main s t r u c t u r e i n the v i c i n i t y of the d e c l i n e i n t e r s e c t i o n i s apparently  developed as the r e s u l t of c o n t r o l by a conjugate  j o i n t s e t ; v e i n o r i e n t a t i o n changes by approximately 60° t h i s p o i n t , and point 3.3  (Figure  a s m a l l e r v e i n c o n t i n u e s p a s t the  inflection  3.2.1).  Sampling and The  Analysis  g o a l of the p a r a g e n e t i c study of the v e i n s a t  S i l v e r Queen mine was evolutionary associated  summary as p o s s i b l e f o r the Number Three  and  s t r u c t u r e s . For t h i s t o be done, a s e r i e s of  at approximately e q u a l i n t e r v a l s from n o r t h t o south, and  the  t o p r o v i d e as complete a m i n e r a l  v e r t i c a l s e c t i o n s through the Number Three v e i n , and  devised  at  spaced was  sampled. Four t o s i x samples were taken per  v e r t i c a l s e c t i o n . F i f t y - s e v e n samples (see Appendix A f o r  46  s i t e s ) were taken from s u r f a c e , d r i l l h o l e , and underground i n t e r s e c t i o n s on t h e v e i n , w i t h i n d i v i d u a l samples composed of complete v e i n c r o s s s e c t i o n s from each p o i n t . Three samples were a l s o taken from d r i l l hole i n t e r s e c t i o n s o f t h e NG3 s t r u c t u r e , i n c l u d i n g m a t e r i a l from t h e o r i g i n a l NG3 d r i l l h o l e . Approximately 60 samples were taken from  other  v e i n s i n t e r s e c t e d a t t h e S i l v e r Queen mine, w i t h i n d i v i d u a l samples comparable t o those from the Number Three v e i n . The Camp, P o r t a l , and C o l e Lake systems were sampled e x t e n s i v e l y t o d e f i n e m i n e r a l o g i c a l trends  o c c u r r i n g w i t h i n these  systems (and w i t h nearby systems) and a l s o t o take advantage of t h e r e l a t i v e l y l a r g e amount o f m a t e r i a l a v a i l a b l e . Smaller v e i n systems, i n c l u d i n g the Chisholm, "NG4", George Lake, Twinkle Zone, and Church v e i n were a l s o sampled. The most r e p r e s e n t a t i v e  samples were then made i n t o  e l e c t r o n microprobe q u a l i t y 1" p o l i s h e d t h i n s e c t i o n s i n order t o d e f i n e t h e m i n e r a l o g i c a l trends  from hangingwall t o  f o o t w a l l i n each s e c t i o n . A number o f samples were a l s o selected t o evaluate  s u l f i d e populations  i n t h e immediate  a l t e r a t i o n h a l o o f t h e p r i n c i p a l v e i n s . L a t e r analyses o f the minor v e i n s o r o f s p e c i f i c s u l f i d e stages were undertaken on p o l i s h e d c h i p s o f v e i n m a t e r i a l , w i t h o n l y a perfunctory  e v a l u a t i o n o f gangue mineralogy. Samples  c o n t a i n i n g anomalous v a l u e s also targeted  o f Ag,Au, Ga, Ge, and I n were  f o r p o l i s h e d t h i n s e c t i o n a n a l y s i s i n order t o  more c l o s e l y a p p r a i s e p o t e n t i a l mineral  hosts f o r these  47 TABLE 3.3.1:  MINERAL SPECIES IDENTIFIED AT SILVER QUEEN MINE ( t h i s study)  PHASE  COMPOSITION  Ore M i n e r a l s Pyrite Marcasite Arsenopyrite Pyrrhotite Sphalerite Galena Tetrahedrite Tennantite Freibergite Bismuthinite Cuprobismutite Proustite Pyrargyrite Covellite Chalcocite Chalcopyrite Bornite Aikinite Matildite Berryite Pearceite Polybasite Arsenpolybasite Seligmannite Bournonite Gustavite Geocronite Acanthite Electrum  FeS FeS FeAsS FeS!_ ZnS PbS Cu Sb S Cu As S 3 (Cu Ag)i Sb S 3 Bi2S3 CuBiS Ag AsS Ag SbS CuS Cu S CuFeS Cu5FeS CuPbBiS3 AgBiS Pb2(Cu Ag)3Bi5Sn (Ag,Cu) (As,Sb Bi) S (Ag Cu) (Sb As) S i (Ag Cu) (Sb As) S PbCuAsS3 PbCuSbS Ag Pb Bi S 4 Pb (As Sb) S Ag S Ago.3 0.7 2  2  x  1 2  4  1 2  1 3  4  1  /  2  4  1  2  3  3  3  3  2  2  4  2  f  1 6  f  2  /  1 6  /  2  1  /  1 6  f  2  1 1  1 1  3  3  5  5  1 1  2  /  2  8  2  Au  Oxides Hematite Magnetite Rutile/Anatase  Fe 0 Fe 0 Ti0 2  3  3  4  2  Gancrue M i n e r a l s Barite Hinsdalite Svanbergite Quartz Calcite Mn-siderite Rhodochrosite Dolomite Bitumen  BaS0 (Pb,Sr)Al (P0 )(S0 )(OH) (Sr Ca)Al (P0 )(S0 )(OH) Si0 CaC03 (Fe,Mn)C0 MnC03 MgC03 (C,H,0) 4  3  /  3  2  3  4  4  4  6  4  6  48  e l e m e n t s . Ore  minerals i d e n t i f i e d  are  summarized i n T a b l e  3.4  Number T h r e e v e i n  3.4.1  3.3.1. and  Associated  Number T h r e e v e i n has  300  drill  The  vein varies  t h a n two veining  holes,  veining  vein,  underground d r i f t  i n w i d t h from a generally  few  has  crustiform  and  layering  (Figure  associated  3.4.1)  i n the  adjacent wallrocks  north  veining  the  vein, with quartz,  forming the  bulk of  the  in  the with  entrained  the  pyrite  s p h a l e r i t e n o t e d i n a l l samples  r e p r e s e n t i v i t y of  degree of mineralogic  scale mineralogic  tetrahedrite-  As  study i s  a r e s u l t , paragenetic several  the  samples, r e s u l t i n g from  v a r i a t i o n along the  average of  with  examined.  changes o c c u r o v e r r e l a t i v e l y  of meters) d i s t a n c e s . the  and  t h i s type of  hematite,  assemblage.  most a b u n d a n t s u l f i d e m i n e r a l s ,  A p o t e n t i a l l i m i t a t i o n of l a c k of  barite,  gangue  s p h a l e r i t e , galena, chalcopyrite,  reflect  segment  i s pervasive,  are  will  vein  from r e p e t i t i v e  tennantite  high  The  uncommon. Gangue p r e d o m i n a t e s o v e r s u l f i d e s  carbonate  possible  greater  subsidiary  overgrowths of m i n e r a l s over the  t h r o u g h o u t most o f  and  trenching.  centimeters to  t o abundant m a s s i v e p y r i t i c  fragments not  i n more t h a n  surface  immediately adjacent wallrock.  south. B r e c c i a t i o n of  Pyrite,  been i n t e r c e p t e d  a wide v a r i e t y of t e x t u r e s ,  monomineralic the  an  m e t e r s and i n the  displays  and  S i l v e r Queen mine  Introduction The  of  at the  vein; short  large(tens  diagrams  c l o s e l y spaced  a  49  intersections  (where a v a i l a b l e ) r a t h e r than a s i n g l e sample  site.  3.4.2 a.)  Vein  Mineralogy  Pyrite P y r i t e i s the most abundant s u l f i d e phase w i t h i n  Number Three v e i n , i n p l a c e s forming up t o 99% of  the  the  s u l f i d e assemblage. S e v e r a l episodes of p y r i t e d e p o s i t i o n have been i d e n t i f i e d , the most voluminous of which i s accompanied by q u a r t z . P y r i t e - q u a r t z forms the f i r s t  episode  of m i n e r a l i z a t i o n w i t h i n the v e i n , i n which p y r i t e occurs p r i n c i p a l l y as f i n e g r a i n e d anhedral  grains  (with  quartz)  t h a t have been b r e c c i a t e d and subsequently surrounded by l a t e r s u l f i d e s (eg. F i g u r e 3 . 4 . 2 ) .  In the southern segment  of the Number Three v e i n , p y r i t e commonly e x h i b i t s c o l l i f o r m t e x t u r e t h a t i n p l a c e s has been b r e c c i a t e d and  partially  (Figure 3 . 4 . 3 ) . L o c a l l y , as many as  inverted to marcasite  t h r e e p y r i t e episodes are e v i d e n t . P y r i t e i s observed most commonly as massive, f i n e g r a i n e d m a t e r i a l , i n aggregates t o s e v e r a l centimeters more common as euhedral  a c r o s s . Towards the n o r t h , p y r i t e i s g r a i n s up t o 2 mm  a c r o s s , but i s a  s m a l l e r p r o p o r t i o n of the t o t a l assemblage ( l e s s than  5%).  P y r i t e g r a i n s commonly c o n t a i n s u b - f i f t y micron i n c l u s i o n s of v a r i o u s m i n e r a l s .  up  In the southernmost underground  exposures of the Number Three v e i n , f i n e - g r a i n e d p y r i t e l a y e r s c o n t a i n replacements ( i n c l u s i o n s and r a r e f r a c t u r e i n f i l l i n g s ) of c h a l c o p y r i t e and b o r n i t e . Segments of  the  Figure 3 . 4 . 1 : I n t e r l a y e r e d carbonate-sphalerite  vein, northernmost Number Three v e i n . From sample s i t e 2CHN90-2 (Appendix A ) .  51  F i g u r e 3.4.2: M u l t i - e p i s o d i c q u a r t z m i n e r a l i z a t i o n f r o m t h e s o u t h e r n Number T h r e e v e i n . F i n e g r a i n e d "Qz A" h a s b e e n b r e c c i a t e d , w i t h c o a r s e r "Qz B" e n c r u s t i n g f r a g m e n t s . F o l l o w e d b y l a t e r b a r i t e (ba) a n d g a l e n a (gn) m i n e r a l i z a t i o n . From s a m p l e s i t e 3CHN89-24 ( A p p e n d i x A ) .  F i g u r e 3.4.3: B r e c c i a t e d c o l l i f o r m p y r i t e ( p y A ) , f o l l o w e d b y f i n e g r a i n e d i n t e r g r o w n p y r i t e (pyB) a n d q u a r t z ( q z ) m i n e r a l i z a t i o n . From s a m p l e s i t e 3CHN89-3 ( A p p e n d i x A) o n NG3 v e i n .  52  v e i n t h a t c o n t a i n hematite i n c l u d e p y r i t e g r a i n s  that  surround s p e c u l a r hematite l a t h s , w i t h p y r i t e o r galena commonly r e p l a c i n g a l l o r p a r t of the hematite. I n c l u s i o n s of f i n e g r a i n e d p y r i t e have a l s o been observed i n growth zoned q u a r t z g r a i n s throughout the v e i n . In r a r e c a s e s , p y r i t e has a l s o been observed as minute vermiform i n c l u s i o n s in tetrahedrite. b.)  Sphalerite S p h a l e r i t e d i s p l a y s a broad degree o f v a r i a t i o n of form  i n the Number Three system. I t i s the most abundant  sulfide  i n the northernmost p o r t i o n s of the v e i n , where i t forms more than 50% of t h e s u l f i d e assemblage. S p h a l e r i t e from t h i s v e i n segment i s i n t e r l a y e r e d w i t h manganoan carbonate (Figure 3.4.1) and g e n e r a l l y forms s p e c t a c u l a r l y coarse grained  (up t o s e v e r a l cm.), euhedral masses. F a r t h e r south,  s p h a l e r i t e i s more abundant as massive t o c o l l i f o r m m a t e r i a l (Figure 3.4.4) . S p h a l e r i t e l o c a l l y i s b r e c c i a t e d and surrounded by carbonates and l a t e r s u l f i d e s i n the c e n t r a l s e c t i o n o f the Number Three system. Towards the south, s p h a l e r i t e i s found most commonly i n pods o f massive t o l a y e r e d m a t e r i a l up t o 10 cm.  i n width. S p h a l e r i t e i n t h i s  p o r t i o n of the v e i n occurs i n two forms: as b l a c k ,  resinous  g r a i n s t h a t c o n t a i n abundant c h a l c o p y r i t e and t e t r a h e d r i t e i n c l u s i o n s , and as p a l e r brown, l o c a l l y growth zoned g r a i n s . The l a t t e r v a r i e t y i s more abundant  i n the s o u t h end and  l o c a l l y forms w e l l l a y e r e d masses up t o 3 cm. t h i c k . At the southernmost exposures o f the Number Three v e i n , and i n the  53  Figure 3 . 4 . 4 : C o l l i f o r m low-Fe s p h a l e r i t e from t h e n o r t h c e n t r a l p a r t o f t h e Number T h r e e v e i n a t sample s i t e 3CHN8987 ( A p p e n d i x A ) . Note l a t e r m a n g a n o s i d e r i t e ( c b ) v e i n l e t s .  F i g u r e 3 . 4 . 5 : " C h a l c o p y r i t e d i s e a s e " i n s p h a l e r i t e from the deep n o r t h Number T h r e e v e i n . B e r r y i t e (ber) and galena (gn) a l s o p r e s e n t as rounded i n c l u s i o n s i n s p h a l e r i t e ( s i ) . Note f r a c t u r e f i l l i n g by c h a l c o p y r i t e (cpy) i n r i g h t h a l f o f photo. From sample s i t e 3CHN89-88 (Appendix A ) .  54  NG3 v e i n , s p h a l e r i t e a g a i n becomes the predominant s u l f i d e , forming up t o 40-50% o f t h e opaque assemblage. c. )  Chalcopyrite Chalcopyrite  centered  i s most abundant i n the segment o f v e i n  on t h e B u l k l e y c r o s s c u t , where i t forms up t o 30%  of t h e s u l f i d e assemblage. Masses are g e n e r a l l y t o quartz  interstitial  and/or carbonates and a r e intergrown w i t h  l a t e r sulfides. Chalcopyrite  other  i s a l s o present as  " c h a l c o p y r i t e d i s e a s e " , where i t occurs as m i c r o s c o p i c i n c l u s i o n s i n s p h a l e r i t e masses (Figure 3.4.5). The abundance o f f r a c t u r e i n f i l l i n g s o f c h a l c o p y r i t e i n s p h a l e r i t e , and t h e l o c a l l i z a t i o n o f the i n c l u s i o n s near f r a c t u r e s and along t h e rims o f s p h a l e r i t e g r a i n s suggests a replacement o r i g i n r a t h e r than e x s o l u t i o n . C h a l c o p y r i t e occurs along margins between adjacent sphalerite grains.  t e t r a h e d r i t e and  T e t r a h e d r i t e and c h a l c o p y r i t e a r e l i k e l y  synchronous, a s u g g e s t i o n of m y r m e k i t i c a l l y  also  supported by the r a r e occurrence  intergrown c h a l c o p y r i t e , t e t r a h e d r i t e , and  galena i n t h e n o r t h p o r t i o n o f the v e i n . C h a l c o p y r i t e  occurs  i n t r a c e amounts i n t h e southern s e c t i o n o f t h e v e i n , where it  i s most abundant as i n c l u s i o n s i n p y r i t e , s p h a l e r i t e , and  galena. d. ) Galena Galena i s w i d e l y d i s t r i b u t e d i n the Number Three system and  i n some i n t e r s e c t i o n s forms up t o 30% o f t h e s u l f i d e  assemblage. The m i n e r a l  i s most p r e v a l e n t  as a m a t r i x f o r  p y r i t e b r e c c i a s i n t h e c e n t r a l and southern s e c t i o n s o f the  55  v e i n , a n d commonly i s c o m p l e x l y (Figure 3.4.6).  intergrown with t e t r a h e d r i t e  I n the northern and southern  extremities o f  t h e Number T h r e e s t r u c t u r e , g a l e n a o c c u r s w i t h s p h a l e r i t e a s subhedral  t o euhedral  g e n e r a l l y occurs  g r a i n s u p t o 1 mm. a c r o s s .  Galena  as i r r e g u l a r g r a i n s c o n t a i n i n g symplectic  i n t e r g r o w t h s o f Cu-As-Sb m i n e r a l s , m o s t n o t a b l y seligmannite-bournonite  and t e t r a h e d r i t e (Figure 3.4.7).  Anomalous A g and B i c o n t e n t s analysis  determined through  microprobe  ( A p p e n d i x C) s u g g e s t t h a t i n t e r g r o w t h s o f s i l v e r -  b e a r i n g p h a s e s may a l s o b e p r e s e n t ,  although they could n o t  be r e s o l v e d b y r e f l e c t e d l i g h t m i c r o s c o p y o r b y backscattered e l e c t r o n detection. I n general, galena p a r a g e n e t i c a l l y l a t e mineral and occurs  isa  i n association with  t e t r a h e d r i t e and c h a l c o p y r i t e . e.)  Tetrahedrite The o c c u r r e n c e  o f t e t r a h e d r i t e i n t h e Number T h r e e v e i n  i s c l o s e l y asociated w i t h the presence o f galena; p h a s e s a r e commonly i n t e r g r o w n  (Figure 3.4.6).  i s most abundant i n t h e s o u t h e r n  t h e two  Tetrahedrite  p a r t o f t h e v e i n , where i t  occurs w i t h galena as a matrix f o r b r e c c i a t e d p y r i t e and quartz  ( F i g u r e 3 . 4 . 8 ) . Where a s s o c i a t e d w i t h c h a l c o p y r i t e ,  t e t r a h e d r i t e commonly o c c u r s infillings  i n s e v e r a l forms: as a f r a c t u r e  i n c h a l c o p y r i t e (Figure 3.4.9),  intergrowths w i t h galena  as myrmekitic  and c h a l c o p y r i t e , and as rims and  replacements w i t h f i n e grained p y r i t e andmarcasite. As fracture i n f i l l i n g s ,  t e t r a h e d r i t e commonly d i s p l a y s e n  e c h e l o n - l i k e forms and i s r a r e l y observed  cutting  late  56  F i g u r e 3 . 4 . 6 : I n t e r g r o w n g a l e n a (gn) and t e n n a n t i t e ( t n ) on m a r g i n o f l a r g e s p h a l e r i t e g r a i n ( s i ) . From n o r t h e r n m o s t i n t e r s e c t i o n o f NG3 v e i n a t sample s i t e 3CHN89-36 ( A p p e n d i x A).  57  3 . 4 . 7 : B a c k s c a t t e r e d e l e c t r o n photomicrograph o f galena (gn) g r a i n from southern Number Three v e i n . Included are complex intergrowths o f s e l i g m a n n i t e ( s e l ) and t e n n a n t i t e ( t n ) . G r a i n i s surrounded by s p h a l e r i t e ( s i ) . From sample s i t e 3CHN89-5 (Appendix A ) . Figure  F i g u r e 3 . 4 . 8 : B r e c c i a t e d p y r i t e (py) w i t h l a t e r i n f i l l i n g t e n n a n t i t e ( t n ) f r o m s o u t h e n d o f Number T h r e e v e i n (sample s i t e 2CHN89-35-see A p p e n d i x A ) .  59  F i g u r e 3 . 4 . 9 : Fracture i n f i l l i n g s of tennantite (tn) i n chalcopyrite (cpy) from Portal vein Three. E a r l i e r p y r i t e (PY) grains are also present i n photo. From sample s i t e 3CHN89-70 (Appendix A).  60  s u l f o s a l t phases. T e t r a h e d r i t e fracture f i l l i n g s  has a l s o been seen as  i n s p h a l e r i t e and p y r i t e i n a l l p o r t i o n s  of t h e v e i n , and i n the deep p a r t o f t h e n o r t h e r n segment (sample s i t e 3CHN90-1; see Appendix A) t e t r a h e d r i t e f i l l i n g s cut chalcopyrite In g e n e r a l ,  fracture  fracture i n f i l l i n g s i n sphalerite.  t e t r a h e d r i t e r e p r e s e n t s among t h e l a t e s t  s u l f i d e - s u l f o s a l t phases. f. ) A i k i n i t e  CuPbBiS3  A i k i n i t e , l o c a l l i z e d i n t h e Number Three v e i n near t h e decline intersection, i s c l o s e l y associated  w i t h massive  galena and t e t r a h e d r i t e , and commonly d i s p l a y s textures  "spider web"  w i t h these two phases. Masses a r e up t o 0.1 mm.  a c r o s s and l o c a l l y form up t o 5% o f t h e s u l f i d e assemblage. A i k i n i t e has a l s o been noted i n t r a c e q u a n t i t i e s w i t h galena i n t h e deep NG3 v e i n . g. ) B e r r y i t e  Pb2 (Cu,Ag)3 B i s l l s  H a r r i s and Owens (1973) d e s c r i b e d  b e r r y i t e from S i l v e r  Queen mine as the f i r s t Canadian o c c u r r e n c e o f t h i s m i n e r a l . D i s t r i b u t i o n o f t h e unusual Ag-Bi-Cu-Pb phase i s r e s t r i c t e d to the c h a l c o p y r i t e - r i c h , northern part of the vein, with the phase found i n seven sample s i t e s . B e r r y i t e occurs as l a t h - s h a p e d g r a i n s up t o 1 mm long, chalcopyrite,  tetrahedrite, or matildite  3.4.10 and 3.4.11). Galena r e p l a c e s  generally  i n a matrix of  (Figures  b e r r y i t e l a t h s along  cleavage d i r e c t i o n s i n s e v e r a l o f t h e s i t e s , and t e t r a h e d r i t e has been noted t o r i m and r e p l a c e grains  smaller  ( F i g u r e 3.4.12). The phase forms a maximum o f 2-3% o f  61  F i g u r e 3 . 4 . 1 0 : B a c k s c a t t e r e d e l e c t r o n photomicrograph o f l a t h shaped b e r r y i t e (ber) g r a i n s t h a t have undergone p a r t i a l replacement by m a t i l d i t e (md). From sample s i t e 3CHN90-2 (Appendix A) i n n o r t h - c e n t r a l segment o f Number Three v e i n .  62  F i g u r e 3.4.11: B a c k s c a t t e r e d e l e c t r o n p h o t o m i c r o g r a p h o f elongate b e r r y i t e (ber) g r a i n r e p l a c e d along cleavage by g a l e n a ( g n ) . From d e e p n o r t h p a r t o f Number T h r e e v e i n a t s a m p l e s i t e 3CHN89-88 ( A p p e n d i x A ) .  63  F i g u r e 3.4.12: B e r r y i t e ( b e r ) g r a i n u n d e r g o i n g r e p l a c e m e n t b y t e n n a n t i t e ( t n ) a l o n g g r a i n m a r g i n s . From deep n o r t h p a r t o f Number T h r e e v e i n a t s a m p l e s i t e 3CHN89-88 ( A p p e n d i x A ) .  )  64  I  the s u l f i d e assemblage and has a l s o been noted as f r a c t u r e f i l l i n g s i n sphalerite. h. ) M a t i l d i t e  AgBiS  2  M a t i l d i t e has been noted c o e x i s t i n g w i t h b l a d e d b e r r y i t e i n one sample on t h e Number Three v e i n ( F i g u r e 3.4.10). Masses a r e up t o 0.5 mm.  a c r o s s and appear t o be  pseudomorphs o f an e a r l i e r bladed phase ( p o s s i b l y b e r r y i t e ) . M a t i l d i t e may a l s o be p r e s e n t as sub-microscopic i n t e r g r o w t h s i n g a l e n a , thus e x p l a i n i n g t h e u n u s u a l l y h i g h Ag and B i c o n t e n t s i n much o f t h e galena. i . ) Seligmannite-Bournonite  PbCu(As,Sb)S3  M i n e r a l s o f t h e s e l i g m a n n i t e - b o u r n o n i t e s e r i e s a r e an important,  i f d i s p e r s e d , component o f p a r a g e n e t i c a l l y l a t e  s u l f i d e s . I n g e n e r a l , t h e s e r i e s occurs as sub-0.1  mm.  i n c l u s i o n s and i n t e r g r o w t h s i n galena and t e t r a h e d r i t e ( F i g u r e 3.4.7). I n c l u s i o n s i n t e t r a h e d r i t e a r e g e n e r a l l y vermiform and r e l a t i v e l y r a r e , whereas i n c l u s i o n s i n galena are widespread and m o s t l y occur as i n c l u s i o n t r a i n s t o cleavage d i r e c t i o n s  parallel  ( F i g u r e 3.4.13). The occurrence o f  m y r m e k i t i c a l l y intergrown s e l i g m a n n i t e - b o u r n o n i t e i n t h e southern p a r t o f t h e v e i n suggests t h a t s e l i g m a n n i t e bournonite i s p r o b a b l y t h e r e s u l t o f e x s o l u t i o n from galena. For t h e most p a r t , t h i s s e r i e s forms l e s s than 1% o f t o t a l sulfides  , i n c r e a s i n g t o 3-5% i n the v i c i n i t y o f t h e d e c l i n e  intersection.  65  F i g u r e 3.4.13: B a c k s c a t t e r e d e l e c t r o n photomicrograph of exsolved b o u r n o n i t e (bour) i n galena (gn) from northernmost Number Three v e i n (sample s i t e lCHN89-83-see Appendix A ) .  66  j . ) Polybasite, F r e i b e r g i t e , and Pyrargyrite These t h r e e phases, found o n l y i n sample s i t e 3CHN89-24 (see Appendix A) i n the south segement of the v e i n , occur as i n c l u s i o n s o r as f r a c t u r e f i l l i n g s i n the s p h a l e r i t e  and  have r e l a t i v e l y r e c t i l i n e a r boundaries w i t h each o t h e r . Galena i s a l s o a s s o c i a t e d w i t h these t h r e e phases.  k.) Bismuthinite and associated Sulfosalts B i s m u t h i n i t e , c u p r o b i s m u t i t e , and a number o f u n i d e n t i f i e d Cu-Bi-Pb s u l f o s a l t s were found w i t h i n bismuthian t e t r a h e d r i t e  ( F i g u r e s 3.4.14 and 3.4.15) from  sample s i t e 3CHN89-3 on the NG3 B i s m u t h i n i t e was approximately  v e i n (Appendix  A).  the most abundant of the phases,  2-3%  forming  of the s u l f i d e assemblage. The o t h e r  Cu-  B i phases were seen i n a s i n g l e g r a i n i n t e t r a h e d r i t e . Complex intergrowths o f b i s m u t h i n i t e and t e t r a h e d r i t e are widespread  bismuthian  w i t h i n the NG3  v e i n surrounding  sample 3CHN89-3, where they occur i n t e r s t i t i a l l y t o p y r i t e ( F i g u r e 3.4.15).  1.) Proustite and Geocronite P r o u s t i t e and G e o c r o n i t e form a s i g n i f i c a n t component i n g a l e n a - r i c h v e i n m a t e r i a l from sample s i t e 3CHN89-1 on the NG3  v e i n (Appendix A ) . The two phases o c c u r w i t h an  u n i d e n t i f i e d Ag-Pb-Sb s u l f o s a l t as rounded i n c l u s i o n s myrmekitic  intergrowths  and  ( F i g u r e 3.4.16) i n massive galena  w i t h i n d i v i d u a l g r a i n s as l a r g e as 0.2  mm  a c r o s s . The phases  have been observed t o g e t h e r and as separate  monomineralic  c l u s t e r s , a p p a r e n t l y the r e s u l t of e x s o l u t i o n .  67  Figure 3.4.14: Inclusion of cuprobismutite B i s u l f o s a l t (ss) i n bismuthian tennantite s i t e 3CHN89-3 o n c e n t r a l NG3 v e i n .  ( c p b ) a n d Cu-Pb( t n ) . From s a m p l e  2 0.0 k U  4 4 n  F i g u r e 3.4.15: B a c k s c a t t e r e d e l e c t r o n photomicrograph o f unmixing t e x t u r e s i n bismuthian t e n n a n t i t e (tn) and b i s m u t h i n i t e ( b i s ) i n p y r i t e . Uneven s u r f a c e appearence i s r e s u l t of r e l a t i v e softness of bismuthinite to p y r i t e gangue. From sample s i t e 3CHN89-3 (Appendix A) on c e n t r a l NG3 v e i n .  F i g u r e 3.4.16: B a c k s c a t t e r e d e l e c t r o n photomicrograph of exsolved g e o c r o n i t e ( g c ) , p r o u s t i t e ( p r ) , and u n i d e n t i f i e d Ag-Pb-Sb s u l f o s a l t (ss) i n massive galena (gn). From sample s i t e 3CHN89-1 (Appendix A) on deep NG3 v e i n .  70  F i g u r e 3 . 4 . 1 7 : Euhedral m a r c a s i t e (mc) from deep n o r t h Number Three v e i n (sample s i t e 3CHN89-88; see Appendix A ) . M a t r i x i s s p h a l e r i t e ( s i ) and q u a r t z ( q z ) .  71  m.)  Arsenopyrite Arsenopyrite  occurs s c a t t e r e d i n r e l a t i v e l y deep p a r t s  of t h e Number Three system, g e n e r a l l y as intergrowths w i t h f i n e - g r a i n e d p y r i t e , o r as c o a r s e - g r a i n e d have been r e p l a c e d by p y r i t e . A r s e n o p y r i t e replaces  (with p y r i t e ) s p e c u l a r  aggregates t h a t a l s o encrusts and  hematite, but r a r e l y  d i s p l a y s t h e c h a r a c t e r i s t i c diamond-shaped c r o s s - s e c t i o n . I t has  not been i d e n t i f i e d i n t h e southern p o r t i o n s o f t h e  v e i n , o r w i t h i n t h e NG3 v e i n , n.) M a r c a s i t e M a r c a s i t e i s almost u n i v e r s a l l y a s s o c i a t e d w i t h p y r i t e i n t h e Number Three system, r e a c h i n g maximum abundance i n the s e c t i o n s o f t h e v e i n c o n t a i n i n g Marcasite i s prevalent euhedral grains  abundant c h a l c o p y r i t e .  i n t h i s m a t e r i a l as subhedral t o  (up t o 0.5 mm. wide) (Figure 3.4.17) and i s  g e n e r a l l y r e p l a c e d by low-Sb t e t r a h e d r i t e . The m i n e r a l has a l s o been found i n t h e c e n t r a l (eg sample s i t e 3CHN89-102) (Appendix A) s e c t i o n o f t h e v e i n as c o l l i f o r m t o massive aggregates t h a t appear t o have r e p l a c e d p y r i t e and form up t o 10% o f t h e s u l f i d e assemblage. M a r c a s i t e has not been i d e n t i f i e d w i t h i n the southernmost s e c t i o n s o f t h e v e i n , o r w i t h i n t h e NG3 v e i n , o.)Electrum E l e c t r u m i s one o f t h e most important economic phases w i t h i n t h e Number Three system, forming an important r e p o s i t o r y f o r both Au and Ag i n the v e i n . In g e n e r a l , t h e phase o c c u r s i n t r a c e amounts, w i t h approximately 90% o f t h e  72  g r a i n s c o n t a i n e d i n galena. E l e c t r u m i n galena commonly i s a s s o c i a t e d w i t h f i n e - g r a i n e d p y r i t e aggregates  (eg. F i g u r e  3.4.18, from the P o r t a l v e i n s ) . T h i s c h a r a c t e r i s t i c o c c u r r e n c e i s o f p a r t i c u l a r importance  with respect to  b e n e f i c i a t i o n , because much of the g o l d grades have been l o s t t o t a i l s d u r i n g p a s t e x p l o i t a t i o n ( r e f e r t o Chapter E l e c t r u m has a l s o been i d e n t i f i e d w i t h i n s p h a l e r i t e ,  6).  pyrite,  c h a l c o p y r i t e , and t e t r a h e d r i t e , a l t h o u g h i n a l l cases, galena i s a s s o c i a t e d . Grains t y p i c a l l y are l e s s than microns  i n diameter and are rounded t o i r r e g u l a r i n form. In  one s i t e from the southernmost exposures vein  30  of the Number Three  (sample s i t e 2CHN89-35; Appendix A ) , e l e c t r u m forms  i n f i l l i n g s within early tetrahedrite. p.) B o r n i t e , C h a l c o c i t e , and  Covellite  B o r n i t e , c h a l c o c i t e , and c o v e l l i t e occur w i t h i n s e v e r a l s i t e s i n t h e southern p a r t of the Number Three v e i n , where t h e y o c c u r as sub-0.1 mm outermost  s i z e i n c l u s i o n s w i t h i n the  growth zones of p y r i t e g r a i n s . A l l t h r e e phases  are a p p a r e n t l y primary, w i t h the most unusual the A g - b e a r i n g  feature being  c h a r a c t e r of c h a l c o c i t e . C h a l c o c i t e and  c o v e l l i t e were a l s o i d e n t i f i e d as supergene m i n e r a l s w i t h manganese o x i d e s a t the t o p o g r a p h i c a l l y h i g h e s t sample s i t e (1CHN89-83; Appendix A ) , q.)  Pyrrhotite P y r r h o t i t e was  i d e n t i f i e d i n o n l y two  samples w i t h i n  the a l t e r a t i o n h a l o adjacent t o the southern p o r t i o n of the  73  v e i n . In both c a s e s , the m i n e r a l was found as s m a l l (<0.1 mm.)  rounded i n c l u s i o n s i n p y r i t e .  r.) Hematite and Magnetite Hematite i s l o c a l l y abundant as s p e c u l a r i t e ,  totalling  up t o 10-15% o f t h e m i n e r a l assemblage. In g e n e r a l , hematite i s c o n f i n e d t o t h e c e n t r a l p o r t i o n o f t h e v e i n , i n the area between sample s i t e s 2CHN89-27 and 3CHN89-102 (Appendix A ) . Masses o f s p e c u l a r hematite up t o s e v e r a l cm. a c r o s s a r e found w i t h carbonate, q u a r t z , and p y r i t e w i t h i n b r e c c i a t e d w a l l r o c k a d j a c e n t t o t h e v e i n . Hematite commonly i s r e p l a c e d by F e - s u l f i d e s , galena, and carbonate, where i t i s a l e s s important component o f t h e v e i n . Overgrowths o f p y r i t e and a r s e n o p y r i t e on hematite have a l s o been i d e n t i f i e d . Magnetite  i s much r a r e r w i t h i n t h e Number Three v e i n ,  o c c u r r i n g as i n t e r g r o w t h s w i t h hematite l o c a l e s . No t r e n d i n magnetite s.) T i t a n i u m  i n a few s c a t t e r e d  d i s t r i b u t i o n was r e c o g n i z e d ,  Oxides  Euhedral T i - o x i d e phases (eg. r u t i l e ) were noted i n s c a t t e r e d l o c a l i t i e s i n t h e Number Three system and a r e presumed t o r e p r e s e n t oxides scavenged from t h e adjacent w a l l r o c k d u r i n g m i n e r a l i z a t i o n . Grains t e n d t o be l e s s 20 microns  than  i n s i z e and p r e s e n t i n o n l y t r a c e q u a n t i t i e s  within the v e i n , t.)  Quartz Quartz  i s t h e most u b i q u i t o u s gangue phase w i t h i n the  Number Three v e i n . F i n e - g r a i n e d , anhedral q u a r t z i s intergrown w i t h p y r i t e and was b r e c c i a t e d d u r i n g the f i r s t  74  F i g u r e 3.4.18: E l e c t r u m ( e l ) i n i n t e r g r o w n g a l e n a (gn) and m a t i l d i t e (md), a l o n g t h e m a r g i n o f p y r i t e (py) g r a i n s . From s a m p l e s i t e 2CHN90-9 on P o r t a l v e i n T h r e e .  75  stage of m i n e r a l i z a t i o n , w i t h c o a r s e r c r y s t a l l i n e v a r i e t i e s occurring later  ( F i g u r e 3.4.2). Quartz from the  southern  p a r t of the Number Three v e i n i s g e n e r a l l y s u b h e d r a l t o euhedral  and  commonly c o n t a i n s minute p y r i t e i n c l u s i o n s  w i t h i n the o u t e r growth zones of c r y s t a l s . B a r i t e blades q u a r t z - p y r i t e b r e c c i a fragments commonly are e n c r u s t e d l a y e r of f i n e - g r a i n e d (<0.2 the c e n t r a l and  northern  mm.)  q u a r t z . Much quartz  and  by  a  from  p a r t s of the s t r u c t u r e d i s p l a y s  drusy and cockscomb t e x t u r e s upon which l a t e r s u l f i d e s have been d e p o s i t e d .  Quartz from these s e c t i o n s o f the v e i n  l a t e r p a r a g e n e t i c a l l y and much c o a r s e r g r a i n e d than of the south end  (up t o 1 cm.  are  quartz  f o r cockscomb masses).  Very l a t e , f i n e - g r a i n e d quartz v e i n l e t s which c u t s u l f i d e s are a l s o p r e s e n t c e n t r a l and u.)  northern  late  w i t h i n v e i n m a t e r i a l from the  p o r t i o n s of the Number Three v e i n ,  Carbonates  S e v e r a l v a r i e t i e s of carbonate m i n e r a l s  occur  throughout the Number Three v e i n , w i t h the  greatest  abundances o c c u r r i n g i n the n o r t h .  are s p a r r y  Grains  and  w e l l zoned, w i t h l a y e r e d m a t e r i a l most abundant w i t h i n  the  northernmost p o r t i o n s of the v e i n . Carbonates from the  north  end  are g e n e r a l l y M n - r i c h (manganosiderite t o  rhodochrosite),  w i t h s m a l l amounts of l a t e r  calcite.  Manganese-bearing carbonates appear t o c o r r e l a t e c l o s e l y w i t h c h a l c o p y r i t e - r i c h v e i n s ; t h e r e f o r e , as  chalcopyrite  decreases t o the south, c a l c i t e becomes the main carbonate phase. Carbonates i n the south occur i n s e v e r a l m i n e r a l i z i n g  76  e p i s o d e s ; e a r l i e r carbonate i s b r e c c i a t e d and l a t e r carbonate and  surrounded  by  s u l f i d e s ( F i g u r e 3.4.19). Zoning w i t h i n  carbonates seems to be due  t o v a r i a t i o n s i n Fe-content, w i t h  the most a n k e r i t i c compositions o c c u r r i n g w i t h i n the c e n t r a l p a r t of the v e i n . F a r t h e r  south, unzoned c a l c i t e i s the  dominant carbonate m i n e r a l , assemblage and,  forming up t o 5% of the  total  i n s e v e r a l l o c a l i t i e s c e n t e r e d around  d e c l i n e , occurs i n bladed form w i t h b a r i t e . The sample of the Number Three v e i n , and m a t e r i a l  the  southernmost  from the  NG3  v e i n , c o n t a i n a l a t e r stage c a l c i t e t h a t c u t s a l l o t h e r phases and v.)  l o c a l l y f i l l s b r e c c i a spaces ( F i g u r e  3.4.20).  