Open Collections

UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

The structural geology of the Ruth-Hope and Silversmith mines Sharp, William McMillan 1950

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

Item Metadata

Download

Media
831-UBC_1950_A7 S4 S7.pdf [ 23.4MB ]
Metadata
JSON: 831-1.0053506.json
JSON-LD: 831-1.0053506-ld.json
RDF/XML (Pretty): 831-1.0053506-rdf.xml
RDF/JSON: 831-1.0053506-rdf.json
Turtle: 831-1.0053506-turtle.txt
N-Triples: 831-1.0053506-rdf-ntriples.txt
Original Record: 831-1.0053506-source.json
Full Text
831-1.0053506-fulltext.txt
Citation
831-1.0053506.ris

Full Text

THEE STRUCTURAL GEOLOGY OF THS RUTH-HGEE5 ANB SILVERSMITH MBTBS A thesis submit ted in p a r t i a l f u l f i l m e n t of the requirements f o r the degree of Master of Applied Science in the Department of Geol ogy and Geography. University of B r i t i s h Columbia April,1950 William McMillan Sharp ABSTRACT The Ruth-Hope and Silversmith areas are mainly under-l a i n by structurally-competent quaxtzites, sandy limestones, and thick a r g i l l i t e s . Bedding attitudes are steep; several major and minor recumbent folds occur within the l o c a l section of bedding structures.. The strong northeasterly-trending Standard-Silversmith lode system i s represented l o c a l l y by the Hope, New Ruth, and Silversmith lodes. The Old Ruth-Stewart section l i e s about one-half mile north, and in the footwall of the main b e l t , ,I»odes strike easterly to northeasterly across the trend of bedding structures; they dip to the southeast at moderate to high angles, The most important ore minerals are argentifer-ous galena, sphalerite., and grey copper. The major bedding structure of the Old Ruth-Stewart section is a recumbent a n t i c l i n e which i s convex to the south-west. Bedding within the New Ruth-West Silversmith section dips moderately to steeply southwest. The pattern of lode and cross-fault displacements i s reasonably consistent within the mines area. From evidence provided by minor structures, the r e l a t i v e displacements were such that lode hanging walls moved downward to the east and (i) Abstract - 2 southeast; normal displacements occurred on a l l c r o s s - f a u l t s . Within the productive part of the Old Buth Mine, mineralization apparently followed a late normal displacement within a major strand of the lode. Lode movements, at least l a t e r ones, were, to some extent, transmitted by cross-faults which j o i n the off-set segments of the lodes. Also, to a minor extent, the cross-f a u l t s contain ore minerals which probably entered by way of fault-lode l i n k i n g fractures. Apparently porphyry, a l t e r a t i o n , and ore were em-placed consecutively, but concurrently with displacements on ths lodes and cross-faults. The stronger mineralization of the northeasterly-trending fractures was probably due to a close timing of ore deposition with more intense late movements on this set of fractures. In addition, deeper fore channels" could be expected within fractures which cross-cut, rather than p a r a l l e l the bedding, That the West Silversmith porphyry "plug" was em-placed as a separate body, and i s not a faulted block from the main Silversmith Stock was proved by the study of flow struc-tures within the "plug". ( i i ) A GKNOWLEDGEMHSM TS The writer i s indebted to the o f f i c e r s and senior members of the staff of the Kelowna Exploration Company f o r permission to use, and submit to the University of B r i t i s h Col-umbia, the information embodied in this t h e s i s . The author wishes to acknowledge his spe c i a l obliga-tion to Mr. Paul B i l l i n g s l e y f o r the use of his early interp-retations of the stru c t u r a l geology of the mines area. This thesis is confined to a detailed study of the s t r u c t u r a l patt-ern established mainly by him and Dr. Evans B. Mayo. P a r t i c u l a r thanks are due to Br. Mayo for his personal advice and encour-agement throughout the preparation of the maps and text, and for permission to use the results of his detailed studies with-in the mines area. The writer is gra t e f u l for the h e l p f u l guidance of Br. H.C. Gunning during the preparation of much of the text. Thanks are also due to Dr. K. BeP. Watson for his assistance in petrographic determinations. To Mr. A.B. B u l l e r , B>r. R.S. Moelhman, and Mr. John Lamb, the writer's thanks are extended f o r the use of th e i r geological maps and sketches. The sources of the data referred to are indicated where they appear in the text. ( i i i ) TABLE OF CONTENTS Abstract • • i Acknowledgements i i i Introduction ••: iv General Geology of the Mines Area 1 Details of Structural Geology Introduction 10 Old Ruth-Stewart Section General • • 12 Pattern of Major Structures 13 Silversmith Fault 15 Stewart Fault . - 17 Wall Rock Types and Structures 26 Old Ruth Lode 33 No . 1 Level 35 No. 2 Level 36 No. 3 Level 38 No. 4 Level . 40 No. 5 Level . 42 Stewart Lode and Ruth Fault 43 Stewart No. 4 Level 44 Stewart No. 5 Level 46 Old'Ruth No . 3 Level 48 Old Ruth No. 4 Level 49 Old Ruth No . 4150 Level •. 50 Old Ruth No. 5 Level 51 Summary Old Ruth-Stewart ..-. 52 Mascot-Ho-pe Section . .. .. 57 New Ruth Section Introduction 62 Rock Types and Structures 64 Mineralization and Orebodies 64 Silversmith Lode 65 Ruth Fault 66 Lone Star Fault 67 West Silversmith Lode 68 Cross-Fault 69 West Silversmith Porphyry .70 Minor Structures and Movement Patterns 71 Ruth Fault 71 West Silversmith Lode • 72 Lone Star F a u l t 73 West Silversmith Porphyry 76 T a b l e o f C o n t e n t s - 2 P e t r o g r a p h i c F e a t u r e s o f t h e W e s t S i l v e r s m i t h P l u g ( a ) M e g a s c o p i c 7 8 ( h ) M i c r o s c o p i c 7 9 E s s e n t i a l M i n e r a l s - 7 9 A c c e s s o r y M i n e r a l s 8 0 A l t e r a t i o n 8 0 S u m m a r y 8 1 Specimen H o . 4 ' 8 3 S p e c i m e n N o . 5 8 3 S p e c i m e n N o . 6 8 4 S p e c i m e n N o . 7 , 8 4 S e q u e n c e o f G e o l o g i c a l E v e n t s ; N e w R u t h - S i l v e r s m i t h A r e a s . . . . 8 5 R e f e r e n c e s 8 7 M a p s i n P o c k e t M a p N o . 1 - S u r f a c e a n d . U n d e r g r o u n d G e o l o g y o f t h e M a s c o t - H o p e - R u t h - S i l v e r s m i t h A r e a M a p N o . 2 - S p r e a d C o m p o s i t e P l a n , O l d R u t h M i n e M a p N o . 4 - U n d e r g r o u n d G e o l o g y , N e w R u t h A r e a a d C o m p o s i C r o s s - S e c t i o n " O l d R u t h L o d e s INTRODUCTION The Sand on area of the Slocan mining d i s t r i c t l i e s a few miles east of New Denver, B.C., which is situated on the east shore of Slocan Lake. Descriptions of a c c e s s i b i l i t y , climate, topography, history of mining, and general geology may be found in Memoir 173, by C E . Cairnes, of the Geological Survey of Canada. Early in 1946 the Kelowna Exploration Company started a program of surface and underground geological mapping of t h e i r large group of claims l y i n g to the south and west of Sandon. This work has been carried on continu-ously to the present time under the general direction of Mr. Paul B i l l i n g s l e y , Consulting Geologist for the Company. The d i r e c t i o n of f i e l d work has been the r e s p o n s i b i l i t y of Mr. A.E. B u l l e r , during the 1946 season, of Dr. E.B. Mayo during the 1947 and 1948 seasons, and of the writer's, under Chief Resident Geologist Dr. E.B. Mayo, during the 1949 season. The object of t h i s thesis i s the detailed descrip-t i o n of the structural geology of the Ruth-Hope and S i l v e r -smith mines. The description of minor fold and fracture structures, with interpretations, w i l l he emphasized. To this end, i t ia hoped that the maps and other illustrations accomp-anying this thesis w i l l provide a maximum of assistance in following the text. GENERAL GEOLOGY OF THE MINE AREA The mine area including, from west to east, the Mascot, Hope, Ruth, Silversmith, and Slocan Star properties i s situated immediately to the south of Sandon (Map No. 1). It l i e s cm the steep slopes forming the south side of Carpen-ter Creek v a l l e y , between the east fork of Tributary Creek on the west, and Sandon Creek on the east. The most important mine workings range in elevation from 4000 feet at Ruth No.5 adit to about 5300 feet at Hope No.l a d i t . Mining a c t i v i t y in the area commenced in 1891 with the location of the Slocan Star claim, in what i s now the east-e r l y section of the Silversmith mine. The f i r s t locations on Ruth-Hope ground were made in 1892. Intensive mining of the various orebodies took place u n t i l the early 1930's. L i t t l e production, excepting that from intermittent small scale mining by leasers,, has ensued since low metal prices forced a general shut-down at the l a t t e r date. - 1 -- 2 -Geologically, the mine area straddleB one of the prominent northwesterly-trending belts of q u a r t z i t i c rocks, occupying a c e n t r a l position in the Slocan Series of highly-folded quartzites, a r g i l