Barite B a r i t e occurs almost e x c l u s i v e l y i n b l a d e d form and  is  most abundant i n the southern p a r t of the Number Three system. Blades are v e r y e a r l y p a r a g e n e t i c a l l y and t o two  can be  up  c e n t i m e t e r s i n l e n g t h , w i t h s u l f i d e s commonly  o c c u r r i n g i n t e r s t i t i a l l y . B a r i t e , l o c a l l y , forms up t o of the t o t a l assemblage and v e i n selvage.  10%  i s e s p e c i a l l y prominent i n the  Towards the n o r t h end,  however, b a r i t e i s  r a r e l y p a r t of the gangue assemblage; t r a c e amounts were noted a t h i g h e l e v a t i o n s  i n two  h o l e s . Thomson et al.  (1991)  note a p a r a g e n e t i c a l l y l a t e b a r i t e phase i n minor v e i n s a d j a c e n t t o the Number Three system; l a t e b a r i t e was found by the author i n the main s t r u c t u r e .  not  77  w.) S v a n b e r g i t e Hinsdalite  (Sr,Ca)Al (Pb Sr)Al /  3 3  (PO4)(SO4)(OH)5 (PO4)(SO4)(OH) 6  Two unusual phosphate phases, s v a n b e r g i t e and hinsdalite,  were noted t o form up t o 1% o f t h e assemblage  i n sample s i t e 3CHN89-5 (Appendix A ) , where they occur w i t h b a r i t e as t a b u l a r g r a i n s up t o two m i l l i m e t e r s a c r o s s . Several grains display basal sections with a c h a r a c t e r i s t i c a n d a l u s i t e - l i k e e x t i n c t i o n . M a t e r i a l w i t h i n t h e NG3 v e i n i s interstitial  t o e a r l y p y r i t e g r a i n s and i s d i f f i c u l t t o  i d e n t i f y w i t h o u t S.E.M. a n a l y s i s  (Figure  3.4.21).  S v a n b e r g i t e and h i n s d a l i t e were a l s o i d e n t i f i e d i n s e v e r a l i n t e r s e c t i o n s from t h e southermost p o r t i o n s o f t h e Number Three v e i n , w i t h t h e former phase noted r e p l a c i n g w a l l r o c k plagioclase x.)  (Thomson, P e r s . Comm.).  Pyrobitumen Pyrobitumen was found i n b o t h t h e n o r t h e r n and southern  p o r t i o n s o f t h e Number Three system as i r r e g u l a r masses up to  t h r e e m i l l i m e t e r s a c r o s s . M a t e r i a l from t h e n o r t h end  p o s t d a t e s s u l f i d e m i n e r a l i z a t i o n and i s g e n e r a l l y v i s i b l e i n hand sample.  I n t h e south, pyrobitumen i s a p p a r e n t l y  contemporaneous w i t h b a r i t e , w i t h which i t i s commonly a s s o c i a t e d . I n both a r e a s , v e i n pyrobitumen i s a t best a minor phase, forming l e s s than 1% o f t h e t o t a l  3.4.3  Paragenesis  and Mineralogic  assemblage.  Variation  M i n e r a l i z a t i o n i n t h e Number Three system can be d i v i d e d r o u g h l y i n t o f o u r major p a r a g e n e t i c stages ( F i g u r e  78  Figure 3 . 4 . 1 9 : Zoned and b r e c c i a t e d carbonate (cb A, B, C) from c e n t r a l n o r t h e r n p a r t o f Number Three v e i n . From sample s i t e 3CHN89-87 (Appendix A ) .  F i g u r e 3 . 4 . 2 0 : Stage IV c a l c i t e (cc) v e i n i n g c u t t i n g e a r l i e r q u a r t z (qz) and s p h a l e r i t e ( s i ) . From sample s i t e 3CHN89-36 (Appendix A) on NG3 v e i n .  F i g u r e 3.4.21: S e c o n d a r y e l e c t r o n image o f s v a n b e r g i t e ( grain i n t e r s t i t i a l to pyrite ( A p p e n d i x A ) , NG3 v e i n .  ( p y ) , sample s i t e  3CHN89-3  81  3.4.22 and Appendix B). Stage I, i n i t i a t e d by pyrite-guartz deposition, and  i s most p r e v a l e n t  fine-grained  i n the c e n t r a l  southern segments of the v e i n . A second massive p y r i t e -  q u a r t z - b a r i t e e p i s o d e commonly f o l l o w e d b r e c c i a t i o n of  the  e a r l i e r q u a r t z - p y r i t e stage, w i t h much q u a r t z o c c u r r i n g as a drusy r i m on b r e c c i a fragments (Figure 3.4.2). Hematite carbonate are dominant i n the c e n t r a l p a r t o f the v e i n  and (from  sample s i t e 3CHN89-102 t o the B u l k l e y c r o s s c u t ) , w i t h the former phase o f t e n a s s o c i a t e d w i t h e x t e n s i v e the a d j a c e n t w a l l r o c k . arsenopyrite,  b r e c c i a t i o n of  Svanbergite, h i n s d a l i t e , pyrobitumen,  and m a r c a s i t e are a l s o p r e s e n t w i t h i n Stage I  material. Stage I I i s dominated by s p h a l e r i t e , c a l c i t e , and  the  manganoan c a r b o n a t e s , commonly w i t h a d i f f u s e boundary w i t h e a r l i e r Stage I m i n e r a l o g i e s . Stage I I , and  P y r i t e i s important l o c a l l y i n  i n s e v e r a l s i t e s a c t u a l l y surrounds  fragments o f massive s p h a l e r i t e . G a l l i u m enriched  and  brecciated  germanium,  e r r a t i c a l l y i n s p h a l e r i t e , a l s o appear t o  be  a s s o c i a t e d p a r a g e n e t i c a l l y w i t h s p h a l e r i t e . Quartz, galena, and  arsenopyrite  the c e n t r a l and  are a l s o p a r t of Stage I I m i n e r a l i z a t i o n i n n o r t h e r n p o r t i o n s of the v e i n . M i n e r a l s  Stage I I commonly s e a l the v e i n , w i t h v e i n o c c u r r i n g between Stage I I and  re-opening of  Stage I I I .  Stage I I I i s dominated by Cu-bearing phases c h a l c o p y r i t e and  t e t r a h e d r i t e ) and  (eg.  forms r e - b r e c c i a t e d  sections or stringers c u t t i n g e a r l i e r minerals. sulfosalts  the  Complex  (eg. b e r r y i t e , a i k i n i t e , and p o l y b a s i t e )  are  from  TABLE 3.422: PARAGENESIS OF THE NUMBER THREE SYSTEM  STAGE Type at SUntn  IB J  U U l  quartz aphBlentB araanopy. btiumnn tjarttB  ffflitntsiB ihodoctwoo. hotnsttB  magnetite estate skkitu utuL bum  AMores  peace/to-  pymgyr. chutoopf. ocannnB  tenyita a/praoam. COVBttiB-  tarnto boumorito geoaontB  AgSbPb-  Zn-MnGe  Ag-Cv-Pb^l  IV  83  l o c a l l y abundant w i t h i n Stage I I I , and q u a r t z and manganoan carbonate predominate as gangue phases. Stage I I I i s a l s o important from an economic  s t a n d p o i n t ; a l l p r e c i o u s metal  b e a r i n g phases a t S i l v e r Queen mine are a s s o c i a t e d w i t h Stage I I I m i n e r a l i z a t i o n . T e t r a h e d r i t e marks the t e r m i n a t i o n of  t h i s s t a g e where i t o c c u r s as f r a c t u r e i n f i l l i n g s i n  chalcopyrite  ( F i g u r e 3.4.9) .  Stage IV, m i n i m a l l y p r e s e n t i n the Number Three system, c o n s i s t s o f minor f i n e - g r a i n e d s i l i c e o u s v e i n i n g and v e i n pyrobitumen i n the n o r t h p a r t o f the Number Three v e i n , and c a l c i t e v e i n i n g i n the s o u t h segment and NG3  system  (Figure  3.4.20). The m i n e r a l o g y o f t h e Number Three system appears t o d i s p l a y a rough n o r t h t o s o u t h zoning which may  reflect  changes i n w a l l r o c k c o m p o s i t i o n , f l u i d c o n d i t i o n s , and v a r i a b l e degree o f v e i n d i l a t i o n d u r i n g the f o u r stages o f m i n e r a l i z a t i o n (see F i g u r e s 3.4.23 t o 3.4.26). Stage I m i n e r a l s a r e most abundant intersection  i n the v i c i n i t y o f the d e c l i n e  ( F i g u r e 3.4.23). F o r the most p a r t , massive  p y r i t e ' and b a r i t e are l o c a l l i z e d w i t h i n the v i c i n i t y o f t h e d e c l i n e i n t e r s e c t i o n , w i t h a moderate degree o f c o r r e l a t i o n w i t h h i g h p r e c i o u s metal grades ( F i g u r e 3.4.24). Stage I hematite and carbonate a r e l i m i t e d t o the r e g i o n around and immediately t o the south o f t h e B u l k l e y c r o s s c u t ; t o then o r t h o f t h i s r e g i o n , the o v e r a l l abundance o f Stage I drops off  s h a r p l y and Stage I I dominates  (Figure  3.4.23).  A r s e n o p y r i t e appears t o be c o n c e n t r a t e d i n the lowest p a r t s  84  of t h e c e n t r a l and n o r t h e r n segments o f t h e v e i n ( F i g u r e 3.4.24). The h a b i t o f quartz and p y r i t e a l s o changes from n o r t h t o south, w i t h c o a r s e r g r a i n e d , euhedral forms becoming i n c r e a s i n g l y dominant i n t h e northernmost  segment  of t h e v e i n . Stage I I m i n e r a l o g i e s a r e most abundant i n the southernmost and n o r t h e r n p a r t s o f t h e Number Three system, w i t h s p h a l e r i t e everywhere an important component ( F i g u r e 3.4.23). Perhaps t h e most important v a r i a t i o n observed i n s p h a l e r i t e i s t h e change from massive o r c o l l i f o r m masses i n the south t o c o a r s e g r a i n e d , euhedral g r a i n s i n the n o r t h . Manganoan carbonates a r e important  i n vein material  a s s o c i a t e d w i t h c h a l c o p y r i t e and/or hematite, w i t h peak abundance i n t h e northernmost  e x t r e m i t y o f t h e v e i n (sample  s i t e 2CHN90-2; see Appendix A) ( F i g u r e 3.4.25). Conversely, c a l c i t e i s r e s t r i c t e d t o t h e r e g i o n from sample s i t e 3CHN8998  (Appendix  been observed  A) south t o the d e c l i n e v i c i n i t y , and has n o t i n e i t h e r s h a l l o w e r o r deeper p a r t s o f t h e  v e i n . Both p y r i t e and galena a r e l o c a l l y abundant as Stage II phases. P r e v a l e n c e o f Stage I I I m i n e r a l i z a t i o n i s h i g h l y v a r i a b l e , b e i n g most abundant near t h e B u l k l e y c r o s s c u t and i n s c a t t e r e d s i t e s i n the south end o f t h e v e i n ( F i g u r e 3.4.23). In t h e n o r t h , Stage I I I m a t e r i a l i s dominated by c h a l c o p y r i t e and s u l f o s a l t s such as b e r r y i t e , w i t h t h e l a t t e r phase r e s t r i c t e d t o deep, c h a l c o p y r i t e - b e a r i n g v e i n m a t e r i a l between sample s i t e s 3CHN90-2 and 2CHN89-27  85  (Appendix A)  ( F i g u r e 3.4.26). C h a l c o p y r i t e  i s widely  d i s p e r s e d throughout the Number Three system, o c c u r r i n g i n the south as " c h a l c o p y r i t e d i s e a s e "  i n s p h a l e r i t e and i n the  north as i r r e g u l a r masses i n t e r s t i t i a l t o gangue m i n e r a l s . Chalcopyrite  increases  from t r a c e amounts near the B u l k l e y  c r o s s c u t , northward t o where Stage I I I becomes unimportant (at  the v e r y  3.4.26).  l i m i t o f exposed m i n e r a l i z a t i o n )  (Figure  In t h e south, galena and t e t r a h e d r i t e are the  •dominant Stage I I I phases, w i t h a i k i n i t e an i r r e g u l a r p a r t of the assemblage near the d e c l i n e i n t e r s e c t i o n (Figure 3.4.26). S e l i g m a n n i t e / b o u r n o n i t e s e r i e s m i n e r a l s sporadic  are  throughout the v e i n .  As mentioned p r e v i o u s l y , the r e l a t i v e l y  insignificant  Stage IV m i n e r a l i z a t i o n i s l i m i t e d t o c a l c i t e i n the southernmost Number Three v e i n , and f i n e - g r a i n e d s i l i c a and pyrobitumen i n the northernmost and s h a l l o w e s t v e i n . The NG3  p a r t s o f the  v e i n , p o s s i b l y a southern e x t e n s i o n  Number Three zone,  o f the  does not d i s p l a y p a r t i c u l a r  m i n e r a l o g i c a l t r e n d s , perhaps due t o t h e p a u c i t y of a v a i l a b l e samples, although m a t e r i a l from sample s i t e 3CHN89-36 (Appendix A) i s more o r l e s s s i m i l a r t o the southermost e x t r e m i t y  3.5 3.5.1  of the Number Three v e i n .  M i n e r a l i z a t i o n i n Other Veins Camp Vein  System  The Camp v e i n s  ( F i g u r e 2.3.1) o c c u r on the west s i d e o f  the Owen Lake f a u l t and a t present  a r e known o n l y from a  00  \RGURE 3.4.24  LONGITUDINAL SECTION OF NUMBER THREE VEIN STAGE I MINERAL ABUNDANCE  1  2  l 1  4 5  1  4  •  15  O  O  4  °r  1 2  o  Y KEY  1 3  8 21  w  l_J-14.10,11,13,14  °  O  92  I  i  ^10,11  8i — 41 f-2  ± ± 2  0  meters  o °  4  1 12,13  200  sample site 1  p/ritia 1 ft... .pyrite 2  tarib to.  tvanbsrgte /nsrcos/ts tf—n/nsofefito 12 pymbSumen 4 quartz 1 5..- ftamatfe 13. Thmda a.._.CGltXXTBtB 14 PJpthdOB OTonqpyrito 15. nmyituBki a.._.quartz 2  a  co  LONGITUDINAL SECTION OF NUMBER THREE VEIN STAGE II MINERAL ABUNDANCE  FIGURE 3.4.25  173  1  2  O  3  O O  O  o o  o  o  o 1  >4  2  0  KEY  meters  2 3  M  o°  7,3 1  6  1  200  sample site sp/jaferite  1 Z  quartz  a  pyrite  4  a.  carbonate  arsenopyrite betite 7_„.galena  &  co co  LONGITUDINAL SECTION OF NUMBER THREE VEIN  RGURE 3.4.28  STAGE a M1NERALABUNDANCE  34  X ' 5  E W  6  6  3  4 8,6  9 48  4 c  4  KEY  0  o "  -1>-2,6,10 9 39  4  .I 3  '5,11,12,10,6,14  -  meters 200  sumpls sito to bonite 1 quartz 2 cftafcopyrfte 11 paarcete3 fehtofo 4 gatens 12 mbfsSvem  .teSgmannltB- 13. sphaterfe boumonrte 14 fterbargite 15—geocronfe a efectrum  5 7  8 9  carbonate  bsnyte aftfnrte  18 HmUBmlB 17 cupiobi&iivUbi 18. AfStyPbauBoul  co  5|  90  s e r i e s of d r i l l 1988.  h o l e i n t e r s e c t i o n s completed i n 1987  The v e i n s are s i n g u l a r due  grades (commonly) and  to t h e i r unusually  and high  Ag  a s s o c i a t e d Ag-bearing mineralogy.  D e l i n e a t i o n o f the i n d i v i d u a l v e i n s i s d i f f i c u l t due  the  l a c k of s u r f a c e exposure, but from mineralogy and s t r u c t u r a l information  from d r i l l  h o l e s , f i v e v e i n s were d e f i n e d .  northernmost and perhaps most important e c o n o m i c a l l y  The  ("Ruby  S i l v e r v e i n " ) i s dominated by the presence of Ag-bearing minerals  ( t e t r a h e d r i t e , p e a r c i t e , and p y r a r g y r i t e ) , l o c a l l y  forming up t o 10 volume percent symplectic  intergrowths  of the v e i n . Complex  of these minerals  w i t h galena are  common ( F i g u r e 3.5.1) i n the l a r g e r masses, l o c a l l y w i t h l a t e r rims o f a c a n t h i t e . The v e i n i s a l s o c h a r a c t e r i z e d the  " b r e c c i a zone" nature of m i n e r a l i z a t i o n , w i t h the  a c t u a l l y f i l l i n g the i n t e r s t i c e s of b r e c c i a t e d  f o l l o w e d by l a t e r quartz, p y r i t e , b a r i t e ,  manganoan carbonate (or l e s s commonly, c a l c i t e ) . is  also present  as i r r e g u l a r masses up t o t h r e e  vein  wallrock.  W a l l r o c k fragments are surrounded by f i n e - g r a i n e d , quartz,  by  sparry and Sphalerite  millimeters  across. A smaller, the  l e s s A g - r i c h v e i n occurs t o the southeast o f  "Ruby S i l v e r " v e i n d e s c r i b e d above, near the Number F i v e  v e i n p o r t a l . V e i n m a t e r i a l i s dominated by massive manganoan carbonate, w i t h l e s s e r b a r i t e , f i n e - g r a i n e d  arsenopyrite^  s p h a l e r i t e , and q u a r t z . P y r i t e commonly d i s p l a y s b l a d e d forms t h a t r e f l e c t an o r i g i n a l arsenopyrite-dominated m i n e r a l i z a t i o n t h a t has  been almost c o m p l e t e l y  replaced.  Figure 3.5.1: Backscattered e l e c t r o n photomicrograph of s y m p l e c t i c i n t e r g r o w t h s o f p y r a r g y r i t e (pyg) and g a l e n a (gn f r o m n o r t h e r n m o s t p a r t o f Camp v e i n s ( s a m p l e s i t e 3CHN89-13 see Appendix A ) .  92  F i g u r e 3.5.2: Overgrowths o f a r s e n o p y r i t e (aspy) on b l a d e d phase t h a t has been r e p l a c e d by p y r i t e ( p y ) . M a t r i x i s manganoan c a r b o n a t e (cb) and q u a r t z ( q z ) . Note r e p l a c e m e n t of F e - r i c h zones i n c a r b o n a t e by a l a t e r a r s e n o p y r i t e m i n e r a l i z a t i o n ( a r r o w ) . From sample s i t e 3CHN89-15 (Appendix A) on Camp v e i n s .  93  Figure 3.5.3: Backscattered e l e c t r o n photomicrograph of p y r r h o t i t e (po) and p y r i t e (py) t h a t have r e p l a c e d b l a d e d m i n e r a l . L a t e r a r s e n o p y r i t e ( a s p y ) a l s o p r e s e n t . From sample s i t e 3CHN89-15 ( A p p e n d i x A) on Camp v e i n s .  94  Minor galena, c h a l c o p y r i t e , pyrobitumen, p y r r h o t i t e , and u n i d e n t i f i e d gangue phase are a l s o present disseminations.  The  an  as  presence of the p y r r h o t i t e  and  u n i d e n t i f i e d gangue phase bears a marked s i m i l a r i t y t o v e i n material  from the  " P o r t a l 11.5"  vein, described  ( s e c t i o n 3.5.3); abundances of the two the two  elsewhere  m i n e r a l s suggest t h a t  occurrences might i n f a c t be separate p a r t s of a  single vein. Two  o t h e r v e i n s were d e f i n e d  i n d r i l l c o r e from  the  westernmost i n t e r s e c t i o n s on the Camp v e i n systems, w i t h more s o u t h e r l y of the two  the  c o n s i s t i n g of r e p e t i t i v e l y  layered  mangnaoan carbonate w i t h l e s s e r disseminated q u a r t z ,  pyrite,  arsenopyrite,  and  l a y e r s up t o two  g a l e n a . S p h a l e r i t e i s l o c a l l y abundant i n mm.  t h i c k . The  abundant l a y e r e d carbonate, but predominance of a r s e n o p y r i t e  and  phases. Euhedral a r s e n o p y r i t e  northern v e i n a l s o  contains  i s c h a r a c t e r i z e d by p y r i t e among the  the  sulfide  forms unusual c r u s t i f o r m  overgrowths (with p y r i t e ) on a p r e - e x i s t i n g b l a d e d phase (probably  h e m a t i t e ) , t h a t has  p y r r h o t i t e (Figures carbonate, q u a r t z , Arsenopyrite  was  3.5.2 and  and  followed  earlier  by d e p o s i t i o n of galena,  c h a l c o p y r i t e , p e a r c i t e , and  deposition  3.5.3), as w e l l as  and  even euhedral s p h a l e r i t e .  followed  m i n e r a l i z a t i o n was  been r e p l a c e d by p y r i t e  f r e i b e r g i t e . The  marked by massive  end  of  pyrite-arsenopyrite  by a f i n a l carbonate e p i s o d e .  Pyrobitumen and b a r i t e are a l s o p a r t of the gangue assemblage, but are p a r a g e n e t i c a l l y e a r l i e r than  the  95  majority  of the s u l f i d e m i n e r a l i z a t i o n  (Figures  3.5.4 and  3.5.5) . The  f i f t h and southernmost v e i n t o be d e f i n e d  i n the  Camp v e i n system i s d i s t i n g u i s h e d by t h e dominance o f e a r l y b a r i t e and pyrobitumen i n t h e gangue assemblage.  Later  carbonate, s u l f i d e s , and q u a r t z occur i n t e r s t i t i a l l y t o t h e b a r i t e blades;  l a t e s u l f i d e s (eg. galena, p y r a r g y r i t e ) a r e  l a c k i n g . Both p y r i t e and carbonate g r a i n s show w e l l zonation,  defined  w i t h t h e former a l s o d i s p l a y i n g abundant  i n t e r g r o w n p y r r h o t i t e w i t h i n t h e outermost zones. The  r e g i o n immediately t o t h e south o f t h e Camp v e i n s  i s r e l a t i v e l y unknown due t o a t h i c k cover o f overburden and limited d r i l l - h o l e definition. Available intersections i n d i c a t e t h e presence o f s e v e r a l small v e i n s  and widespread  s t r i n g e r m i n e r a l i z a t i o n i n t h e v i c i n i t y o f t h e t a i l i n g pond and  d e c l i n e p o r t a l . Two v e i n s  and t h e s o - c a l l e d "Twinkle  zone" ( F i g u r e 2.3.1) were sampled and examined i n r e f l e c t e d l i g h t . M a t e r i a l from t h e Twinkle zone c o n s i s t s o f simple sulfides quartz, small  ( p y r i t e , galena, s p h a l e r i t e , and t e t r a h e d r i t e ) w i t h i n narrow s t r i n g e r s r a t h e r than a d i s t i n c t v e i n . A  (about 20 cm. t r u e t h i c k n e s s ) , but unusual v e i n was  noted i n a d r i l l  i n t e r s e c t i o n from the northeast  side of the  t a i l i n g s pond; s u l f i d e m i n e r a l s were almost e n t i r e l y f i n e grained  p y r i t e , w i t h v e r y r a r e , sub-0.1 mm. i n c l u s i o n s o f  p y r r h o t i t e and s p h a l e r i t e d i s s e m i n a t e d throughout. Another s m a l l e r v e i n nearby more c l o s e l y resembled t h e Camp v e i n s t o  96  F i g u r e 3.5.4: Bladed b a r i t e (ba) i n m a t r i x of manganoan carbonate (cb) and v u g - i n f i l l i n g quartz ( q z ) . From sample s i t e 3CHN89-15 (Appendix A) on Camp v e i n s .  Figure 3 . 5 . 5 : carbonate 3CHN89-15  B r o k e n p y r o b i t u m e n ( p y b i t ) mass i n manganoan (cb) and a r s e n o p y r i t e (aspy) from sample s i t e ( A p p e n d i x A) o n Camp v e i n s .  98  the n o r t h , w i t h abundant bladed b a r i t e , carbonate, and arsenopyrite  3.5.2  i n c l u d e d w i t h i n t h e assemblage.  Chisholm The  Veins  Chisholm v e i n system c o n s i s t s o f f o u r small and  h i g h l y i r r e g u l a r v e i n s l o c a t e d i n t h e southwestern p a r t o f the study a r e a . The v e i n s a r e g e n e r a l l y l e s s than 30 cm. in... width, l o c a l l y t h i c k e n i n g t o " p o d l i k e " masses. Mineralogy i s s i m i l a r t o t h a t o f the Camp v e i n s , w i t h Ag-bearing b a r i t e , and a r s e n o p y r i t e  minerals,  r e l a t i v e l y abundant compared t o t h e  Number Three system. B a r i t e commonly o c c u p i e s a p a r a g e n e t i c a l l y intermediate  p o s i t i o n i n t h e v e i n s and has  been noted r a d i a t i n g from s p h a l e r i t e fragments i n the Mae Three and Owl v e i n s the area,  (Figure 3.5.6). U n l i k e other v e i n s i n  s p h a l e r i t e i s among t h e f i r s t m i n e r a l s  forming l a y e r s o f c o a r s e - g r a i n e d  m a t e r i a l adjacent  v e i n w a l l s . P y r i t e and a r s e n o p y r i t e intermediate  deposited, t o the  are e i t h e r e a r l y or  p a r a g e n e t i c a l l y , o c c u r r i n g as f i n e - g r a i n e d  intergrown masses b o r d e r i n g  s p h a l e r i t e bands. Two stages  c o n t a i n i n g galena were a l s o noted, w i t h t h e l a t e r stage frequently c o n t a i n i n g exsolved  vermiform i n c l u s i o n s o f  p y r a r g y r i t e , p e a r c i t e , f r e i b e r g i t e , and b o u r n o n i t e . F r e i b e r g i t e i s e s p e c i a l l y important w i t h i n the Owl v e i n , where i t o c c u r s as i r r e g u l a r masses i n s p h a l e r i t e , forming up t o 3% o f t h e v e i n assemblage ( F i g u r e 3.5.7). A f i n a l stage o f m i n e r a l i z a t i o n i n c l u d e s carbonate ( c a l c i t e ? ) , w i t h rare p y r i t e .  •I  0 1  b  n  6  Id  8  d  )S L  S  , •» | U I 9  •  . i . l . i , I j . l j J . i i l . i i l ^ J i i . i j . i , i jMJjih.l,i,1,1.1,i.l,i.l.i.l.i.I, F i g u r e 3.5.6:  C r o s s - s e c t i o n a l s l a b o f Mae T h r e e v e i n , Chisholm v e i n group. Note b a r i t e (ba) b l a d e s overgrowing e a r l i e r l a y e r e d s p h a l e r i t e ( s i ) . F r o m s a m p l e s i t e 1CHN89-57 (Appendix A ) .  14  15  W  17 18 1  • ':  1  n  iljlllt 19  d  20  21  23  1  24  SS9|Uii  ; s  •lililil.i.;.- ! 1,1,' !• xW^^^^^^^tkx I F i g u r e 3.5.7: A r g e n t i a n t e t r a h e d r i t e ( t t ) p o d s , w i t h 6  8  s p h a l e r i t e ( s i ) a n d g a l e n a (gn) i n a b a r i t e - d o m i n a t e d (sample s i t e 1CHN89-65; s e e A p p e n d i x A ) .  matrix  F i g u r e 3.5.8: B a c k s c a t t e r e d e l e c t r o n p h o t o m i c r o g r a p h o f l a r g e e l e c t r u m ( e l ) g r a i n i n i n t e r g r o w n g a l e n a (gn) and m a t i l d i t e (md) from sample s i t e 2CHN89-4 (Appendix A ) , P o r t a l v e i n Three.  101  3.5.3  Portal The  Veins  P o r t a l v e i n s a r e between the Owen Lake f a u l t and  the Number Three v e i n ( F i g u r e 2.3.1) and form perhaps the most m i n e r a l o g i c a l l y complex system on the p r o p e r t y . I n d i v i d u a l v e i n s a r e h i g h l y i r r e g u l a r , w i t h widths o f up t o more than f i f t y centimeters  and then o f f s e t o r t a p e r i n g t o  zero over a few tens o f meters along s t r i k e .  No two o f t h e  v e i n s d i s p l a y t h e same assemblages. In g e n e r a l , t h e v e i n s can be d i v i d e d i n t o f o u r c a t e g o r i e s on.the b a s i s o f bulk mineralogy. The f i r s t ,  and most important  economically,  i n c l u d e s t h e c h a l c o p y r i t e - r i c h Number F i v e and P o r t a l Three v e i n s , both o f which c o n t a i n s p e c t a c u l a r c o n c e n t r a t i o n s o f Ag-sulfosalts i n t e r s t i t i a l  t o s p a r r y quartz  gangue.  Electrum  ( F i g u r e s 3.5.8 and 3.4.18) i s a l s o abundant, r a r e l y a t t a i n i n g s u f f i c i e n t s i z e t o be seen i n hand specimen. Textures a r e s i m i l a r t o those noted f o r t h e n o r t h e r n  Number  Three system, w i t h massive, coarse g r a i n e d s p h a l e r i t e forming t h e v e i n margins, followed by euhedral p y r i t e . The quartz  quartz and  and p y r i t e a r e f o l l o w e d by open-space  f i l l i n g c h a l c o p y r i t e and r a r e s u l f o s a l t s , which a r e f r a c t u r e d and c u t by t e t r a h e d r i t e and g a l e n a - s u l f o s a l t veinlets  ( F i g u r e 3.5.9). Galena and t h e s u l f o s a l t s  (most  commonly m a t i l d i t e ) g e n e r a l l y occur as s y m p l e c t i c intergrowths  ( F i g u r e 3.5.10) i n masses up t o s e v e r a l  m i l l i m e t e r s a c r o s s . Galena a l s o occurs  along  cleavage  d i r e c t i o n s w i t h i n e a r l i e r b e r r y i t e and g u s t a v i t e masses, an  102  occurrence which may  be the r e s u l t of replacement  3.5.11). T e t r a h e d r i t e assemblage and  and  (Figure  rare fine-grained p y r i t e cut  r e p l a c e e a r l i e r p y r i t e masses o r form  myrmekitic intergrowths w i t h galena and m a t i l d i t e .  Well-  zoned manganoan carbonate i s l o c a l l y abundant w i t h i n l a t e r s u l f i d e assemblage, w i t h i n d i v i d u a l zones changes i n Fe-content  vugs and mark the t e r m i n a t i o n  the  recording  ( F i g u r e 3.5.12). F i n e - g r a i n e d  and masses of pyrobitumen up t o one  veins  the  quartz  c e n t i m e t e r across  infill  of m i n e r a l i z a t i o n i n these  ( F i g u r e 3.5.13). The  second type of v e i n i n the P o r t a l system i s  d i s t i n g u i s h e d by the l a c k of s u l f o s a l t m i n e r a l i z a t i o n includes  the Switchback v e i n and  Portal veins  i n the  and eastern  s e c t i o n of the system. In g e n e r a l , m i n e r a l i z a t i o n i s dominated by one  o r more q u a r t z - p y r i t e +  episodes, followed  by b l a d e d b a r i t e and  specular layered  hematite carbonate  d e p o s i t i o n . Late m i n e r a l s are t y p i c a l l y r e s t r i c t e d t o galena, c h a l c o p y r i t e , and recognized  s p h a l e r i t e , w i t h no s u l f o s a l t s  w i t h i n the assemblage. The  exception  to  the  unremarkable assemblages observed i n t h i s group of v e i n s found i n " P o r t a l 11.5" (magnetite and  v e i n , where two  opaque phases  h e m a t i t e ? ) a r e disseminated w i t h i n  l a y e r e d carbonate. Abundant p y r r h o t i t e was  a l s o noted w i t h i n  the same v e i n , o c c u r r i n g as i r r e g u l a r g r a i n s t h a t had rimmed and  r e p l a c e d by l a t e r c h a l c o p y r i t e . M a t e r i a l  t h i s v e i n was  is  been  from  found t o be s i m i l a r t o the easternmost of  the  103  F i g u r e 3.5.9: P o l i s h e d s e c t i o n of t y p i c a l Number f i v e v e i n m a t e r i a l , showing inward growth of s p h a l e r i t e ( s i ) , c h a l c o p y r i t e ( c p y ) , and q u a r t z - s u l f o s a l t (qz, s s ) e p i s o d e s . From sample s i t e 1CHN89-117 (Appendix A ) .  104  F i g u r e 3.5.10: I n t e r g r o w n g a l e n a (gn) and m a t i l d i t e (md) e x s o l v e d from P b - B i s o l i d s o l u t i o n . From sample s i t e 3CHN897OB, P o r t a l v e i n s (Appendix A ) .  F i g u r e 3.5.11: B a c k s c a t t e r e d e l e c t r o n photomicrograph of b e r r y i t e (ber) l a t h s i n g u s t a v i t e (gs) m a t r i x , w i t h galena (gn) r e p l a c i n g both phases along cleavage d i r e c t i o n s . From sample s i t e 2CHN89-11 (Appendix A) on " P o r t a l 10.5 v e i n " .  106  r 2 0 .0 0 V  l=M3  2 0 .0 k U  7 .7 6 n H  Figure 3.5.12: Backscattered electron photomicrograph of zoning i n Portal vein Three carbonate. Variations are due to changing Fe content, with brightest zones representing highest Fe content. From sample s i t e 2CHN89-4 (Appendix A).  107  F i g u r e 3.5.13: L a t e s t a g e (Stage IV) pyrobitumen i n f i l l i n g vugs i n P o r t a l v e i n Three. From sample 2CHN89-4 (Appendix A ) .  (pybit) site  108  Camp v e i n s examined, and a p o s s i b l e connection between t h e two  veins The  i s suggested. t h i r d s t y l e of m i n e r a l i z a t i o n within the P o r t a l  system i s e x e m p l i f i e d  by v e i n s  i n t h e westernmost  portions  of t h e system. M i n e r a l i z a t i o n from t h e P o r t a l One and P o r t a l Two v e i n s  i s dominated by t h e presence o f a  coarse-grained  ( g r a i n s up t o 1 cm. i n diameter) s p h a l e r i t e l a y e r i n t h e hangingwall o f t h e v e i n , f o l l o w e d  by massive manganoan  carbonate m i n e r a l i z a t i o n , and f i n a l l y by v o l u m e t r i c a l l y minor c h a l c o p y r i t e , p y r i t e , q u a r t z ,  and s u l f o s a l t s . The  arrangement o f m i n e r a l o g i e s w i t h i n these two v e i n s  suggests  t h a t they a r e r e l a t e d t o t h e f i r s t s t y l e observed w i t h i n t h e P o r t a l system, w i t h t h e dominant phases being t h e e a r l i e r s p h a l e r i t e and carbonate r a t h e r than t h e l a t e r  Cu-rich  phases observed i n t h e P o r t a l Three v e i n . B a r i t e and arsenopyrite  a l s o p r e s e n t i n t h e assemblage, s u g g e s t i n g a  p o s s i b l e r e l a t i o n s h i p w i t h t h e Camp v e i n s . The  f i n a l c l a s s o f P o r t a l v e i n s c o n s i s t s o f those t h a t  do not f i t i n t o o t h e r w e l l - d e f i n e d  categories,  specifically  the P o r t a l Four and F i v e v e i n s . The P o r t a l Four v e i n i s a b r e c c i a zone w i t h i n f i l l i n g by massive quartz and galena ( F i g u r e 3.5.14).  Carbonate and c h a l c o p y r i t e a r e p r e s e n t i n  v e r y minor q u a n t i t i e s i n t h i s v e i n . The P o r t a l F i v e v e i n i s dominated by coarse g r a i n e d  s p h a l e r i t e and q u a r t z ,  with  a c c e s s o r y amounts o f p y r i t e , m a r c a s i t e , and a r s e n o p y r i t e . I n both v e i n s , a minor f r a c t u r e i n f i l l i n g quartz episode i s present.  109  3.5.4  Cole  Lake  Veins  The C o l e Lake system o f v e i n s covers a s p a t i a l l y broader r e g i o n than o t h e r l o c a l v e i n systems d i s c u s s e d here. M i n e r a l o g y i s h i g h l y v a r i a b l e both between a d j a c e n t v e i n s and over t h e e n t i r e v e i n system. The Cole v e i n - C o l e shear v e i n has t h e b e s t exposure,  and t h e l o n g e s t d e f i n e d s t r i k e  l e n g t h o f a l l t h e Cole Lake v e i n s . M a t e r i a l exposed i n trenches b o r d e r i n g Cole Lake ( F i g u r e 2.3.1), i s m a i n l y c o a r s e - g r a i n e d , euhedral galena and s p h a l e r i t e i n a m a t r i x of  massive t o l a y e r e d manganoan carbonate, q u a r t z , and  b l a d e d b a r i t e . R e p e t i t i v e l a y e r i n g i s w e l l developed i n s e v e r a l l o c a t i o n s o f the v e i n , w i t h s e v e r a l episodes o f a l t e r n a t i v e s u l f i d e and quartz m a t e r i a l r e c o v e r e d from d r i l l  ( F i g u r e 3.5.15). Cole v e i n h o l e NGF8 (Map 1) t o the n o r t h  of  t h e main area o f t r e n c h i n g d i s p l a y s a mineralogy  to  some o f t h e Camp v e i n s , i n c l u d i n g the presence o f  similar  a r s e n o p y r i t e and p y r i t e t h a t has r e p l a c e d and e n c r u s t e d a p r e - e x i s t i n g bladed phase, p o s s i b l y hematite  (Figure  3.5.16). In t h i s s e c t i o n o f t h e v e i n , b a r i t e i s l e s s abundant than i n the c e n t r a l s e c t i o n , w i t h galena, f r e i b e r g i t e , and r a r e c h a l c o p y r i t e forming t h e l a t e r assemblage. The segment of v e i n known as t h e Cole  sulfide  shear  o c c u r s south o f t h e main area o f t r e n c h i n g , and d i s p l a y s a more complex m i n e r a l assemblage than elsewhere.  The Cole  shear v e i n l o s e s i t s w e l l - d e f i n e d nature a t depth, however, forming a s e r i e s o f m i n e r a l i z e d s t r i n g e r s where i n t e r s e c t e d in  drill  h o l e . Layered carbonate  forms l e s s than 30% o f t h e  110  F i g u r e 3.5.14: C r o s s - s e c t i o n a l  s l a b o f P o r t a l v e i n Four, s h o w i n g " b r e c c i a " n a t u r e o f m i n e r a l i z a t i o n . From sample s i t e 2CHN90-8 ( A p p e n d i x A ) .  Ill  F i g u r e 3.5.15: Well l a y e r e d carbonate ( c b ) , s p h a l e r i t e ( s i ) , and galena (gn) m i n e r a l i z a t i o n from the c e n t r a l Cole v e i n , sample s i t e 1CHN89-12 (Appendix A ) .  