l i t e s , and limestones. This belt i s predominantly q u a r t z i t i c f o r a considerable distance to the northwest, but within a short distance to the southeast the rocks become rather calcareous. This change i s , i n a sense, gradational, and i s due to an increase in the proportion of limey beds, with a corresponding decrease of the number of qu a r t z i t i c beds which normally make up the bulk of the form-ation to the northwest. Southeast of the mine area, the i n -creasingly calcareous composition of the sediments, with a corresponding increase in the development of shallow-water cross-bedding within coarse sandy layers, suggests that t h i s section of the area p e r s i s t e n t l y maintained a " r e l a t i v e l y p o s i t i v e " position with respect to deeper parts of the or i g -i n a l basin of deposition. The orebodies of the mine area l i e towards the east-e r l y end of the main through-going lode system of the d i s t r i c t . C E . Cairnes, on page 28 of Memoir 184, suggests the possible continuity of the Standard, Mammoth, Carnation, and Ruth-Hope lodes in a northeasterly direction across the Slocan mining area. On page 122 he points also to the possible continuity l I - 3 -of the Hope and Silversmith lodes. This apparently continu-ous system of the major lodes of the d i s t r i c t i s , i n d e t a i l , a composite structure formed by the roughly-parallel develop-ment of a few strong fracture-shear zones separated by panels of country rock that are generally more deformed than the bounding formations. Individual lodes may unite to form a single structure, or s p l i t into a number of weaker Bhear strands separated by relatively-undeformed sections of country rock. In addition the lodes may curve in s t r i k e , or be offset abruptly, where they intersect strong northwesterly-trending f a u l t s . At such bends and o f f s e t s mineralization i s sometimes continuous, although e r r a t i c a l l y d i s t r i b u t e d , through the fault-lode i n t e r s e c t i o n . In such cases, i t i s evident that cross-faulting took place p r i o r to mineralization, and perhaps at a time close to the development of the north-e a s t e r l y - s t r i k i n g lodes. In general, the lodes dip south-easterly, and the stronger cross-faults dip southwesterly in the mine area. When fault-lode intersections are cl o s e l y examined, the intersecting structures are often found to be linked by curved shear strands which merge with both struc-tures at small angles. As already stated, these l i n k s are frequently mineralized. Bedding throughout the mine area i s generally folded along northwesterly- to northerly-trending axes, - 4 -except where i t has been l o c a l l y deformed adjacent to the walls of a lode. North of the old Ruth and Stewart workings (Map No.l) surface exposures of hard, thinly-bedded a r g i l l -i t e s dip to the west and north, with bedding "tops" f a c i n g east and north respectively, indicating a section of up-side-down bedding. Between the outcrop of the Hope orebody and the surface over the New Ruth section, i s a wide b e l t of c a l -careous a r g i l l i t e s and quartzites dipping to the west, and with "tops" also facing westerly. To the east of t h i s cen-t r a l b e l t , outcrops over the Silversmith and Slocan Star mines, between White and Sandon Creeks, are mainly of mass-ive, s l i g h t l y calcareous quartzites, with minor inter-bedded blocky and sl a t y a r g i l l i t e s . Bedding dips are steep to the east and west, with "tops" consistently to the west. To the west of the Hope-New Ruth central b e l t , and to the south of the Mascot-Hope lode outcrop, i s a strong section of massive, variably-calcareous quartzites. The beds dip moderately to steeply east with bedding "tops" to the west. The few short tunnels of the Mascot property l i e within a westerly part of t h i s b e l t . To the north across the Mascot lode, there i s a marked change from the massive q u a r t z i t i c hanging wall beds to thinly-bedded argillaceous rocks. Within the l a t t e r , occasional pronounced cross-folds, with northeasterly-trending axes, have developed l o c a l l y . Farther north, small exposures - 5 -of up-aide-down bedding show the e f f e c t s of extreme over-f o l d i n g . Further examples of thi s type of bedding deformation are afforded in the v e r t i c a l section including the outer part of Ruth No.5 l e v e l and the surface area above. Here, calcar-eous quartzites and th i n , slaty a r g i