112  F i g u r e 3.5.16: C r u s t i f o r m g r o w t h o f a r s e n o p y r i t e ( a s p y ) o v e r a p r e - e x i s t i n g b l a d e d p h a s e t h a t has b e e n r e p l a c e d b y a s p y , p y r i t e ( p y ) , a n d g a l e n a ( g n ) . From s a m p l e s i t e 3CHN89-66 o n northern Cole vein.  113  v e i n volume, w i t h f i n e - g r a i n e d intergrown s p h a l e r i t e and carbonate c o m p r i s i n g up t o 20% o f t h e d r i l l  intersections  s t u d i e d . As w i t h most v e i n s a t Owen Lake, p y r i t e and quartz mark the i n i t i a t i o n o f v e i n m i n e r a l i z a t i o n , w i t h a second p e r i o d o f p y r i t e d e p o s i t i o n t h a t post-dates  sphalerite  empalcement. L a t e m i n e r a l s a r e g e n e r a l l y dominated by galena and l e s s e r t e t r a h e d r i t e ; s e l i g m a n n i t e / b o u r n o n i t e i s a l s o present as minute vermiform The Copper v e i n  i n c l u s i o n s w i t h i n t h e galena.  (Figure 2.3.1) i s much l e s s  important  than the C o l e v e i n , both i n e x t e n t and from an economic s t a n d p o i n t . The mineralogy, than t h a t observed  however, i s much more complex  i n the Cole v e i n system. As w i t h the Cole  v e i n , p y r i t e and/or m a r c a s i t e w i t h q u a r t z form t h e i n i t i a l stage o f m i n e r a l i z a t i o n system) i n m a t e r i a l hematite  (the "Stage I" o f t h e Number Three  from the s u r f a c e  intergrown w i t h magnetite  and a t depth.  Specular  i s a l s o p r e s e n t near the  footwall of the v e i n , i n a s s o c i a t i o n with euhedral p y r i t e and f i n e - g r a i n e d carbonate. Massive t o c o a r s e - g r a i n e d euhedral s p h a l e r i t e , and manganoan carbonate,  form the  "Stage I I " assemblage w i t h i n the a v a i l a b l e d r i l l i n t e r s e c t i o n f o r t h e Copper v e i n . The l a t e r  hole  sulfide  assemblage i s much more complex, dominated by massive c h a l c o p y r i t e t h a t has been c u t by l a t e r t e t r a h e d r i t e v e i n l e t s . Galena and a i k i n i t e occur as s y m p l e c t i c intergrowths  ( F i g u r e 3.5.17), w i t h l e s s e r amounts o f  e l e c t r u m and m a t i l d i t e ( F i g u r e 3.5.18) a l s o p r e s e n t (as i r r e g u l a r grains to f i f t y  m i c r o n s ) . I n d i v i d u a l masses o f  114  g a l e n a - a i k i n i t e are up t o 0.5 mm.  across, with smaller  masses t h a t have rimmed o r r e p l a c e d p y r i t e a l o n g cleavage directions  ( F i g u r e 3.5.19). Galena and a i k i n i t e a l s o occur  as myrmekitic  i n t e r g r o w t h s w i t h t e t r a h e d r i t e , although  these  are r a r e . The m i n e r a l o g i e s of the c e n t r a l v e i n s o f the C o l e Lake system ( B a r i t e , NG6,  and Lead) are g e n e r a l l y q u i t e s i m i l a r ,  dominated by an i n t e r m e d i a t e stage  ("Stage I I " ) c o n s i s t i n g  of coarse g r a i n e d , euhedral s p h a l e r i t e and l e s s e r galena i n a m a t r i x of b l a d e d b a r i t e , carbonate, and q u a r t z . F i n e g r a i n e d , o f t e n e u h e d r a l p y r i t e , a r s e n o p y r i t e , and form the e a r l i e s t m i n e r a l i z a t i o n , w i t h galena t e t r a h e d r i t e dominating  quartz  and  "Stage I I I " . Some t e t r a h e d r i t e rims  galena g r a i n s , w i t h p e a r c i t e , s e l i g m a n n i t e / b o u r n o n i t e ,  and  an u n i d e n t i f i e d s u l f o s a l t as vermiform i n c l u s i o n s i n both t e t r a h e d r i t e and galena  ( e s p e c i a l l y w i t h i n the Lead v e i n ) .  The Bear v e i n i s the westernmost major v e i n of the Cole Lake system, w i t h s p e c u l a r hematite and r a r e intergrown magnetite, - forming up t o 50% of the v e i n assemblage. E a r l i e r bladed b a r i t e and anhedral quartz and l a t e r p y r i t e / m a r c a s i t e form most of the remaining v e i n m a t e r i a l , w i t h minor amounts of s p h a l e r i t e and galena as the l a t e s t phases d e p o s i t e d . T e t r a h e d r i t e , carbonate, and p e a r c i t e a l l occur i n t r a c e amounts w i t h g a l e n a .  115  F i g u r e 3.5.17: B a c k s c a t t e r e d e l e c t r o n photomicrograph o f s y m p l e c t i c i n t e r g r o w t h s of galena (gn) and a i k i n i t e ( a i k ) i n t e r s t i t i a l t o hematite-magnetite (he-mt). From sample s i t e 3CHN89-79 (Appendix A ) , Copper v e i n .  116  F i g u r e 3.5.18: I n c l u s i o n o f i n t e r g r o w n galena ( g n ) , m a t i l d i t e (md), and e l e c t r u m ( e l ) i n p y r i t e ( p y ) . From sample s i t e 3CHN89-79 (Appendix A ) , Copper v e i n .  F i g u r e 3.5.19: I n t e r g r o w n g a l e n a (gn) and m a t i l d i t e (md) along margin of p y r i t e g r a i n ( p y ) , i n matrix of c h a l c o p y r i t e ( c p y ) . From sample s i t e 3CHN89-79 (Appendix A ) , Copper v e i n .  117  3.5.5  George Drill  Lake  Veins  i n t e r s e c t i o n s o f v e i n s w i t h i n the George Lake  lineament show t h a t the George Lake "vein" t o be a s e r i e s o f smaller en-echelon-like  veins  i n a shear zone up t o 30  meters wide. The s e v e r a l s i t e s s t u d i e d along the George Lake structure  (Figure 2.3.1) have  m i n e r a l o g i e s s i m i l a r t o those  i n the Number Three v e i n . C o a r s e - g r a i n e d p y r i t e and q u a r t z are the i n i t i a l stage o f m i n e r a l i z a t i o n i n t h e v e i n , w i t h l o c a l l y abundant s p e c u l a r  hematite i n the n o r t h and b a r i t e  p r e s e n t throughout. Hematite g r a i n s commonly a r e surrounded by massive p y r i t e and subsequently r e p l a c e d by carbonate, w i t h o n l y l o c a l r e l i c t s o f hematite. In the southern segment, t h e mineralogy i s r e l a t i v e l y simple, c o n s i s t i n g o f "Stage I I " s p h a l e r i t e and up t o 10% complexly intergrown t e t r a h e d r i t e , galena, and c h a l c o p y r i t e have i n f i l l e d  ("Stage I I I " )  that  f r a c t u r e d and b r e c c i a t e d p y r i t e and q u a r t z .  In t h e c e n t r a l and north p a r t s o f the v e i n , q u a r t z and carbonate a r e i n c r e a s i n g l y abundant, w i t h quartz  deposition  e x t e n d i n g over a r e l a t i v e l y long p e r i o d . V e i n m a t e r i a l the B u l k l e y c r o s s c u t  i n t e r s e c t i o n o f the v e i n  from  ( F i g u r e 2.3.1)  d i s p l a y s massive, f i n e - g r a i n e d , white quartz t h a t has infilled  open spaces i n b r e c c i a t e d  m i n e r a l i z a t i o n and a p p a r e n t l y  "Stage I" and "Stage I I "  spans the e n t i r e "Stage I I I "  i n f l u x . Carbonate i s l a t e p a r a g e n e t i c a l l y , occupying a temporally  short period during the l a t t e r h a l f of the  aformentioned quartz m i n e r a l i z a t i o n . In t h e n o r t h p a r t o f the v e i n , c h a l c o p y r i t e a l s o becomes i n c r e a s i n g l y important  118  i n the l a t e s u l f i d e mineralogy.  assemblage,  forming up to 5% of the  Galena, t e t r a h e d r i t e ,  unidentified sulfosalt l a r g e r masses of  (possibly  chalcopyrite.  pearceite, berryite)  and an  occur w i t h i n  vein  F i g u r e 3 . 5 . 2 0 : I n t e r g r o w n p e a r c e i t e (pc) and e l e c t r u m ( e l ) i n c a r b o n a t e v e i n l e t c u t t i n g c h a l c o p y r i t e ( c p y ) . From sample s i t e 2CHN89-48, " J a x e l " v e i n .  120  COMPOSITIONAL V A R I A T I O N IN  4.0  4.1  Introduction Mineral  and  zoning  Objectives  can be i d e n t i f i e d  o r absence o f i n d i v i d u a l s p e c i e s 1982), (2) s y s t e m a t i c  (eg. Barton and  through (1) presence  (eg. Susak and  Crerar,  v a r i a t i o n s i n the abundance of a  p a r t i c u l a r s p e c i e s , and i n d i v i d u a l mineral  SULFIDES  (3) c o m p o s i t i o n a l  variations in  s p e c i e s c h a r a c t e r i z e d by s o l i d s o l u t i o n  S k i n n e r , 1979). T e x t u r a l v a r i a t i o n ,  e s p e c i a l l y predominant, a l s o c o n t r i b u t e s t o the p a t t e r n mineral  zonation.  These v a r i o u s  aspects of m i n e r a l  provide  important i n s i g h t i n t o the changing nature of  of  zonation the  hydrothermal system. R e f l e c t e d and cross-sections  transmitted  l i g h t microscopy of v e i n  from the Number Three and. s u b s i d i a r y  s t r u c t u r e s r e v e a l the general  nature of  mineralogical  v a r i a t i o n , b o t h l o c a l l y and over the l e n g t h and breadth of the e n t i r e zone. S.E.M. a n a l y s i s i n d i c a t e s t h a t  three  mineral  carbonates)  groups ( t e t r a h e d r i t e s , s p h a l e r i t e s , and  d i s p l a y a l a r g e degree of chemical v a r i a b i l i t y across and  from sample s i t e t o sample s i t e . T e t r a h e d r i t e s  grains  and  s p h a l e r i t e s were chosen f o r d e t a i l e d q u a n t i t a t i v e a n a l y s i s due  t o the l a r g e number of t r a c e elements t h a t can  incorporated 1986;  into t h e i r structures  Fryklund  and  F l e t c h e r , 1956)  (eg. Johnson et  be al.,  and because they are  w i d e l y d i s t r i b u t e d throughout the Number Three s t r u c t u r e .  121  In a d d i t i o n t o p r o v i d i n g  i n s i g h t s i n t o the b e h a v i o r of  t r a c e elements i n t e t r a h e d r i t e s and  sphalerites,  d i s t r i b u t i o n of the component metal s p e c i e s information and  regarding  also provides  the e v o l u t i o n of Stage I I  Stage I I I ( t e t r a h e d r i t e ) m i n e r a l i z a t i o n s .  tetrahedrites  the  i n o t h e r hydrothermal d e p o s i t s  (sphalerite)  S t u d i e s of have r e v e a l e d  c o r r e l a t i o n between d i s t a n c e  from f l u i d source and  major  element (As, Sb,  and  and  P e t e r s e n , 1977; al.,  Ag,  Cu,  Zn,  Hackbarth and  Fe)  c o n t e n t s (Wu  Petersen, 1984;  P e t e r s e n et  1990). Moreover, chemical v a r i a t i o n i n s i n g l e  t e t r a h e d r i t e c r y s t a l s c o u l d o u t l i n e the c o n d i t i o n s during  deposition  (Johnson and  Jeanloz,  1983;  present  Hackbarth  and  Petersen, 1984). A s i m i l a r s i t u a t i o n e x i s t s f o r s p h a l e r i t e , with i r o n contents providing the presence of p y r r h o t i t e  a p o t e n t i a l geothermometer i n  (Barton and  Skinner, 1979). At  S i l v e r Queen, however, analyses of s p h a l e r i t e s were undertaken p a r t l y t o a s c e r t a i n the locus of the metals Ga, Ge  and  Ge,  and  In. Anomalous (up t o 2000 ppm)  In were d e t e c t e d d u r i n g  of core and  F r y k l u n d and  l e v e l s of  e a r l i e r geochemical  underground samples; s p h a l e r i t e was  t o be most l i k e l y  unusual  analysis  considered  host f o r the metals (eg. B e r n s t e i n ,  Fletcher,  1956). Thus, s e v e r a l  sphalerite  g r a i n s were a n a l y z e d t o examine p o s s i b l e d i s t r i b u t i o n patterns  f o r Ga,  Ge,  and  In.  1985;  a  122  4 .2  S a m p l i n g T e c h n i qiies  The  c o n t i n u i t y and  a v a i l a b i l i t y of i n t e r s e c t i o n s on  the  Number Three v e i n made the s t r u c t u r e the best c h o i c e f o r evaluating  changes i n t e t r a h e d r i t e and  sphalerite  c o m p o s i t i o n s . R e p r e s e n t a t i v e t e t r a h e d r i t e samples were chosen from a s e r i e s of v e r t i c a l s e c t i o n s , produce an adequate r e p r e s e n t a t i o n  i n order to  of the e n t i r e v e i n .  Twenty-one s i t e s on the Number Three v e i n and  3 from the  NG3  v e i n were sampled f o r t e t r a h e d r i t e s , w i t h 10 of these s i t e s a l s o e v a l u a t e d f o r s p h a l e r i t e compositions and s u l f o s a l t compositions. T e t r a h e d r i t e s C o l e , Chisholm, and  George Lake systems were a l s o a n a l y z e d  E l e c t r u m from f o u r v e i n s ,  4_J  also  for  from the Camp, P o r t a l ,  i n o r d e r t o p r o v i d e a more complete r e g i o n a l  was  several  picture.  i n c l u d i n g the Number Three v e i n ,  sampled.  Analytical  MethoHol oqy  Samples t h a t were chosen f o r microbeam a n a l y s i s were made i n t o p o l i s h e d t h i n s e c t i o n s  and  immediately c o a t e d  a n a l y z e d i n o r d e r t o minimize e r r o r due polished  s u r f a c e . An  t o o x i d a t i o n of  i n i t i a l S.E.M. study was  p a r t i c u l a r t e t r a h e d r i t e , s p h a l e r i t e , and  and the  undertaken of  s u l f o s a l t grains  to  a s c e r t a i n those elements f o r which some v a r i a b i l i t y might  be  expected. The  samples were then t r a n s f e r e d t o the  microprobe f o r q u a n t i t a t i v e c o m p o s i t i o n a l Tetrahedrite s  Ka/  Z n  Ka/  Fe  Ka#  a beam c u r r e n t  s b  electron  analysis.  g r a i n s were analyzed u s i n g the C u £ , A g L , a  La/  A s  Ka/  of 10 nA,  pb  Ma/ 9Ma H  a  n  d  B i  Ma  a  peaks, a t  an a c c e l e r a t i n g v o l t a g e  of 20  kV,  123  and a spot s i z e of one micron. T e t r a h e d r i t e g r a i n were used  standards  f o r c a l i b r a t i n g Cu, As, Zn, S, and Sb, galena f o r  Pb, HgTe f o r Hg, t r o i l i t e f o r Fe, and pure metal forms f o r Ag and B i . Zonation w i t h i n t h e i n d i v i d u a l g r a i n s was determined  through  photomicrographs,  (1) b a c k s c a t t e r e d e l e c t r o n and (2) t e t r a h e d r i t e  t r a v e r s e l i n e s from core t o r i m .  "stratigraphy", along  Repeat analyses were done  on some o f t h e l a r g e r zones i n o r d e r t o determine r e p r o d u c i b i l i t y . The r o u t i n e f o r s u l f o s a l t analyses i s s i m i l a r t o t h a t f o r t e t r a h e d r i t e , w i t h the A S L Q peak used i n s t e a d o f ASJ^Q, i n order t o a v o i d a Pb-As i n t e r f e r e n c e problem. F o r s u l f o s a l t s o n l y spot analyses were done f o r i d e n t i f i c a t i o n purposes;  no c o m p o s i t i o n a l z o n a t i o n was  noted. S p h a l e r i t e was not analyzed as e x t e n s i v e l y as t e t r a h e d r i t e , but samples were examined from s e v e r a l s i t e s on t h e Number Three v e i n . Peaks f o r Z n j , SR , Fe^a, M n £ , a  C^La,  Hc  JMa/ ^ Kai a  GeRa/ and I n L  a  a  a  were e v a l u a t e d a t a beam  c u r r e n t o f 30 nA, a c c e l e r a t i n g v o l t a g e o f 20 kV, and a spot s i z e o f f i v e microns. S p h a l e r i t e g r a i n standards were used f o r c a l i b r a t i n g Zn, Fe, and S, GaAs f o r Ga, HgTe f o r Hg, and pure metal  forms f o r the remaining elements.  T r a v e r s e s were  done from c o r e t o r i m (where i d e n t i f i a b l e ) o r across t h e g r a i n i n most cases. As w i t h t h e t e t r a h e d r i t e s , some s i t e s were r e p e a t e d f o r r e p r o d u c i b i l i t y , o r t o o b t a i n a b e t t e r total.  124  E l e c t r u m g r a i n s were e v a l u a t e d and  Hg^a  f o r C u £ , AuR , A g L a  peaks, a t a beam c u r r e n t of 10 nA,  voltage  of 20 kV,  and  a  an  accelerating  a spot s i z e of f i v e microns. Standards  used f o r the c a l i b r a t i o n were pure metals f o r Au, Cu,  4.4  4.4.1  and HgTe f o r  Tpt.rahpdrit.s  a /  Ag,  and  Hg.  Zonat-.irm  Introduction Compositional v a r i a t i o n within s i n g l e t e t r a h e d r i t e  g r a i n s has  been documented from s e v e r a l l o c a l i t i e s worldwide  (Hackbarth and Hackbarth and  P e t e r s e n , 1984;  Johnson e t a l .  P e t e r s e n (1984) have e x p l a i n e d  f  1986).  the v a r i a t i o n  to be the r e s u l t of f r a c t i o n a l c r y s t a l l i z a t i o n , w i t h different depositional sites receiving fluids i n different stages of c o m p o s i t i o n a l  e v o l u t i o n . The  the S i l v e r Queen mine d i s p l a y u n u s u a l l y growth zoning w i t h i n i n d i v i d u a l g r a i n s t e t r a h e d r i t e s c o v e r a temporally  t e t r a h e d r i t e s from dramatic examples of ( F i g u r e 4.4.1).  The  broad p o r t i o n of Stage I I I  m i n e r a l i z a t i o n a t S i l v e r Queen ( F i g u r e 3.4.22), and  thus  p r o v i d e e x c e l l e n t documentation of the e v o l u t i o n of  the  hydrothermal system a t p a r t i c u l a r p o i n t s . On  a whole-vein  s c a l e , however, c h a r a c t e r i z a t i o n of the hydrothermal c e l l becomes i n c r e a s i n g l y d i f f i c u l t  due  t o the  zoned nature of  the i n d i v i d u a l g r a i n s . As a r e s u l t , l o n g i t u d i n a l s e c t i o n s the Number Three v e i n d e s c r i b i n g v a r i a t i o n s i n composition (Figures  4.4.6  t o 4.4.12) are based on average v a l u e s f o r  of  125  the  "cores" and "rims" o f each g r a i n . In c o n j u n c t i o n w i t h  the nature of s i n g l e g r a i n zonation, these  "element maps"  may a l l o w f o r b e t t e r a p p r a i s a l of c o n d i t i o n s d u r i n g Stage III mineralization. The composition generalized  o f t e t r a h e d r i t e , g i v e n by t h e  formula:  (Cu,Ag)6Cu4(Fe,Zn,Cu,Hg,Cd)2(Sb,As,Bi,Te)4(S,Se)!3 (Johnson et a l . , 1986) allows f o r widespread v a r i a t i o n i n the metal and semimetal contents between s p a t i a l l y d i s p a r a t e samples. Three atomic r a t i o s , however, a r e thermodynamically important al.,  (Sack et  1987): X  = Zn/(Zn+Fe)  1  X 2 = As/(As+Sb) X 3 = Ag/(Ag+Cu) The s i g n i f i c a n c e o f these three r a t i o s w i l l be d i s c u s s e d l a t e r . The u n u s u a l l y b i s m u t h - r i c h nature o f s e v e r a l t e t r a h e d r i t e - samples r e q u i r e s t h a t the weight percent bismuth be c o n s i d e r e d  (Figure 4.4.12) and t h e r e f o r e  a new atomic r a t i o i s d e f i n e d : X  4  =As/(As+Sb+Bi)  A n a l y t i c a l d a t a summaries f o r S i l v e r Queen t e t r a h e d r i t e g r a i n s a r e i n T a b l e s 4.4.1 t o 4.4.4.  4.4.2  Single  Grain  Zonation  in  Tetrahedrites  T e t r a h e d r i t e s i n the Number Three and NG3  veins  commonly d i s p l a y o s c i l l a t o r y zoning on b a c k s c a t t e r e d  126  e l e c t r o n photomicrographs  ( F i g u r e 4.4.1). In most c a s e s , the  d i f f e r e n c e s between i n d i v i d u a l zones r e p r e s e n t t h e c o u p l e d s u b s t i t u t i o n o f Sb f o r As and Ag f o r Cu; zones t h a t appear b r i g h t e r on b a c k s c a t t e r e d photos a r e more antimony- and silver-rich.  In t e t r a h e d r i t e s from sample s i t e s 2CHN89-27,  3CHN89-88, 3CHN89-3, 1CHN89-117, and 3CHN90-1 (Appendix A ) , the v a r i a t i o n i n zone b r i g h t n e s s i s a s s o c i a t e d w i t h i n c r e a s i n g B i contents  ( F i g u r e 4.4.2), however, t h i s  s i t u a t i o n i s r e l a t i v e l y uncommon (eg. Appendix C ) . T e t r a h e d r i t e s throughout  t h e Number Three system show a  g e n e r a l outward t r e n d from A s - r i c h cores t o S b - r i c h rims, w i t h i n d i v i d u a l zones l e s s than 5 microns  i n width. A  c o r r e s p o n d i n g i n c r e a s e i n t h e v a l u e o f X3 a l s o o c c u r s , w i t h the outermost  zones g e n e r a l l y v o l u m e t r i c a l l y l e s s  important  than zones near the c o r e (Tables 4.4.1 t o 4.4.4). Zoning o f X i r a t i o s i s r a r e , w i t h Zn/(Zn+Fe) t e n d i n g t o c o n c e n t r a t e around 0.9 and showing l i t t l e v a r i a t i o n . A n o t a b l e e x c e p t i o n i s sample 3CHN89-46 ( F i g u r e 4.4.3), where X^ d i s p l a y s an initial of  sharp drop b e f o r e g r a d u a l l y c l i m b i n g back t o a v a l u e  0.95. One should note, however, t h a t s p h a l e r i t e i s l e s s  abundant i n t h i s sample than i n any o t h e r on the. Number Three system ( F i g u r e 3.4.25), and both p y r i t e and t e t r a h e d r i t e a r e widespread  ( F i g u r e s 3.4.24 and 3.4.26).  Thus, l e s s Zn may have been a v a i l a b l e t o be p a r t i t i o n e d the  into  tetrahedrites. In g e n e r a l , no s y s t e m a t i c t r e n d from c o r e t o r i m was  noted f o r bismuth contents i n t e t r a h e d r i t e , a l t h o u g h i n two  127  F i g u r e 4.4.1 O s c i l l a t o r y zoned t e t r a h e d r i t e g r a i n from s a m p l e s i t e 2CHN89-19 ( A p p e n d i x A) o n t h e n o r t h e r n Number Three v e i n a t t h e i n t e r s e c t i o n o f t h e B u l k l e y c r o s s c u t and t h e South End d r i f t . I n c r e a s i n g b r i g h t n e s s c o r r e s p o n d s t o a d e c r e a s e i n t h e r a t i o As/(As+Sb+Bi) and an i n c r e a s e i n t h e r a t i o A g / ( A g + C u ) . S u r r o u n d i n g gangue i s m a n g a n o s i d e r i t e . S c a l e b a r on l o w e r l e f t o f p h o t o .  F i g u r e 4.4.2 T e t r a h e d r i t e from sample s i t e 3CHN90-1 (Appendix A) on deep n o r t h Number Three v e i n . S c a l e bar on lower l e f t c o r n e r o f photo. T a b l e 4.4.1 Element  Zonal a n a l y s i s o f t e t r a h e d r i t e 3CHN90-1 1  2  3  4  5  6  7  8  Cu S Zn Fe Sb As Pb Ag Bi Hg  42 .92 42.94 42.54 43.04 42. 33 43. 27 42.56 42. 96 28 .13 27.97 27.65 27.42 27. 39 27. 82 27.89 27. 85 7.96 8 .13 8.05 7.92 8.10 7.94 8.07 8.09 0 .61 0.62 0.58 0.61 0.52 0.60 0.61 0.60 0 .33 0.17 0.17 0.41 0.37 0.27 0.31 0.28 19 .17 18.77 18.02 18.37 17. 87 18. 98 18.70 18. 48 0 .00 0.00 0.09 0.00 0.00 0.00 0.00 0.00 0 .21 0.39 0.35 0.42 0.35 0.30 0.31 0.36 1.82 2 .64 0.62 2.18 1. 36 0 .22 1.45 2.83 0 .05 0.09 0.10 0.13 0.00 0.00 0.00 0.00  Total  99 .77 100.5 100.3 100.3 99. 42 99. 94 100.6 99. 85  •Values g i v e n a r e element weight percents * * S i t e numbers i n c r e a s e from core t o r i m  129  Table  4.4.1  (continued)  10  11  12  13  14  15  16  17  Cu S Zn Fe Sb As Pb Ag Bi Hg  42.21 41.99 42.82 41.93 43.00 42.70 42.74 42.19 42.51 27.56 27.46 27.92 27.41 28.21 27.70 28.11 27.55 27.63 8.00 8.05 8.02 7.95 8.03 8.14 8.00 8.02 8.23 0.55 0.59 0.56 0.59 0.59 0.60 0.58 0.56 0.61 0.40 0.40 0.36 0.32 0.11 0.23 0.20 0.23 0.17 18.14 18.51 18.37 17.82 19.20 18.75 19.33 18.53 18.91 0.00 0.00 0.00 0.00 0.00 0.10 0.09 0.00 0.00 0.40 0.38 0.35 0.40 0.25 0.43 6.40 0.26 0.23 3.00 2.47 1.76 3.08 0.43 1.70 1.13 2.28 1.28 0.00 0.13 0.21 0.00 0.00 0.00 0.00 0.04 0.06  Tot.  100.3 99.97  18  100.4 99.51 99.87 100.3 100.6 99.67 99.61  19  20  21  22  23  24  25  Cu S Zn Fe Sb As Pb Ag Bi Hg  42.94 43.32 42.46 42 .85 42.75 43.14 42 .01 42 .78 27.46 27.87 27.67 28 .01 27.60 27.77 27 .76 27 .99 7.92 8.10 8.18 7 .85 7.91 7 .91 7 .92 8.06 0.64 0.58 0.63 0 .66 0.60 0.70 0 .60 0 .71 0.32 0.17 0.28 0 .38 0.22 0 .49 0.43 0 .25 18.34 19.67 18.16 19 . 10 18.66 18.86 18 .07 18 .87 0.07 0.15 0.00 0 .00 0 .14 0.00 0.06 0 .12 0.38 0.33 0.46 0 .32 0.29 0 .30 0 .24 0.31 2.36 0.42 2.46 0 .44 2 .13 1.53 0.15 0 .34 0.07 0.00 0.00 0 .00 0 .04 0 .17 0.15 0.00  Total  100.4  100.7 100.3 99 .59 99.93 99.24 99 .45 99 .38  130  r 2 0 .OOP  2 0 .0 kU  F i g u r e 4 . 4 . 3 T e t r a h e d r i t e from sample s i t e 2CHN89-46 (Appendix A) on s o u t h - c e n t r a l Number Three v e i n . S c a l e b a r on lower l e f t c o r n e r o f photo. T a b l e 4.4.2 1  Cu s  Zn Fe Sb As Pb Ag Bi Hg  43.51 28.11 8.43 0.32 0.11 19.62 0.00 0.07 0.00 0.00  Z o n a l A n a l y s i s o f t e t r a h e d r i t e 2CHN89-46 2  3  4  41.31 42 .78 40. 65 27.18 28 .26 26. 68 8.10 6 .35 7. 28 1 .95 0.35 0. 89 10.28 0 .75 13. 12 13.24 19 .06 10. 69 0.00 0 .56 0. 00 0 .10 0.23 0. 37 0.00 0 .05 0. 00 0.00 0 .05 0. 07  5  6  7  8  9  41 .57 40.95 42 .38 42.71 42 .06 26 .85 26.50 27 .33 28.04 27 .71 7 .72 7 .30 7.54 7 .50 7.59 1 .07 0.94 0 .82 0 .89 0.65 5 .53 2.60 3 .25 10 .42 15.49 12 .49 9.37 15 .35 17.55 17 .25 0 .41 0 .05 0.00 0 .12 0.59 0 .19 0.20 0 .14 0 .00 0.08 0 .00 0 .00 0 .00 0.07 0.05 0 .00 0 .00 0.00 0 .00 0.00  Tot. 100.2 100.7 99 .91 99. 77 99 .75 100.8 99 .42 100.2 99 .20  131  Figure 4.4.4 T e t r a h e d r i t e from sample s i t e bar on l o w e r l e f t c o r n e r o f photo. T a b l e 4 .4.3  3CHN89-5.  Zonal A n a l y s i s o f t e t r a h e d r i t e 1  2  3  4  5  3CHN89-5 6  Cu  4 1 . 6 8  39.02  4 1 . 1 5  4 1 . 5 0  4 1 . 6 5  39.83  s  2 7 . 5 5  2 5 . 8 7  2 7 . 5 4  2 7 . 6 3  2 7 . 8 2  26.66 7.95  Zn Fe Sb As Pb Ag Bi Hg Total  8.01  7.86  7.94  7.95  8.06  0.61  0.33  0.40  0.53  1.37  0.65  6.12  2 1 . 1 6  10.68  5.98  3.21  14.98  15.82  5.45  12.84  15.78  17.33  9.36  0.00  0.00  0.00  0.00  0.11  0.00  0.13  0.33  0.07  0.11  0.00  0.17  0.00  0.18  0.15  0.08  0.17  0.12  0.06  0.00  0.00  0.15  0.00  0.00  100.0  100.2  100.8  9 9 . 7 1  99.72  9 9 . 7 1  Scale  LO LO  CO 4*.  0  meters 200  FIGURE 4.4.11  CONTOUR PLOT OFAal(Aa+Sb+Bd TETRAHEDRITE QRAIN'RIMS NUMBER THREE VEIN LONGITUDINAL SECTION  meters 200  139  samples, the most B i - r i c h zones o c c u r r e d over a s m a l l time p e r i o d r e l a t i v e t o the t e t r a h e d r i t e m i n e r a l i z i n g event ( F i g u r e 4.4.5). Samples were a l s o a n a l y z e d f o r Pb and w i t h both elements commonly below d e t e c t i o n l i m i t s ,  Hg,  and,  where d e t e c t e d , showing no evidence of c o m p o s i t i o n a l t r e n d s (Tables 4.4.1  t o 4.4.4; Appendix C ) .  A problem which may  a r i s e from a zone-by-zone  analysis  of t e t r a h e d r i t e g r a i n s i s the p o s s i b i l i t y t h a t a d j a c e n t zones may r e s u l t may  be e x c i t e d by the beam d u r i n g a n a l y s i s and as a g i v e a "bulk" a n a l y s i s from s e v e r a l zones r a t h e r  than f o r t h e o r i g i n a l t a r g e t . Such a problem would not be d e t e c t a b l e i n the weight p e r c e n t t o t a l s due t o the c o m p o s i t i o n a l s i m i l a r i t i e s between the juxtaposed zones, and n e c e s s i t a t e s c l o s e comparison o f Sb, As, and B i weight p e r c e n t s w i t h the d e f i n e d zones i n the photomicrographs. "Fuzzy" demarcations between zones, and anomalously h i g h Zn, Fe, and Pb v a l u e s were a l s o found t o be i n d i c a t i v e of " a n a l y t i c a l " i n t e r f e r e n c e from a d j a c e n t zones o r phases.  4.4.3  Deposit-scale  Variations  in Tetrahedrite  Composition  In o r d e r t o e v a l u a t e l a r g e s c a l e t e t r a h e d r i t e c o m p o s i t i o n a l v a r i a t i o n , v a r i o u s atomic r a t i o s were p l o t t e d on l o n g i t u d i n a l s e c t i o n s d e s c r i b i n g the d i s t r i b u t i o n of t e t r a h e d r i t e c o r e and r i m c o m p o s i t i o n s . Four r a t i o s were found t o be u s e f u l f o r t h i s purpose:  Zn/(Zn+Fe),  As/(As+Sb+Bi),  Ag/(Ag+Cu), and weight percent bismuth  ( F i g u r e s 4.4.6  t o 4.4.12). Average g r a i n compositions were  140  found t o be u n r e p r e s e n t a t i v e due t o an i n a b i l i t y t o determine a p p r o p r i a t e three-dimensional w e i g h t i n g t o the i n d i v i d u a l c o m p o s i t i o n a l zones. An attempt was "marker elements" ( B i , Fe, Hg, deposit-wide  and Pb)  made a t u s i n g  f o r developing a  t e t r a h e d r i t e " s t r a t i g r a p h y " . T h i s , however,  found t o be i m p o s s i b l e due t o the s p o r a d i c occurrence bismuthian  was  of  t e t r a h e d r i t e s , which p r o v i d e d the b e s t  opportunity to correlate a p a r t i c u l a r mineralizing i n t e r v a l . Twenty-three t e t r a h e d r i t e s i t e s on the Number Three and  NG3  v e i n s were a n a l y z e d and r e s u l t s are shown on manually contoured  diagrams. The Zn/(Zn+Fe) r a t i o  l e a s t amount of v a r i a t i o n of the p l o t s  (Xi) d i s p l a y e d the  ( F i g u r e s 4.4.6  and  4.4.7) f o r both c o r e s and rims. T e t r a h e d r i t e s w i t h i n the Number Three v e i n have Zn/(Zn+Fe) r a t i o s mostly t o 0.95  i n the  0.90  range, w i t h the notable e x c e p t i o n o c c u r r i n g i n the  northernmost i n t e r s e c t i o n s of the v e i n . Samples from t h i s p o r t i o n c o n t a i n e d X^ v a l u e s as low as 0.64  and  a s s o c i a t e d m i n e r a l o g i c a l l y w i t h coarse g r a i n e d ,  are euhedral  s p h a l e r i t e and c h a l c o p y r i t e . The occurrence of the most i r o n - e n r i c h e d s p h a l e r i t e s w i t h t h i s p a r t i c u l a r , zone i s a l s o noteworthy and w i l l be d i s c u s s e d l a t e r . A second, l e s s prominent zone of low Zn/(Zn+Fe) t e t r a h e d r i t e s occurs around sample s i t e s 3CHN89-24 and 3CHN89-44 (Appendix A) i n the southern p o r t i o n of the v e i n and i s d e f i n e d by both core r i m a n a l y s e s . Samples from the two NG3  and  sites containing  abundant t e t r a h e d r i t e a l s o showed r e l a t i v e l y low Zn/(Zn+Fe) ratios.  141  The Ag/(Ag+Cu) (X3)  and As/(As+Sb+Bi) (X4)  r a t i o s are  known to d i s p l a y s t r o n g p o s i t i v e c o r r e l a t i o n i n many n a t u r a l systems (eg. Wu 1984)  and  Petersen,1977; Hackbarth and  Petersen,  and data c o l l e c t e d from the Number Three system  support t h i s o b s e r v a t i o n values  are h i g h e s t  v e i n , and  ( F i g u r e 4.4.13). In g e n e r a l ,  a t the northernmost sample s i t e s on  i n a region centered  i n the south end.  silver  Tetrahedrites  on the d e c l i n e i n t e r s e c t i o n from the l a t t e r p o r t i o n of  the v e i n are c l o s e l y a s s o c i a t e d w i t h cosanguineous i n p o l i s h e d s e c t i o n and  the  r e l a t i v e l y h i g h g o l d and  aikinite  silver  grades (Nowak, 1991). A second r e g i o n of anomalously Ag/(Ag+Cu) t e t r a h e d r i t e s occurs i n the deeper n o r t h  low portion  of the v e i n , where t e t r a h e d r i t e i s a s s o c i a t e d w i t h galena and b e r r y i t e ( F i g u r e 3.4.26) and p r e c i o u s metal grades are moderate. An occurrence of f r e i b e r g i t e , a s s o c i a t e d p o l y b a s i t e and  pyrargyrite, within material  with  from sample  3CHN89-24 i s the o n l y known occurrence of t h i s t h r e e phase assemblage i n the Number Three v e i n . D e f i n i t i o n o f  the  anomalous zones i s r e f l e c t e d i n the As/(As+Sb+Bi) diagrams (Figures 4.4.10 and  4.4.11), w i t h the most S b - r i c h  t e t r a h e d r i t e s o c c u r r i n g w i t h i n the northernmost  and  t o p o g r a p h i c a l l y h i g h e s t p o r t i o n of the v e i n .  4.4.4  Tetrahedrites  from Other  Veins  A number of o t h e r s m a l l e r v e i n s a t the S i l v e r Queen p r o p e r t y were a l s o sampled f o r t e t r a h e d r i t e s i n o r d e r compare the c o m p o s i t i o n a l  v a r i a t i o n s w i t h those of  the  to  142  Number Three system. T e t r a h e d r i t e s  from v e i n s  located  f u r t h e s t away from t h e Number Three v e i n , most n o t a b l y t h e Owl  and n o r t h Cole v e i n s , c o n t a i n e d  unzoned g r a i n s w i t h up  t o 18 weight p e r c e n t s i l v e r . In t h e Owl v e i n , occurs i n masses up t o 3 mm. across  tetrahedrite  (Figure 3.5.7), and i s  a s s o c i a t e d w i t h p y r a r g y r i t e and p e a r c i t e . One s i t e on t h e George Lake v e i n was a l s o sampled (Appendix C), relatively  displaying  low s i l v e r and h i g h bismuth contents (up t o 0.22  weight p e r c e n t ) and an a s s o c i a t i o n w i t h an u n i d e n t i f i e d sulfosalt material and  ( b e r r y i t e ? ) t h a t bear a marked s i m i l a r i t y from sample s i t e 3CHN90-1 (Appendix A ) .  with  The P o r t a l  Camp v e i n systems were sampled i n s e v e r a l s i t e s ,  number o f t r a v e r s e s  across  were completed (eg. F i g u r e  w e l l zoned t e t r a h e d r i t e 4.4.2). Camp v e i n  d i s p l a y e d t h e most s p e c t a c u l a r  and a  grains  material  examples o f zoning, w i t h  i n d i v i d u a l tetrahedrites generally associated  with  p y r a r g y r i t e and p e a r c i t e g r a i n s as w e l l . P o r t a l v e i n material  ( i n c l u d i n g t h e Number F i v e vein) i s unusual due t o  the presence o f t h i n c o m p o s i t i o n a l  zones c o n t a i n i n g  e i g h t weight p e r c e n t bismuth ( F i g u r e 4.4.5). from t h e P o r t a l Three v e i n a r e e n r i c h e d  up t o  Tetrahedrites  i n s i l v e r and a r e  commonly found i n a s s o c i a t i o n w i t h s i l v e r b e a r i n g  phases  such as m a t i l d i t e .  4.4.5  Bismuthian The  Tetrahedrites-An  occurrence o f e l e v a t e d  t e t r a h e d r i t e has been r e p o r t e d  Unusual  Occurrence  bismuth contents i n o n l y r a r e l y (eg. Oen and  Figure 4.4.5:  Backscattered e l e c t r o n photomicrograph of z o n a t i o n i n B i - c o n t e n t s i n t e t r a h e d r i t e f r o m t h e Number F i v e v e i n (sample s i t e 1CHN89-117). B r i g h t e s t a r e a s c o r r e s p o n d t o highest Bi-contents.  