l l i t e s are buckled from a westerly-dipping, right-side-up attitude to westerly-dipping up-side-down attitudes within a few feet of v e r t i c a l distance. Immediately below, in the a d i t , bedding i s i n t r i c a t e l y folded, about v e r t i c a l a x i a l planes, into gentle and ti g h t r o l l s super-imposed upon a generally s l i g h t dip to the east. The most s i g n i f i c a n t feature of the larger bedding structures within the mines area i s the development of complex folds with e s s e n t i a l l y horizontal axes. An east-west v e r t i c a l section through the h i l l between the long southerly crosscut from Ruth No.5 d r i f t and the surface area immediately above would bring out t h i s feature. On the surface the majority of beds dip, right-side-up, to the west; at crosscut l e v e l the bedding dips, up-side-down, to the east. Correlation of these exposures i s most e a s i l y accomplished by the assumption of one or more recumbent f o l d s with an approximately horizontal axis, or axes. Minor recumbent folds mapped on the surface and underground lend support to the assumption that s i m i l a r major structures do e x i s t . One excellent example was mapped - 6 -in a cut-bank a short distance west of Sandon on the S i l v e r Ridge mine road, l a t e r in the text, in describing the geol-ogy of the Old Ruth mine, the relationship of higher westerly-dipping beds and underlying easterly-dipping beds to a well-defined recumbent f o l d w i l l be discussed in d e t a i l . The mapping of these complex recumbent folds would be impossible without an adequate number of primary bedding structures of the type required to distinguish between r i g h t -3lde-up and overturned sections of bedding. Of these primary structures truncated cross-bedding provides the most conclu-sive determinations. Second in usefulness are secondary structures in the form of minor drag-folds within the bedding. These structures, used in conjunction with occasional "top* determinations by the study of cross-bedding, enable the geologist to map wider normal or overturned sections of bedding. The p r i n c i p l e on which t h e i r application i s based i s that these structures are overturned in the d i r e c t i o n of. the axes of major f o l d s . They are best developed where the folded section i s composed of inter-bedded firm, hard and soft, p l a s t i c rock types, thus allowing a maximum of i n t e r -bed movement and the consequent development of drag-folds in the more p l a s t i c layers. In t h i s type of folding beds farther from the center of curvature move towards an a n t i c l i n a l axis - 7 -with respect t o those c l o s e r to the c e n t e r . F o l d i n g a l s o i n -v o l v e s simple f l e x u r e of the more competent rock l a y e r s , and d i f f e r e n t i a l movements, accompanied by the p l a s t i c flowage of m a t e r i a l w i t h i n less-competent l a y e r s . An i d e a l assemblage f o r the development of minor d r a g - f o l d s i s one of i n t e r -bedded q u a r t z i t e B and s o f t a r g i l l i t e B . The re a s o n i n g by which these d r a g - f o l d s are used to extend " t o p s " d e t e r m i n a t i o n over a wider s e c t i o n i s as f o l l o w s : W e s t e r l y - d i p p i n g s e c t i o n s of Slocan sediments a r e , w i t h very l o c a l e x c e p t i o n s , r i g h t - s i d e -up. Consequently, minor d r a g - f o l d s i n these w e s t e r l y - d i p p i n g s e c t i o n s are overturned to the west towards a major recumbent a n t i c l i n a l f o l d a x i s . Thus, i f a d r a g - f o l d i s seen t o be over-turned t o the west, the s e c t i o n of bedding i n v o l v e d i s prob-a b l y p a r t of a major w e s t e r l y - d i p p i n g , r i g h t - s i d e - u p s e c t i o n of bedding. A s i m i l a r l i n e of re a s o n i n g a p p l i e s to the i n t e r -p r e t a t i o n of d r a g - f o l d s overturned to the east as l y i n g w i t h i n a s e c t i o n of e s s e n t i a l l y e a s t e r l y - d i p p i n g , up-side-down bedding. Thus, a l a r g e p a r t of the s o l u t i o n of major bedding f o l d s r e -s o l v e s i t s e l f i n t o the p i e c i n g - t o g e t h e r of r i g h t - s i d e - u p and up-side-down bedding. At t h i s p o i n t i t may be s a i d that the displacements on bedding f a u l t s are g e n e r a l l y a s s o c i a t e d with i n t e r - b e d adjustments w i t h i n the e n c l o s i n g s t r a t a . S i m i l a r l y , the occurence of d r a g - f o l d s , shear cleavage, and " g a s h - f r a c -t u r e s " i s u s e f u l i n determining r e l a t i v e d isplacements. - 8 -The main orebodies of the mines area (Map No.l) l i e within three major lodes, each s t r i k i n g generally to the north-east and dipping to the southeast. The strongest lodes are those that contained the Hope orebodies in the westerly part of the area, and the New Ruth, Silversmith, and Slocan Star orebodies in the southern and eastern parts. Recent i n v e s t i -gations confirm C E . Cairnes opinion that the Hope and S i l -versmith lodes are continuous structures, linked by the strong southwesterly-dipping Ruth and Lone Star f a u l t s . A weaker lode strand, the West Silversmith lode, continues along the hanging wall of the West Silversmith porphyry "plug", and probably p a r a l l e l s the Hope lode, which appears to be close to the footwall of the "plug" in the v i c i n i t y of the Ruth 501 l a t e r a l (Map No.4). The Old Ruth orebodies are situated within a f r a c -ture zone p a r a l l e l to, but 2500 feet north of the Silversmith lode, With respect to a l i n e representing the northeasterly projection of the Mascot-Hope lode, they would l i e approx-imately 2000 feet north. Occupying a fracture-shear zone situated between the Hope and Old Ruth lodes, i s the Stewart orebody. Possibly the Hope-Stewart lodes are linked through a northwesterly-trending f a u l t zone, much as the Stewart and Old Ruth lodes are, as w i l l be pointed out in another section of the text. - 9 -A number of northwesterly-trending f a u l t zones s p l i t the mine area into rather d i s t i n c t panels within which lode and bedding structures may be correlated between the steep southwesterly-dipping fault-boundaries of each i n d i v i d u a l panel. However, the effect of displacements which have occurred on these fault-boundaries should be considered when corr e l a t i n g similar sections of bedding that l i e within d i f f -erent panels. Generally, lodes are interrupted, within i n t e r -vals of a few hundred feet of strike-length, by these zones of c r o s s - f a u l t s . As was pointed out in the discussion of inter-bed motion related to f l e x u r a l - s l i p f o l d i n g within re-cumbent fo l d s , most of these cross-faults which are roughly p a r a l l e l to the bedding show normal displacements. Conse-quently, when a southeasterly-dipping lode i s interrupted by a southwesterly-dipping cross-fault, the effect i s an appar-ent right-hand displacement of the lode. Also, as these i n t e r -sections are frequently characterized by curved shear-links, on which displacements, l o c a l l y , represent a compromise be-tween the t y p i c a l f a u l t and lode movements, i t appears that the development of lodes and cross-faults was rather closely timed. From past experience in mapping these structures, one would not necessarily expect a similar lode structure on both sides of a c r o s s - f a u l t . It i s safer to assume that sections of a through-going lode may have a c h a r a c t e r i s t i c development that varies within different panels separated by c r o s s - f a u l t s . E S T A I L S O F S T R U C T U R A L G E O L O G Y Introduction Detailed underground mapping, p a r t i c u l a r l y of minor structures within the lode and wall rock, involved the use of the "Sander Method" - a technique devised by the Austrian geologist, Dr. Bruno Sander. This method saves much time in recording those structures in the f i e l d and, at the same time, emphasizes the fundamental r e l a t i o n s h i p between d i f f e r e n t structures r e s u l t i n g from the same stress and movement. The method was introduced, probably for the f i r s t time in t h i s country, by Dr. E.B. Mayo in mapping the new section of the Ruth Mine. The "Sander Method" employs a system of axes, as i l l u s t r a t e d in the following three-dimensional diagram. c b ( 1 0 ) - 11 -"b" - the direction of the f o l d axes; axes of rotation; any l i n e a t i o n developed by d i f f e r e n t i a l movement and which l i e s normal to the l i n e of movement. An arrowhead and number gives the direction and plunge . "a" - a di r e c t i o n at right angles to "b" and l y i n g in the movement plane. This axis, representing a d i r e c t i o n , i s shown as an arrow with a number giving the direction and i n c l i n a t i o n of the l i n e of movement, "a" i s taken as the direction of overturn-ing of minor folds on f a