144  Kleft,  1976,  Johnson et a l . , 1986)  and a p p a r e n t l y never  w i t h i n an e p i t h e r m a l v e i n system. Bismuth s u b s t i t u t e s i n the semimetal s i t e w i t h no apparent  c o r r e l a t i o n w i t h Sb o r As  contents  ( F i g u r e 4.4.14). A  (Johnson  et a l . , 1986)  c l u s t e r i n g o f data p o i n t s i n F i g u r e 4.4.15 suggests  the  p o s s i b i l i t y o f a moderate c o r r e l a t i o n between a r s e n i c and bismuth,  but i n g e n e r a l , bismuth data are w i d e l y s c a t t e r e d .  Data from S i l v e r Queen are d e r i v e d from t h r e e p r i n c i p a l s i t e s ; i n the deep North p o r t i o n of the Number Three v e i n , i n the NG3  v e i n a t sample s i t e 3CHN89-3, and i n the Number  F i v e v e i n ( F i g u r e 4.4.5). In a l l t h r e e l o c a l e s ,  the  bismuthian t e t r a h e d r i t e i s zoned and c o e x i s t s w i t h o t h e r bismuth-bearing  phases such as b e r r y i t e . Bismuth contents  are l o c a l l y up t o 10 weight p e r c e n t  ( F i g u r e 4.4.14) and  occur w i t h i n t e t r a h e d r i t e s t h a t are otherwise a r s e n i c endmembers and r e l a t i v e l y s i l v e r poor. cases  In the most extreme  (eg. sample s i t e 3CHN89-3; Appendix A ) , b i s m u t h i n i t e  has a p p a r e n t l y e x s o l v e d from the t e t r a h e d r i t e and forms a s i g n i f i c a n t p a r t of the Stage I I I assemblage ( F i g u r e 3.4.15). Other p a r t s of the Number Three system a l s o c o n t a i n bismuth-bearing  t e t r a h e d r i t e , although, w i t h a  few  e x c e p t i o n s , l e s s than one weight p e r c e n t i s p r e s e n t ( F i g u r e 4.4.12).  4.4.6  Discussion  The presence of growth-zoned t e t r a h e d r i t e s a t the S i l v e r Queen mine allows f o r b e t t e r understanding of l a t e  * * * * * 1.20  4.4.13  Ag/(Ag+Cu)  r  vs.  tl  CQ +  FIGURE  (ft*  0.80  (7)  +  in  <  \ 0 . 4 0 00  **  <  o.o  8<  '  00  '  I '  ' ''''I' ' 0.10  i  ii  i  Ii  i  i  0.20  g/(Ag+Cu  i  I ii ii  0.30  i  ii ii I 0.40  As/(As+Sb+Bi)  12.00 r  if)  * * * * * FIGURE 4.4.14 Bi Atoms vs'. Sb Atoms  8.00  £ o  <  _*  _Q  in  4.00  0.  m.  a»  I)  0.50  H-»A  r.00  t»i i i i I i i i i i i  II  i I i i i i if I l l  1.50  I L.I I  2.00  Bi Atoms  i  I  *l  I I I I  I  2.50  I I I I I I I I I  I  3.00  15.00 r * * * * *  FIGURE  4.4.15  Bi Atoms  00  vs. As Atoms  •* *  10.00  o  •4—'  <  \- *  (7)  ^  5.00  00  i i i I i i i i i i i i i I i i i i i i ii  0.50  1.00  i I i i i i i i i i i I i i i i i i i i i  1.50  2.00  Bi Atoms  I  i i i i i I i i i I  2.50  3.00  148  stage e v o l u t i o n o f hydrothermal f l u i d s w i t h i n the Number Three system and a s s o c i a t e d v e i n s Petersen,  (eg. Hackbarth and  1984). T e t r a h e d r i t e s show a wide v a r i a b i l i t y of  compositions throughout the v e i n and c o n t o u r i n g  o f important  metal and semimetal r a t i o s r e v e a l s s e v e r a l d i s t i n c t i v e tetrahedrite  " r e g i o n s " over t h e l e n g t h o f t h e v e i n  (Figures  4.4.6 t o 4.4.12). T e t r a h e d r i t e has been d e s c r i b e d by s e v e r a l authors (eg. S p r i n g e r ,  1969; Johnson and J e a n l o z ,  1983; Sack  and Loucks, 1985; O'Leary and Sack, 1987) as obeying the simple  stoichiometry:  {Cu,Ag)  T R G 6  [(Cu,Ag)2/3(Fe,Zn)  d e s c r i b e d by O ' l e a r y "corresponding  1 / 3  ]  T E T 6  (Sb,As,Bi)4 (S) 3 S M  1  and Sack (1987) as  t o an i d e a l s t r u c t u r e w i t h 208 valence  e l e c t r o n s p e r u n i t c e l l and f u l l occupancy o f the 6 t r i g o n a l planar  (TRG), 6 t e t r a h e d r a l (TET), and 4 semimetal (SM)  s i t e s i n t h e 1 3 - s u l f u r formula u n i t . " Pb, Mn, Au, Cd, and Hg have a l s o been i d e n t i f i e d as s u b s t i t u t i n g i n t h e t e t r a h e d r a l metal s i t e s , Te i n t o the semimetal s i t e , and Se i n t o the s u l f u r s i t e s al.,  (Johnson et  1986). In most n a t u r a l systems, however, the b i n a r y  s u b s t i t u t i o n s o f Fe f o r Zn, Ag f o r Cu, and As f o r Sb, are most p r e v a l e n t  (Johnson et al., 1986; C h a r l a t and Levy,  1974). In t h e case o f t h e Number Three v e i n , t h e s u b s t i t u t i o n o f B i f o r Sb and/or As i s a l s o (through m o d i f i c a t i o n o f the X  2  considered  r a t i o ) i n order t o  accomodate s i g n i f i c a n t B i l e v e l s . S e v e r a l authors have noted a s t r o n g p o s i t i v e c o r r e l a t i o n between Sb-As and Ag-Cu  149  substitutions  (eg. Wu  and  Petersen, 1977;  Johnson et a l . ,  1986), w i t h the most S b - r i c h compositions g e n e r a l l y , not n e c e s s a r i l y , a s s o c i a t e d ( M i l l e r and  Craig,  w i t h the h i g h e s t  and  Fe  with a resultant equivalent (Raabe and  ( P a t t r i c k and  and A s - e n r i c h e d  study, t h e r e f o r e ,  was  and  Petersen  found nearer  the goals of the S i l v e r Queen  t o examine the use  of  tetrahedrite sources of  fluids. Results  system and of Sb  o f t e t r a h e d r i t e analyses from the Number Three  associated  f o r As,  w i t h Ag  veins  support the c o u p l e d s u b s t i t u t i o n  f o r Cu  (Figure 4.4.13). The  majority  of t e t r a h e d r i t e specimens, however, do not d i s p l a y the and  S b - r i c h c o r e s noted f o r o t h e r d e p o s i t s  and  P e t e r s e n , 1984). I t may  mineralization was  in  Ag-rich  compositions i n u n d e r s t a n d i n g flow d i r e c t i o n and ore  Sb  tetrahedrites  were t h e r e f o r e more l i k e l y t o be  f l u i d s o u r c e . One  1983),  Sack, 1984). Hackbarth and  p r e c i p i t a t e d p r e f e r e n t i a l l y r e l a t i v e to Sb-  t o the  Hall,  c o r r e l a t i o n between Fe and  (1984) a l s o noted t h a t Cu-  v a r i e t i e s and  s i l v e r values  1983). A l s o present i s a p o s i t i v e  c o r r e l a t i o n between Ag  tetrahedrites  though  d i d not  be t h a t  (eg. Hackbarth  tetrahedrite  i n i t i a t e u n t i l the hydrothermal c y c l e  d e c l i n i n g , - an o b s e r v a t i o n  paragenetic r e l a t i o n s h i p s  t h a t i s supported  (Figure 3.4.22). The  hydrothermal c e l l , w i t h the c o n t r a c t i o n of therefore  Ag-  by cooling  isotherms,  produced an e f f e c t i v e encroachment on the  cell  edge t h a t r e s u l t e d i n p r e c i p i t a t i o n of s u c c e s s i v e l y more r i c h c o m p o s i t i o n s . In some t e t r a h e d r i t e g r a i n s ,  Sb-  individual  150  zones progress from an e a r l y S b - r i c h core to a more A s - r i c h r i m , suggesting may  t h a t o v e r a l l zonation  i n t e t r a h e d r i t e grains  be governed by a r a p i d l y f l u c t u a t i n g hydrothermal  compositional  environment than by simple v a r i a t i o n s i n  p a r t i t i o n i n g from a homogeneous f l u i d . The  almost  exclusive  a s s o c i a t i o n of i n t r i c a t e l y zoned t e t r a h e d r i t e g r a i n s w i t h highly brecciated wallrock  o r Stage I m a t e r i a l c o u l d be  r e s u l t of h i g h l y v a r i a b l e o r  "chaotic" f l u i d  the  circulation  a s s o c i a t e d w i t h f l u i d s moving through a b r e c c i a zone as opposed t o a simple f r a c t u r e ( F i g u r e 4.4.16). In the f i n e s c a l e zoning  and  general,  sharp boundaries i n d i c a t e t h a t  the  t e t r a h e d r i t e s d i d not s i g n i f i c a n t l y r e e g u i l i b r a t e w i t h t h e i r parent s o l u t i o n s (Barton r a p i d d e p o s i t i o n and  and  Skinner, 1979),  suggesting  l i t t l e d i f f u s i o n were t a k i n g  place  d u r i n g l a t e Stage I I I m i n e r a l i z a t i o n . T e t r a h e d r i t e s w i t h the h i g h e s t Ag/(Ag+Cu) and As/(As+Sb+Bi) r a t i o s were found t o occur i n the p a r t s of the Number Three v e i n and the main system (Figures 4.4.8  lowest  northernmost  i n v e i n s most d i s t a l  t o 4.4.11). These s i t e s  a s s o c i a t e d w i t h narrow v e i n i n g and  to are  a l t e r a t i o n zones, w i t h  abundant vuggy carbonate and v e i n pyrobitumen i n d i c a t i n g a. low-temperature environment of d e p o s i t i o n . As a r e s u l t , f l u i d source i s i n t e r p r e t e d as being southern p a r t of the p r o p e r t y , compositions are  l o c a t e d towards the  where more A s - r i c h  located.  The A g - S b - r i c h zone c e n t e r e d  around the d e c l i n e  may  have r e s u l t e d from s e v e r a l f a c t o r s . C o p r e c i p i t a t i o n w i t h  the the  151  a i k i n i t e may  have p r e f e r e n t i a l l y e n r i c h e d the t e t r a h e d r i t e  m i n e r a l i z i n g s o l u t i o n s i n s i l v e r r e l a t i v e t o copper and thus g i v e n r i s e t o more s i l v e r - r i c h forms, an o b s e r v a t i o n which agrees w i t h the l e s s pronounced change i n the X4  ratio  w i t h i n the same a r e a . Another p o s s i b l e mechanism f o r s i l v e r enrichment i n these t e t r a h e d r i t e s i s an abrupt change i n salinity  (eg. by b o i l i n g o r d i l u t i o n ) . Sack and Loucks  (1985) have demonstrated t h a t f l u i d s  fractionally  p r e c i p i t a t i n g t e t r a h e d r i t e a l o n g t h e i r flowpaths would undergo a marked i n c r e a s e i n s i l v e r content w i t h o n l y a 2% decline i n s a l i n i t y . The second anomalous zone, d i s t i n g u i s h e d by low Ag-Sb c o n t e n t s , l o c a t e d i n the deep n o r t h p o r t i o n of the Number Three v e i n , may  have r e s u l t e d from removal of s i l v e r from  s o l u t i o n by c o p r e c i p i t a t i o n w i t h b e r r y i t e , o r p o s s i b l y from the presence o f a second, s m a l l e r f l u i d source beneath the n o r t h p o r t i o n o f the v e i n . A p a r t i c u l a r p o i n t of note i s the presence o f e l e v a t e d bismuth c o n t e n t s and the c o e x i s t a n c e w i t h b i s m u t h i a n m i n e r a l o g i e s w i t h i n both anomalous zones. The Zn/(Zn+Fe) r a t i o s a r e e s s e n t i a l l y c o n s t a n t f o r the b u l k o f the Number Three v e i n and o n l y show s i g n i f i c a n t v a r i a t i o n i n the northernmost segment o f the system, where the r a t i o X  2  i s as low as 0.65.  P a t t r i c k and H a l l  (1983)  have noted an apparent c o r r e l a t i o n o f Fe w i t h Ag f o r l e v e l s of g r e a t e r than two atoms, a s i t u a t i o n which i s p r e s e n t i n the n o r t h end m a t e r i a l . A l e s s p l a u s i b l e reason was noted by Wu  and P e t e r s e n (1977), who  found t h a t t e t r a h e d r i t e  152  F i g u r e 4.4.16: Schematic diagram of environment of tetrahedrite deposition in a vein breccia. T e t r a h e d r i t e g r a i n "A" r e c e i v e s a c o n s t a n t replenishment of hydrothermal f l u i d s , t h e r e f o r e , zoning i s t i e d t o t h e e v o l u t i o n o f t h e h y d r o t h e r m a l s y s t e m . As a r e s u l t , z o n i n g d e v e l o p e d w i l l be a g r a d u a l change i n one d i r e c t i o n d u r i n g t h e d u r a t i o n o f one p u l s e . T e t r a h e d r i t e g r a i n "B" i s s u b j e c t t o p e r i o d i c r e p l e n i s h m e n t d u r i n g a h y d r o t h e r m a l p u l s e . As a r e s u l t , t h e z o n i n g p a t t e r n may show a t e n d e n c y t o w a r d s o s c i l l a t i o n due t o v a r y i n g amounts o f d e p o s i t i o n from " a c t i v e " and "stagnant" f l u i d s . T e t r a h e d r i t e g r a i n "C" i s l e a s t e x p o s e d t o i n f l u x e s o f h y d r o t h e r m a l s o l u t i o n s and e v o l v e s i n a c c o r d a n c e t o c h a n g i n g m e t a l c o n t e n t s i n the ambient s o l u t i o n s . Z o n i n g i s g r a d u a l , w i t h sudden changes or o s c i l l a t i o n s marking exposure t o l e s s e v o l v e d s o l u t i o n s (as t h e r e s u l t o f t u r b u l e n c e ) .  153  associated with chalcopyrite i s enriched the c h a l c o p y r i t e was  i n Fe. Leaching of  c i t e d as the mechanism of  Fe  enrichment. 4.5  Sphalerite  4.5.1  Zonation  Introduction Sphalerites  form an almost u b i q u i t o u s  Stage II m i n e r a l i z a t i o n , and t e t r a h e d r i t e s , provided e v o l u t i o n . The compositional  thus, as w i t h  a valuable  the  tool for evaluating  most important f a c e t of the  Ge,  and  sphalerite  In i n both a p a r a g e n e t i c c o n t e x t  on a vein-wide s c a l e . Sampling and not as e x t e n s i v e  a n a l y s i s of  sphalerites  mineralogically  d i s s i m i l a r s i t e s i n c l u d i n g 9 whole-grain t r a v e r s e s . s i t e 3CHN89-5 (Appendix A ) , ppm  Ga and  In p a r t i c u l a r , was  n e a r l y 2000 ppm  Ge  i n t e r s e c t i o n . Complete a n a l y s e s are given i n Tables 4.2.1  4.5.2  Systematic  and  as f o r the t e t r a h e d r i t e s ; p o i n t s were  chosen from 12 w i d e l y separated and  assays of 320  fluid  d a t a , however, i s the l o c a t i o n of anomalous  contents of Ga,  was  component of  Sample  chosen due  from a  to  drill  i n Appendix C  and  t o 4.2.3.  trends  in Sphalerite  Zonation  S p h a l e r i t e samples from the Number Three v e i n commonly display well defined resolved  growth-zoning o r l a y e r i n g which  i n r e f l e c t e d l i g h t microscopy i n t o zones  abundant minute c h a l c o p y r i t e i n c l u s i o n s and i n f i l l i n g s . Analysis  across  was  containing  fracture  these l a y e r s d e t e c t e d  little  v a r i a t i o n i n e i t h e r the i r o n contents o r i n t r a c e element  l e v e l s . In g e n e r a l , s p e c i f i c p e r i o d s of m i n e r a l i z a t i o n f o r any of the t r a c e elements c o u l d not be determined.  Ga,  Ge,  and In are near d e t e c t i o n l i m i t s f o r most s i t e s examined, and Hg and Cd l e v e l s were found t o be h i g h l y v a r i a b l e i n a l l samples. A sample t r a v e r s e a c r o s s s p h a l e r i t e from  sample  s i t e 3CHN89-5, which d i s p l a y e d perhaps the b e s t zoning observed,  i s g i v e n i n T a b l e 4.5.1. Two  samples d i s p l a y i n g the h i g h e s t Ga  other t r a v e r s e s from  (3CHN89-1) and In (3CHN90-  1) contents are a l s o g i v e n i n Tables 4.5.2  and 4.5.3. In  both cases, c o n c e n t r a t i o n s of the anomalous elements exceeded 0.5  weight p e r c e n t l o c a l l y along the t r a v e r s e s .  S p h a l e r i t e s throughout  the Number Three v e i n t y p i c a l l y  have Fe c o n t e n t s of l e s s than one weight p e r c e n t w i t h the s i n g l e observed e x c e p t i o n of sample s i t e 3CHN90-1  (Appendix  A ) . T h i s sample a l s o c o n t a i n e d the h i g h e s t In c o n t e n t s i n the Number Three v e i n (Table 4.5.3) and was  noted  unique  amongst s p h a l e r i t e s i t e s e v a l u a t e d i n t h a t i t c o n t a i n e d a p p r e c i a b l e amounts of c h a l c o p y r i t e i n c l u s i o n s w i t h i n the Stage I I I assemblage. E l d r i d g e et a l . (1988) have  suggested  t h a t c h a l c o p y r i t e " d i s e a s e " w i l l grow by the replacement the FeS component i n s p h a l e r i t e ; s p h a l e r i t e s from  of  the  v i c i n i t y of t h i s sample (and o t h e r areas?) thus may  have had  h i g h Fe contents t o b e g i n w i t h . A p a r t i c u l a r i l y noteworthy o c c u r r e n c e of h i g h In assays i n the c h a l c o p y r i t e - r i c h Number F i v e v e i n suggests t h a t c h a l c o p y r i t e may  be an  important  p a t h f i n d e r f o r h i g h In s p h a l e r i t e s . F e - d e f i c i e n t  sphalerites  were a l s o noted i n the n o r t h e r n Cole v e i n and P o r t a l v e i n s .  155  4.5.3  Discussion One  of the important c o n t r i b u t i o n s of a study of the  l o c i of Ga,  Ge and In p e r t a i n s t o t h e i r p a r a g e n e t i c  r e l a t i o n s h i p s and the p o t e n t i a l f o r economic c o n c e n t r a t i o n s w i t h i n the Number Three and a s s o c i a t e d v e i n s . G a l l i u m , germanium, and indium  appear t o be be c o n c e n t r a t e d w i t h i n  the s p h a l e r i t e s i n amounts up t o 0.6  weight percent w i t h i n  the samples analyzed, but no s i n g l e p e r i o d of m i n e r a l i z a t i o n f o r any of the t h r e e metals was  noted.  Instead, peak  c o n c e n t r a t i o n s were found t o v a r y s p a t i a l l y w i t h i n the v e i n , w i t h the most notable example b e i n g the a s s o c i a t i o n of h i g h In assays w i t h s p h a l e r i t e s accompanying abundant c h a l c o p y r i t e . High Fe contents i n these g r a i n s suggest In m i n e r a l i z a t i o n may  have been connected  that  w i t h Stage I I I  c h a l c o p y r i t e emplacement which l e d t o the development of extensive "chalcopyrite disease" i n sphalerites. K i e f t Damman (1990) noted t h a t primary skarns i n c e n t r a l Sweden was and r o q u e s i t e (CuInS2). r e v e r s e a c t i o n may  and  In i n s p h a l e r i t e s from  remobilized into chalcopyrite  In the Number Three system, the  have o c c u r r e d , w i t h In and  Fe  s u b s t i t u t i n g f o r Zn i n the s p h a l e r i t e s t r u c t u r e . A second p o s s i b i l i t y i s t h a t the I n - b e a r i n g s p h a l e r i t e may  represent  a t e m p o r a l l y d i s p a r a t e event r e l a t i v e t o o t h e r s p h a l e r i t e s i n the Number Three v e i n , a h y p o t h e s i s supported by s p o r a d i c occurrences  of In-bearing m a t e r i a l throughout  by the absence of In i n c h a l c o p y r i t e .  the system and  156  F i g u r e 4.5.1 Banded s p h a l e r i t e from sample s i t e 3CHN89-5, s o u t h e r n Number Three v e i n . M a t e r i a l from t h i s s i t e c o n t a i n e d t h e h i g h e s t Ge a s s a y s a t t h e S i l v e r Queen mine. Scale bar i n lower l e f t corner. T a b l e 4.5.1  Element  Zonal A n a l y s e s o f S p h a l e r i t e Sample 3CHN89-5  1  2  3  4  5  6  7  8  Zn S Fe Mn Cd Hg Ga Ge In  66. 94 66. 52 66. 87 66. 14 66 06 66 05 67. 34 66 51 33. 28 33. 40 33. 21 33. 17 33 06 32 87 33. 20 32 98 0. 00 0. 00 0. 00 0. 00 0 00 0 00 0. 00 0 00 0. 00 0. 00 0. 00 0. 00 0 00 0 00 0. 00 0 .00 0. 12 0. 34 0. 26 0. 65 0 .72 0 46 0. 15 0 .12 0. 00 0. 00 0. 00 0. 00 0 .00 0 00 0. 00 0 .00 0. 00 0. 00 0. 00 0. 00 0 .05 0 03 0. 00 0 .00 0. 03 0. 00 0. 00 0. 00 0 .05 0 04 0. 00 0 .06 0. 00 0. 00 0. 00 0. 00 0 .00 0 00 0. 00 0 .00  Total  100 .4 100 .3 100 .4 100 .0 99 .93 99 48 100 .7 99 .70  157 T a b l e 4.5.1 Element  (continued) c) 10  Zn S Fe Mn Cd Hg Ga Ge In  66 33 0 0 0 0 0 0 0  Totals  99 80  Element Zn S Fe . Mn Cd. Hg Ga Ge In Total  21 16 00 00 37 00 00 03 00  18  11  12  13  14  .64 .85 .00 .00 .00 .00 .00 .07 .00  67 .41 33 .27 0 .00 0 .00 0 .00 0 .00 0 .00 0 .00 0 .00  67 .38 33 .24 0 .00 0 .00 0 .00 0 .04 0 .00 0 .00 0 .00  66 .89 33 .16 0 .00 0 .00 0 .54 0 .07 0 .00 0 .05 0 .10  66 33 0 0 0 0 0 0 0  99 .59  100.7  100.7  100.8  99 .96  22  25  28  66 32 0 0 0 0 0 0 0  21  .35 .11 .00 .00 .39 .00 .00 .07 .00  33  15 66 33 0 0 0 0 0 0 0  .01 .04 .00 .00 .75 .00 .00 .00 .00  99 .84  37  65 .66 33 .42 0 .00 0 .00 0 .53 0 .00 0 .00 0 .04 0 .00  66. 69 33. 13 0. 00 0. 04 0. 10 0. 04 0. 03 0. 03 0. 00  66 .91 33 .07 0 .00 0 .00 0 .13 0 .00 0 .00 0 .08 0 .00  66 .42 33 .14 0 .00 0 .00 0 .04 0 .00 0 .00 0 .07 0 .00  66 .47 33 .40 0 .21 0 .07 0 .42 0 .00 0 .00 0 .00 0 .00  65 .91 33 .17 0 .22 0 .15 0 .40 0 .00 0 .00 0 .06 0 .00  66 .54 32 .93 0 .00 0 .00 0 .00 0 .00 0 .00 0 .00 0 .00  99 .65  100 .1  100.2  100.2  100.6  99 .93  99 .51  * Values g i v e n are element weight percents ** S i t e numbers i n c r e a s e from r i m t o c o r e *** S e l e c t analyses are g i v e n f o r s i t e s 18 t o 37 i n d i v i d u a l r a t i o s ( F i g u r e s 4.4.6 t o 4.4.12).  158 T a b l e 4.5.2  Zonal A n a l y s i s o f S p h a l e r i t e sample 3CHN89-1 1  3  6  11  9  17  13  19  Zn S Fe Mn Cd Hg Ga Ge In  65.57 65.65 65.43 65.38 66 .32 33.50 33.05 32.81 32.77 32 .98 0.00 0.03 0.00 0.03 0 .04 0.66 0.00 0 .00 0.00 0.00 0.74 0.10 0.97 1.81 0 .94 0.04 0.00 0.12 0.00 0 .00 0.22 0.14 0.00 0.00 0 .00 0.07 0.09 0.07 0.08 0 .00 0.00 0.03 0.07 0 .00 0.03  66 .34 33 .01 0 .00 0 .00 0 .60 0 .07 0 .15 0 .03 0 .09  66 .81 33 .00 0 .00 0 .11 0 .12 0 .00 0 .15 0 .00 0 .00  66 .57 32 .74 0 .04 0 .09 0 .09 0 .00 0 .16 0 .07 0 .00  Total  100.0 99.79 99.65 100.1 100.3  100.3  100.2  99 .80  24  22 Zn S Fe Mn Cd Hg Ga Ge In  25  27  28  29  30  66.57 33.02 0.00 0.09 0.12 0.00 0.00 0.00 0.00  66.56 33.02 0.00 0.00 1.14 0.00 0.00 0.11 0.00  66.37 32.86 0.00 0.00 1.05 0.00 0.00 0.00 0.00  66. 23 33. 11 0. 00 0. 52 0. 06 0. 11 0. 05 0. 00 0. 00  66. 31 33. 14 0. 00 0. 32 0. 06 0. 07 0. 15 0. 00 0. 00  66. 10 32. 85 0. 00 0. 00 0. 71 0. 00 0. 10 0. 05 0. 03  66. 10 32. 87 0. 00 0. 04 0. 66 0. 00 0. 07 0. 05 0. 03  T o t a l 99.81  100.9  100.3  100 .1  100 .1  99. 85  99. 88  T a b l e 4.5.3  Zonal A n a l y s i s o f S p h a l e r i t e sample NGV4,#1 1  2  4  5  7  8  9  11  Zn S Fe Mn Cd Hg Ga Ge In  63.38 63 .35 63.80 63.50 63.40 63.42 63.55 62.87 33.25 33 .36 33.00 33.25 33.14 33.26 33.10 33.67 2 .65 2.30 2.68 2.30 2.95 2.63 2.86 2.49 0.07 0.07 0.05 0 .05 0.06 0.06 0.06 0.07 0.32 0.28 0.22 0 .35 0.20 0.28 0.34 0.29 0.00 0.00 0.00 0 .00 0.00 0.00 0.00 0.00 0.04 0.00 0.04 0.00 0 .00 0.00 0.00 0.00 0.00 0.10 0.08 0.03 0 .00 0.03 0.00 0.00 0.55 0.23 0.20 0 .07 0.10 0.10 0.22 0.22  Total  99.79 99.84 99.51 100.3 100.0 99.78 99.99 100.2  •Values a r e g i v e n as element weight p e r c e n t s * * S i t e numbers a r e a c r o s s g r a i n (NGV4,#1) and c o r e t o r i m (3CHN89-1). S e l e c t analyses g i v e n f o r l a r g e t r a v e r s e s .  159  Germanium d i s p l a y s a more even d i s t r i b u t i o n i n the Number Three system and i s a p p a r e n t l y contemporaneous w i t h the main s p h a l e r i t e m i n e r a l i z i n g event. B e r n s t e i n (1985) r o u g h l y c h a r a c t e r i z e d the g e o l o g i c environment  f o r high  c o n c e n t r a t i o n s o f Ge i n s p h a l e r i t e s and found t h a t the h i g h e s t c o n c e n t r a t i o n s o f Ge were found i n l a t e stage, low temperature s p h a l e r i t e s , predominantly those hosted by sedimentary r o c k s . The h i g h e r temperature  hydrothermal  m i n e r a l i z a t i o n s i m i l a r t o t h a t present i n the Number Three v e i n tended t o have lower Ge contents than  "epigenetic"  m i n e r a l i z a t i o n s . I n c o r p o r a t i o n of Ge i n t o s p h a l e r i t e s  was  c o n s i d e r e d t o be a s s o c i a t e d w i t h low t o moderate l o g a g v a l u e s , w i t h o t h e r s u l f i d e s o r independent Ge phases  2  forming  a t a h i g h e r l o g a g ( F i g u r e 4.5.2). B e r n s t e i n (1985) a l s o 2  suggested t h a t Ge c o n t a i n e d i n hydrothermal d e p o s i t s may have been d e r i v e d from one o f two s o u r c e s : a) f r a c t i o n a l c r y s t a l l i z a t i o n of igneous  fluids  b) i n c o r p o r a t i o n o f Ge from c o u n t r y r o c k s , p a r t i c u l a r i l y those e n r i c h e d i n o r g a n i c matter. A p o s s i b i l i t y e x i s t s t h a t independent Ge m i n e r a l s are p r e s e n t i n some p a r t s o f the Number Three system  because,  germanium c o n t e n t s o f s p h a l e r i t e s are too low t o account f o r r e p o r t e d a s s a y s . Germanium may  a l s o be p r e s e n t i n t r a c e  amounts i n s i l i c a t e s and base metal s u l f i d e s from the Number Three v e i n , a l t h o u g h t h i s p r o b a b l y c o u l d not account f o r the observed anomalous l e v e l s .  160  G a l l i u m i s c o n c e n t r a t e d p r i n c i p a l l y i n sample 3CHN89-1 m a t e r i a l and, l i k e Ge, appears t o be a component o f Stage I I m i n e r a l i z a t i o n and not c o n f i n e d t o any one event. Cadmium l e v e l s i n the Number Three v e i n d i s p l a y p a t t e r n s s i m i l a r t o those of the t h r e e "semiconductor metals". Cadmium contents are h i g h e s t i n sample 3CHN89-1, a t 1.8 weight p e r c e n t ; the e x i s t e n c e o f independent Cd-bearing phases has not been r u l e d out. S p h a l e r i t e s from sample 3CHN89-1 are a l s o e n r i c h e d i n Mn  (up t o 0.7 weight p e r c e n t ) , w i t h Mn contents  v a r y i n g i n v e r s e l y w i t h Cd c o n t e n t s . In g e n e r a l , Hg contents i n s p h a l e r i t e are below o r near d e t e c t i o n l i m i t s i n a l l p a r t s o f the v e i n . The r e l a t i v e l y F e - d e f i c i e n t nature of S i l v e r Queen s p h a l e r i t e i s unusual i n i t s c o n t i n u i t y . A p o s s i b l e reason f o r low Fe contents i s the removal of Fe from the hydrothermal system by the c r y s t a l l i z a t i o n o f p y r i t e p r e c e d i n g the main s p h a l e r i t e m i n e r a l i z i n g event. P a r a g e n e t i c r e l a t i o n s h i p s support t h i s c o n c l u s i o n , w i t h a widespread  p y r i t e d e p o s i t i o n a l event commonly noted t o  i n i t i a t e Stage I I m i n e r a l i z a t i o n . 4.6  S u l f o s a l t and E l e c t r u m Chemistry  4.6.1  Introduction Sulfosalts  (other than t e t r a h e d r i t e ) and e l e c t r u m form  a v o l u m e t r i c a l l y minor component of Stage I I I m i n e r a l i z a t i o n i n the Number Three and o t h e r systems a t S i l v e r Queen; n e v e r t h e l e s s , e v a l u a t i o n o f the compositions o f these phases was  necessary i n order to confirm uncertain i d e n t i t i e s . A  161  l e s s important  aspect o f s u l f o s a l t a n a l y s i s was the  p o s s i b i l i t y o f comparison o f s u l f o s a l t c o m p o s i t i o n a l change t o t e t r a h e d r i t e c o m p o s i t i o n a l v a r i a t i o n . Gemmel et al. (1989) have noted t h a t s u l f o s a l t s p e c i e s such as the p e a r c e i t e - p o l y b a s i t e s e r i e s and t h e ruby s i l v e r s may d i s p l a y c o m p o s i t i o n a l trends s i m i l a r t o c o e x i s t i n g t e t r a h e d r i t e s , w i t h t h e p o t e n t i a l t o develop  a geothermometer i f enough  f l u i d i n c l u s i o n analyses a r e a v a i l a b l e f o r the s u l f o s a l t m i n e r a l i z a t i o n . In p a r t i c u l a r , i d e n t i f i c a t i o n of s e v e r a l phases was necessary  i n o r d e r t o account f o r anomalous  s i l v e r c o n t e n t s w i t h i n a number o f the samples. E v a l u a t i o n o f these phases was undertaken p r i n c i p a l l y f o r the purposes o f s p e c i e s i d e n t i f i c a t i o n , w i t h repeat  analyses  c a r r i e d o u t on e l e c t r u m and b e r r y i t e g r a i n s i n o r d e r t o d e f i n e modal compositions 4.6.2  Sulfosalt Seligmannite  f o r each.  Compositions ( B e r n s t e i n , 1987), b e r r y i t e  Owens, 1973), and b o u l a n g e r i t e  ( H a r r i s and  (Marsden, 1985) a r e among t h e  s u l f o s a l t phases p r e v i o u s l y noted a t S i l v e r Queen. In a l l c a s e s , t h e s u l f o s a l t assemblage corresponds  w i t h Stage I I I  m i n e r a l i z a t i o n , w i t h the g r e a t e s t v a r i e t y o f s u l f o s a l t species associated with chalcopyrite-bearing v e i n material and h i g h s i l v e r grades. M i n e r a l s o f t h e s e l i g m a n n i t e bournonite  s e r i e s appear t o have the g r e a t e s t s p a t i a l  d i s t r i b u t i o n o f the s u l f o s a l t s i n both the Number Three v e i n and i n s e v e r a l o f the s m a l l e r v e i n s  ( r e f e r t o Chapter 3 ) .  162  The h i g h l y intergrown nature of s e l i g m a n n i t e and i n the Number Three v e i n produced  bournonite  several d i f f i c u l t i e s  d u r i n g a n a l y s i s , w i t h i n t e r f e r e n c e from the host galena o f t e n p r o d u c i n g unreasonably  h i g h t o t a l s . S.E.M. a n a l y s i s  c o u p l e d w i t h t h r e e probe analyses allowed, however, f o r a rough d e t e r m i n a t i o n of i n c r e a s i n g Sb contents towards the n o r t h e r n p o r t i o n of the v e i n . T e t r a h e d r i t e and s e l i g m a n n i t e / bournonite are commonly c l o s e l y a s s o c i a t e d s p a t i a l l y  and  t e m p o r a l l y i n the Number Three system and t h e r e f o r e c o u l d p r o v i d e an o p p o r t u n i t y t o e v a l u a t e changing  hydrothermal  c o n d i t i o n s w i t h adequate f l u i d i n c l u s i o n analyses the c o n s t r u c t i o n of c o m p o s i t i o n a l t i e - l i n e s al,  through  (e.g. Gemmel et  1989). The  f i r s t recorded Canadian occurrence of the m i n e r a l  b e r r y i t e i s the S i l v e r Queen mine ( H a r r i s and Owens, 1973). The exact formula of b e r r y i t e i s s t i l l u n c e r t a i n , although c o m p o s i t i o n a l l y the m i n e r a l f a l l s w i t h i n the b e n j a m i n i t e s o l i d s o l u t i o n f i e l d d e s c r i b e d by Chang e t a l (1988).  The  composition o f b e r r y i t e from the Number Three v e i n (Table 4.6.1) shows a s l i g h t  (2.5 wt.%)  v a r i a t i o n i n B i content,  and the formula c a l c u l a t e d f o r the two t o match c l o s e l y t h a t determined  "end members"  appears  by H a r r i s and Owens (1973)  f o r m a t e r i a l from the same d e p o s i t . Some r e v i s i o n may  be  n e c e s s a r y due t o the s l i g h t l y lower B i contents observed i n the new  samples, which are probably the r e s u l t of improved  p r e c i s i o n i n microprobe observed  a n a l y s e s . The h i g h Ag  contents  i n the samples from the deep n o r t h p o r t i o n of the  163  Number Three v e i n may a l s o support an h y p o t h e s i s t h a t c o p r e c i p i t a t i o n o f t e t r a h e d r i t e and b e r r y i t e r e s u l t e d i n p a r t i t i o n i n g o f Ag p r e f e r e n t i a l l y i n t o b e r r y i t e , producing unusually The  low Ag c o n t e n t s i n t h e t e t r a h e d r i t e . ruby s i l v e r s and minerals  of the pearceite-  p o l y b a s i t e s e r i e s d i s p l a y a wide range i n compositions i n the Number Three and a s s o c i a t e d v e i n s . G e n e r a l l y ,  end member  p y r a r g y r i t e i s t h e predominant form o f t h e ruby s i l v e r s , w i t h more A s - r i c h compositions noted i n t h e southern p o r t i o n of t h e Number Three v e i n and end member p r o u s t i t e i n t h e NG3. v e i n (Table 4.6.1). As f o r t h e  seligmannite/bournonite  s e r i e s , t h e change i n compositions roughly t e t r a h e d r i t e compositional  p a r a l l e l s the  changes and appear t o r e f l e c t an  increase i n Sb-substitution with increasing distance the f l u i d s o u r c e . An important fact' t o c o n s i d e r  from  i s that the  p r o u s t i t e l o c a l i t y occurs a t a lower e l e v a t i o n than any other v e i n i n t e r s e c t i o n on t h e p r o p e r t y  and t h e r e f o r e might  be c l o s e s t t o t h e heat source. Minerals  o f t h e p e a r c e i t e - p o l y b a s i t e s e r i e s do not  d i s p l a y any r e c o g n i z e d  systematic  compositional  trends i n  the S i l v e r Queen system, a s i t u a t i o n t h a t may p a r t i a l l y be the r e s u l t o f t h e g e n e r a l property.  s c a r c i t y o f these m i n e r a l s  Compositions range from end member  (arsenian)  p e a r c e i t e t o a r s e n i a n p o l y b a s i t e , w i t h one sample 3.21  weight p e r c e n t  on the  containing  B i s u b s t i t u t i n g f o r Sb and As. S e v e r a l  samples from t h e Camp v e i n s a l s o c o n t a i n e d of B i , an o c c u r r e n c e which connects  trace quantities  pearceite-polybasite  164  m i n e r a l i z a t i o n w i t h much o f t h e t e t r a h e d r i t e event  (which  also contains appreciable B i ) . A i k i n i t e , m a t i l d i t e , and g u s t a v i t e (?) were a l l i d e n t i f i e d i n s u l f o s a l t m a t e r i a l from the P o r t a l v e i n s and Copper v e i n , w i t h no unusual d e v i a t i o n s from r e c o g n i z e d formulae. The l a t t e r phase i s r a r e i n the v e i n s and r e p r e s e n t s n e a r l y complete Ag-Bi s u b s t i t u t i o n o f t h e l i l l i a n i t e - g u s t a v i t e solid solution  (Makovicky and Karup-  M o l l e r , 1977). Sb-bearing b i s m u t h i n i t e and c u p r o b i s m u t i t e were i d e n t i f i e d i n a s s o c i a t i o n w i t h bismuthian t e n n a n t i t e s from the NG3 v e i n , from which they appear t o have e x s o l v e d . S e v e r a l o t h e r p o s s i b l e phases were a l s o i d e n t i f i e d by b a c k s c a t t e r e d e l e c t r o n imagery;  although t o t a l s f o r these  phases were low (90 t o 97 wt.%), a l l were found t o be Cu-PbB i phases, p o s s i b l y o f t h e b i s m u t h i n i t e - a i k i n i t e  solid  s o l u t i o n s e r i e s . A m i s c i b i l i t y gap t h a t e x i s t s w i t h i n t h i s s e r i e s below 300°C may be r e f l e c t e d w i t h i n t h i s because  series  no compositions between 60 and 80 mole p e r c e n t  Bi2 S3 were noted ( H a r r i s and Chen, 1976). As a r e s u l t , an upper  l i m i t on temperature might be a p p l i e d t o a r e g i o n o f  the Number Three-NG3 system t h a t i s c l o s e t o t h e i n t e r p r e t e d heat source. 