u l t surfaces and in f a u l t zones, and as the attitudes of movement s t r i a e ( s l i c k -ensides) on f a u l t surfaces. "c" - a reference axis perpendicular to "a" and "b"; i t does not appear on the maps or fi g u r e s , but i s used soley to r e f e r to features l y i n g i n , or of, the three p r i n c i p a l planes defined by the coordinates "a", Mb", and "c". Mapping by t h i s method w i l l present a clearer pattern of the movement in related f a u l t s and lodes and the adjacent wall rocks, provided that s u f f i c i e n t minor struc-tures are present, lh order to group the lineations related to d i s t i n c t i v e classes of displacement an additional r e f i n e -ment was added: a^ and b]_ - those lineations related to i n t e r -bed or bedding-fault movements. ag and b2 - those lineations related to predom-inantly s t r i k e - s l i p displacements on lodes. as and b3 - those lineations related to predomin-antly normal displacements on lodes. OLB RUTH-STEWART SECTION General The following description of the workings in this section of the area may be followed on Maps No.l and No.2. As both the Old Ruth and Stewart workings l i e within steeply-dipping lodes, several l e v e l s of the mine would appear one over the other on a conventional composite plan. Consequently Map No.2 was designed to show the geology of each l e v e l with-out confusing overlaps of det a i l s from other l e v e l s . This "spread composite plan" i s act u a l l y the projection of a true composite plan upon a plane that dips at 45 degrees, with the dip - l i n e bearing at about south 30 degrees east. To obtain the actual plan r e l a t i o n s h i p of a l l l e v e l s they would have to be shifted so that a l l the green-dashed l i n e s , which are numbered from 1 to 5, would be superimposed. The cross-sections shown on Map No.3 were derived from a true composite plan. The Old Ruth lode was explored and developed on f i v e l e v e l s , with connecting r a i s e s , over a v e r t i c a l distance of about 600 fe e t . No's. 1, 2, and 3 Levels are, in the i r east-e r l y parts, d r i f t s which were driven southwestward from the (12) - 1 3 -outcrop. To the southwest, beyond the Stewart f a u l t zone, each l e v e l becomes a system of exploratory crosscuts, l a t e r a l s , and d r i f t s . No's. 4 and 5 l e v e l s s t a r t as acute crosscuts, but continue mainly as d r i f t s , with frequent crosscuts, to the Stewart f a u l t zone. In t h i s area crosscuts were driven south-ward to, and on the downward extension of the Stewart lode. No. 5 was the main haulage l e v e l , and drew on both the Old Ruth stopes above, and the Hew Ruth section to the south. Ho.2 Level, which extends farthest to the southwest, reached a pos i t i o n below and in the footwall of the Hope orebodies. On the southwest s i ( J e o f t h e Stewart f a u l t zone, a long crosscut was driven south on Ho.2 Level to intersect the Stewart lode. The subsequent d r i f t on the Stewart lode i s the lowest l e v e l within the main Stewart ore shoot. Pattern of Major Structures The Old Ruth and Stewart lodes (Map Ho.2) l i e to the northeast and southwest, respectively, of the Stewart f a u l t ; the i n d i v i d u a l parts forming the Ruth and the Stewart "seg-ments". The northwest-southeast separation of these segments, across the southwesterly-dipping Stewart f a u l t , i s roughly 100 feet, as measured on Ho.2 Level. On approaching the Stewart f a u l t from the northeast, strands of the Ruth lode turn gently and sharply south to j o i n strands of the Stewart f a u l t . South-- 14 ward, strands of the Stewart f a u l t curve westward to j o i n strands of the southeasterly-dipping Stewart lode. Although strands of the lode segments do not appear to continue d i r e c t -l y through bounding f a u l t s , these major cross-faults do, i n part, appear to continue to the northwest and southeast of their intersections with the lodes. As was stated e a r l i e r , evidence of the continuity of mineralization from lodes to cross-faults, suggests that the cross-faults are of pre-mineral age, and perhaps lodes and cross-faults were developed contemp-oraneously. The southwesterly course of the Stewart lode i s i n -terrupted by the southwesterly-dipping Ruth f a u l t . This i n t e r -section i s marked by a northerly bend of the lode into the footwall of the Ruth f a u l t . This pattern suggests that the lode was "dragged" by a late normal displacement on the f a u l t or by a northerly