4.6.3  Electrum  Compositions  E l e c t r u m i s t h e o n l y observed Au-bearing phase a t the S i l v e r Queen mine and thus generates a c o n s i d e r a b l e degree of i n t e r e s t as t o i t s l o c u s and composition (see Chapter 3 ) .  Electrum  from the Number Three v e i n and s e v e r a l s m a l l e r  v e i n s was, i n g e n e r a l found t o be q u i t e A g - r i c h (560 t o 760 F i n e ) and. t o l a c k zoning i n i n d i v i d u a l g r a i n s The  d i s t r i b u t i o n o f electrum compositions  Number Three system was not e v a l u a t e d  (Table 4.6.2).  throughout the  i n detail,  although  microscopy i n d i c a t e s a p o s s i b l e i n c r e a s e i n Au content toward t h e southern  p o r t i o n o f t h e v e i n . S.E.M. analyses o f  s e v e r a l e l e c t r u m g r a i n s d e f i n e d no unusual t r a c e elements and s l i g h t l y low t o t a l s a r e probably oxidation.  the r e s u l t of surface  166 T a b l e 4.6.1 a.)  Microprobe A n a l y s i s o f S u l f o s a l t Compositions  Berryite Site B  Site A  Wt.%  Wt.%  At. Ct.  Cu S Zn Fe Sb As Pb Ag Bi Hg  6.19 17.34 0.00 0.22 0.00 0.00 20.02 7.36 47.80 0.00  Total S=ll  98.92 Pb (Cu .9 Ag .4)Bi4. S 2  9.14 52.21 0.00 0.38 0.00 0.00 9.33 6.58 22.09 0.00  1  f  1  6.37 17.52 0.00 0.04 0.00 0.00 20.37 7.29 48.75 0.00  7  Cu S Zn Fe Sb As Pb Ag Bi. Hg  2  2  Total S=ll Site Site Site Site  A B C D  Wt.%  9.47 51.58 1.76 0.41 0.00 0.00 9.09 7.11 20.59 0.00  99.92 1.9(Cu /Ag .5)Bi4. Si  from from from from  sample sample sample sample  1  4)  B i  4.7 ll s  At. Ct  6.30 17.44 0.00 0.00 0.00 0.00 20.76 7.62 47.60 0.00  4  9.51 52.20 0.00 0.00 0.00 0.00 9.62 6.78 21.87 0.00  99.73 Pb (Cu Ag •4)  P b  2  1 >  Site D  At. C t .  6.43 17.69 1.23 0.24 0.00 0.00 20.13 8.20 46.01 0.00  9.58 52.19 0.00 0.06 0.00 0.00 9.39 6.46 22.28 0.00  100.37 Pb (Cu ,Ag  1 1  Site C  Wt.%  At. Ct.  2  1  2 /  1  B i  4.6 ll s  s i t e 2CHN89-11 ; " P o r t a l 10.5" v e i n s i t e 3CHN90-2; Number Three v e i n s i t e 3CHN90-1; Number Three v e i n on Number F i v e v e i n  * K a r u p - M o l l e r (1966) gives Pb3 ( C u 3 5 , A g i 5 ) B i 7 S i s f o r b e r r y i t e formula. ** N u f f i e l d and H a r r i s (1966). H a r r i s and Owens (1973) g i v e s Pb (Cu Ag)3 B i s f o r b e r r y i t e formula. >  2  f  >  167  3.)  Pyrargyrite-Proustite  series  Site A  Wt. % Cu S Zn Fe Sb As Pb Ag Bi Hg  0.13 17.51 0.00 0.00 19.61 1.82 0.00 59.76 0.00 0.00  Total  98.92  Site B  At. Ct.  Wt.%  At. Ct.  0.16 42.39 0.00 0.00 12.50 1.89 0.00 43.01 0.00 0.00  0.12 17.67 0.05 0.00 21.83 0.67 0.00 59.77 0.13 0.00  0.14 42.50 0.05 0.00 13.83 0.69 0.00 42.73 0.05 0.00  100.24  Site C  Cu S Zn Fe Sb As Pb Ag Bi Hg Total Site Site Site Site  A B C D  Site D  Wt.%  At. Ct.  0.25 16.64 0.06 0.00 0.33 12.61 0.00 70.58 0.00 0.05  0.30 28.44 0.07 0.00 0.20 12.48 0.00 48.49 0.00 0.00  Wt.% 0.18 17.99 2.86 0.00 10.55 6.29 0.00 62.62 0.10 0.00  100.53 is is is is  from from from from  0.21 41.28 3.22 0.00 6.38 6.18 0.00 42.70 0.04 0.00  100.61  sample sample sample sample  •General formula i s A g  At. Ct.  site site site site 3  1CHN89 -65; Owl v e i n 3CHN89 -39; Camp v e i n s 3CHN89 -1; NG3 v e i n 3CHN89 -24; Number Three vein.  (Sb,As)S  3  168  c.)  Pearceite-Polybasite  series  Site A  Site B  Wt.%  At. Ct.  Wt.%  At. Ct.  Cu S Zn Fe Sb As Pb Ag Bi Hg  11.30 16.51 0.00 0.44 0.34 6.57 0.00 64.40 0.26 0.05  12.79 37.04 0.00 0.56 0.20 6.31 0.00 42.95 0.09 0.02  3.31 14.01 0.56 0.00 6.88 1.54 0.00 74.37 0.07 0.00  4.11 34.55 0.68 0.00 4.47 1.63 0.00 54.53 0.03 0.00  Total  99.89  100.74  Site C  Wt. % Cu S Zn Fe Sb As Pb Ag Bi Hg Total  8.58 16.54 0.00 0.00 0.65 5.48 0.00 65.86 3.21 0.00  Site D  At. Ct. 9.94 38.00 0.00 0.00 0.40 5.39 0.00 44.99 1.13 0.00  100.32  Wt.%  At. Ct.  5.72 15.41 0.00 0.00 5.58 3.06 0.00 70.57 0.00 0.00  6.87 36.63 0.00 0.00 3.50 3.12 0.00 49.87 0.00 0.00  100.34  S i t e A i s from sample s i t e 2CHN89-48; " J a x e l " v e i n . S i t e B i s from sample s i t e 3CHN89-24; Number Three v e i n . S i t e C and s i t e D a r e from t h e Number F i v e v e i n . * General formula i s (Ag Cu)^g f  (As,Sb)2 S n  169  d.) Other  Sulfosalts Matildite  Aikinite  -  Wt.% Cu S Zn Fe Sb As Pb Ag Bi Hg Total  11.02 17.32 0.00 0.00 0.00 0.00 35.87 0.04 36.37 0.00  At. C t .  Wt.%  16.29 50.75 0.00 0.00 0.00 0.00 16.26 0.03 16.35 0.00  0.23 17.12 0.00 0.00 0.00 0.00 0.06 27.80 53.78 0.06  100.32  Cu S Zn Fe Sb As Pb Ag Bi Hg Total  12.42 19.97 0.06 0.00 24.27 0.58 41.73 0.00 0.12 0.00 100.15  0.35 50.68 0.00 0.00 0.00 0.00 0.03 24.46 24.42 0.03  99.07  Bournonite  Wt.%  At. Ct.  Bismuthinite  At. C t .  Wt.%  15.90 50.67 0.08 0.00 16.22 0.63 16.39 0.00 0.05 0.00  0.14 19.40 0.00 0.00 5.18 0.15 0.00 0.00 75.36 0.00  At. C t . 0.22 59.72 0.00 0.00 4.20 0.19 0.00 0.00 35.58 0.00  100.30  A i k i n i t e and m a t i l d i t e samples a r e from the Number F i v e vein. Bournonite sample from sample s i t e 3CHN89-20; Number Three vein. B i s m u t h i n i t e sample from sample s i t e 3CHN89-3; NG3 v e i n .  170  Geocronite  G u s t a v i t e (?)  Wt.%  At. C t .  Cu S Zn Fe Sb As Pb Ag Bi Hg  0.19 16.95 0.00 0.00 0.00 0.00 23.67 8.60 49.91 0.00  0.30 54.80 0.00 0.00 0.00 0.00 11.85 8.27 24.76 0.00  Total  99.34  Wt.%  At. C t .  0.00 17.66 0.08 0.00 7.21 5.95 68.90 0.00 0.17 0.00  0.00 53.74 0.13 0.00 5.78 7.75 32.46 0.00 0.08 0.00  1  100.01  Cuprobismutite (best a n a l y s i s )  Wt.% Cu S Zn Fe Sb As Pb Ag Bi Hg .  17.40 19.87 0.16 0.09 3.52 0.09 0.00 0.06 57.27 0.00  Total  98.45  At.  Ct.  22. 78 51. 56 0. 20 0. 13 2. 40 0. 09 0. 00 0. 05 22. 80 0. 00  C u p r o b i s m u t i t e i s from sample s i t e 3CHN89-3; NG3 v e i n . G e o c r o n i t e i s from sample s i t e 3CHN89-1; NG3 v e i n . G u s t a v i t e (?) i s from sample s i t e 2CHN89-11; " P o r t a l 10.5" vein. •General formula f o r g u s t a v i t e g i v e n as A g Pb5 B i n 2 4 (Makovicky and Karup-Moller, 1977). ••General formula f o r g e o c r o n i t e g i v e n as Pb5 (As,Sb)2 Sg ( B i r n i e and Burnham, 1976). s  3  171  Table 4 . 6 . 2  E l e c t r u m Compositions A  Sample  B  Wt.%  At. Ct.  Wt ..%  At. Ct.  Au Ag Hg Cu  70.51 28.22 0.10 0.00  57.69 42.15 0.08 0.00  73 .73 24 .55 0 .00 0 .00  62.18 37.80 0.00 0.00  Total  98.86  Sample  98 .30  C  Wt.% Au Ag Hg Cu  76.18 22.65 0.00 0.00  Total  98.86  Site Site Site Site  A B C D  is is is is  from from from from  Number sample sample Number  D  A t . Ct:. 64.76 35.16 0.00 0.00  Wt .%  At. Ct.  56 .33 41.15 57.76 43 .47 0 .00 0.00 0 .48 (contam.?) 100 .28  Five site site Five  vein 2CHN89 -4; P o r t a l Three v e i n 3CHN90 -2; Number Three v e i n vein  172  5.0 5.1  DISCUSSION  Introduction The m i n e r a l o g i e s  o f base- and precious-metal  the S i l v e r Queen mine a r e suggestive pressure  veins a t  o f r e l a t i v e l y low  and moderate temperature hydrothermal d e p o s i t i o n .  Open space f i l l i n g t e x t u r e s  a r e present  throughout t h e  Number Three and a s s o c i a t e d v e i n s , w i t h no evidence o f r e m o b i l i z a t i o n i d e n t i f i e d . Paragenetic  s t u d i e s have a l s o  i n d i c a t e d t h a t m i n e r a l i z a t i o n proceeded through a s e r i e s o f stages,  d i s t i n g u i s h e d by v a r i a t i o n s i n the b u l k mineralogy,  t e x t u r e s , and o v e r a l l mode o f d e p o s i t i o n . I n o r d e r t o properly evaluate questions  t h e e v o l u t i o n o f t h i s system, a number o f  must be answered:  1) What were t h e c o n d i t i o n s o f formation  of the vein  system, as d e f i n e d by e q u i l i b r i u m p a i r i n g s ? 2) What was t h e mode o f t r a n s p o r t and d e p o s i t i o n o f the component metals d u r i n g e v o l u t i o n o f t h e hydrothermal system? 3) What were t h e c o n t r o l l i n g f a c t o r s i n f l u e n c i n g t h e nature o f t h e s o l u t i o n s ? 4) What was t h e source o f t h e metals? 5.)What was t h e d r i v i n g force, f o r f l u i d  5.2  Conditions  of Mineral  transport?  Deposition  M i n e r a l i z a t i o n i n Stages I through I I I i s c h a r a c t e r i z e d by a d i v e r s e s u i t e o f phases, i n c l u d i n g p o t e n t i a l l y economic  173  concentrations The  of Au  and Ag  c l o s e temporal and  i n e l e c t r u m and  s p a t i a l a s s o c i a t i o n s of these  minerals indicate that transport was  tetrahedrite.  of the metals i n s o l u t i o n  through s i m i l a r p r o c e s s e s , w i t h d e p o s i t i o n  induced  through a r e l a t i v e l y r a p i d change i n ambient c o n d i t i o n s .  As  noted i n T a b l e 5.2.1, t r a n s p o r t a t i o n of the metals i s dominated by t h r e e p o t e n t i a l s p e c i e s , r e l a t e d t o the pH  and  c h l o r i d e content of the s o l u t i o n (Wood et a l . , 1983). At S i l v e r Queen, the abundance of l a t e v e i n hydrocarbons may i n d i c a t i v e of the importance of o r g a n i c  ligands. as w e l l ,  a l t h o u g h the temperature of the s o l u t i o n s approaches upper s t a b i l i t y l i m i t f o r most o r g a n i c  be  complexes  the  (Barnes,  1979) . Conditions  of d e p o s i t i o n can be approximated c l o s e l y  through the s t a b i l i t i e s of s e v e r a l observed  sulfide  assemblages. The most important of these i s c o e x i s t i n g galena-matildite,  a p a i r i n g t h a t has  been observed i n  s e v e r a l c h a l c o p y r i t e - r i c h v e i n s where Stage I I I m i n e r a l i z a t i o n i s most abundant. C r a i g  (1967) noted t h a t  c h a r a c t e r i s t i c Widmannstaten-like t e x t u r e s e x s o l u t i o n below 215 o f Ag  and  B i i n PbS  + 15° C ,  w i t h complete s o l i d s o l u t i o n  above the s o l v u s .  Portal veins, galena-matildite  formed through  In samples from  intergrowths are  the  observed  w i t h i n the o u t l i n e s of a p r e - e x i s t i n g bladed form which i s i n t e r p r e t e d to represent  the metastable Ag-Pb-Bi phase. I f  t h i s i s the case, the s o l u t i o n s o r i g i n a l l y d e p o s i t e d m e t a s t a b l e phase a t temperatures s l i g h t l y g r e a t e r  the  than t h a t  Metal  Low Chloride  Fe  Fe  In Pb  High Chloride  H1qh £H  Low PH  F  Zn *  ZnOH*. :n(0H) *  :nci  Pb  POOH*; Pb(0H) *  PbCl„2-  2  2  ;  2 +  2  Bi  B1(CH) \  3H0H) '  2  3  e C  ,  - " (n-O-3)  FeOH^, Fe(0H) '  2 +  2 n  2 n  -  n  n  n  Au  Au(HS);-  AuCl*  Ag  AgMS* or HAg(HS)2°  Aa<HS) -  AgCl*  MoO« ~  Unchanged  Mo  H HoO« 2  HM0O4-  2  2  (n-O-3)  3iC1 2-n (n-O-2)  AuHS* or MAu(HS) ' 2  (n-O-3)  or Mo-blcareonate or -carbonate contolexes Sb  Sb'(aQ), HSbSj, H SbS«, Sb(0H) , SMOHlj* +  2  2  Unchanged  TABLE 5.2.1 S p e c i a t i o n o f Ore M e t a l s i n Hydrothermal S o l u t i o n s . [From Wood a t a l (1983)]  175  of the s o l v u s , w i t h e x s o l u t i o n o c c u r r i n g as the phase c o o l e d . Sakharova  (1969) a l s o suggests t h a t m a t i l d i t e i n the  absence of g a l e n a , but i n the presence o f o t h e r c o p r e c i p i t a t e d Pb-bearing s u l f o s a l t s , may r e p r e s e n t f o r m a t i o n a t temperatures l e s s than 215° C. through the breakdown o f c h a l c o p y r i t e . M a t i l d i t e has been noted from  one  l o c a l i t y i n the Number Three system, but i s a p p a r e n t l y the r e s u l t of replacement of b e r r y i t e and i s not n e c e s s a r i l y i n d i c a t i v e of. f o r m a t i o n a t subsolvus temperatures. A l t h o u g h t h e y do not p r o v i d e a d i r e c t approximation of temperature, o t h e r s u l f i d e / s u l f o s a l t assemblages  give  important i n f o r m a t i o n on the composition o f the hydrothermal f l u i d s . The temperatures and p r e s s u r e s of the system a t the time o f d e p o s i t i o n are not known, however, the v a l u e o b t a i n e d from the g a l e n a - m a t i l d i t e assemblage  can be  regarded as a minimum. The presence o f m a r c a s i t e i n Stage I m a t e r i a l i n the northernmost  i n t e r s e c t i o n s from the Number  Three v e i n c o n s t r a i n s the e a r l y m i n e r a l i z a t i o n  temperature  i n the more d i s t a l segments o f the Number Three v e i n a t a maximum o f 240° C.  (Murowchick  and Barnes,  1986).  P r e l i m i n a r y f l u i d i n c l u s i o n work on e a r l y q u a r t z and b a r i t e suggests maximum temperatures of 230  t o 240°  C,  c o r r e s p o n d i n g c l o s e l y w i t h the temperatures o b t a i n e d from m a r c a s i t e and the g a l e n a - m a t i l d i t e p a i r i n g  (M. Thomson,  p e r s . comm. 1991). E s t i m a t e s o f p r e s s u r e f o r the hydrothermal system of S i l v e r Queen mine are d e r i v e d from comparisons w i t h o t h e r  176  m i n e r a l i z i n g systems o f s i m i l a r temperature and environment. For  t h e a n a l y s i s o f f l u i d c o m p o s i t i o n a l parameters, a  temperature w i t h i n 20° o f 250° C , a t a p r e s s u r e o f l e s s than one k i l o b a r  (eg. Berger and Henley, 1989) w i l l be used.  L a t e r a l temperature g r a d i e n t s a r e assumed t o be n e g l i g i b l e over t h e l e n g t h o f t h e S i l v e r Queen system, i n a c c o r d w i t h t o t h e p e r s i s t a n c e o f common p a r a g e n e t i c events over t h e e n t i r e d e p o s i t , and r e l a t i v e l y s m a l l s i z e o f t h e d e p o s i t compared w i t h t h e p r o b a b l e s i z e o f the hydrothermal system ( c f . Berger and Henley,  1989).  Given an i n i t i a l temperature o f 240° C. and p r e s s u r e o f <1 k i l o b a r , c o m p o s i t i o n a l parameters such as l o g a g , l o g 2  aQ2 and pH can be c o n s t r a i n e d by c o e x i s t i n g m i n e r a l p a i r s ( F i g u r e 5.2.1). The assemblage p y r i t e - h e m a t i t e - g u a r t z i s p a r t i c u l a r l y widespread a t S i l v e r Queen, forming a l a r g e percentage o f t h e Stage I assemblage w i t h i n t h e c e n t r a l s e c t i o n o f t h e Number Three v e i n ( r e f e r t o Chapter 3 ) . A minimum l o g a g o f about -11 and l o g arj 2  2  o f about -34.4 a r e  i m p l i e d by t h e c o e x i s t a n c e o f these two phases. I n s e v e r a l i n t e r s e c t i o n s o f t h e Number Three v e i n i n t h e deep c e n t r a l segment, an assemblage  of pyrite+arsenopyrite+quartz  after  hematite has been i d e n t i f i e d . T h i s i n d i c a t e s t h a t a change i n l o g a,Q2 (independant o f pH) from approximately -30 t o s l i g h t l y l e s s than -40 has taken p l a c e d u r i n g t h e t r a n s i t i o n from t h e i n i t i a l the  s p e c u l a r hematite-dominated m i n e r a l o g y t o  l a t e r s u l f i d e assemblage  ( F i g u r e 5.2.2). W i t h i n t h e Camp  v e i n s , the change i s more extreme, w i t h p y r r h o t i t e  also  -8 bn + py  FIGURE 5.2.1 Log ag2~log aQ2 diagram showing t h e s t a b i l i t y f i e l d s o f common hydrothermal m i n e r a l s i n the presence o f q u a r t z . Temperature i s 250° C. w i t h the standard s t a t e s f o r S and 0 as i d e a l d i a t o m i c gases a t 1 atm. and 250° C.. From Barton e t a l (1977), as a p p l i e d t o d a t a from Creede. Note t h a t S i l v e r Queen o r e s do not c o n t a i n hydrothermal c h l o r i t e i n t h e v e i n assemblage; thus, the magnetite f i e l d i s not preempted by t h e c h l o r i t e f i e l d . 2  2  178  FIGURE 5.2.2 Log aQ2~pH diagrams showing common hydrothermal m i n e r a l s t a b i l i t i e s a t 250° C. and l o g t o t a l s u l f u r o f - 3 . Shaded f i e l d " I l a " represents low l o g a g c h a l c o p y r i t e - b e a r i n g assemblage. From Hayba e_£_aJL (1985), as a p p l i e d to Summitville ores. 2  . 250 °C  F e - A s - S - O - H with excess Fe  I  :  !  I  0  2  U  6  i  l  i  I  8  10  12  H  PH  FIGURE 5.2.3 L o g a Q 2 p H d i a g r a m s h o w i n g s t a b i l i t y f i e l d s o f common h y d r o t h e r m a l m i n e r a l s a n d a r s e n i c s p e c i e s a t a t e m p e r a t u r e o f 2 5 0 ° C. a n d l o g ag2. o f -2. From H e i n r i c h a n d E a d i n g t o n (1986). Note t r a n s i t i o n from h e m a t i t e assemblage t o p y r i t e - p y r r h o t i t e - a r s e n o p y r i t e assemblage a t lower l o g aQ2/ e x e m p l i f i e d b y s e v e r a l o f t h e Camp v e i n s . _  a  s  180  o c c u r r i n g w i t h i n the l a t e r s u l f i d e assemblage 5.2.2), and s e v e r a l p e r i p h e r a l v e i n s  (Figure  (eg. the northernmost  C o l e v e i n i n t e r s e c t i o n , B a r i t e v e i n ) a l s o d i s p l a y evidence of a s i m i l a r t r a n s i t i o n . The pH o f each s i t e i s more d i f f i c u l t t o determine, due t o t h e near-complete replacement of hematite by p y r i t e i n most s i t e s  (erasing p o t e n t i a l  evidence t h a t t h e assemblage passed through the magnetite stability field).  In the northernmost s e c t i o n o f the Number  Three v e i n and i n . the P o r t a l v e i n s , the presence o f p r i m a r y m a r c a s i t e i s i n s t e a d used t o e s t i m a t e the pH o f Stage I f l u i d s . Murowchick and Barnes, (1986) found t h a t m a r c a s i t e c o u l d be p r e c i p i t a t e d from p y r i t e - s u p e r s a t u r a t e d  f l u i d s at a  pH o f l e s s than 5.4, w i t h the pH of d e p o s i t i o n dependent the p o l y s u l f i d e s p e c i e s a s s o c i a t e d w i t h F e - t r a n s p o r t .  on  Minor  amounts o f m a r c a s i t e are p r e s e n t i n s e v e r a l l o c a l i t i e s  from  the c e n t r a l Number Three v e i n as w e l l , t h e r e f o r e , 5.4 i s regarded as a maximum pH f o r most Stage I assemblages.  The  pH. e s t i m a t e i s i n agreement w i t h the s t a b i l i t y f i e l d of kaolinite  ( F i g u r e 5.2.2), found i n the a l t e r a t i o n assemblage  a t S i l v e r Queen mine. A p a r t i c u l a r i l y unusual Stage I m i n e r a l assemblage occurs w i t h i n the Copper v e i n i n the C o l e v e i n system, where hematite, magnetite, and p y r i t e c o e x i s t . On F i g u r e 5.2.1, the assemblage p l o t s on an i n v a r i a n t p o i n t a t l o g a g  2  of  about -11 and l o g a.Q2 °f about -34.4. The pH e s t i m a t e ( F i g u r e 5.2.3) i s somewhat h i g h e r (6.5 t o 7.0) determined from the presence o f m a r c a s i t e .  than t h a t  181  1 0 0 0 / T , °K  FIGURE 5.2.4 Log ag2-Temperature diagram f o r s e l e c t e d s u l f o s a l t s u l f i d a t i o n c u r v e s . From C r a i g a n d B a r t o n ( 1 9 7 3 ) .  182  The  r a r e presence o f c o e x i s t i n g b a r i t e and p y r i t e i n  the southern s e c t i o n o f t h e Number Three v e i n , t h e Camp v e i n s , and the Chisholm v e i n s specialized conditions I mineralization  i s i n d i c a t i v e of r e l a t i v e l y  e x i s t i n g i n the l a t t e r h a l f o f Stage  (eg. see F i g u r e  5.2.2). The q u e s t i o n o f  whether t h e s u l f i d e - s u l f a t e e q u i l i b r i u m was e s t a b l i s h e d cannot be e v a l u a t e d  sufficiently until sulfur  isotope  s t u d i e s a r e completed, and f o r the purposes o f t h i s d i s c u s s i o n t h e phases i n v o l v e d a r e assumed t o be a t equilibrium. Holland  and M a l i n i n  (1979) noted t h a t  p r e c i p i t a t i o n o f b a r i t e may be induced through simple c o o l i n g o f t h e hydrothermal s o l u t i o n s . Ohmoto and Lasaga (1982) found, however, t h a t the times r e q u i r e d  for sulfate-  s u l f i d e e q u i l i b r a t i o n were i m p r a c t i c a l f o r hydrothermal systems, i n s t e a d p r o p o s i n g t h a t mixing o f t h e hydrothermal waters w i t h a s e p a r a t e , r e l a t i v e l y o x i d i z i n g s o l u t i o n i s responsible  f o r t h e s u l f i d e - s u l f a t e p a i r i n g s observed a t  temperatures o f below 350° C . Holland considered  and M a l i n i n  (1979)  t h i s process t o involve p a r t i c u l a r i l y d e l i c a t e  adjustments i n t h e s o l u t i o n chemistry i n o r d e r t o prevent r e s o r p t i o n o f s u l f i d e g r a i n s . Both b a r i t e and o t h e r phases which a p p a r e n t l y conditions  p r e c i p i t a t e d under sulfate-dominant  (eg. hematite) d i s p l a y t e x t u r a l r e l a t i o n s w i t h  o t h e r s u l f i d e m i n e r a l s t h a t a r e s u g g e s t i v e o f simple e q u i l i b r i u m as d e f i n e d by Barton et al. (1963) and i t i s p o s s i b l e t h a t s u l f a t e - s u l f i d e e q u i l i b r i u m was a t t a i n e d within the r e s e r v o i r f l u i d s before transport  and d e p o s i t i o n .  183  A second p o s s i b i l i t y i s t h a t times f o r m i n e r a l  deposition  were r e l a t i v e l y p r o t r a c t e d and s u f f i c i e n t l o c a l was a t t a i n e d i n the observed s i t e s  equilibrium-  (Ohmoto and Lasaga,  1982) . Stage I I m i n e r a l o g i e s , and  s p h a l e r i t e , provide  dominated by carbonate  fewer o p p o r t u n i t i e s t o e v a l u a t e t h e  conditions during mineral  deposition. Coexisting sphalerite  and p y r i t e o r p y r r h o t i t e may p r o v i d e a  S2  minerals  information  about l o g  ( 9* F i g u r e 5.2.1), but c o p r e c i p i t a t e d s p h a l e r i t e and e  p y r i t e were not p o s i t i v e l y i d e n t i f i e d w i t h i n t h e Number Three assemblage. S p h a l e r i t e a t S i l v e r Queen i s g e n e r a l l y v e r y Fe-poor, and from F i g u r e 5.2.1 and T a b l e s 4.5.1 t o 4.5.3, l o g a£2 f o r much o f t h e Number Three v e i n i s about -10  i f p y r i t e s a t u r a t i o n was achieved. Barton e t al. (1977)  noted t h a t abrupt i n c r e a s e s  i n Fe-content i n s p h a l e r i t e s  from t h e OH v e i n a t Creede corresponded t o f l u i d p u l s e s o f r e l a t i v e l y reducing  c h e m i s t r y . A t S i l v e r Queen, no such Fe-  r i c h zones have been i d e n t i f i e d , suggesting constant  oxidizing conditions  (induced  that  relatively  perhaps by m i x i n g  w i t h c o o l e r meteoric waters) p e r s i s t e d . Bernstein  (1985) has suggested t h a t h i g h Ge c o n t e n t s i n  s p h a l e r i t e , such as those p r e s e n t  a t S i l v e r . Queen mine, a r e  i n d i c a t i v e o f a low t o moderate l o g ag2 environment. A r n o r s s o n (1984), however, found t h a t Ge remained i n s o l u t i o n i n a mixing environment such as t h a t proposed f o r the S i l v e r Queen system. Ge p r e c i p i t a t i o n was favoured by simple c o n d u c t i v e c o o l i n g , s u g g e s t i n g  t h a t such a process  184  may  have been r e s p o n s i b l e f o r the d e p o s i t i o n of Ge-bearing  s p h a l e r i t e s i n the Number Three system. I f the e f f e c t of c o n d u c t i v e c o o l i n g was  s u f f i c i e n t t o induce p r e c i p i t a t i o n of  Ge, then the r e s u l t may  r e f l e c t an i n a b i l i t y t o m a i n t a i n  ambient v e i n temperatures, and perhaps the i n i t i a t i o n o f a d e c l i n e i n hydrothermal  activity.  The d e p o s i t i o n o f carbonate m i n e r a l s d u r i n g Stage I I and much of Stage I I I ( F i g u r e 3.4.22) was  sensitive to  changes i n d i s s o l v e d CO2 c o n t e n t of the s o l u t i o n s and  pH  (Holland and M a l i n i n , 1979). S o l u b i l i t i e s f o r a l l carbonates are a l s o lowered w i t h i n c r e a s i n g temperature  (Fournier,  1985). In t h e Number Three v e i n , the abundance of carbonate i n c r e a s e s w i t h i n c r e a s i n g d i s t a n c e from the source of f l u i d s ( F i g u r e s 3.4.23 and 3.4.25), i n d i c a t i n g t h a t d e p o s i t i o n  was  independent of temperature g r a d i e n t . Furthermore, the abrupt changes i n CO2 content r e q u i r e d f o r carbonate p r e c i p i t a t i o n cannot be generated without CO2  l o s s through b o i l i n g . As a  r e s u l t , the d e p o s i t i o n o f carbonate m i n e r a l s i s proposed t o r e p r e s e n t e i t h e r a change i n pH caused by mixing w i t h more n e u t r a l , o x i d i z e d waters  (or by H  with wallrock a l t e r a t i o n  [ H o l l a n d and M a l i n i n ,  The m i n e r a l assemblages  +  metasomatism a s s o c i a t e d 1979]).  generated d u r i n g Stage I I I  m i n e r a l i z a t i o n are the most complex a t the S i l v e r Queen mine i n terms o f c o m p o s i t i o n and d i s t r i b u t i o n . A l l of the Au,  Ag,  B i , Sb, As and Cu, and most o f the Pb m i n e r a l s are a s s o c i a t e d w i t h t h i s stage and as a r e s u l t numerous o p p o r t u n i t i e s are a v a i l a b l e t o e v a l u a t e s o l u t i o n c h e m i s t r y  185  d u r i n g t h i s s t a g e . The  conditions  of d e p o s i t i o n  are  i n t e r p r e t e d t o have been v a r i a b l e over s h o r t p e r i o d s time, as i s e v i d e n c e d by the presence of tetrahedrite-tennantite represent  " o s c i l l a t o r y zoned"  i n some l o c a l e s . These s i t e s  may  l o c a l e s where f l u i d compositions were h i g h l y  a n i s o t r o p i c due wallrock  of  to i n t e r a c t i o n with brecciated vein  m a t e r i a l . The  f a h l o r e s have e a r l i e r  (Chapter  been i n t e r p r e t e d t o d i s p l a y p o s s i b l e evidence of a hydrothermal c e l l and  or IV)  shrinking  o v e r a l l present an outward t r e n d  towards i n c r e a s i n g l y e v o l v e d (Sb-rich)  compositions.  In  s e v e r a l g r a i n s , however, the zone t o zone t r a n s i t i o n s are sharp, and  r a t h e r than d i s p l a y i n g a t r a n s i t i o n from  one  c o m p o s i t i o n t o another, appear t o have been abrupt.  The  turbulent  n a t u r e of the f l u i d flow i n a b r e c c i a t e d  environment may the  r e s u l t i n l o c a l v a r i a t i o n s i n the a b i l i t y of  f l u i d s to deposit  the g r a i n s may  t e t r a h e d r i t e - t e n n a n t i t e s . As  d i s p l a y sharp zonal boundaries w i t h  scale compositional  v a r i a t i o n s , but w i l l r e f l e c t  d e v e l o p i n g w h o l e - v e i n chemistry across g r a i n . Hackbarth and compositional  a result, small-  the  the w i d t h of  the  P e t e r s e n (1984) proposed t h a t  v a r i a t i o n s w i t h i n s i n g l e g r a i n s may  f r a c t i o n a l c r y s t a l l i z a t i o n , with compositional  be due  to  heterogeneity  generated by v a r y i n g exposure t o more o r l e s s e v o l v e d f l u i d s . I f t h i s i s indeed the case, then a r e l a t i v e l y degree of c o m p o s i t i o n a l Stage I I I  fluids.  large  v a r i a t i o n c o u l d be expected f o r the  186  Cu-bearing phases  (tetrahedrite-tennantite,  s e l i g m a n n i t e - b o u r n o n i t e and c h a l c o p y r i t e )  a r e t h e most  widespread o f t h e Stage I I I assemblages. A number o f c o n s t r a i n t s can thus be applied, t o the d e p o s i t i o n a l conditions  as i m p l i e d by t h e i r presence. F i g u r e  5.2.1 p l o t s  the boundary f o r t h e c h a l c o p y r i t e t o p y r i t e + b o r n i t e transition at a l o g a g  v a l u e o f about -8.6. S i m i l a r i l y , the  2  t r a n s i t i o n from e n a r g i t e a  to tetrahedrite i s placed  at alog  S 2 v a l u e o f approximately -9.7, w i t h n e i t h e r o f t h e phase  changes a f f e c t e d by l o g arj  2  and t o a l e s s e r e x t e n t , pH  v a r i a t i o n . I n t h e S i l v e r Queen mine, t h e phase e n a r g i t e has not been i d e n t i f i e d , and b o r n i t e has been noted as r a r e i n c l u s i o n s i n p y r i t e a t the southern e x t e n t o f t h e Number Three v e i n . As a r e s u l t , t h e v a l u e o f l o g a g Stage I I I m i n e r a l i z a t i o n i s c o n s t r a i n e d  2  present  during  by an upper l i m i t o f  about -9.7. To e v a l u a t e the lower l i m i t s f o r l o g a g  2  values,  s u l f i d a t i o n curves f o r p r o u s t i t e and m a t i l d i t e a r e c o n s u l t e d ( F i g u r e 5.2.4). A t 250° C , t h e t r a n s i t i o n from t h e assemblage a r g e n t i t e + r e a l g a r ag  2  t o p r o u s t i t e occurs a t a l o g  o f -12.5, whereas t h e t r a n s i t i o n from s i l v e r + b i s m u t h  to  m a t i l d i t e occurs a t -16. The s t a b i l i t y o f p r o u s t i t e and m a t i l d i t e i n t h e Number Three system thus c o n s t r a i n s the lower l i m i t o f l o g a g  2  a t about -12.5. The l a s t major  c o n s t r a i n i n g element p r o v i d e d  by Stage I I I m i n e r a l o g i e s i s  the presence o f t h e assemblage g a l e n a + a n g l e s i t e i n t h e P o r t a l v e i n s , Lead v e i n , Number Two v e i n , and Owl v e i n . These v e i n s r e p r e s e n t  systems t h a t a r e among t h e most d i s t a l  187  t o the  "source" as d e f i n e d by t e t r a h e d r i t e compositions  (Chapter IV) and  thus may  represent  i n the S i l v e r Queen system due  the most o x i d i z e d areas  to i n t e r a c t i o n s with d i l u t e  o x i d i z e d meteoric waters. A maximum l o g an,2 °f -31.4 5.2.1) i s i n f e r r e d f o r t h i s  5.3  (Figure  assemblage.  E v o l u t i o n of the Hydrothermal System The  epithermal veins  a t S i l v e r Queen developed along a  s e r i e s of near v e r t i c a l f r a c t u r e s i n response t o upward  and  l a t e r a l movement of hydrothermal f l u i d s , p o s s i b l y generated by  "seismic  pumping" (Thomson and  simple p l u t o n d r i v e n c o n v e c t i v e  Sinclair,  Initial  or  by  motion (eg. Barton et a l . ,  1977). An a s s o c i a t i o n w i t h U n i t 6 dykes may contributed  1991)  have a l s o  t o the l o c a l l i z a t i o n of m i n e r a l i z i n g s o l u t i o n s .  f l u i d i n c l u s i o n and  C^ 1  i s o t o p e s t u d i e s by Thomson  (pers comm.) i n d i c a t e t h a t f l u i d s were dominantly meteoric i n o r i g i n , w i t h temperatures o f up t o 240° C . assemblage e v a l u a t i o n ,  From m i n e r a l  the heat source t h a t drove the  fluids  i s l o c a t e d at depth i n the southern s e c t i o n of the mine area ( F i g u r e 2.3.1), w i t h the southern end system r e p r e s e n t i n g  of the Number Three  the v e i n segment c l o s e s t t o the  source. F l u i d s are i n t e r p r e t e d t o have undergone a degree of l a t e r a l motion due mineralogical  zonation  the S i l v e r Queen area,  heat large  t o the o v e r a l l outward  away from the s o u t h - c e n t r a l  block  l a t e r a l variation i n fahlore  compositions i n the Number Three v e i n changes i n the c h a r a c t e r  (Chapter I V ) ,  and  of m i n e r a l i z a t i o n from south t o  of  Gel  precipitates  Fibrous Very  crystals  fine  Skeletal  crystals crystals  S e c t o r - zoned I Selective Delicate 1  Large  SATURATION  =  replacement. growth  banding,  crystals EQUILIBRIUM  Selective Mild  crystals  etching  etching  Deep  etching  Total  removal  FIGURE 5.3.1 T e x t u r a l p r o p e r t i e s i n d i c a t i v e o f degree s a t u r a t i o n . From Barton e t a l (1977). A t S i l v e r Queen, p y r i t e and s p h a l e r i t e d i s p l a y t e x t u r a l v a r i a t i o n s t h a t p r o b a b l y r e l a t e d t o degree of s a t u r a t i o n .  189  FIGURE 5.3.2 S o l u b i l i t y of b a r i t e contoured on a t e m p e r a t u r e - s a l i n i t y diagram, showing p r e d i c t e d t r a j e c t o r i e s f o r b o i l i n g and mixing. pH i s s e t a t 5.5. From Hayba fit, a l (1985).  190  n o r t h . Of p a r t i c u l a r note i s t h e change i n form o f Stage I p y r i t e and.Stage Number Three v e i n  I I s p h a l e r i t e from south t o n o r t h i n the ( r e f e r t o F i g u r e 5.3.1).  In t h e south,  s p h a l e r i t e and p y r i t e a r e c h a r a c t e r i s t i c a l l y c o l l o f o r m o r as f i n e g r a i n e d aggregates, i n d i c a t i v e o f a h i g h degree o f s u p e r s a t u r a t i o n f o r these two phases. Towards the n o r t h , the t e x t u r e s appear t o r e p r e s e n t d e c r e a s i n g degrees o f s u p e r s a t u r a t i o n , u n t i l near e q u i l i b r i u m t e x t u r e s a r e developed i n t h e northernmost  intersections.  