component of hanging wall movement along the f a u l t . The southwesterly continuation of the Ruth-Stewart lode system beyond the Ruth f a u l t may be represented by the Dorothy vein which outcrops on the westerly slope of Ruth Ridge. As the 4800-foot contour of the Dorothy vein would l i e at least 300 feet south of the southwesterly projection of the Stewart lode at this elevation, there i s probably another southerly offset within the lode system similar to that at the Stewart - 15 f a u l t , but apparently opposed to that at the Ruth f a u l t . To the northeast, the Ruth segment i s rather sharp-l y bounded by the so-called Silversmith f a u l t . This south-westerly-dipping f a u l t correlates approximately with the Silversmith f a u l t mapped on No.10 l e v e l of that mine. Within the Old Ruth i t appears on No's. 4 and 5 l e v e l s , and projects upward to a position near, but probably east of, No.3 l e v e l . Following this general description of the structure pattern, the following pages w i l l deal with s p e c i f i c d e t a i l s of the component structures as shown i n plan, l o n g i t u d i n a l v e r t i c a l projection, and cross-section on Maps No. 2, No.2A, No.2B and No. 3. Silversmith Fault This structure was mapped on No. 4 Level, by A.E. Buller*,before the main zone was t i g h t l y timbered. At sta.408 two strands, each including several feet of broken- to sheared graphitic wall rock and gouge, dip to the southwest at 60 de-grees. F i f t y feet to the southwest, smaller hanging wall strands provide f a i r evidence of the nature of the displace-ment across the f a u l t zone. Map No.SA shows the structure of the hanging wall strands in cross-section. Minor drag f o l d s , with axes plunging f l a t l y southeast, l i e in b i . Rotation about b i i s counter-clockwise; hence the r e l a t i v e hanging wall motion was down to the southwest. In the hanging wall of this - 16 -strand closely-spaced fractures, resembling s l a t y cleavage, p a r a l l e l the f a u l t plane. With reference to the l o c a l axes of movement they would p a r a l l e l the a i - b i plane. A few feet east of sta. 404 i s a t i g h t l y timbered section through what appears to have been a strong footwall strand of the f a u l t . L o c a l l y , though poorly exposed, the easterly lode segment appears to have been displaced to the south across the f a u l t . This right-hand displacement i s in accord with a normal d i s -placement on a southwesterly-dipping normal f a u l t , or l i k e that on the hanging wall strand. On No.5 Level the most d i s t i n c t i v e strand of the Silversmith f a u l t cuts the adit 85 feet east of sta.503. It includes about 18 inches of fine b r e ccia and gouge between sharply-defined walls dipping at 80 degrees to the west. Shear cleavage within the gouge dips southwesterly, i n d i c a t -ing a normal displacement. Close by, a p a r a l l e l fracture has minor "gash" fractures dipping to the southwest, l o g i c -a l l y developed by a normal displacement on the parent f r a c -ture. At 150 feet west of 503 a pair of strong f a u l t s , dipping at 40 degrees to the west, contains minor drag folds and shear cleavage so oriented as to suggest that these f a u l t s are thrusts. This would imply a displacement opposed to that already deduced. However, i t appears that these thrusts are - 1 7 -more closely related to late interbed motion than to a late movement associated with the development of the Silversmith f a u l t . The Silversmith f a u l t , in summary, i s a c t u a l l y a wide zone of approximately p a r a l l e l f a u l t strands, dipping moder-ately to steeply westward on the upper l e v e l s , but steepening below No.4 Level to a dip of 80 degrees west on No. 5 Level. Below No.5 a reversal to an easterly dip may a c t u a l l y occur. Mainly from evidence obtained on No.4 Level, i t i a considered to be a normal f a u l t . Stewart Fault This f a u l t zone, bounding the Ruth segment on the west, i s composed, generally, of several strong, c l o s e l y -spaced bedding f a u l t s . As the major bedding structure is a recumbent f o l d convex to the southwest, the Stewart f a u l t re-verses from a westerly dip on and above No.3 Level to an east-e r l y dip through No's. 4 and 5 Levels (Map 2-B). Where the zone is most compact, that i s on No's. 2- , 4-, and 5 Levels, i t is composed of intensely-sheared graphitic material. As i t apparently represents a zone of l o c a l i z e d inter-bed adjustments