Finely  laminated carbonate o c c u r r i n g i n t h e n o r t h e r n segments o f the Number Three s t r u c t u r e i s a l s o i n d i c a t i v e o f a d i s t a l p o s i t i o n i n the. hydrothermal system. Examples o f u n d e r s a t u r a t i o n a r e minor, i d e n t i f i e d by t h e absence o f p a r t i c u l a r phases  (eg. p y r i t e i n Stage I I I ) r a t h e r than by  dissolution. The p o t e n t i a l complexes i n v o l v e d i n t h e t r a n s p o r t o f metals i n t h e hydrothermal system a r e summarized i n Table 5.2.1. C h l o r i d e c o n t e n t s i n f l u i d i n c l u s i o n s a r e i n c o n c l u s i v e , a l t h o u g h r e l a t i v e l y low s a l i n i t i e s a r e commonly found i n i n c l u s i o n s w i t h i n s p h a l e r i t e . In most hydrothermal systems, Zn t r a n s p o r t i s accomplished by a c h l o r i d e complex (Reed and Spycher, 1985) r a t h e r than a b i s u l f i d e complex, as may be t h e case f o r some o t h e r metals. As a r e s u l t , t h e v a l u e s o b t a i n e d f o r NaCl e q u i v a l e n t percent (<6 molal) may, t h e r e f o r e , r e p r e s e n t a mixed v a l u e r a t h e r than t h e s t a r t i n g v a l u e f o r t h e s o l u t i o n s . Another p o i n t o f note i n v o l v e s t h e t r a n s p o r t o f Pb, which a t t h e temperatures  191  i n d i c a t e d f o r t h e Number Three v e i n , occurs dominantly as a carbonate complex  (Reed and Spycher, 1985). In the S i l v e r  Queen system, t r a n s p o r t o f the remainder o f the economic metals (Cu, Ag, Au, Cd, and Hg) may have been accomplished by s u l f i d e / s u l f a t e o r c h l o r i d e complexing. T r a n s p o r t a t i o n of Ge, Ga, In, and t h e semimetals was p r o b a b l y accomplished by h y d r o x y l complexes  (Arnorsson, 1984; H e i n r i c h and Eadington,  1986; C r e r a r et a l . ,  1985)  Ore d e p o s i t i o n a t Owen Lake appears t o have been dependent on a number o f f a c t o r s . P r e c i o u s metal grades are e l e v a t e d and r e l a t i v e l y c o n s i s t e n t (Nowak, 1991) deeper s o u t h e r n segment o f the Number Three v e i n .  i n the The  i n c r e a s e i n o v e r a l l A u a n d Ag grades corresponds t o two s i g n i f i c a n t f e a t u r e s : (1) the change i n d i r e c t i o n o r  "bend"  in: the v e i n , where s t r u c t u r a l c o n t r o l of the v e i n o r i e n t a t i o n s w i t c h e d from one j o i n t s e t t o another, and (2) the approximate l i t h o l o g i c boundary between the f e l d s p a r porphyry u n i t and t h e more porous fragmental r o c k s .  The  former p o i n t i s important i n t h a t a s i m i l a r e f f e c t i s seen throughout the S i l v e r Queen area; east-west t r e n d i n g v e i n s are dominated by Stage I I I assemblages  and t e n d t o be  e n r i c h e d i n A g - b e a r i n g m i n e r a l s r e l a t i v e t o t h e more e x t e n s i v e northwest t r e n d i n g v e i n s . T h i s e f f e c t c o u l d be r e p r e s e n t a t i v e o f opening a l o n g the second f r a c t u r e s e t towards the end o f Stage I I m i n e r a l i z a t i o n , w i t h Au and Ag grades i n f l u e n c e d by t h e enrichment i n Stage I I I m i n e r a l i z a t i o n r e l a t i v e t o e a r l i e r assemblages. More  192  e s s e n t i a l t o the d e p o s i t i o n of e l e v a t e d l e v e l s of Au and however, may  Ag,  be the e f f e c t of the host l i t h o l o g y on the  nature of the m e t a l - b e a r i n g s o l u t i o n s . Au and Ag  contents  i n c r e a s e d r a m a t i c a l l y i n response t o c r o s s i n g i n t o  the  fragmental r o c k s , although v e i n t h i c k n e s s a p p a r e n t l y decreases towards the south  (Nowak, 1991). M i n e r a l o g i c a l l y ,  the assemblage a t t h i s p o i n t i s d i s t i n g u i s h a b l e by the appearence of a i k i n i t e and a r g e n t i a n t e t r a h e d r i t e i n Stage I I I m i n e r a l i z a t i o n . These changes i n the c h a r a c t e r of the o r e c o u l d be l i n k e d t o a change i n the p e r m e a b i l i t y of the host r o c k s . Cheng et a l . (1991) have noted a r e l a t i v e l y abrupt i n c r e a s e i n the width of the s t r o n g l y a l t e r e d envelope which corresponds  r o u g h l y t o the p o s i t i o n of the  c o n t a c t w i t h the fragmental r o c k s . Furthermore,  disseminated  Stage I I and Stage I I I s u l f i d e s are present throughout  the  a l t e r e d t u f f a c e o u s r o c k s , s u g g e s t i n g t h a t f l u i d s were a b l e t o c i r c u l a t e i n the w a l l r o c k and d e p o s i t s u l f i d e w e l l i n t o Stage I I I . From these o b s e r v a t i o n s , one might i n f e r t h a t w a l l r o c k p l a y s an important r o l e i n determining the  solution  c h e m i s t r y of a l l m i n e r a l i z i n g episodes where the m i n e r a l i z a t i o n was s o l u t i o n s passed  hosted by the fragmental r o c k s . As  from the t u f f a c e o u s rocks i n t o the  permeable and l e s s a l t e r e d f e l d s p a r porphyry  the  less  and  m i c r o d i o r i t e u n i t s , pH b u f f e r i n g , of the f l u i d s by the w a l l r o c k became l e s s important and m i n e r a l d e p o s i t i o n was c o n t r o l l e d by simple c o o l i n g and  dilution.  193  M i n e r a l d e p o s i t i o n a t S i l v e r Queen i s proposed t o have been i n i t i a t e d by i n t e r a c t i o n and mixing of two f l u i d s . An o r i g i n by b o i l i n g Drummond and Ohmoto, 1985)  separate  (eg. Reed and Spycher,  1985;  i s r e j e c t e d due t o the f r e q u e n t l y  c o a r s e g r a i n e d nature of the o r e , p r e l i m i n a r y  fluid  i n c l u s i o n a n a l y s e s , l a c k of b l a d e d c a l c i t e , the l a c k of c o r r e l a t i o n between carbonates and p r e c i o u s metals, and depth of f o r m a t i o n of the system. The heated m i n e r a l i z i n g f l u i d s t r a v e l l e d along f r a c t u r e s u n t i l mixing w i t h a c o o l e r , l e s s s a l i n e meteoric water o c c u r r e d , r e s u l t i n g i n a temperature  decrease a t a near c o n s t a n t or s l i g h t l y  i n c r e a s i n g pH. The temperature s o l u b i l i t i e s of the s u l f i d e  d e c l i n e would reduce the  (or c h l o r i d e ) s p e c i e s by one o r  more o r d e r s of magnitude w h i l e h a v i n g a much l e s s e r e f f e c t on metal c o n c e n t r a t i o n s (Reed and Spycher,  1985).  Lateral  v a r i a t i o n s i n mineralogy i n the v e i n system would be c o n t r o l l e d by the s t a b i l i t i e s and c o n c e n t r a t i o n s of the metal complexes (Susak and C r e r a r , 1982). Barnes 1975)  (1963,  and Likhachev (1975) d e f i n e d a g e n e r a l i z e d  hydrothermal  zoning sequence outward from the f l u i d  as Fe-Ni-Sn-Zn-Pb-Ag-Au-Sb-Hg f o r both b i s u l f i d e c h l o r i d e complexed metals. Barnes  source  and  (1975) noted however, t h a t  c h l o r i d e complexed metals were l e s s l i k e l y t o f o l l o w the proposed sequence,  r e s u l t i n g i n v a r i a t i o n s i n the outward  sequence of m i n e r a l d e p o s i t i o n . A t S i l v e r Queen, the o v e r a l l p a r a g e n e t i c sequence c o u l d r e p r e s e n t the zoning p a t t e r n proposed by Barnes  (1975), w i t h l e a s t s o l u b l e and most  194  c o n c e n t r a t e d F e - s u l f i d e s and b a r i t e o c c u r r i n g paragenetically, and  earliest  f o l l o w e d by s p h a l e r i t e (Zn), galena  (Pb),  s u l f o s a l t s (Ag, Sb, A s ) . In t h e extreme case,  i n t e r a c t i o n s w i t h c o o l e r , o x i d i z i n g groundwaters c o u l d  lead  t o t h e p r e c i p i t a t i o n o f s u l f a t e phases i n t h e " p e r i p h e r a l " veins  (eg. F i g u r e  5.3.2). A t S i l v e r Queen, t h e v e i n s which  are i n t e r p r e t e d t o have been most d i s t a l from t h e heat source (Camp, Chisholm, and e a s t e r n C o l e v e i n s ) do c o n t a i n abundant b a r i t e and s i l v e r m i n e r a l s w i t h i n t h e i r assemblages which may r e p r e s e n t  t h i s e f f e c t . A s i m i l a r s i t u a t i o n has  been proposed f o r t h e OH v e i n a t Creede, where b a r i t e (and associated end  s i l v e r mineralization)  occurs, toward t h e southern*  o f t h e v e i n where f l u i d i n c l u s i o n s a l i n i t i e s and  temperatures a r e lowest (Hayba e t a l . , 1985). In summary, t h e hydrothermal system i s i n t e r p r e t e d t o have been i n i t i a t e d as an expanding c e l l o f heated meteoric waters. M e t a l t r a n s p o r t  i s uncertain, with b i s u l f i d e or  c h l o r i d e complexing expected t o be t h e dominant mode of. transport reacted  f o r base- and p r e c i o u s - m e t a l s . The heated waters  almost immediately w i t h c o o l e r , more o x i d i z i n g  m e t e o r i c waters, r e s u l t i n g i n a zone o f q u a r t z - p y r i t e - b a r i t e i n t h e s o u t h e r n s e c t i o n of t h e system, moving northward i n t o a hematite-pyrite-quartz  assemblage where s u l f a t e was the  dominant s u l f u r s p e c i e s . A t t h e maximum e x t e n t o f t h e hydrothermal c e l l , p y r i t e and quartz were t h e dominant phases p r e c i p i t a t e d , w i t h b a r i t e and p y r i t e formed towards the margins o f t h e system where t h e e f f e c t o f t h e c o o l e r  195  waters was  more important. The e f f e c t of the expanding  cell  i s expressed i n the assemblage change from hematite t o p y r i t e t o p y r i t e - p y r r h o t i t e - a r s e n o p y r i t e , r e f l e c t i n g the i n c r e a s i n g l y r e d u c i n g nature of the s o l u t i o n s . As was  reduced t o s u l f i d e  Mn  ), H  J  was  sulfate  (coupled w i t h o x i d a t i o n of Mn^  e x t r a c t e d from the s o l u t i o n s  to  ( H o l l a n d and  M a l i n i n , 1979), r e s u l t i n g i n an i n c r e a s e i n CO3 c o n c e n t r a t i o n and concomittant carbonate  precipitation.  D e p o s i t i o n of the carbonate, coupled w i t h c o l l a p s e of the hydrothermal  cell  and a s s o c i a t e d c o o l i n g , r e s u l t e d i n  d e s t a b i l i z a t i o n of the z i n c c h l o r i d e complex and p r e c i p i t a t i o n o f s p h a l e r i t e . Continued i n t e r a c t i o n of the f l u i d s w i t h the c o o l e r meteoric waters  lowered  the  s o l u b i l i t i e s of o t h e r metals, r e s u l t i n g i n the p r e c i p i t a t i o n of  Stage I I I s u l f i d e s and g o l d . Gold d e p o s i t i o n took p l a c e  near p y r i t e g r a i n s u r f a c e s , where exposure  to f l u i d s  u n d e r s a t u r a t e d w i t h r e s p e c t t o p y r i t e caused Iron r e l e a s e d by from the g r a i n sufaces was F e ^ , whereas g o l d was +  reduced from A u  +  dissolution. o x i d i z e d to  t o Au° and d e p o s i t e d  near the p y r i t e g r a i n s u r f a c e . Zonation i n the v e i n  was  c o n t r o l l e d by the. amount of opening the v e i n e x p e r i e n c e d d u r i n g m i n e r a l i z a t i o n , the nature of the w a l l r o c k , and the r e l a t i v e s t a b i l i t i e s o f the metal s p e c i e s i n s o l u t i o n . The source of the metals i n the m i n e r a l i z i n g  solutions  i s a t p r e s e n t u n c e r t a i n . Analyses of v e i n bitumen (Stage  IV)  by Thomson e t al.  ( i n prep.) d i s p l a y carbon i s o t o p i c values  r a n g i n g from -25.7  t o -29 per m i l , s u g g e s t i n g a t e r r e s t r i a l  196  o r i g i n f o r the carbon. E l e v a t e d Ge contents i n s p h a l e r i t e are a l s o s u g g e s t i v e o f metal d e r i v a t i o n from r o c k s c o n t a i n i n g o r g a n i c matter Furthermore,  sedimentary  (eg. B e r n s t e i n , 1985).  preliminary f l u i d inclusion results  indicate  t h a t s a l i n i t i e s were r e l a t i v e l y low and t h a t f l u i d s were dominantly  o f meteoric o r i g i n . Late Cretaceous  sedimentary  r o c k s c o n t a i n i n g s u b s t a n t i a l amounts o f o r g a n i c matter a r e known t o occur i n t h e r e g i o n , i n p a r t i c u l a r t o t h e west o f the study area on t h e s l o p e s o f Mt. Nadina (Lang,  1929). As  a r e s u l t , o r g a n i c - b e a r i n g sediments are suggested t o have been an important, the hydrothermal  5.4  i f not t h e dominant, metal c o n t r i b u t o r t o  solutions.  Comparison w i t h Other V e i n Deposits T a b l e 5.4.1 summarizes t h e d e f i n i n g f a c t o r s f o r  " a d u l a r i a - s e r i c i t e " and " a c i d - s u l f a t e " type e p i t h e r m a l d e p o s i t s , w i t h t h e S i l v e r Queen system i n c l u d e d f o r comparison.  The S i l v e r Queen v e i n s do not f a l l n e a t l y i n t o  e i t h e r c a t e g o r y , perhaps a r e s u l t o f the nature o f t h e metal source and p r o b a b l e i n t e r a c t i o n o f two d i s p a r a t e f l u i d s d u r i n g m i n e r a l d e p o s i t i o n . In g e n e r a l , the S i l v e r Queen system more c l o s e l y resembles  an A d u l a r i a - s e r i c i t e - t y p e  environment, w i t h t h e absence o f a d u l a r i a and t h e presence of. b i s m u t h i n i t e b e i n g t h e most notable e x c e p t i o n s . Of t h e major p r o d u c i n g e p i t h e r m a l d i s t r i c t s , the one most c l o s e l y resembling S i l v e r Queen i s Creede, w i t h i t s s i m i l a r l i t h o l o g i e s , h o s t - m i n e r a l i z a t i o n age r e l a t i o n s h i p s and v e i n  197  m i n e r a l o g i e s . In p a r t i c u l a r , Creede i s a l s o proposed t o have o r i g i n a t e d i n p a r t as the r e s u l t of i n t e r a c t i o n between two f l u i d s of d i s p a r a t e temperature and c o m p o s i t i o n . As w i t h Creede, b a r i t e - A g - m i n e r a l - r i c h v e i n s are l o c a t e d near the p e r i p h e r y o f the S i l v e r Queen system, where m i n e r a l i z i n g f l u i d s e x p e r i e n c e d a g r e a t e r i n f l u e n c e from c o o l e r o x i d i z i n g groundwaters. The absence of c h l o r i t e i n t h e v e i n s , and a d u l a r i a i n the a l t e r a t i o n  (perhaps due t o a s u s t a i n e d low  pH), however, d i s t i n g u i s h e s the S i l v e r Queen system from the ores a t Creede.  TABLE 5.4.1 Comparative Anatomy o f V o l c a n i c - H o s t e d Spithermal D e p o s i t s . Type A: A d u l a r i a - s e r i c i t e 1.)Host Rock  silicic  to intermediate volcanics  2.)Ore/host age relations  ages of ore and h o s t d i s t i n c t  3.)Mineralogy  Fahlores, argentite c h l o r i t e common selenides present Mn gangue p r e s e n t no b i s m u t h i n i t e  4.)Alteration  s e r i c i t i c to a r g i l l i c abundant a d u l a r i a occasional kaolinite  5.)Temperature  200 t o 300° C.  6.)Salinity  0 t o 13 wt% NaCl e q u i v .  7.)Source o f sulfide sulfur  Leaching of w a l l r o c k s deep i n system  198  Type B: A c i d - s u l f a t e 1. )Host Rock  rhyodacite  typical  2. )Ore/host age relations  s i m i l a r ages f o r ore and host  3. ) M i n e r a l o g y  enargite, pyrite c h l o r i t e rare no s e l e n i d e s Mn-minerals r a r e b i s m u t h i n i t e present  4. ) A l t e r a t i o n  advanced a r g i l l i c e x t e n s i v e hypogene no a d u l a r i a  5. )Temperature  200 t o 300° C.  6. ) S a l i n i t y  1 t o 24 wt% NaCl equiv.  7 .)Source o f sulfide sulfur  probably  alunite  magmatic  S i l v e r Queen v e i n s 1. )Host Rocks  intermediate v o l c a n i c s / i n t r u s i v e s  2. )Ore/host age relations  20 Ma  3. ) M i n e r a l o g y  F a h l o r e s abundant, r a r e a c a n t h i t e abundant e a r l y p y r i t e and b a r i t e no c h l o r i t e i n v e i n s no s e l e n i d e s abundant Mn-carbonates trace bismuthinite  4. ) A l t e r a t i o n  S e r i c i t i c to a r g i l l i c no a d u l a r i a o r a l u n i t e  5. )Temperature  230 t o 280° C.  6. ) S a l i n i t y  <10 wt% NaCl equiv.  7 . )Source of sulfide sulfur  p o s s i b l y from o r g a n i c - r i c h tuffaceous volcanics/sediments  difference  199  6.0 6.1  PRACTICAL ASPECTS OF MINERALOGIC STUDIES  INTRODUCTION An important  consequence o f m i n e r a l o g i c a l s t u d i e s a t  the S i l v e r Queen mine i s the p r o v i s i o n o f data the form and occurrence  concerning  o f economic m i n e r a l i z a t i o n i n t h e  v e i n s . A number of p o t e n t i a l l y v a l u a b l e commodities a r e p r e s e n t i n t h e S i l v e r Queen v e i n s , and the aim o f t h i s c h a p t e r i s t o f u r t h e r e l a b o r a t e on how these r e s o u r c e s might be l o c a t e d and developed  i n t h e most e f f i c i e n t manner. Two  p r a c t i c a l aspects o f t h e m i n e r a l i z a t i o n w i l l be d i s c u s s e d : (1) The d i s t r i b u t i o n and l i b e r a t i o n c h a r a c t e r i s t i c s o f important  phases and phase a s s o c i a t i o n s ,  i n c l u d i n g p o t e n t i a l problems w i t h r e c o v e r y o f significant  minerals.  (2) The d e l i n e a t i o n o f , and e x p l o r a t i o n f o r , a d d i t i o n a l ore r e s e r v e s as p r e d i c t e d through e x i s t i n g mineralogic  trends.  The Number Three v e i n system, i n c l u d i n g the NG3 v e i n e x t e n s i o n , i s the most important  o f the known v e i n s a t  S i l v e r Queen. The v e i n system i s open a t the south and a t depth, and p r o v i d e s the b e s t o p p o r t u n i t y t o expand e x i s t i n g r e s e r v e s . Other v e i n systems w i l l be c o n s i d e r e d , and a base for be  f u t u r e comparison o f v e i n systems on the p r o p e r t y  will  provided. Gold,  silver,  and z i n c a r e the metals w i t h the g r e a t e s t  economic p o t e n t i a l a t S i l v e r Queen, and the d i s t r i b u t i o n and  200  recovery"of  these p a r t i c u l a r metals  importance.  Potentially  copper  r e s o u r c e s o f l e a d and  a r e a l s o present throughout  galena,  chalcopyrite,  number o f l e s s gallium,  byproduct  germanium, i n d i u m ,  Occurrence The  t h e v e i n system as  and t e t r a h e d r i t e . A d d i t i o n a l l y , a  important  somewhat e r r a t i c a l l y  6.2  important  i s of critical  metals,  cadmium, a n d b i s m u t h a r e a l s o  distributed within the deposit.  and B e n e f i c i a t i o n o f Economic  Electrum,  less  than  found  30 m i c r o n s  i n diameter  some o f w h i c h a r e v i s i b l e  Number F i v e v e i n s  Figure pyrite,  identified,  3.4.18).  (Figure 3.5.8).  (Table 6.1.2).  Larger  i n hand s p e c i m e n , were  I n most c a s e s ,  electrum  f i n e - g r a i n e d p y r i t e (eg.  E l e c t r u m may a l s o o c c u r  interstitial  inclusions  g a l e n a - A g - s u l f o s a l t masses,  associated with  tetrahedrite,  a Pb-concentrate  as rounded  (Tables  Au- and A g - r i c h P o r t a l Three and  i n galena o r intergrown  commonly c l o s e l y  grains  I t generally occurs  i n t h e abnormally  occurs  t h e o n l y Au m i n e r a l  i n t h e Number T h r e e a n d a s s o c i a t e d s y s t e m s  and 6 . 1 . 2 ) .  grains,  (Table  100% o f t h e A u a n d p e r h a p s 5% o f t h e A g  contains e f f e c t i v e l y  6.1.1  as s u l f i d e s  i nthe  w i t h e l e c t r u m b e i n g t h e o n l y economic n o n - s u l f i d e  phase i d e n t i f i e d .  present  Minerals  m a j o r i t y o f p o t e n t i a l l y economic metals  Number T h r e e v e i n s y s t e m a r e p r e s e n t 6.1.1),  including  i n sphalerite,  c h a l c o p y r i t e o r even as i s o l a t e d  t o gangue q u a r t z . Most s h o u l d r e p o r t t o  (given that s u f f i c i e n t  separation  from  f i n e - g r a i n e d p y r i t e has been a c h i e v e d - r e f e r t o T a b l e  6.1.1).  201  S i l v e r i s d i s t r i b u t e d throughout  a number o f s u l f i d e  m i n e r a l s t h a t m o s t l y r e p r e s e n t Stage I I I m i n e r a l i z a t i o n . A r g e n t i a n t e t r a h e d r i t e i s the most important  Ag-bearing  phase w i t h i n t h e Number Three, George Lake, and Cole Lake systems, c o n t a i n i n g up t o 90% o f the Ag i n these systems (Table 6.1.1). I n t h e Camp and Chisholm  systems, a r g e n t i a n  t e t r a h e d r i t e occurs w i t h s i g n i f i c a n t q u a n t i t i e s o f o t h e r Agb e a r i n g phases, n o t a b l y p y r a r g y r i t e and p e a r c e i t e (Table 6.1.1). T e t r a h e d r i t e i s r e p l a c e d by o t h e r A g - s u l f i d e s as the most important Ag-bearing m i n e r a l i n t h e P o r t a l v e i n s ( m a t i l d i t e , g u s t a v i t e , b e r r y i t e , p e a r c e i t e ) and NG3 v e i n ( p r o u s t i t e , Ag-Pb-Sb s u l f o s a l t ) . In a l l v e i n s , Ag-bearing m i n e r a l s a r e c l o s e l y a s s o c i a t e d with, galena and c h a l c o p y r i t e . T e t r a h e d r i t e masses commonly c u t ( F i g u r e 3.4.9) o r a r e intergrown w i t h ( F i g u r e 3.4.6) o t h e r Stage I I I phases, w i t h g r a i n s i z e s averaging about 0.1 t o 0.3 mm.. Much o f t h e Ag would r e p o r t t o a Cu-concentrate,  dominated  e i t h e r by c h a l c o p y r i t e o r t e t r a h e d r i t e . In d i s t a l  systems  such as t h e Camp and Chisholm v e i n s , t h e e l e v a t e d  Ag-content  of t h e mineralogy  (see Chapters  s i z e s up t o s e v e r a l mm.  3 and 4) combined w i t h g r a i n  (eg. F i g u r e 3.5.7) a l l o w s f o r much  e a s i e r r e c o v e r i e s o f Ag-bearing phases. Contamination Cu-concentrate  of the  i n a l l cases would mostly be t h e r e s u l t o f  galena i n c l u s i o n s w i t h o r along t h e margins o f t h e l a r g e r t e t r a h e d r i t e masses. I n sample s i t e 3CHN89-1 (Appendix A) i n the deep south NG3 v e i n , Ag-bearing phases occur as f i n e g r a i n e d i n t e r g r o w t h s and i n c l u s i o n s i n massive galena  (Table  202  6.1.1). As a r e s u l t , Ag (and Au) should r e p o r t e n t i r e l y t o the  Pb-concentrate. Recovery o f base metals  (Cu, Pb, and Zn) from Number  Three v e i n ores w i l l be e a s i e s t w i t h v e i n m a t e r i a l from the northernmost  and southernmost extensions o f t h e system. In  the n o r t h , the c o a r s e - g r a i n e d , euhedral nature o f galena and s p h a l e r i t e (Table 6.1.1) should a l l o w f o r r e l a t i v e l y  easy  l i b e r a t i o n and h i g h r e c o v e r y , w i t h gangue mineralogy dominated by r e l a t i v e l y s o f t carbonate m i n e r a l s . W i t h i n the c h a l c o p y r i t e - r i c h zone, Zn-,Cu- and Pb- phases mostly a r e i n t i m a t e l y intergrown  (eg. F i g u r e 3.4.5), w i t h t h e  appearence o f the Cu-Ag-Pb-Bi phase b e r r y i t e p r e s e n t i n g the s p e c i a l problem o f p r o v i d i n g a p o t e n t i a l contaminant f o r both the Pb- and t h e Cu-concentrates.  B e r r y i t e from  this  p a r t o f the v e i n i s commonly intergrown w i t h o r r e p l a c e d by galena  ( F i g u r e 3.4.11), but most o f the s m a l l e r b e r r y i t e  grains are contained i n c h a l c o p y r i t e or s p h a l e r i t e (Figure 3.4.5), c r e a t i n g a p a r t i c u l a r i l y complex d i s t r i b u t i o n f o r much o f the Ag and Pb i n t h e deep, n o r t h e r n p a r t o f the Number Three v e i n . Toward the south, the complex m i n e r a l assemblage i s r e p l a c e d by s i m p l e r , commonly c o a r s e - g r a i n e d m i n e r a l o g i e s (Table 6.1.1) i n c l u d i n g s p h a l e r i t e and galena. U n f o r t u n a t e l y , m a t e r i a l i n the c e n t r a l segment o f the Number Three v e i n i s dominated by hard quartz and p y r i t e gangue, and galena from t h i s s e c t i o n o f the v e i n i s s c a r c e and m o s t l y l o c k e d i n p y r i t e . S p h a l e r i t e from the c e n t r a l p a r t o f the Number Three v e i n i s more abundant and e a s i e r t o  203  r e c o v e r ; w i t h t h e g r e a t e r v e i n widths, the c e n t r a l  section  r e p r e s e n t s a p o t e n t i a l l y important r e s e r v e o f Zn (eg. Nowak, 1991). F u r t h e r south, t h e percentage of s p h a l e r i t e , galena, and t e t r a h e d r i t e i n t h e v e i n i n c r e a s e s . G r a i n s i z e s a r e much s m a l l e r than i n t h e n o r t h , although s p h a l e r i t e masses a r e commonly up t o s e v e r a l mm.  i n diameter. Galena i s t y p i c a l l y  intergrown w i t h t e t r a h e d r i t e  ( F i g u r e 3.4.6), a i k i n i t e , o r  seligmannite, necessitating f i n e r grinding sizes to e l i m i n a t e t h e problem Approximately  o f Cu- and Pb-mineral  contamination.  10% o f t h e galena i n the southern p a r t o f t h e  vein i s t i g h t l y locked i n sphalerite or fine-grained p y r i t e masses, p r o b a b l y forming t h e g r e a t e s t source o f Pb l o s s d u r i n g p r o c e s s i n g . South o f t h e d e c l i n e area, the degree o f i n t e r g r o w t h w i t h galena appears t o decrease. W i t h i n t h e NG3 v e i n , l i b e r a t i o n o f base-metal  s u l f i d e s i s improved.  Masses  of galena, s p h a l e r i t e , and t e t r a h e d r i t e are l a r g e r and l e s s intergrown (Table 6.1.1) i n t h e NG3 v e i n , w i t h phases l a r g e l y absent from t h e southernmost intersection  Cu-bearing  and deepest  (3CHN89-l-see Appendix A ) . Sample s i t e 3CHN89-1  i s e s p e c i a l l y important i n t h a t t h e base-metal c o n s i s t s o f two phases:  assemblage  galena, which c o n t a i n s a l l o f t h e Ag  and Au, and s p h a l e r i t e , which a l s o c o n t a i n s a p p r e c i a b l e q u a n t i t i e s o f Ga, Cd, Ge, and I n (Table 4.5.2). Contamination almost n i l ,  from intergrown phases i n t h i s i n t e r s e c t i o n i s  and t h e gangue m i n e r a l assemblage i n c l u d e s a  l a r g e amount o f carbonate.  204  C o n c e n t r a t i o n s o f base-metal  s u l f i d e s i n other  s t r u c t u r e s a t S i l v e r Queen a r e much l e s s  important  e c o n o m i c a l l y , e i t h e r because o f l a c k o f d e f i n i t i o n o f a v a i l a b l e r e s e r v e s (as i n the George Lake v e i n ) o r because of predominance o f p r e c i o u s - m e t a l - b e a r i n g phases (as i n t h e Camp and P o r t a l v e i n s ) .  The George Lake and Cole Lake v e i n s  c o n t a i n t h e l a r g e s t p o t e n t i a l r e s e r v e s o u t s i d e o f the Number Three system, and much d e l i n e a t i o n remains t o be done. In the George Lake v e i n , b e n e f i c i a t i o n would be d i f f i c u l t due t o t h e i n t e r l o c k e d nature o f t h e major s u l f i d e s p e c i e s ( i n c l u d i n g p y r i t e ) ( T a b l e 6.1.1). Furthermore, f i n e - g r a i n e d q u a r t z i s p r e s e n t throughout  much o f the known v e i n ,  c r e a t i n g p o t e n t i a l problems w i t h s u l f i d e l i b e r a t i o n . In t h e southern segment o f the v e i n , s u l f i d e g r a i n s i z e i n c r e a s e s , w i t h i n d i v i d u a l t e t r a h e d r i t e g r a i n s up t o 1 mm.  across.  The C o l e v e i n i s s i m i l a r t o t h e n o r t h end o f t h e Number Three system, w i t h v e r y c o a r s e - g r a i n e d (Table 6.1.1) e u h e d r a l g a l e n a and s p h a l e r i t e g e n e r a l l y p r e s e n t i n a s o f t , dominantly  carbonate gangue. In t h e south, the Cole  shear  c o n t a i n s l a r g e r amounts o f t e t r a h e d r i t e and p y r i t e , and base-metal  s u l f i d e s become much more i n t e r l o c k e d  (and ease  of v e i n d e f i n i t i o n d e c l i n e s where t h e v e i n i s i n t e r s e c t e d as a s e r i e s o f c l o s e l y spaced  stringers).  In o t h e r systems a t S i l v e r Queen, base-metal  sulfides  become l e s s important w i t h a c o r r e s p o n d i n g i n c r e a s e i n t h e Ag-mineral  c o n t e n t . Galena, c h a l c o p y r i t e , and s p h a l e r i t e a r e  the most abundant phases (Table 6.1.1) and occur commonly as  205  r e l a t i v e l y c o a r s e , e u h e d r a l g r a i n s o r as masses intergrown with s u l f o s a l t s  (eg. P o r t a l v e i n s ) . The l a t t e r occurrence  c r e a t e s p o t e n t i a l d i f f i c u l t i e s where the p r e c i o u s metalb e a r i n g m i n e r a l s are intergrown w i t h more than one  base-  metal phase, thus p o t e n t i a l l y d i s t r i b u t i n g the Au o r Ag t o more than one c o n c e n t r a t e . T h i s problem i s p a r t i c u l a r i l y prominant  i n the P o r t a l v e i n s , where m a t i l d i t e  (AgBiS2) i s  intergrown w i t h galena and, l e s s commonly, c h a l c o p y r i t e . Unusual m e t a l s , i n c l u d i n g Ga, Ge,  In, and Cd, are  p o t e n t i a l l y important byproducts from the p r o c e s s i n g of base-metal s u l f i d e ores a t S i l v e r Queen. Microprobe analyses of s p h a l e r i t e s  (summarized  anomalous l e v e l s o f Ga wt. % ) , and Cd  (1.8 wt.  i n Chapter 4) have i n d i c a t e d t h a t  (0.4 wt.  % ) , Ge  (0.3 wt.  % ) , In.(0.7  %) s u b s t i t u t e f o r Zn o r Fe w i t h i n  s p h a l e r i t e s from S i l v e r Queen. Indium was  found t o be most  e n r i c h e d i n s p h a l e r i t e from c h a l c o p y r i t e - b e a r i n g v e i n material  (Table 4.5.3),  c h a l c o p y r i t e may  and thus the presence of  be regarded as a p a t h f i n d e r f o r anomalous  In l e v e l s . Ga, Ge, and Cd were more unevenly d i s t r i b u t e d , w i t h the g r e a t e s t contents noted i n s p h a l e r i t e s from sample 3CHN89-1 (Appendix A) on the deep southern NG3  structure.  The a m e n a b i l i t y of the s p h a l e r i t e from t h i s s i t e t o beneficiation  (eg. T a b l e 6.1.1) and the e l e v a t e d contents o f  the metals Ga, Ge, Cd, and t o a l e s s e r e x t e n t In, suggests a p o t e n t i a l l y l a r g e u n t e s t e d r e s o u r c e o f these metals i n the NG3  v e i n . Ge-  and G a - r i c h s p h a l e r i t e was  southern p a r t o f the Number Three v e i n  a l s o found i n the  (Table 4.5.1).  206  6.3  Recommendations f o r Future E x p l o r a t i o n M i n e r a l o g i c s t u d i e s have i n d i c a t e d t h a t t h e heat  t h a t drove  source  f l u i d c i r c u l a t i o n i s l o c a t e d a t depth towards the  southern edge o f known m i n e r a l d e p o s i t s a t S i l v e r Queen. T e t r a h e d r i t e a n a l y s e s a l s o suggest t h a t t h e o r e f l u i d had a l a t e r a l , s o u t h - t o - n o r t h component d u r i n g m i n e r a l i z a t i o n , w i t h the most Ag- and A u - r i c h m i n e r a l i z a t i o n o c c u r r i n g w i t h i n the fragmental rocks a t the southern end o f t h e Number Three system. I f the fragmental rocks d i d i n f a c t i n f l u e n c e t h e d e p o s i t i o n o f Au from hydrothermal  fluids,  then perhaps the b e s t o p p o r t u n i t y t o extend proven r e s e r v e s i s w i t h i n t h e fragmental r o c k s . T h i s s u g g e s t i o n i s supported by s c a t t e r e d , r e l a t i v e l y high-grade v e i n i n t e r s e c t i o n s on the NG3 s t r u c t u r e . V e i n m a t e r i a l from the southernmost and deepest d r i l l h o l e on t h e NG3 v e i n (sample s i t e 3CHN89-1) i s m i n e r a l o g i c a l l y simple, w i t h few observable problems, w i t h b e n e f i c i a t i o n and anomalous l e v e l s of Pb, Zn, Ge, Ga, In, Cd, Au, and Ag. Thus, t h e p a r t o f the S i l v e r Queen p r o p e r t y w i t h the g r e a t e s t p o t e n t i a l , f o r f u t u r e e x p l o r a t i o n i s the area c e n t e r e d around, and t o the south o f , t h e sample 3CHN89-1 (Appendix  A) . E x p l o r a t i o n i n t h i s area has been  n e g l i g i b l e due t o a t h i c k cover of overburden,  but there i s  no obvious reason t h a t t h e Number Three-NG3 s t r u c t u r e shouldn't c o n t i n u e t o t h e south o f the known i n t e r s e c t i o n s . S i m i l a r i l y , t h e p a r a l l e l George Lake s t r u c t u r e may d i s p l a y s i m i l a r m i n e r a l o g i c t r e n d s t o the Number Three v e i n , and thus develop h i g h e r grade i n t e r s e c t i o n s f u r t h e r south  from  207  p r e s e n t l y known v e i n l i m i t s . E x p l o r a t i o n f o r high-grade Ag resources  should  a l s o be undertaken i n the area  surrounding  the Camp v e i n system, and i n the r e g i o n s u r r o u n d i n g sample s i t e 3CHN89-66 north o f t h e Cole v e i n (Figure 2.3.1). The appearence o f Ag-minerals such as p y r a r g y r i t e suggests a pronounced Ag-enrichment towards the margins o f t h e system, and  t h i s should be taken i n t o c o n s i d e r a t i o n when e x p l o r i n g  for Ag-rich  veins.  208  T a b l e 6.1.1:  Vein North  Economic M i n e r a l o g y o f t h e S i l v e r Queen Property  Phase  % of Opaques  Max. G r a i n size  gn  2-5%  2mm.  tt-tn  0-5%  1mm.  si  30-80%  >lcm.  cpy  0-20%  > 1cm.  cpy  10-60%  >lcra.  si  2-30%  >lcm.  gn  0-10%  1cm.  ber  0-2%  0.4mm.  tt-tn  0-5%  1mm.  #3  Cpy Section #3  Central #3  aik  <1%  0.05mm.  cpy  0-3%  0.06mm.  gn  5-15%  3mm.  Liberation*  lib'n(80)=0.1mm coarse-grained Minor contam. from cpy, t t - t n Reports t o Cucon. due t o fine-grained, locked nature. lib'n(90)=lmm. minor contam. from cpy, t t , and gn. lib'n(90)=0.1ram Often t i g h t l y locked with py. lib'n(90)=0.1mm Abundant contam from s u l f o s a l t s and gn. lib'n(80)=0.1ram Abundant contam from a l l o t h e r phases. lib'n(80)=0.08 mm. About 20% i s locked i n s i and cpy. lib'n(50)=0.05 mm. Often c l o s e l y assoc. w i t h galena. Locked i n cpysee cpy e n t r y . Locked i n cpysee cpy e n t r y . Locked i n s i (50%) and i n tt-tn(50%) lib'n(70)=0.08 mm. Contains abundant f i n e g r a i n e d py.  209  South #3  NG3  Twinkle Zone  si  20-50%  5mm.  tt-tn  0-2%  0. 8mm.  sel gn  <1% 3-15%  0.05mm. 1mm.  aik  0-2%  0. 1mm.  tt-tn  2-10%  1mm.  si  10-40%  1mm.  pb fr cpy pyg sel  0-1%  0.05mm.  lib'n(80)=0.08 mm. Minor contam. from cpy and gn inclusions. lib'n(60)=0.05 mm. Always i n ass'n. w i t h gn. Locked i n gn. lib'n(70)=0.08 mm. O f t e n q u i t e locked with t t - t n and py. lib'n(70)=0.05 mm. Well l o c k e d w i t h gn. lib'n(75)=0.05 Losses t o Pbcon. expected. lib'n(80)=0.1mm Contam. from gn cpy, and a i k . Locked i n s i .  0-1%  0. 1mm.  Locked i n gn.  gn  10-40%  >lcm.  si  40-60%  >lcm.  tt-tn  0-10%  0. 8mm.  cpy  0-2%  0.05mm.  Pr geoc Ss gn  0-2%  0.06mm.  0-5%  0. 6mm.  tt-tn  0-8%  1mm.  lib'n(80)=0.1mm Hosts minor amounts o f sulfosalts. lib'n(90)=0.25 mm. R e l a t i v e l y free of inclusions. lib'n(90)=0.08 mm. Weakly t o moderately locked with gn. Locked i n s i and gn. Locked i n gn. lib'n(80)=0.07 mm. Weakly locked with s i and t t - t n . lib'n(80)=0.07 mm.-see gn.  210  Portal  Camp  si  2-10%  cpy  <1%  0.0 3mm.  mtd/ gn  5-35%  3mm.  gust/ ber tt-tn/ pc cpy  0-5%  0. 5mm.  0-5%  0. 6mm.  5-40%  >lcm.  si  10-30%  1cm.  PC  1-10%  3mm.  0-5% 0-10%  0.2mm. 2mm.  gn  5-30%  0. 6mm.  si  10-20%  3mm.  cpy CC  1-2% <1%  0.2mm. 0.04mm.  cpy  0-10%  1mm.  si  30-50%  >lcm.  gn  1-3%  0. 8mm.  pyg tt-tn fr  ac bn George Lake  1mm...  lib'n(80)=0.08 mm. Contam. from py and tt. Locked i n s i and t t - t n . lib'n(80)=0.1mm Intimately intergrown and are thus considered together. L i b ' n as f o r gn/mtd. Locked i n cpy. lib'n(80)=0.1mm. Contam. from mtd/gn and py. lib'n(80)=0.1mm Rel. inclusionfree. l i b ' n highly variable-approx the same as f o r tt-tn. Locked i n pc. lib'n(80)=0.08 mm. Commonly quite intergrown with. pc and pyg. lib'n(80)=0.05 mm. Common as inclusions i n tt-tn. lib'n(90)=0.1mm Minor contam. from cpy and gn Locked i n s i . Locked i n py and t o l e s s e r extent s i . lib'n(50)=0.05 mm. W e l l l o c k e d i n s i and t t - t n lib'n(90)=0.2mm Widespread contam. from cpy and py. Well locked i n  211  Cole  0. 5mm.  tt-tn  1-5%  ber  <1%  0.06mm.  cpy  0-20%  >lcm.  aik mtd gn  0-3%  2mm.  5-40%  >lcm.  <1%  0.05mm.  0-5%  0.2mm.  30-60%  >lcm.  pc pyg tt-tn fr si  Chisholm/ s i Owl  10-40%  0. 5cm.  tt-tn fr  1-3%  0 .5cm.  gn  1-8%  1cm.  pc pyg cpy  0-2%  0.05mm.  s i  20-60%  1cm.  #2  py(50%) and i n tt-tn(50%). lib'n(75)=0.05 mm. Contains inclusions of other s u l f i d e s , Locked i n cpy. f o r Cu-vein: lib'n(80)=0.06 mm, otherwise locked i n s i . Locked i n gn. lib'n(80)=0.15 mm. M a t e r i a l i n Cu-vein i s intergrown w i t h a i k and mtd. Locked i n gn. lib'n(75)=0.04 Commonly w e l l l o c k e d w i t h gn and F e - s u l f i d e s For Cu-vein: lib'n(80)=0.05 mm. Otherwise lib'n(90)=0.2mm Abundant i nc1's of cpy, gn, and tt-tn lib'n(80)=0.1mm Relatively free of i n c l ' s . lib'n(90)=0.1mm Commonly c o n t a i n s pyg inclusions. l i b ' n as f o r t t - t n . Contains abundant pyg and pc i n c l ' s . Locked i n gn and t t - t n . lib'n(90)=0.3mm Abundant inclusions of cpy, gn, and  212  gn  2-3%  0.2mm.  pc-pb pr-pyg tt-tn cpy  <1%  0.0 3mm.  tt-tn. Locked i n s i and w i t h t t - t n and py. Locked i n t t - t n  1% 2-3%  0. 1mm. 0.15mm.  as f o r gn. as f o r gn.  * " l i b ' n ( 8 0 ) " r e f e r s t o t h e p r o p e r t y t h a t 80% o f t h e observed g r a i n s would be l i b e r a t e d a t t h e p a r t i c l e s i z e l i s t e d afterward. I n d i v i d u a l m i n e r a l a b b r e v i a t i o n s are as f o l l o w s : cpy= c h a l c o p y r i t e sl= gn= galena bn= b o r n i t e py= p y r i t e tt-tn= ac= a c a n t h i t e pr= fr= f r e i b e r g i t e geoc= g e o c r o n i t e gust= g u s t a v i t e mtd= pb= p o l y b a s i t e pc= p e a r c e i t e pyg= aik= a i k i n i t e ber= b e r r y i t e sel= s e l i g m a n n i t e ss= Ag-Sb-Pb s u l f o s a l t  sphalerite fahlores proustite matildite pyrargyrite  213 Table 6.1.2; Vein  Electrum Grain  Size  Occurrence; S i l v e r Queen Property Host/No. o f Grains  Recovery  North #3  <15u  galena(5) pyrite(1) gangue(1)  much o f galena c o n t a i n i n g the electrum would r e p o r t t o Cuconcentrate .  #3-Cpy-rich section  <70u  pyrite(7) chalcopyrite(5) galena(4)  C e n t r a l #3  <15u  galena(7) pyrite(l)  galena i s d i f f i c u l t to l i b e r a t e due to a f i n e g r a i n e d nature  South #3  <25u  galena(20) sphalerite(5) fahlores(3)  electrum i n galena i s commonly c l o s e l y assoc. with f i n e grained p y r i t e May r e s u l t i n . l o s s e s up t o 20% of e l e c .  NG3  <30u  galena(7) sphalerite(2) fahlore(1)  as f o r South #3  Portal  <160u  galenamat i l d i t e ( 56) pyrite(6) chalcopyrite(3) fahlore(1)  Camp  <20u  pyrite(1) chalcopyrite(1)  electrum i n cpy would be l o s t to pyrite (tails)  #5  <50u  galenamatildite(36) chalcopyrite(4)  abundant and easy t o recover.  George Lake  <20u  pyrite(2) sphalerite(2)  significant loss to t a i l s expected.  abundant and easy t o recover  214  Chisholm/ Owl  <15u  galena(4)  e l e c . assoc. with Ag-rich m i n e r a l s , but may be d i f f i c u l t to liberate.  Cole  <20u  pyrite(2) galena(4) fahlore(1)  occurrence i n pyrite i s probably unusual f o r Cole v e i n s .  #2  <25u  sphalerite(15) gangue(3)  easy r e c o v e r y due t o s i n g l e l o c u s nature, but s p o t t y distribution.  215  7.0  B a s e - and  SUMMARY AND  CONCLUSIONS  precious-metal-bearing veins at the  Queen m i n e , s o u t h e a s t  of Houston, B r i t i s h Columbia,  been e v a l u a t e d i n terms o f m i n e r a l o g y  and  through  and  less  going  commonly e a s t - w e s t  fractures  filling)  faults.  northwest  Generation  i s commonly a s s o c i a t e d w i t h  intrusion. Mineralization  i s i n the  crustiform sulfides  and  form  have  mineral  p a r a g e n e s i s . V e i n systems g e n e r a l l y o c c u r a l o n g trending  Silver  of  (open  of  dyke  space  gangue m i n e r a l s w i t h i n t h e  fractures. M i n e r a l assemblages w i t h i n the v e i n s are grouped f o u r paragenetic stages, each with a d i s t i n c t i v e Stage I i s r e p r e s e n t e d by  fine-grained pyrite  mineralization,  ubiquitous i n the l a r g e s t  v e i n as w e l l as  lesser  hinsdalite  near  NG3  quartz  (Number T h r e e )  structures. Barite,  v e i n s , and  mineralogy.  and  svanbergite,  r e a c h peak abundance i n t h e s o u t h e r n  Number T h r e e and  into  and  parts of  the  i n s i l v e r - r i c h veins located  t h e m a r g i n s o f t h e known s y s t e m . H e m a t i t e i s most  abundant i n Stage I m a t e r i a l near Number T h r e e v e i n and marcasite  i n a few  the c e n t r a l  segment o f  smaller veins, while  i s most a b u n d a n t i n t h e n o r t h p a r t o f t h e  Number  Three v e i n . Stage I I m i n e r a l o g i e s a r e dominated by sphalerite  and  layered carbonate  amounts o f p y r i t e ,  q u a r t z , and  the  massive  minerals, with  g a l e n a . The  dominated by manganese-bearing s p e c i e s  minor  carbonates  are  ( r h o d o c h r o s i t e and  216  manganosiderite) i n the n o r t h and  calcium-magnesium  species  i n the south. Stage I I I , however, i s f a r more complex.  The  m i n e r a l o g y i s most commonly galena, c h a l c o p y r i t e , electrum, and  tetrahedrite-tennantite  notably  ( f a h l o r e s ) . S u l f o s a l t s , most  b e r r y i t e w i t h i n the c h a l c o p y r i t e - r i c h zone i n the  n o r t h Number Three v e i n , and  a i k i n i t e i n the v i c i n i t y of  the  "bend" i n the Number Three v e i n , are a l s o abundant i n Stage I I I . Stage IV i s v o l u m e t r i c a l l y minor and quartz,  pyrobitumen, and  c o n s i s t s of  calcite.  Minor element trends i n s p h a l e r i t e and  tetrahedrite  were examined i n o r d e r t o b e t t e r assess the nature of m i n e r a l i z i n g f l u i d s and Tetrahedrites respect  the d i s t r i b u t i o n of the  were found t o be c o m p o s i t i o n a l l y  t o Sb, As,  B i , Ag,  and  the  elements. zoned w i t h  Cu on both s i n g l e g r a i n  and  d e p o s i t - w i d e s c a l e s . U n u s u a l l y B i - r i c h v a r i e t i e s were a l s o noted. S p h a l e r i t e s were found t o be compositionally,  l e s s w e l l zoned  and most g r a i n s analyzed were found t o  q u i t e Fe poor. Gallium,  Germanium, and  be p r e s e n t i n a p p r e c i a b l e  be  Indium were found t o  q u a n t i t i e s i n s p h a l e r i t e s from  S i l v e r Queen, although no d i s t i n c t zoning p a t t e r n  was  recognized. The  S i l v e r Queen v e i n s  are proposed t o have formed i n  an environment s i m i l a r t o t h a t proposed by Hayba et  al.  (1985) f o r e p i t h e r m a l v e i n s a t Creede, Colorado. F l u i d s t r a v e l l i n g a l o n g f r a c t u r e s mixed w i t h c o o l e r , more o x i d i z e d m e t e o r i c waters, r e s u l t i n g i n d e p o s i t i o n of Stage I mineralogies.  A change i n pH  from a c i d towards n e u t r a l  217  r e s u l t e d i n carbonate  and s p h a l e r i t e d e p o s i t i o n , f o l l o w e d by  d e s t a b l i z a t i o n o f m e t a l - l i g a n d complexes and p r e c i p i t a t i o n of Stage I I I . Data from t e t r a h e d r i t e analyses and m i n e r a l assemblages suggests t h a t the heat source d r i v i n g the system i s p r e s e n t a t depth and t o the south o f the Number Three v e i n . The presence  o f Ga, Ge, and In i n anomalous amounts i s  s u g g e s t i v e o f a (non-exposed o r removed) o r g a n i c - r i c h u n i t as a metal  source.  Development o f t h e S i l v e r Queen d e p o s i t s has c e n t e r e d around p o t e n t i a l l y economic c o n c e n t r a t i o n s o f Au, Ag, Pb, Zn, and Cu. A l l o f the Au and much o f t h e s i l v e r i s i n the form o f 60 t o 70 f i n e electrum, as g r a i n s g e n e r a l l y l e s s than 50 microns  i n diameter. An important c o n s i d e r a t i o n - f o r  removal o f t h e e l e c t r u m i s i t s host; much o f t h e e l e c t r u m occurs i n g a l e n a t h a t i s a s s o c i a t e d w i t h f i n e - g r a i n e d p y r i t e . S i l v e r i s a l s o present i n t e t r a h e d r i t e s and sulfosalts. Future e x p l o r a t i o n and development a t S i l v e r Queen mine i s recommended t o be concentrated i n the southern p a r t o f the p r o j e c t a r e a , i n the v i c i n i t y o f the NG 3 v e i n . Fragmental  r o c k s a r e a p p a r e n t l y condusive t o t h e d e p o s i t i o n  of p r e c i o u s metals  and m a t e r i a l from t h e southernmost  i n t e r s e c t i o n on t h e s t r u c t u r e i n d i c a t e s a r e l a t i v e ease o f r e c o v e r y . Furthermore,  the width o f t h e a l t e r a t i o n h a l o i s  seen t o expand markedly towards the southern end o f the Number Three v e i n , suggesting a p o s s i b l e i n c r e a s e i n p r o x i m i t y t o t h e heat  source.  218 8.0  REFERENCES  Armstrong, R.L. (1988): Mesozoic and e a r l y Cenozoic magmatic e v o l u t i o n o f the Canadian C o r d i l l e r a ; Geol. soc. Amer. spec. Paper 218, pages 55-91. Arnorsson, S. (1984): Germanium i n I c e l a n d i c geothermal systems; Geochim. et Cosmochim. Acta, v o l 48, pages 2489-2502. Barnes, H.L. (1975): Zoning of ore d e p o s i t s : Types and Causes; Trans. Royal Soc. Edinburgh, v o l 69, pages 295-311. Barnes, H.L. (1979): S o l u b i l i t i e s of Ore M i n e r a l s in Geochemistry o f Hydrothermal Ore D e p o s i t s , Barnes, H.L.,ed., New York, pages 404-460. Barton, P.B. J r . , Bethke, P.M. and Roedder, E. (1977): Environment o f ore d e p o s i t i o n i n the Creede M i n i n g D i s t r i c t , San Juan Mountains, Colorado: P a r t I I I . Progress toward i n t e r p r e t a t i o n of t h e c h e m i s t r y of the o r e - f o r m i n g f l u i d f o r the OH v e i n . Econ. Geol., v o l 72, pages 1-24. Barton, P.B. J r . , Bethke, P.M. and Toulmin, P., I l l (1963): E q u i l i b r i u m i n o r e d e p o s i t s ; Mineral. Soc. Am. Spec. Paper No. 1, pages 171-185. Barton, P.B. J r . and Skinner, B.J. (1979): 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 in Geochemistry of Hydrothermal Ore D e p o s i t s , Barnes, H.L., ed., New York, pages 278-403. Berger, B.R. and Henley, R.W. (1989): Advances i n the understanding o f E p i t h e r m a l G o l d - S i l v e r d e p o s i t s , w i t h s p e c i a l r e f e r e n c e t o the Western U n i t e d S t a t e s ; Econ. Geol., Mon. 6, pages 405-419. B e r n s t e i n , L.R. (1985): Germanium geochemistry and mineralogy; Geochim. et Cosmochim. Acta, v o l 49, pages 2409-2422. B e r n s t e i n , L.R. (1987): M i n e r a l o g y and Petrography of some ore samples from the S i l v e r Queen Mine, near Houston, B r i t i s h Columbia; Unpublished Report by M i n e r a l Search, 380 Willow Road, Menlo Park, CF 94025, Aug. 1, 1987, 13 pages. B i r n i e , R.W. and Burnham, CW. (1976): The c r y s t a l s t r u c t u r e and e x t e n t of s o l i d s o l u t i o n of G e o c r o n i t e . Am. Mineral., v o l 61, pages 963-970.  219 C a r t e r , N.C. (1981): Porphyry Copper and Molybdenum D e p o s i t s , W e s t - c e n t r a l B r i t i s h Columbia; British Columbia Ministry of Energy, Mines and Petroleum Resources, B u l l e t i n 64, 150 pages. Chang, L.L.Y., Wu, D. and Knowles, C R . (1988): Phase r e l a t i o n s i n t h e system Ag2S-Cu2S-PbS-Bi2S3; Econ. Geol., v o l 83, pages 405-418. C h a r l a t , M. and Levy, C. (1974): S u b s t i t u t i o n s m u l t i p l e s dans l a s e r i e T e n n a n t i t e - T e t r a h e d r i t e ; B u l l . Soc. fr. Mineral. Crystallogr., v o l 97, pages 241-250. Cheng, X., S i n c l a i r , A . J . , Thomson, M.L. and Zhang, Y. (1991): Hydrothermal a l t e r a t i o n a s s o c i a t e d w i t h t h e S i l v e r Queen p o l y m e t a l l i c v e i n s a t Owen Lake, C e n t r a l B r i t i s h Columbia (93 L / 2 ) ; British Columbia Ministry of Energy, Mines and Petroleum Resources, Geological Fieldwork 1990, Paper 1991-1, pages 179-183. Church, B.N. (1970): Nadina ( S i l v e r Queen); British Columbia Ministry of Energy, Mines and Petroleum Resources, Geology, E x p l o r a t i o n and M i n i n g 1969, pages 126-139. Church, B.N. (1971): Geology o f t h e Owen Lake, P a r r o t t Lakes and G o o s l y Lake area; British Columbia Ministry of Energy, Mines and Petroleum Resources, Geology, Exploration and Mining 1970, pages 119-125. Church, B.N. (1973): Geology o f t h e Buck Creek area; British Columbia Ministry of Energy, Mines and Petroleum Resources, Geology, E x p l o r a t i o n and M i n i n g 1972, pages 353-363. Church, B.N. (1973b): Code Fen; British Columbia Ministry of Energy, Mines and Petroleum Resources, Geology, Exploration and Mining 1972, pages 373-379. Church, B.N. (1984): Geology o f t h e Buck Creek T e r t i a r y O u t l i e r ; British Columbia Ministry of Energy, Mines and Petroleum Resources. Unpublished 1:100,000 s c a l e map. Church, B.N. (1985): Update on t h e Geology and M i n e r a l i z a t i o n i n t h e Buck Creek area-the E q u i t y S i l v e r Mine r e v i s i t e d (93 L/1W); British Columbia Ministry of Energy, Mines and Petroleum Resources, G e o l o g i c a l F i e l d w o r k 1984, Paper 1985-1, pages 175 -187.  220 Church, B.N. and Barakso, J . J . (1990): Geology, L i t h o c h e m i s t r y and M i n e r a l i z a t i o n i n the Buck Creek a r e a , B r i t i s h Columbia; British Columbia Ministry of Energy, Mines and Petroleum Resources. Paper 1990-2, 95 pages. C r a i g , J.R. (1967): Phase r e l a t i o n s and m i n e r a l assemblages i n t h e Ag-Bi-Pb-S system; Mineral. Deposita, v o l 1, pages 278-306. C r a i g , J.R. and Barton, P.B. J r . (1973) Thermochemical approximations f o r s u l f o s a l t s ; Econ. Geol., v o l 68, pages 493-506. C r e r a r , D.A., Wood, S.A., B r a n t l e y , S.L. and B o c a r s l y , A. (1985): Chemical c o n t r o l s on s o l u b i l i t y o f Ore-forming m i n e r a l s i n hydrothermal s o l u t i o n s ; Can. Mineral., v o l 23, pages 333-352. Drummond, S.E. and Ohmoto, H. (1985): Chemical e v o l u t i o n and m i n e r a l d e p o s i t i o n i n b o i l i n g hydrothermal systems; Econ. G e o l . , v o l 80, pages 126-147. E l d r i d g e , C.S., B o u r c i e r , W.L., Ohmoto, H. and Barnes, H.L. (1988): Hydrothermal i n n o c u l a t i o n and i n c u b a t i o n o f the C h a l c o p y r i t e d i s e a s e i n S p h a l e r i t e ; Econ Geol, v o l . 83, pages 978-989. F o u r n i e r , R.O. (1985): The b e h a v i o r o f s i l i c a i n hydrothermal s o l u t i o n s ; J?ev. Econ. Geol., v o l 2, pages 45-72. F r y k l u n d , V.C. and F l e t c h e r , J.D. (1956): Geochemistry o f S p h a l e r i t e from t h e S t a r Mine, Couer d'Alene D i s t r i c t , Idaho; Econ. Geol., v o l 51, pages 223-247. Gemmel, J.B., Zantop, H. and B i r n i e , R.W. (1989): S i l v e r S u l f o s a l t s o f the Santo Nino V e i n , F r e s n i l l o D i s t r i c t , Zacatecas, Mexico; Can. Mineral., v o l 27, pages 401418. Hackbarth, C . J . and P e t e r s e n , U. (1984) A f r a c t i o n a l c r y s t a l l i z a t i o n model f o r t h e d e p o s i t i o n o f a r g e n t i a n T e t r a h e d r i t e ; Econ. Geol., v o l 79, pages 448-460. H a r r i s , D.C. and Chen, T.T. (1976): C r y s t a l c h e m i s t r y and re-examination o f nomenclature o f s u l p h o s a l t s i n t h e a i k i n i t e - b i s m u t h i n i t e s e r i e s ; Can. Mineral., v o l . 14, pages 194-205. H a r r i s , D.C. and Owens, D.R. (1973): B e r r y i t e , a Canadian o c c u r r e n c e . Can. Mineral., v o l 11, pages 1016-1018.  Hayba, D.O., Bethke, P.M., Heald, P and F o l e y , N.K. (1985): G e o l o g i c , m i n e r a l o g i c , and geochemical c h a r a c t e r i s t i c s of V o l c a n i c - h o s t e d e p i t h e r m a l p r e c i o u s - m e t a l d e p o s i t s ; Rev. Econ. Geol., v o l 2, pages 129-167. H e i n r i c h , C.A. and Eadington, P.J. (1986): Thermodynamic p r e d i c t i o n s o f t h e hydrtothermal c h e m i s t r y o f A r s e n i c , and t h e i r s i g n i f i c a n c e f o r t h e P a r a g e n e t i c sequence o f some C a s s i t e r i t e - A r s e n o p y r i t e - B a s e metal s u l f i d e d e p o s i t s ; Econ. Geol., v o l 81, pages 511-519. H o l l a n d , D.H. and M a l i n i n , S.D. (1979): The S o l u b i l i t y and Occurrence o f t h e Non-Ore M i n e r a l s in Geochemistry o f Hydrothermal Ore D e p o s i t s , Barnes, H.L., ed., New York pages 461-508. Hood, C.T., L e i t c h , C.H.B. and S i n c l a i r , A . J . (1991): M i n e r a l o g i c v a r i a t i o n observed a t t h e S i l v e r Queen mine, Owen Lake, C e n t r a l B r i t i s h Columbia (93 L/2); British Columbia Ministry of Energy, Mines and Petroleum Resources Geological Fieldwork 1990, Paper 1991-1, pages 185-191. Johnson, N.E., C r a i g , J.R. and R i m s t i d t , J.D. (1986): C o m p o s i t i o n a l t r e n d s i n T e t r a h e d r i t e . Can. Mineral., v o l 24, pages 385-397. Johnson, M.L. and J e a l o z , R. (1983): A B r i l l o u i n - z o n e model f o r c o m p o s i t i o n a l v a r i a t i o n i n T e t r a h e d r i t e ; Am. Mineral., v o l 68, pages 220-226. Karup-Moller, S. (1966): B e r r y i t e from Greenland; Can. Mineral., v o l . 8, pages 414-423. K i e f t , K. and Damman, A.H. (1990): Indium-bearing C h a l c o p y r i t e and S p h a l e r i t e f r o n t h e Gasborn area, West B e r g s l a g e n , c e n t r a l Sweden; Mineral. Mag., v o l 54 pages 109-112. Krogh, T.E. (1973): A low-contamination method f o r hydrothermal decomposition o f Z i r c o n and e x t r a c t i o n o f Uranium and Lead f o r i s o t o p i c age d e t e r m i n a t i o n s ; Geochim. et Cosmochim. Acta, v o l . 37, pages 485-494. Lang, A.H. (1929): Owen Lake M i n i n g Camp, B r i t i s h Columbia; Geological Survey of Canada Summary Report 1928, P a r t A, pages 62A-93A. L e i t c h , C.H.B., Hood, C.T., Cheng, X. and S i n c l a i r , A . J . (1990): Geology of t h e S i l v e r Queen Mine area, Owen ^Lake, C e n t r a l B r i t i s h Columbia (93 L ) : British Columbia Ministry of Energy, Mines and Petroleum Resources Geological Fieldwork 1989, Paper 1990-1, pages 287-295.  222  L e i t c h , C.H.B., S i n c l a i r , A . J . , Cheng, X. and Hood, C.T. (1991-in p r e s s ) : S t r u c t u r a l c h a r a c t e r o f e p i t h e r m a l p o l y m e t a l l i c v e i n s and b e a r i n g on g e o s t a t i s t i c a l s t u d i e s a t t h e S i l v e r Queen Mine, near Owen Lake, West-Central B r i t i s h Columbia; C.I.M. Bulletin. L e i t c h , C.H.B., S i n c l a i r , A . J . and Godwin, C.I. (1991-in p r e s s ) : A Galena Lead i s o t o p e study o f p o l y m e t a l l i c d e p o s i t s i n t h e Buck Creek area, c e n t r a l B r i t i s h Columbia; Can. Inst. Min. Metall. Geol. Quart.. L i k a c h e v , A.P. (1975): R e d e p o s i t i o n of o r e - p r o d u c i n g and p e t r o g e n e t i c components by aqueous s o l u t i o n s ; Geochemistry International, v o l 12, pages 101-113. M a c i n t y r e , D. (1985): Geology and M i n e r a l Resources o f t h e Tahtsa Lake D i s t r i c t , W e s t - c e n t r a l B r i t i s h Columbia; British Columbia Ministry of Energy, Mines and Petroleum Resources, B u l l e t i n 75, 82 pages. M a c i n t y r e , D.G. and D e s j a r d i n s , P. (1988): Babine P r o j e c t (93 L/15); British Columbia Ministry of Energy, Mines and Petroleum Resources Geological Fieldwork 1987, Paper 1988-1, pages 181-193. Makovicky, E. and Karup-Moller, S. (1977): Chemistry and c r y s t a l l o g r a p h y o f t h e L i l l i a n i t e homologous s e r i e s . II.. D e f i n i t i o n o f new m i n e r a l s : E s k i m o i t e , V i k i n g i t e , O u r a y i t e and T r e a s u r i t e . R e d e f i n i t i o n o f S c h i r m i r i t e and new d a t a on t h e L i l l i a n i t e - G u s t a v i t e s o l i d s o l u t i o n s e r i e s ; Neues Jahrb. Mineral. Abh., v o l 131, pages 5682. Marsden, H.W. (1985): Some aspects o f t h e Geology, M i n e r a l i z a t i o n , and W a l l r o c k A l t e r a t i o n o f t h e Nadina Zn-Cu-Pb-Ag-Au v e i n d e p o s i t , N o r t h - c e n t r a l B r i t i s h Columbia; Unpublished B.Sc. T h e s i s , U n i v e r s i t y o f B r i t i s h Columbia, Vancouver, Canada, 90 pages. M i l l e r , W.J. and C r a i g , J.R. (1983): T e t r a h e d r i t e Tennantite s e r i e s compositional v a r i a t i o n s i n the Cofer D e p o s i t , M i n e r a l D i s t r i c t , V i r g i n i a ; Can. Mineral., v o l 68, pages 227-234. Murowchick, J.B. and Barnes, H.L. (1986): M a r c a s i t e p r e c i p i t a t i o n from hydrothermal s o l u t i o n s . Geochim. et Cosmochim. Acta, v o l 50, pages 2615-2630. Nowak, M.S. (1991): Ore Reserve e s t i m a t i o n , S i l v e r Queen V e i n , Owen Lake, B r i t i s h Columbia; Unpublished M.A.Sc. T h e s i s , University of British Columbia, Vancouver, Canada, 224 pages.  223 N u f f i e l d , E.W. and H a r r i s , D.C. (1966): S t u d i e s of m i n e r a l s u l p h o - s a l t s . XX. B e r r y i t e , a new s p e c i e s ; Can. Mineral., v o l 8, pages 407-413. Oen,  I.S. and K i e f t , C. (1976): B i s m u t h - r i c h T e n n a n t i t e and T e t r a h e d r i t e i n the Mangualde Pegmatite, P o r t u g a l ; Neues Jahrb. Mineral. Monatsh., pages 94-96.  Ohmoto, H. and Lasaga, A.C. (1982): K i n e t i c s o f r e a c t i o n s between aqueous s u l f a t e s and s u l f i d e s i n hydrothermal systems. Geochim. et Cosmochim. Acta, v o l 46, pages 1727-1745. O'Leary, M.J. and Sack, R.O. (1987): Fe-Zn exchange r e a c t i o n s between T e t r a h e d r i t e and S p h a l e r i t e i n n a t u r a l environments; ContriJbs. Min. Petrol., v o l 96, pages 415-425. P a t t r i c k , R.A.D. and H a l l , A . J . (1983): S i l v e r s u b s t i t u t i o n i n t o s y n t h e t i c Z i n c , Cadmium, and I r o n - T e t r a h e d r i t e s ; Mineral. Mag., v o l 47, pages 441-451. P e t e r s e n , E.U., P e t e r s e n , U. and Hackbarth, C.J. (1990): Ore Zoning and T e t r a h e d r i t e c o m p o s i t i o n a l v a r i a t i o n a t Orcopampa, Peru; Econ. Geol., v o l 85, pages 14911503. Raabe, K.C. and Sack, R.O. (1984): Growth zoning i n T e t r a h e d r i t e from the Hocking Mine, Alma, Colorado; Can. Mineral., v o l 22, pages 577-582. Reed, M.H. and Spycher, N.F. (1985): B o i l i n g , C o o l i n g and O x i d a t i o n i n e p i t h e r m a l systems. A n u m e r i c a l m o d e l l i n g approach; Rev. Econ. Geol., v o l . 2, pages 249-272. Sack, R.O., E b e l , D.S. and O'Leary, M.J. (1987): Tennanhedrite thermochemistry and metal zoning, in Helgeson, H.C., ed., Chemical t r a n s p o r t i n metasomatic p r o c e s s e s ; Amsterdam, D. R e i d e l Pub. Co., pages 701731. Sack, R.O. and Loucks, R.R. (1985): Thermodynamic p r o p e r t i e s of T e t r a h e d r i t e - T e n n a n t i t e s : C o n s t r a i n t s on the independence o f the Ag-Cu, Fe-Zn, Cu-Fe and As-Sb exchange r e a c t i o n s ; Am. Mineral., v o l 70, pages 12701289. Sakharova, M.S. (1969): A f i n d of B e t a - M a t i l d i t e i n E a s t e r n T r a n s b a i k a l . DokladyAkad. Nauk SSSR, v o l . 189, pages 418-420. Souther, J.G. (1977): Volcanism and t e c t o n i c environments i n the Canadian C o r d i l l e r a ; A second l o o k ; Geol. Assoc. Canada, S p e c i a l Paper 16, pages 3-24.  224  S p r i n g e r , G. (1969): E l e c t r o n probe analyses o f T e t r a h e d r i t e ; Neues Jahr. Mineral. Mont., pages 24-32. Stacey, J.S. and Kramers, J.D. (1975): Approximation o f t e r r e s t r i a l Lead i s o t o p e e v o l u t i o n by a two-stage model; E a r t h and Planetary Science Letters, v o l . 26, pages 207-221. S t e i g e r , R.H. and Jager, E. (1977): Subcommision on Geochronology: Convention on t h e use o f decay c o n s t a n t s i n Geo- and Cosmochronology; Earth and Planetary Science Letters, v o l . 36, pages 359-362. S t r e c k e i s e n , A.L. (1967): C l a s s i f i c a t i o n and Nomenclature of Igneous r o c k s ; Neues Jahr. Mineral. Abh., v o l 107, pages. 144-214. Susak, N.J. and C r e r a r , D.A. (1982): F a c t o r s c o n t r o l l i n g zoning i n hydrothermal o r e d e p o s i t s ; Econ. Geol., v o l 77, pages 476-482. Thomson, M.L. and S i n c l a i r , A . J . (1991): Syn-hydrothermal development o f f r a c t u r e s i n t h e S i l v e r Queen Mine a r e a , Owen Lake, C e n t r a l B r i t i s h Columbia; British Columbia Ministry of Energy, Mines and Petroleum Resources, G e o l o g i c a l F i e l d w o r k 1990, Paper 1991-1, pages 191-197. 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 o f N o r t h - c e n t r a l B r i t i s h Columbia; Geological Survey of Canada, B u l l e t i n 270, 73 pages. Wood, S.A., C r e r a r , D.A. and B o r s i k , M. (1983): S o l u b i l i t y of a m u l t i - p h a s e s u l f i d e system i n hydrothermal c h l o r i d e s o l u t i o n s . Geol. Soc. Amer.Abstr. Programs, v o l . 15, page 722. Wu, I . and P e t e r s e n , U. (1977): Geochemistry o f T e t r a h e d r i t e - T e n n a n t i t e a t C a s a p a l c a , Peru; Econ. Geol., v o l 72, pages 993-1016.  i  APPENDIX SAMPLE S I T E  A  LOCATIONS  APPENDIX  A  P a r t i t S u r f a c e Sample S i t e s • s u r f a c e sample l o c a t i o n s are p r o v i d e d i n F i g u r e A - l i n pocket* Part l i t Underground  Sample S i t e s  Sample  Material  Location  2CHN89-1 2-2 2-3  Vein section Vein section U n i t 6 Dyke  2-4 2-5  Vein  P o r t a l One v e i n P o r t a l Two v e i n P o r t a l Three v e i n vicinity P o r t a l Three v e i n 50 m. NE o f P o r t a l Three v e i n 120 m. NE o f P o r t a l Three v e i n 150 m. NE o f P o r t a l Three v e i n Near P o r t a l Nine v e i n Near P o r t a l Nine v e i n 20 m. NE o f P o r t a l Nine v e i n P o r t a l 10.5 v e i n 30 m. NE o f P o r t a l E l e v e n vein. 40 m. NE o f P o r t a l Eleven v e i n 50 m. NE o f P o r t a l Eleven v e i n 200 m. SW o f Number Three v e i n i n B u l k l e y Crosscut 180 SW o f Number Three v e i n i n B u l k l e y Crosscut 80 m. SW o f Number Three v e i n i n B u l k l e y Crosscut Number Three v e i n a t Bulkley Crosscut North end d r i f t . — V e i n i n Number Three hangingwall Near S i t e 2-20 i n North end d r i f t Number One v e i n Near Number One v e i n  2-6 2-7  sample  U n i t 4-weak a l t ' n U n i t 6 Dyke  2-8 2-9 2-10  U n i t 6 Dyke A l t ' d Unit 4 U n i t 6 Dyke A l t ' d Unit 5  2.-11 2-12  Vein section Fresh Unit 4  2-13  U n i t 7 Dyke  2-14  U n i t 6 Dyke  2-15  U n i t 6 Dyke  2-16  Fresh Unit 4  2-17 2-18  U n i t 7 Dyke  2-19  Vein section  2-20  Vein  2-21  U n i t 6 Dyke  2-22 2-23  Vein section U n i t 6 Dyke  sample  227 2-24 2-25  Chalcedonic v e i n Fresh Unit 4  2-26 2-27  Vein Vein  2-28 2-29  Chalcedonic v e i n U n i t 6 Dyke  2-30  Vein  section  2-31  Vein  section  2-32  U n i t 7 Dyke  2-33 2-34  U n i t 8 Dyke Vein section  2-35  Vein  section  2-36  Vein  section  2-37  Vein  section  2-38  Vein  section  2-39  Vein  section  2-40 2-41  A l t ' d U n i t 5A A l t ' d Unit 2  2-42 2-43  Pyritic veinlet A l t ' d Unit 3  2-44 2-45  Fresh Unit 4 Vein section  2-46 2-47  U n i t 7 Dyke Vein section  2-48  Vein  section section  section  Near Number One v e i n Between Number One and Number Two v e i n s Number Two v e i n Number Three v e i n a t Number One Crosscut North end face 2nd crosscut, l e a v i n g North end d r i f t ( i n t o Number Three v e i n H.W) Number Three v e i n , i n North end d r i f t where v e i n reappears i n drift Footwall v e i n , a t northernmost exposure in- underground workings 120 m. SE o f B u l k l e y Crosscut i n South End drift Near S i t e 2CHN89-32 Number Three v e i n 300 m. SE: o f B u l k l e y Crosscut i n South End drift Number Three v e i n near southernmost exposure. Number Three v e i n a t "bend", South End drift M3 v e i n exposure, South End d r i f t Footwall v e i n i n 2750 s u b - l e v e l F o o t w a l l v e i n near S i t e 2CHN89-38 South End d r i f t South End d r i f t , i n 1989 c r o s s c u t Near South E n d face South End d r i f t , i n 2nd major d r i f t SE o f Bulkley Crosscut B u l k l e y C r o s s c u t face George Lake vein, a t B u l k l e y Crosscut Near S i t e 2CHN89-45 George Lake v e i n a t Bulkley Crosscut "Jaxel" v e i n at Bulkley Crosscut  228 2-49  Vein section  Veinlet i n Bulkley C r o s s c u t , 60 m. SW of " J a x e l " v e i n  2CHN90-1  Vein section  2-2  Vein section  2-3  Vein section  2-4 2-5 2-6 2-7 2-8 2-9 2-10 2-11 2-12 2-13  Vein section Vein section Vein section Vein section Vein section Vein section. Vein section Grab sample Chalcedonic V e i n Vein section  2-14  Vein  V e i n l e t i n Number Three v e i n hangingwall North End d r i f t Number Three v e i n a t : North End f a c e " P o r t a l 11.5" v e i n , i n P o r t a l Eleven d r i f t P o r t a l Eleven v e i n P o r t a l Ten v e i n P o r t a l Nine v e i n Portal Five vein P o r t a l Four v e i n P o r t a l Three v e i n P o r t a l Two v e i n P o r t a l Three v e i n Near S i t e 2CHN90-9 Number Three v e i n 100 m. SE o f North End f a c e " P o r t a l 12" v e i n NE o f P o r t a l E l e v e n drift  section  229  Part I I I ;  Underground D r i l l H o l e Sample L i s t  Sample  DDH  Interval  3CHN89-1 3-2 3-3 3-4 3-5 3-6 3-7 3-8 3-9 3-10 3-11 3-12 3-13 3-14 3-15 3-16 3-17 3-18 3-19 3-20 3-21 3-22 3-23 3-24 3-25 3-26 3-27 3-28 3-29 3-30 3-31 3-32 3-33 3-34 3-35 3-36 3-37 3-38 3-39 3-40 3-41 3-42 3-43 3-44 3-45 3-46 3-47 3-48 3-49 3-50  NG 3 NG 4 80-1 NFX-1 87-U-19 88-S-53 88-S-54 88-S-54 88-S-58 88-S-53 88-S-51 88-S-ll 88-S-26 88-S-ll 88-S-12 88-S-ll 88-S-ll 88-U-53 88-U-15 88-U-24 88-U-7 89-U-8 89-U-8 89-U-8 89-U-3 89-U-8 89-U-3 88-S-47 88-S-49 88-S-46 88-S-52 88-S-47 88-S-47 88-S-46 88-U-46 87-U-15 87-S-10 87-U-15 87-S-13 87-S-9 87-S-8 89-U-2 88-U-42 88-S-33 88-S-44 88-S-44 88-U-74 S-32 S-33 S-32  1433' 1941.5' 377' 1387' 1.9' 258'9" 311'5" 387'2" 608' 187'6" 482'2" 304' 104'10" 550'4 " 364' 170' 286'3" 308' 333'5" 460' 337'4" 252' 297' 261.5' 285'10" 228.2' 240'2" 600'1" 181' 215'5" 286' 399'8" 316' 383'6" 265' 152'2" 248' 149' 278' 11' 162' 220' 227' 166'4" 170' 172'8" 387' 166.8' 111' 228.5  Vein 1439' 1942.7' 380' 1387'8" 3.7' 261'8" 313'4" 394'4" 616' 189' 483'8" 307' 106'6" 553'8" 366'5" 172'8" 294'2" 318' 336'10" 465' 338'8" 252.5' 298.3' 264.5' 292' 230' 241'10" 602'2" 182' 216'1" 289' 400'11" 320' 383'11" 267' 153'4 " 253' 151' 281'2" 18.5' 168' 220.5' 232' 16.6/10" 171'3" 175'1" 392' 167.5' 114' 231.5'  NG3 —  .  NG3 —  No. 3 Cole Cole Cole No. 3 Cole Cole Camp Camp Camp Camp Camp Camp No. 3 No. 3 No. 3 No. 3 _  —...  No. 3 No-. 3 —  .  G.L. Cole —  Cole —  —  .  G.L. NG3. Camp NG3 Camp Camp Camp — •  No. 3 No, 3 No. 3 No. 3 No. 3 _ _ —  3-51 3-52 3-53 3-54 3-55 3-56 3-57 3-58 3-59 3-60 3-61 3-62 3-63 3-64 3-65 3-66 3-67 3-68 3-69 3-70A 3-7 OB 3-71 3-72 3-73 3-74 3-75 3-76 3-77 3-78 3-79 3-80 3-81 3-82 3-83 3-84 3-85 3-86 3-87 3-88 3-89 3-90 3-91 3-92 3-93 3-94 3-95 3-96 3-97 3-98 3-99 3-100 3-101 3-102 3-103  84-15 88-S-29 88-S-5 88-S-20 88-S-5 88-S-23 87-S-2 87-S-2 88-S-46 88-S-50 88-S-46 88-S-49 87-S-5 BU 107 BU 107 NGF 8 NGF 8 NGF 5 NGF 5 BU 100 S-19 88-U-37 88-U-30 88-U-58 87-U-5 87-U-18 87-U-12 NGF1 NGF1 NGF1 BSR85-1 2-72 4-72 BSR85-2 S-22 S-25 BU 5 BU 159 UG74-3 PH 7 NGF 7 NGF 7 NGF 7 F-X-l NFX-1 NFX-1 K2 UG81-12 88-U-26 88-U-21 88-U-67 88-U-50 88-U-56 88-S-45  230'3" 467'6" 70' 300'10" 212'8" 189' 327.5' 307.5' 503'6" 247'5' 236'3" 384'9" 169.3' 627' 216' 404'4" 1848' 1962' 845' 14' 283.2' 293.3' 214.9' 334' 159' 43.5' 81.9' 126.9' 777.4' 442' 114.7' 462.8' 281' 31.5' 262.3' 158.5' 86' 172.5' 303.5' 288.8' 246.5' 376' 401.5' 71' 1426' 973' 125' 130'4" 309'7" 321'9" 321' 148' 393' 293'10"  231'3" 470' 76' 304'3" 214' 191'4" 336' 309' 505' 249'10" 237'3" 386'3" 171' 633.5' 221' 412' 1848.5' 1962.8' 845.5' 16' 288.4' 298.5' 218.7' 335' 160'6" 44.1' 82.6' 127.7' 782.3' 449.1' 115.2' 464.2' 286.3' 33.5' 264' 163' 93.5' 176.5' 304.2' 290.2' 247.2' 376'3" 402.4' 73.1' 1426'3" 973'3" 125'1" 132'4" 311'7" 331' 324' 151'10" 398'5" 295'  Twinkle Camp —  Camp Camp Camp Switchb Switchb —  Cole —  Cole Camp No.l No. 2 Cole —  _ —  No .3 Portal No. 3 No. 3 No. 3 No. 3 No. 3 No. 3 Cole Cole Cole —  G.L. G.L. —  Switchb "S-26" No. 3 No. 3 No. 3 G.L. Cole Cole Cole Cole —  -  _ —  No.. 3 No. 3 No. 3 No. 3 No. 3 No. 3 No. 3  3-104 3-105 3-106  F-5 F-9 NGV 1  250.9' 229' 724.8'  251.2' 229.7' 733.5'  3CHN90-1 3-2 3-3 3-4 3-5 3-6 3-7 3-8 3-9 3-10 3-11 3-12  NGV 4 BU 158 88-U-17 UG81-18 88-U-76 UG81-15 88-U-8 88-U-31 88-U-55 88-S-57 88-S-30 88-U-3  941.7' 47' 311' 200.8' 435'5" 147.3' 234'1" 235'5" 339'5" 641'8" 147'7" 322'8"  943.5' 48' 314' 202.5' 438'5" 153.6' 237'11" 247' 341' 650' 150' 323'3"  Cole Cole No. 3 No. No. No. No. No. No. No. No. No. No. No. No.  3 3 3 3 3 3 3 3 3 3 3 3  APPENDXA LONGITUDINAL SECTION OF NUMBER THREE VEIN SHOWING SAMPLE SUE POSITIONS  KEY  meters  200  Lettered Sample Key _  sample site 1989 sample 1990 sample surface cx underground sample (sea baton*)  ai2CHN9Q-2 i:2CHNa*34 b:2CHN90-13 j: 1CHN8941 c:2CHN89-27 ft 1CHN8940 d:2CHN8940 1:1CHNB9-78 e: 1CHN89-83 m: 1CHN89-77 t: 1CHN8942n: Decline that g:1CHN89-82 p:2Ctm9-3S h:2CHN39-19 q: 2CHN89-36  Sampling Labels: 2CHN8&35 Sample Location "CH. Nadina, 1989" Sample Number 1= surface 2= underground 3= drill hole  to LO  to  APPENDIX B PARAGENETIC DIAGRAMS FOR MINERALIZED STRUCTURES A T S I L V E R QUEEN MINE  VEIN: George Lake SECTION: Central THICKNESS: 60 cm. SAMPLES: 3CHN89-81, 3CHN89-82  tt-tn py qzA qzB cpy 9n si  //  1  STAGE  ill \ rv  -*mmm— —  —  e/ec cbA  — — •  a.) Elec occurs as Irregular Inclusions In py. b.) QzB is fine-grained and grayish. c.) The gn-tt-tn-cpy+ qzA, cb assemblage occurs as fracture Infflllngs In py and wallrock.  VEIN: George Lake SECTION: South THICKNESS: 30 cm. SAMPLES: 3CHN89-81 STAGE  1  II  III  qz pyA sl cb pyB tt-tn cpy gn a.) sulfides in this section may have been remobilized. Tttn, cpy and gn Infill fractures In sl and py. Cb and tt-tn also interstitial to qz.  VEIN: George Lake? SECTION: Emit Creek THICKNESS: Siliceous Zone (2 m wide) SAMPLES: 1CHN90-2 MH  1  STAGE CD  he tt-tn py cpy si elec  *  —  a.) Qzis very fine-grained. Cb is probably calcite. b. ) Sulfides are disseminated in quartz. He is principally after mafics.  VEIN:JaxBt SECTION: Total vein THICKNESS: 15 cm. SAMPLES: 2CHNB9-48 STAGE he pyA cpy si elec pc gn qz cb pyB  1  III  — — — — —  —  —  -  a.) Elec occurs as two 30 micron grains with pc and cbA in a fracture in cpy. b.) Gn occurs as inclusions in py.  VEIN: Portal One SECTION: Total vein THICKNESS: 25 cm. SAMPLES: 2CHNB9-1  slA cb py  Ill  II  STAGE —  —  qz  cpy ttA sIB ttB gnA mtd  e/ec  — —  _ — — —  UN#1  —  a.) two distinct bands (hangingwall sphalerite and footwall carbonate) predominate. Later sulfides are concentrated near the footwall of the carbonate band.  VEIN: Portal Two SECTION: Total vein THICKNESS: 30 cm. SAMPLES: 2CHN89-2, 2CHN90-10 STAGE  II  III  ba py sl qzA qzB cb gn mtd po aspy tt-tn cpy elec a.) brecciated wallrock noted with this vein. Ba is bladed. b. ) Gn and mtd form myrmekitic intergrowths. Tt-tn is localized around py grains in cpy, and as fracture infillings.  VEIN: Portal Three SECTION: Total vein THICKNESS: 30 cm. SAMPLES: 2CHN90-9,  STAGE  1  2CHN89-4  III  II —  coA cbB SLA  —  cpyA qzA pyA tnA —  cpyB tnB sIB 11 ltd ber  — — — — — —  gn tnC elec mc pybit  —  a.) locally up to 5-e% gn-mtd masses. Intergrowths myrmokttfc  to Wldmannstaten  and frequently  are  fracture fill  chalcopyrftB. Elec Is spotty, in grains up to 160 sulfosalts commonly Interstitial to quartz  microns. Late b.) Pyrobitumen  In vugs In cb and qz.  c.) no layering noted In cb and qz. VEIN: Portal Four SECTION: Total vein THICKNESS: 15 cm. SAMPLES: 2CHN90-B  STAGE py qzA cb ba qzB gn slA sIB tt-tn cpy qzC  1  II  ///  N  —•-  a.) QzC Is a fracture fining phase cutting all other minerals. b. ) vein occupies breccia zone with abundant fine-grained galena. c.) Chalcopyrite occurs as Inclusions on the margins of galena masses  VEIN: Portal Five SECTION: Total vein THICKNESS: 18 cm. SAMPLES: 2CHN90-7 STAGE mcA qzA aspy qzB si cb mcB cpy gn tt-tn qzC  1  III  II  rv  — — —  — — — — —  a.) vein is weakly layered and dominated by coarsegrained sphalerite. b.) QzC is a late, fracture infilling phase and also fills vugs in carbonate gangue.  VEIN: Portal Nine SECTION: Total vein THICKNESS: 25 cm. SAMPLES: 2CHN90-6 STAGE qz ba py si cb gn tt-tn cpy  1  II  ///  -— —  a.) QzA is sparry and lines wallrock fragments. Bladed barite is apparently earlier than qzA. b.) Paragenesis determined from hand sample.  VEIN: Portal Ten SECTION: Total vein THICKNESS: 25 cm. SAMPLES: 2CHN90-5  qzA mc slA cbA pyA cbB cbC qzB ba sIB pyB qzC sIC pyC gn cbD sID cpy tt-tn  Ill  II  1  STAGE\  Z^°\  — — — — — -  — — — — —  — — —  a.) vein material Is well layered.  VEIN: 'Portal 10.5" SECTION: Total vein THICKNESS: 8 cm. SAMPLES: 2CHN89-11 STAGE  1  //  III  qz py ber cpy cb elec gn gust tn pc  —...  — — — —  a.) narrow vein with no layering and visible sutfosait concentrations. b.) Berryite occurs as lath shaped grains in a matrix of gustavite. Galena replaces both phases.  VEIN: 'Portal Twelve' SECTION: Total vein THICKNESS: 10 cm. SAMPLES: 2CHN90-14 STAGE pyA qzA ba pyB qzB cbA cbB qzC sl gn  II  1  ///  —  —  ——  — —  — — —  a.) Paragenesis determined from hand sample. Dominated by massive pyrite band near center. b.) PyA-qzA brecciated, with interstices filled by qzBcbA material. Both cbB and qzC cut ail other phases.  VEIN: Mae One SECTION: Total vein THICKNESS: 20 cm. SAMPLES: 1CHN89-49 to 1CHN6&-B2  STAGE pyA ba slA  Ill  II  1  rv  — —  —  qz  cb gn elec sIB pc-pb tt  —  — — — —  pyg pyB  a.) Pyg, tt, and pc-pb occur as vermiform to Irregular Inclusions In gn. Elec also noted (near pyA grains) In galena. b.) PyB Is a fracture Infilling phase cutting all other minerals.  VEIN: Mae Two SECTION: Total vein THICKNESS: 25 cm. SAMPLES: 1CHN89-55,  STAGE  II  1CHN90-4  III  IV  ba  qz si cpy tt-tn bour cbA cbB UN#1 py gn cbC aspy elec pyg angl  a.) Ba blades are abundant and usually occur In qz. Aspy and py have overgrown/replaced a pre-existing bladed phase. b.) Gn and associated phases were noted to replace a particular py-aspy-rfch band In si. c.) Bour rarely occurs as myrmekttic Intergrowths In gn.  VEIN: Colo SECTION: North (NGFB) THICKNESS: 140 cm. SAMPLES: 3CHN89-66 STAGE  II  III  rv  qzA slA gnA cbA ba qzB qzC cpy tt fret sIB pyB elec gnB pc-pb cbB aspy a.) crustform aspy and pyA occur on pre-existing bladed phase which has been replaced by frei, gn, anrl c/  b.) SlA and GnA are massive, coarse- grained phases within a distinct band, c) Elec and pc-pb occur within frei grains. d.) Ba Is In bladed form e.) Cpy and tt are more abundant In wallrock, where they cut and replace pyrite.  VEIN: Lead SECTION: Total vein THICKNESS: 15 cm. SAMPLES: 1CHN89-36  pyA ba slA qz gn eiec pc UN#1 tt-tn pyB cpy cb  III  II  1  STAGE —  •  —  — — — — —  a.) SI and gn are quite coarse-grained (to several mm.) b.) Pc and UN#1 are closely associated, occurring Intergrown with tt-tn masses near the margins of largo gn grains or Intergrown with gn. c.) PyB noted as fracture Infillings In si  VEIN: Barite SECTION: Total vein THICKNESS: 30 cm. SAMPLES: 1CHN89-20, 1CHN89-37, 3CHN89-31 STAGE py UN#1 ba aspy qz 31 cbA cbB cpy gn pc-pb U-tn UN#2  1  II  Ill  N  —  —  _  a.) py and aspy overgrow and replace an unidentified bladed phase (hematite?) that pre-dates barite. b.) Tt-tn and pc-pb occur as inclusions near the margins of galena grains. c.) UN#2 Is possibly supergene (acanthtte?).  VEIN: Bear SECTION: Total vein THICKNESS: 25 cm. SAMPLES: 1CHN89-22 to 1CHN89-26 STAGE he mt py mc sl ba qz cpy tt-tn gn cbA pc-pb  1  •  — — —  •  —  a.) massive specuiarite and bladed barite dominate this vein. Gn may contain several sulfosalts (including pcpb) but Is relatively rare.  VEIN: Cole Shear SECTION: Total vein THICKNESS: 30 cm. SAMPLES: 1CHN69-13, 1CHN89-14 STAGE qzA cbA ba qzB cbB sl tt-tn sef-bour gn cpy py  i  in  II  —  —  — — — —  —  ——  a.) CbA and cbB are similar In appearence, but apparently paragenetically different CbA forms a prominant band with ba blades along one margin.  VEIN: NG6 SECTION: Total vein THICKNESS: 20 cm. SAMPLES: 1CHN89-30, 3CHN89-90 STAGE  III  II  IV  cb ba qz sl gn cpy pyA tt-tn UN#1 pyB a.) Cb gangue Is interstitial to euhedral sphalerite grains. Cpy replaces zoned sl along zonal boundaries. b.) Tt-tn occurs as fracture tnfilllngs In sl and cpy. c. ) Bladed ba Is locally abundant and very coarse grained, d.) UN#1 is a low-reflectance oxide species associated with py and cb.  VEIN: Copper SECTION: Total vein THICKNESS: 40 cm. SAMPLES: 3CHN69-79 STAGE  1  cpy  Ill  IV  —  he mt mc py aik mtd elec tt-tn pc-pb gn sl cbA cbB cbC 02  II  —  — —  — —  —  a.) many of the later sulfides occur Interstitially to helmt and other gangue minerals. b. ) Gn, aik and mtd occur throughout the section as symplectic intergrowths. These phases and tt-tn also occur as "rims* surrounding py or mc. c) Mc appears to pseudomorph py In several instances, but does not display other paragenetic relationships.  VEIN: Camp (Ruby Silver) SECTION: Total vein THICKNESS: 20 cm. SAMPLES: 3CHN89-37, 3CHN89-39 STAGE  II  III  IV  qzA qzB ba cb pyA pyB pybit si gn tt pc pyg pyC bn cpy UN#1 qzC ac cv  cc a.) Bn, ac, cvlcc, and cpy occur as Inclusions In py. Py Is commonly brecciated. b. ) Vermltomt Inclusions of cpy, py, and gn occur In the cores of large tt grains. c.) Pc, pyg, and tt are Intergrown with galena throughout d.) QzA occurs as crusttform overgrowths on brecciated wallrock. Also as fine-grained aggregates overgrown bv  VEIN: Camp SECTION: Total vein THICKNESS: 15 cm. SAMPLES: 3CHNB9-15, 3CHNB9-14, 3CHNB9-16, 3CHN89-17 1  STAGE qzA cbA pyA pyB aspyA po pybtt cbB cbC gn sl cpy pc frei elec ba qzB aspyB pyC cbO aspyC pyO  II  Ill  rv  — — —  — — —  — — — — — —  — — —  a.) the vein contains crusttform aspyA and pyB over a preexisting bladed phase. AspyB and pyC formrimsaround qz and sl with later Interstitial sulfides. b.) Bladed ba and daisy qz are also present c.) vein Is well layered and cored by cbD. AspyC and pyO are fine-grained massive bands near the vein core.  VEIN: Camp SECTION: Total vein THICKNESS: 15 cm. SAMPLES: 3CHN89-13  III  STAQt ba cbA cbB cbC aspyA pyA si gn tt-tn cpy pyblt UN#1 cbD cbE pyB aspyB po cbF qzA cbG qzB  a. ) Cbln this section Is well banded. b.) Pyln some places pseudomorphs  aspyA.  VEIN: SECTION: Total vein THICKNESS: 10 cm. SAMPLES: 3CHNB9-80  STAGE ba qzA cbA cbB cbC pyA qzB si gn tt-tn cpy pyB  1  II  — — •  •  -  —  a.) Ba blades and sparry  Ill  —  —  —  display cb.  drusy qz rims followed by  collltorm  VEIN: Camp SECTION: Total vein THICKNESS: 15 cm. SAMPLES: 3CHN80-40 STAGE  1  rv  ///  //  —  qz ba cbA pyA cbB  — —  ——  UN#1  — •  pyB si cpy pybtt po aspy  —  — —  —  UN#2 UN#3  gn  a.) Qz Is a final vug-infilling phase. CbA, si and UN#1 occur as masses (breccia?) In a cbB and qz matrix. The cbA-sl-UN#1 association Is very similar to that observed in the Portal 11.5 vein. b.) Po similar In occurrence to that seen with cpy in Portal 11.5 vein. c.) PyA and aspy often appear In bladed form. The two phases commonly surround masses of cbA-sl-UN#1. d.) UN#2 and UN#3 occur In gn, the latter as myrmekttic Intergrowths with a reflectance of about 38-40. e.) Pybtt commonly associated with grains of UN#1. Pybtt fragments were noted in a cbB matrix.  VEIN: Twinkle zone SECTION: Total vein THICKNESS: 1-3 cm. SAMPLES: 3CHN89-51 STAGE py Si gn U-tn cpy qz  _  1  II  III  a.) the Twinkle zone is actually a zone of stringer and disseminated sulfide mineralization.  VEIN: Camp SECTION: Total vein THICKNESS: 15 cm. SAMPLES: 3CHNB9-52  STAGE ba cbA sl pybtt po pyA cpy tt-tn  1  HI  II  —  —• —  gn cbB aspy pyB  —  — —  a.) CbA Is well zoned.  CbA and sl fragments occur in a  CbB  matrix. b.) Ba is bladed and pre-dates all other phases. c.) PyB and aspy surround pyA and po fragments and appear to replace an.unknown bladed phase. PyA and po form grains outwardly zoned to po. d.) Cpy, sl, tt-tn and gn all fracture Infill pyA, pyB, aspy and po.  VEIN: SECTION: Total vein THICKNESS: 15 cm. SAMPLES: 3CHN89-83  STAGE pyA po aspyA pyB cbA ba cbB cbC  1  II  IIIIIV  —  gn sl  pyc aspyB cbD cbE  a.) PyA Is quite massive and fine-grained material with rare ba In vugs. b.) Cb Is banded and zoned; CbE displays breccia textures and has been replaced along partings by aspyB and pyC. c.) AspyA occurs as laths in pyB. Ba is bladed habit  VEIN: Number One SECTION: North THICKNESS: 20 cm. SAMPLES: 3CHNB9-64,  1CHN89-84  STAGE  Ill  cbA qzA cbB qzB pyA pyB sl  1  —  II —  —  —  —  9" tt-tn cpy aspy pr-pyg  —  —  _____  a.) vein Is well banded b.) QzA Is sparry.  and cored by late  sulfides.  VEIN: Number Two SECTION: North Segment THICKNESS: 30 cm. SAMPLES: 3CHN89-65  he slA sIB pyA pyB aspy pybit qzA qzB cpy bour pr-pyg gn tt po qzC pyC cbA cbB  II  1  STAGE  Ill  IV  -—  •  —  —  —  _ —  —— —... .  —  a. ) vein material Is well layered. Some aspy-pyB crustiforrn overgrowth and replacement of a bladed phase, probably hematite. b.) Pr-Pyg and bour Intergrown with galena  shows pre-existing  VEIN: SECTION: Total vein THICKNESS: 20 cm. SAMPLES: 1CHNB9-87 STAGE pyA qzA slA ba qzB pyB sIB cbA cbB cbC cbD pyC gn cpy tt-tn SIC siD aspy UN#1 sallg pr-pyg  1  If/Ill  — — — —  —  —  —  — — — •  a.) Vein Is well layered. Sellg-bour and pr-pyg occur as Intergrowths In gn.  VEIN: Footwail SECTION: Atlmak Raise THICKNESS: 50 cm. SAMPLES: 2CHNB9-38, 2CHNB9-39  1  STAGE si pyA cpy tt-tn pyB aloe cb gn qzA qzB  Ill  —  — —  —  —  a.) Tt-tn tonus a matrix tor si and py breccias. Tt-tn cuts and Is cut by cpy.  VEIN: SECTION: Total vein THICKNESS: 20 cm. SAMPLES: 2CHN89-20  1  STAGE pyA tt-tn si cpy cb qz pyB gn he  ///  II  —  — —  ——  a.) PyB Is a coltomorphio form that has been partially replaced by tt-tn and cpy. b.) Cpy and tt-tn brecclate and fracture Infill si and pyA c.) SI and he have been replaced by cpy as well. d.) Tt-tn is concentrated In a 2 cm. wide layer in the vein core. Minor phases may be present In gn.  VEIN: SECTION: Total vein THICKNESS: 1.5 cm. SAMPLES: 3CHN89-96  II  STAGE  N  III  qzA qzB cbA cbB ba gypsum pyA sl tt-tn cpy gn pyB  a.) veintet is well layered and has sharp contacts with the wallrock. Mn staining suggests that carbonate is manganoan.  VEIN: SECTION: Total vein THICKNESS: 30 cm. SAMPLES: 3CHN89-2  STAGE qzA py cbA cbB sl qzB cbC gn tt cpy  1  ll  III  — —  — —  — —  —  —  a.) cpy occurs as fracture InHlllngs cutting all other phases. Abundance of cpy Is unusual for the south part of the property.  APPENDIX C MICROPROBE ANALYSES  256 APPENDIX C: MICROPROBE ANALYSES PART I i TETRAHEDRITES Sample 3CHN89-101 Site Cu S Zn Fe Sb As Pb Ag Bi Hg Total  1  2  3  4  5  35.69 25.16 7.91 0.17 24.59 2.68 0.00 3.58 0.35 0.14  36.03 25.40 7.56 0.20 21.63 4.67 0.00 3.13 0.14 0.00  38.61 26.38 7.88 0.17 16.35 8.50 0.00 1.24 0.00 0.00  38.68 26.69 8.06 0.21 15.21 9.59 0.00 1.64 0.00 0.19  35.42 24.80 7.68 0.10 24.30 3.42 0.00 3.68 0.00 0.00  100.28  98.78  99.13  100.26  99.39  Sample 2CHN89-2 Site  1  2  3  4  5  Cu S Zn Fe Sb As Pb Ag Bi Hg  36.08 25.32 6.67 1.17 25.11 2.43 0.00 2.26 0.00 0.00  40.01 27.49 5.53 2.66 9.16 13.22 0.00 0.75 0.00 0.00  40.14 27.79 6.07 2.21 8.34 14.12 0.00 0.67 0.00 0.00  40.69 27.77 6.33 2.24 6.26 15.28 0.00 0.40 0.00 0.00  41.03 27.94 7.61 1.26 3.39 17.30 0.00 0.20 0.00 0.15  Total  99.05  98.88  99.35  99.00  98.88  257  Sample 1CHN89-83 Site  1  2  3  Cu S Zn Fe Sb As Pb Ag Bi Hg  33 .61 24 .99 6 .99 0 .75 24 .73 2 .53 0 .00 6 .15 0 .00 0 .14  33 .15 24 .49 7 .13 0 .61 25 .11 2 .25 0 .00 6 .97 0 .00 0 • 29  33 .32 24 .57 7 .05 0 .65 25 .85 1 .61 0 .00 6 .41 0 .00 0 .17  Total  99 .88  99 .99  99 .65  Sample 3CHN89-36 Site  1  2  3  4  5  41.32 27.26 8.15 0.28 8.07 14.64 0.00 0.41 0.00 0.00  42 .36 27 .82 8 .10 0 .52 4 .22 16 .87 0 .00 0 .25 0 .00 0 .00  41 .83 27 .79 8 .33 0 .58 3 .82 17 .18 0 .00 0 .22 0 .00 0 .00  41 .82 27 .86 8 .39 0 .49 4 .43 16 .81 0 .00 0 .27 0 .00 0 .00  40. 27 26. 88 8. 19 0. 17 12. 07 11. 59 0. 00 0. 85 0.00 0.09  100.13  100 .15  99 .76  100 .08  100. 11  1  2  3  Cu S Zn Fe Sb As Pb Ag Bi Hg  24.37 23.33 4.31 2.26 25.66 1.44 0.00 18.61 0.00 0.00  26.37 24.39 4.07 2.62 17.29 6.96 0.00 17.38 0.00 0.09  23.47 23.16 4.41 2.04 20.59 4.16 5.08 17.32 0.10 0.00  Total  99.97  99.22  100.35  Cu S Zn Fe Sb As Pb Ag Bi Hg Total  Sample 1CHN89-65 Site  258  Sample 3CHN89-3 ( G r a i n I) Site  1  2  3  4  5  6  Cu S Zn Fe Sb As Pb Ag Bi Hg  41.60 27.54 6.44 1.78 6.38 15.06 0.00 0.24 0.32 0.00  40.49 26.61 6.76 1.31 11.77 11.50 0.00 0.29 0.19 0.11  40.64 26.84 7.09 1.12 13.01 10.89 0.00 0.34 0.10 0.00  41.35 27.08 6.86 1.36 7.71 14.33 0.00 0.25 0.10 0.00  41.16 27.36 6.60 1.56 6.81 16.84 0.00 0.26 0.16 0.17  40.40 26.62 7.28 1.00 13.45 10.67 0.00 0.46 0.26 0.00  Total  99.36  99.02  100.03  99.04  100.91  100.13  7  8  9  Cu S Zn Fe Sb As Pb Ag Bi Hg  40.13 26.51 7.28 0.89 13.31 10.80 0.09 0.36 0.28 0.00  40.92 26.72 7.13 1.12 9.35 14.30 0.00 0.32 0.10 0.08  41.02 26.71 7.22 0.90 11.96 12.16 0.00 0.15 0.00 0.00  41.60 27.27 7.06 1.06 7.37 15.68 0.00 0.22 0.24 0.00  41.20 27.00 7.31 1.11 6.19 14.68 0.00 0.23 2.12 0.00  41.18 27.26 7.23 1.12 7.94 14.26 0.00 0.20 0.23 0.00  Total  99.67  100.04  100.18  100.49  99.82  99.45  Site  10  11  12  Sample 3CHN89-76 Site Cu S Zn Fe Sb As Pb Ag Bi Hg Total  1  2  3  4  5  6  38.16 26.22 7.98 0.41 17.29 8.40 0.00 2.20 0.07 0.00  37.71 26.16 7.77 0.41 18.52 7.13 0.00 2.44 0.00 0.00  39.57 26.79 8.25 0.59 10.93 12.35 0.00 1.28 0.00 0.00  38.70 26.41 8.08 0.49 13.80 10.16 0.00 1.96 0.29 0.00  40.45 27.03 8.06 0.67 5.44 15.21 0.00 0.87 0.99 0.10  41.00 27.94 8.81 0.63 3.19 17.28 0.00 0r53 0.54 0.00  100.71  100.14  99.76  99.91  98.82  99.91  259  Sample 3CHN89-2 Site  1  2  3  4  5  6  Cu S Zn Fe Sb As Pb Ag Bi Hg  36.74 25.16 8.15 0.33 21.79 5.26 0.00 2.23 0.00 0.00  39.94 26.99 7.56 0.83 8.95 13.98 0.00 0.79 0.00 0.00  40.57 26.74 7.75 0.74 10.90 12.52 0.00 1.08 0.06 0.00  40.97 27.51 8.26 1.23 3.13 17.31 0.00 0.47 0.00 0.00  41.69 28.11 7.62 1.45 0.77 19.32 0.00 0.35 0.13 0.00  41.87 27.72 7.12 1.64 1.71 18.69 0.00 0.33 0.00 0.00  Total  99.69  99.06  100.36  98.91  99.46  99.11  Sample 2CHN89-45 Site Cu S Zn Fe Sb As Pb Ag Bi Hg Total  1  2  3  43.60 28.37 6.27 1.68 0.00 18.99 0.82 0.20 0.15 0.05  40.81 27.75 6.58 1.43 10.40 12.45 0.00 0.22 0.08 0.00  42.85 28.38 8.06 1.07 0.06 19.69 0.00 0.06 0.12 0.00  100.14  99.72  100.30  Sample 3CHN89-87 Site  1  2  3  4  5  Cu S Zn Fe Sb As Pb Ag Bi Hg  37.42 25.04 7.39 0.41 24.68 2.57 0.00 2.16 0.18 0.00  38.16 25.49 7.26 0.57 20.94 5.53 0.00 1.60 0.00 0.00  38.00 25.63 7.37 0.59 21.79 4.88 0.06 1.82 0.00 0.17  38.18 25.57 7.23 0.60 20.41 6.26 0.00 1.45 0.00 0.00  37.96 25.54 7.22 0.52 20.96 5.43 0.00 1.68 0.00 0.00  Total  99.83  99.55  100.32  99.70  99.30  260  Sample 3CHN89-20 Site  1  2  3  4  5  6  Cu S Zn Fe Sb As Pb Ag Bi Hg  41.95 28.09 8.40 0.69 0.32 19.09 0.52 0.30 0.10 0.00  39.12 26.09 8.33 0.17 14.89 9.28 0.00 1.42 0.08 0.00  37.76 25.28 8.01 0.21 21.75 4.62 0.00 1.93 0.00 0.00  37 .93 25 .62 8 .25 0 .23 20 .83 5 .25 0 .00 1 .99 0 .07 0 .00  37 .07 25 .00 7 .97 0 .21 22 .87 4 .37 0 .00 2 .40 0 .00 0 .00  38 .20 25 .60 7 .83 0 .21 19 .89 6 .16 0 .00 2 .26 0 .07 0 .00  Total  99.46  99.36  99.62  100 . 15  99 .88  100 .22  7  8  9  37.59 25.25 8.01 0.15 22.10 4.51 0.00 2.21 0.19 0.00  37.46 24.86 7.97 0.18 23.68 3.83 0.00 2.26 0.21 0.00  38.25 25.48 8.51 0.17 20.17 5.85 0.00 1.76 0.00 0.12  100.01  100.47  100.30  Site Cu S Zn Fe Sb As Pb Ag Bi Hg Total  Sample 3CHN89-21 Site  1  2  Cu S Zn Fe Sb As Pb Ag Bi Hg  34.73 24.39 7.21 0.35 26.80 1.26 0.00 4.05 0.17 0.00  35.80 24.96 7.20 0.43 25.71 2.29 0.00 3.30 0.12 0.00  Total  98.96  99.82  261  Sample 3CHN89-44 Site  1  2  3  Cu S Zn Fe Sb As Pb Ag Bi Hg  40.99 27.87 8.04 1.59 0.99 18.67 0.42 0.54 0.09 0.00  39.46 26.85 7.98 1.47 7.85 13.89 0.13 1.80 0.11 0.00  41.55 27.56 8.19 1.05 3.56 16.95 0.00 0.74 0.12 0.08  Total  99.20  99.53  99.79  Sample 3CHN89-24 ( G r a i n I) Site  1  2  3  Cu S Zn Fe Sb As Pb Ag Bi Hg  42.13 27.68 7.81 1.31 3.05 17.01 0.00 0.36 0.00 0.00  41.15 27.07 7.76 0.74 8.79 13.74 0.00 0.72 0.15 0.00  41.40 27.41. 7.70 0.80 6.65 15.21 0.00 0.42 0.00 0.00  Total  99.35  100.09  99.58  Sample 3CHN89-97 Site Cu S Zn Fe Sb As Pb Ag Bi Hg Total  1  2  3  4  5  6  37.95 25.93 7.89 0.16 18.47 7.42 0.00 2.49 0.58 0.09  38.73 26.08 8.01 0.29 15.46 8.94 0.00 2.34 0.65 0.00  36.26 24.96 7.74 0.20 22.59 3.98 0.00 3.72 0.68 0.00  38.07 25.78 7.27 0.33 18.08 6.73 0.00 2.92 0.22 0.09  37 .67 25 .77 7 .64 0 .30 18 .31 7 .09 0 .00 2 .91 0 .41 0 .00  35 .42 24 .78 7 .36 0 .37 23 .52 3 .16 0 .00 4 .48 1 .18 0 .00  100.96  100.52  100.12  99.50  100 .09  100 .28  262  Sample 1CHN89-117 Site  1  2  3  4  5  Cu S Zn Fe Sb As Pb Ag Bi Hg  42.34 28.21 6.05 2.42 0.05 19.35 0.00 1.19 0.00 0.00  38.86 26.05 6.88 1.11 0.70 14.36 0.00 2.85 8.49 0.13  39.27 26.53 7.10 1.12 0.08 15.58 0.00 2.30 7.78 0.09  40.00 26.44 7.18 1.05 0.08 15.84 0.00 1.91 6.78 0.00  42.04 28.26 6.79 1.96 0.12 19.43 0.00 0.96 0.00 0.00  Total  99.61  99.43  99.84  99.30  99.61  1  2  3  4  35.99 25.65 6.20 2.50 20.31 5.57 0.00 4.04 0.00 0.00  39.25 27.02 7.18 2.55 11.62 11.27 0.00 1.09 0.00 0.15  40.57 28.06 7.03 3.12 5.27 15.22 0.00 0.46 0.00 0.00  40.51 27.52 6.86 2.78 4.08 16.98 0.00 0.72 0.10 0.04  100.25  100.12  99.81  99.60  Sample 2CHN89-26 Site Cu S Zn Fe Sb As Pb Ag Bi Hg Total  Sample 2CHN89-11 Site  1  2  Cu S Zn Fe Sb As Pb Ag Bi Hg  42.55 28.37 2.59 5.51 0.00 19.73 0.00 0.34 0.08 0.00  42.74 28.29 6.21 2.08 0.13 19.62 0.00 0.12 0.00 0.00  Total  99.17  99.19  263  Sample 3CHN89 -7OB (Two G r a i n s : 1,2 and 3,4,5, 6,7) Site  1  2  3  4  5  6  7  Cu S Zn Fe Sb As Pb Ag Bi Hg  42.51 28.10 7.54 1.28 0.00 19.06 0.00 0.71 0.00 0.09  42.33 28.31 6.23 2.79 0.27 19.09 0.00 0.73 0.00 0.00  33.48 24.97 5.40 1.89 24.25 2.65 0.00 6.54 0.00 0.06  34.70 25.29 5.72 2.17 22.13 4.41 0.00 4.66 0.05 0.04  34.33 25.31 6.49 1.18 21.69 4.21 0.00 6.04 0.00 0.00  33.26 24.73 5.34 2.09 24.01 2.31 0.07 6.92 0.08 0.00  33.13 24.65 5.66 1.91 25.02 2.16 0.00 6.52 0.27 0.00  Total  99.31  99.82  99.26  99.17  99.25  98.82  99.33  Sample 3CHN89-19 Site Cu S Zn Fe Sb As Pb Ag Bi Hg Total  1  2  3  4  5  37.45 26.03 7.50 0.52 22.90 4.04 0.00 1.68 0.14 0.00  38.99 26.46 7.79 0.40 18.26 6.96 0.00 1.40 0.00 0.00  37.36 25.62 7.56 0.78 22.69 4.21 0.00 1.79 0.00 0.09  38.88 26.84 7.62 1.03 14.66 9.73 0.00 1.13 0.13 0.10  36.37 25.24 7.66 0.69 23.48 3.49 0.00 2.80 0.16 0.00  100.25  100.26  100.11  100.11  99.86  Sample 3CHN89-100 Site  1  2  Cu S Zn Fe Sb As Pb Ag Bi Hg  33.34 25.07 6.84 0.51 19.67 5.45 0.00 7.30 0.06 0.09  38.71 26.30 7.89 0.31 13.12 10.88 0.00 2.54 0.08 0.00  Total  98.32  99.83  Sample 2CHN90-2 Site  1  2  Cu S Zn Fe Sb As Pb Ag Bi Hg  36.69 25.45 4.84 2.35 24.43 3.09 0.00 2.60 0.00 0.00  35.57 25.30 5.58 1.80 25.71 2.37 0.00 2.99 0.00 0.13  Total  99.46  99.46  Sample 3CHN89-98 Site  1  2  3  Cu S Zn Fe Sb As Pb Ag Bi Hg  39.11 26.87 7 .73 0.35 10.71 12.47 0.00 1.43 0.18 0.00  38.71 26.70 7.75 0.33 12.08 11.53 0.00 1.79 0.06 0.00  38.62 27.06 7.88 0.37 12.24 11.42 0.00 1.81 0.14 0.04  Total  98.86  98.97  99.58  1  2  3  4  5  6  Cu S Zn Fe Sb As Pb Ag Bi Hg  42.63 28.56 6.80 1.60 0.04 19.68 0.00 0.43 0.08 0.00  41.36 27.66 8.40 0.67 0.08 17.77 0.00 0.55 3.58 0.11  42.10 28.41 8.28 1.01 0.00 19.21 0.00 0.34 0.86 0.06  42.13 28.16 8.59 0.67 0.00 18.54 0.00 0.49 2.23 0.11  42.27 28.23 8.51 0.94 0.03 19.38 0.00 0.40 0.25 0.04  41.30 27.69 8.72 1.10 0.00 17.45 0.00 0.52 3.56 0.04  Total  99.80  100.17  100.29  100.91  100.03  100.41  Sample 2CHN89-27 Site  265  Sample 3CHN89-66  Sample 3CHN89-3 ( G r a i n  Site  Site  Cu S Zn Fe Sb As Pb Ag Bi. Hg Total  1 25.50 24.14 6.15 2.24 20.71 4.60 0.00 17.32 0.00 0.00 100.66  1  2  Cu S Zn Fe Sb As Pb Ag Bi Hg  39.90 27.17 3.98 3.16 11.29 11.37 0.00 0.47 1.31 0.18  39.22 26.41 4.39 2.33 16.17 6.90 0.00 0.70 3.84 0.13  Total  98.82  100.07  Sample 3CHN89-3 ( G r a i n I I I )  Sample 3CHN89 -3  Site  Site  1  2  Cu S Zn Fe Sb As Pb Ag Bi Hg  38.87 25.89 6.71 1.19 3.49 12.84 0.00 0.38 9.99 0.00  39.26 26.97 7 .24 1.27 8.26 13.40 0.00 0.25 2.18 0.00  Cu S Zn Fe Sb As Pb Ag Bi Hg  Total  99.36  98.83  Sample 3CHN89-88 Site Cu. S Zn Fe Sb As Pb Ag Bi Hg Total  1  ( G r a i n IV)  1  2  3  40.13 26.22 3.74 3.13 10.55 11.02 0.00 0.65 4.56 0.32  46.96 32.42 0.33 1.12 2.48 17.31 0.00 0.00 0.15 0.00  42.63 28.65 3.40 4.33 2.71 18.43 0.00 0.25 0.20 0.00  T o t a l 100.32  100.75  100.66  Sample 3CHN89-15 2_  Site  40.43 27.72 7.12 2.53 0.11 17.37 0.00 0.49 4.23 0.13  41.72 29.00 7.70 1.83 0.00 18.69 0.00 0.24 0.74 0.00  Cu S Zn Fe Sb As Pb Ag Bi Hg  100.12  99.92  Total  1 26.36 23.68 0.70 6.28 26.64 1.02 0.00 16.32 0.00 0.00 101.02  Sample 2CHN89-19  Sample 2CHN89-34  Site  Site  1  1  2  Cu S Zn Fe Sb As Pb Ag Bi Hg  39.71 26.45 7.78 0.73 14.34 9.61 0.00 0.14 0.11 0.10  Cu S Zn Fe Sb As Pb Ag Bi Hg  37.88 25.76 7.77 0.21 20.95 5.25 0.00 0.79 0.00 0.00  41.59 28.23 7.70 0.62 0.89 18.68 0.00 0.12 0.18 0.00  Total  98.98  Total  98.64  98.01  Sample 3CHN89-24 ( G r a i n I I )  Sample 2CHN90-9  Site  Site  1  1  2  Cu S Zn Fe Sb As Pb Ag Bi Hg  19.50 22.03 6.48 1.23 23.62 1.53 0.00 24.61 0.00 0.05  Cu S Zn Fe Sb As Pb Ag Bi Hg  35.58 25.31 7.52 0.19 20.36 6.10 0.16 3.60 0.04 0.07  36.63 25.80 7.66 0.17 17.70 6.96 0.28 2.99 0.08 0.00  Total  99.04  Total  98.95  98.27  Sample 3CHN89-79 Site  1  Cu S Zn Fe Sb As Pb Ag Bi Hg  41.51 28.47 6.40 2.29 0.00 19.51 0.00 0.47 0.13 0.00  Total  98.79  267 Part l i t  Sphalerites  Sample 3CHN89-66 Site Zn S Fe Mn Cd Hg Ga Ge In Total  Site Zn S Fe Mn Cd Hg Ga Ge In Total  1  2  3  4  5  6  66.42 33.33 0.11 0.05 0.36 0.00 0.00 0.06 0.00  66.38 33.29 0.10 0.03 0.45 0.00 0.00 0.00 0.00  66.47 33.40 0.21 0.07 0.42 0.00 0.00 0.00 0.00  65.59 33.22 0.43 0.34 0.38 0.00 0.00 0.00 0.00  65.96 33.11 0.23 0.07 0.41 0.00 0.00 0.04 0.00  66.10 33.12 0.15 0.00 0.39 0.00 0.00 0.04 0.00  100.33  100.26  100.60  99.96  99.83  99.83  7  8  9  66.25 33.40 0.08 0.00 0.41 0.00 0.00 0.00 0.00  65.19 33.17 0.22 0.15 0.40 0.00 0.00 0.06 0.00  66.34 33.37 0.40 0.00 0.42 0.00 0.00 0.03 0.00  66.23 33.14 0.23 0.04 0.40 0.00 0.00 0.00 0.00  65.99 33.19 0.34 0.14 0.43 0.00 0.00 0.06 0.00  66.54 32.93 0.00 0.00 0.00 0.00 0.00 0.00 0.00  100.16  99.93  100.58  100.09  100.14  99.51  10  11  12  Sample 3CHN89-20 Site  1  2  3  4  5  6  Zn S Fe Mn Cd Hg Ga Ge In  63.18 33.11 2.55 0.07 0.00 0.00 0.04 0.00 0.00  65.35 33.21 0.68 0.00 0.06 0.00 0.00 0.00 0.00  65.74 33.27 0.00 0.00 0.17 0.07 0.00 0.00 0.00  65.86 33.15 0.00 0.00 0.14 0.00 0.00 0.00 0.00  65.58 33.21 0.00 0.00 0.28 0.00 0.00 0.00 0.04  65.37 33.22 0.00 0.00 0.64 0.04 0.000.07 0.08  Total  98.98  99.34  99.27  99.20  99.11  99.42  268 Site  7  8  9  Zn S Fe Mn Cd Hg Ga Ge In  65.80 32.90 0.00 0.00 0.44 0.00 0.00 0.05 0.10  65.29 33.03 0.00 0.00 0.56 0.00 0.00 0.05 0.19  66.04 33.21 0.00 0.00 0.11 0.00 0.00 0.00 0.00  65.82 32.97 0.00 0.00 0.38 0.05 0.00 0.03 0.07  66.06 33.18 0.00 0.00 0.20 0.00 0.00 0.03 0.00  65.39 33.08 0.00 0.00 0.54 0.06 0.00 0.00 0.18  Total  99.31  99.14  99.42  99.34  99.48  99.28  Site  13  14  15  10  16  11  17  12  18  Zn S Fe Mn Cd Hg Ga Ge In  65.80 32.97 0.00 0.00 0.29 0.00 0.03 0.07 0.05  65.70 32.73 0.00 0.00 0.71 0.00 0.03 0.05 0.09  66.12 33.29 0.00 0.00 0.13 0.00 0.00 0.00 0.00  65.40 32.98 0.46 0.00 0.39 0.00 0.00 0.00 0.00  65.33 33.43 0.69 0.00 0.17 0.07 0.00 0.07 0.00  65.91 32.84 0.21 0.00 0.34 0.00 0.00 0.05 0.00  Total  99.21  99.31  99.56  99.23  99.77  99.38  Sample 3CHN89-20 Site  19  (continued) 20  21  22  23  24  Zn S Fe Mn Cd Hg Ga Ge In  66.06 33.28 0.47 0.00 0.14 0.00 0.00 0.03 0.00  63.25 33.57 2.51 0.00 0.00 0.00 0.00 0.00 0.00  65.55 33.03 0.29 0.00 0.15 0.00 0.00 0.09 0.00  66.28 33.24 0.23 0.00 0.08 0.00 0.00 0.05 0.00  65.96 32.94 0.31 0.00 0.23 0.00 0.00 0.00 0.00  66.27 33.17 0.05 0.04 0.24 0.00 0.00 0.00 0.03  Total  99.99  99.37  99.12  99.87  99.44  99.82  269 Sample 3CHN89-36 Site Zn S Fe Mn Cd Hg Ga Ge In Total Site  1  2  3  4  5  6  66.65 33.09 0.00 0.09 0.17 0.00 0.00 0.00 0.03  66.12 32.92 0.00 0.07 0.18 0.00 0.00 0.00 0.00  66.17 33.04 0.00 0.43 0.36 0.00 0.00 0.00 0.00  66.34 32.97 0.00 0.34 0.30 0.00 0.00 0.00 0.07  66.30 33.01 0.00 0.21 0.34 0.00 0.00 0.04 0.00  66.64 33.04 0.00 0.08 0.38 0.00 0.04 0.00 0.00  100.03  99.36  100.03  100.05  99.91  100.22  7  8  9  Zn S Fe Mn Cd Hg Ga Ge In  65.93 32.95 0.00 0.00 0.68 0.00 0.00 0.00 0.00  65.81 33.20 0.00 0.14 0.29 0.08 0.00 0.03 0.00  66.28 33.04 0.00 0.06 0.30 0.00 0.00 0.06 0.00  Total  99.64  99.55  99.73  Sample 2CHN89-4 Site  1  2  3  4  Zn S Fe Mn Cd Hg Ga Ge In  64.88 33.26 0.98 0.00 0.34 0.00 0.00 0.03 0.00  65.71 33.05 0.24 0.00 0.42 0.00 0.05 0.00 0.10  65.50 33.24 0.43 0.00 0.42 0.00 0.00 0.10 0.04  65.28 33.17 0.28 0.00 0.42 0.00 0.00 0.08 0.00  Total  99.51  99.59  99.74  99.23  270 Sample 3CHN89-18 Site Zn S Fe Mn Cd Hg Ga Ge In Total  1  2  3  4  5  6  66.64 33.03 0.00 0.00 0.44 0.06 0.00 0.07 0.04  65.88 32.98 0.00 0.00 0.60 0.00 0.03 0.05 0.00  66.24 33.10 0.00 0.00 0.53 0.07 0.04 0.06 0.00  66.26 33.10 0.00 0.00 0.52 0.00 0.04 0.00 0.00  66.77 32.99 0.00 0.00 0.42 0.00 0.00 0.00 0.00  66.75 32.99 0.00 0.00 0.42 0.00 0.00 0.00 0.00  100.31  99.57  100.06  99.98  100.20  100.18  Site Zn S Fe Mn Cd Hg GaGe In Total  7  8  66.62 33.07 0.00 0.00 0.35 0.00 0.00 0.00 0.00  66.73 33.06 0.00 0.00 0.35 0.00 0.00 0.07 0.00  100.07  100.28  Sample 2CHN89-27 Site Zn S Fe Mn Cd Hg Ga Ge In Total  1 65.83 33.04 0.89 0.00 0.44 0.00 0.00 0.07 0.00 100.31  - Sample 3CHN89-21 Site Zn S Fe Mn Cd Hg Ga Ge In Total  1  2  3  4  5  66.03 33.32 0.46 0.00 0.82 0.00 0.00 0.00 0.00  66.67 33.20 0.44 0.00 0.37 0.00 0.00 0.03 0.00  65.62 33.07 0.52 0.00 0.54 0.00 0.00 0.00 0.04  66.23 33.36 0.57 0.28 0.36 0.07 0.03 0.05 0.00  66.69 32.64 0.43 0.00 0.55 0.04 0.00 0.03 0.00  100.65  100.73  99.81  100.96  100.39  Sample 1CHN89-83 Site  1  2  3  4  5  6  Zn S Fe Mn Cd Hg Ga Ge In  65.97 33.10 0.32 0.00 0.50 0.00 0.00 0.06 0.00  66.19 33.17 0.32 0.00 0.51 0.07 0.03 0.03 0.00  66.73 33.03 0.30 0.00 0.47 0.04 0.03 0.00 0.00  66.40 33.06 0.33 0.00 0.59 0.00 0.00 0.00 0.03  66.37 33.04 0.31 0.00 0.46 0.00 0.00 0.00 0.00  66.06 32.75 0.30 0.00 0.48 0.04 0.00 0.00 0.00  Total  99.98  100.34  100.60  100.43  100.20  99.64  Sample 2CHN90-2 Best A n a l y s i s Site  1  Zn S Fe Mn Cd Hg Ga Ge In  64.27 33.34 0.32 0.00 0.51 0.00 0.03 0.00 0.00  Total  98.53  272 Sample 3CHN89-97 Site  1  2  Zn S Fe Mn Cd Hg 6a Ge In  65.84 32.96 0.00 0.00 0.08 0.00 0.00 0.06 0.04  66.68 32.88 0.00 0.00 0.00 0.00 0.00 0.03 0.00  Total  99.01  99.67  273 P a r t I I I : M i s c e l l a n e o u s S u l f i d e Analyses *A11 analyses done u s i n g s u l f o s a l t r o u t i n e **Values a r e weight p e r c e n t s . F o r s e v e r a l galena samples, atom counts g e n e r a l l y show Ag=Bi, s u g g e s t i n g a p o s s i b l e u n r e s o l v a b l e intergrown m a t i l d i t e component Sample 3CHN89-79 (Galena)  Sample 3CHN89-79 ( C h a l c o p y r i t e )  Site  Site  Cu S Zn Fe Sb As Pb Ag Bi Hg Total  1 0.00 14.32 0.00 0.04 0.00 0.00 82.85 1.20 2.47 0.00 100.88  1  Cu S Zn Fe Sb As Pb Ag Bi Hg  33.42 34.55 0.00 31.50 0.00 0.06 0.00 0.00 0.25 0.09  Total  99.91  Sample 3CHN89-88 (Galena)  Sample 2CHN89-45  Site  Site  1  2  Cu S Zn Fe Sb As Pb Ag Bi Hg  0.98 13.69 0.14 2.01 0.06 0.00 76.75 1.90 3.86 0.00  0.48 14.07 0.00 0.00 0.00 0.00 80.99 1.24 3.72 0.00  Total  99.42  100.54  Cu S Zn Fe Sb As Pb Ag Bi Hg Total  1 34.42 35.06 0.00 30.42 0.00 0.00 0.00 0.06 0.21 0.00 100.23  

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
http://iiif.library.ubc.ca/presentation/dsp.831.1-0052415/manifest

Comment

Related Items