between fi r m hard beds of the Ruth segment and soft p l a s t i c beds of the Stewart segment, i t most n a t u r a l l y developed in the l a t t e r . Consequently minor movement structures such as drag-f o l d s , shear cleavage, and f a u l t striae are exceptionally well - 18 -developed. L o c a l l y , several feet of gouge or "breccia have been produced where i t involves r e l a t i v e l y b r i t t l e beds, and f r a c t u r i n g occurred in preference to f o l d i n g . On No.2 Level, about 10 feet west of sta.212, the f a u l t includes up to four feet of brecciated s i l i c e o u s a r g i l l -i t e . Within the stub crosscut, minor drag-folds on the f o o t ' wall plunge at 15 degrees south. The counter-clockwise ro-tation about b i points to a downward and s l i g h t l y northward movement of the hanging w a l l . Southward, 50 feet from sta.212, a f a u l t strand curves from the footwall of the Ruth lode to j o i n the f a u l t zone in the crosscut. Small drag-folds within t h i B strand again have t h e i r axes plunging southward at a small angle; rotation about b i i s also counter-clockwise, substantiat-ing the inference of a downward hanging wall movement. In addition, these minor drag-folds have been f i l l e d with quartz and sphalerite - thereby providing excellent evidence of the continuity of mineralization from lode to c r o s s - f a u l t , and of the pre-mineral development of the Stewart f a u l t . The Stewart f a u l t zone may be followed southward to i t s intersection with a footwall strand of the Stewart lode near the end of the cross-cut marked R-2. P a r a l l e l i n g drag-folds within t h i s section of the f a u l t , drag-folds within the enclosing bedding are also overturned to the west and southwest about axes plunging - 19 -s l i g h t l y to the south. A hanging wall strand of the Stewart Fault zone may be seen in the main crosscut to the Stewart No. 5 Level. Here, the pattern of minor f a u l t - and bedding struc-tures i s much the same as before. In addition, s t r i a e on fa u l t surfaces plunge westward, and being related to counter-clockwise rotations on related drag-folds, confirm the down-ward and s l i g h t northerly hanging wall movement on strands of the Stewart f a u l t . On No.3 Level, west of sta. 317, strong elements of . the Stewart f a u l t cut off the Ruth lode to the southwest. In par t i c u l a r a strong shear-fracture, cutting squarely across the d r i f t and curving westward to the south of i t , appears to be the footwall member of the f a u l t zone. Farther to the south-west, t h i s shear apparently curves back into the crosscut on a more westerly strand of the zone to continue i t s sinuous south-e r l y course out of the workings. Along i t s course i t warps from a westerly-to easterly-to westerly dip in p a r a l l e l i n g the bedding planes of the intensely-folded bedding in t h i s easterly section of the Stewart segment. Within the stubs west of sta. 318 soft a r g i l l i t e s are intensely folded, evidently l y i n g be-tween strong f a u l t strands. In section, the bedding i s seen to be completely involved i n closely-packed drag-folds. In the more westerly of these, f o l d axes p a r a l l e l the strike of - 20 -the Stewart f a u l t zone with no apparent plunge. About these axes, lying in b±, rotation i s counter-clockwise, in accord with the normal displacement on the Stewart f a u l t and the inferred inter-bed motion within the westerly-dipping beds forming t h i s part of the major recumbent f o l d . Within the greater part of the crosscut southwest of sta. 318, t h i s westerly and downward movement of upper-over-lower beds and the corresponding displacement on strands of the Stewart f a u l t i s evident. L o c a l l y , however, a c o n f l i c t i n g movement pattern is suggested by the contrasting behaviour of minor drag-folds at, and southwest of, sta. 318. Here,, drag-folds are over-turned to the southeast and l i e adjacent to a narrow f a u l t dipping at 45 degrees southeast. Fold axes plunge at 10 de-grees southwest, rotation about b i i s clockwise; hence the displacement on the f a u l t i s e s s e n t i a l l y normal. This f r a c -ture may be considered as a minor lode segment within the Stewart f a u l t . Brag-folds with a similar orientation and symmetry appear in the stub north of sta. 318. Bossibly these inter-bed displacements, p a r a l l e l i n g that of the lode segment, are related to another lode segment to the north of t h i s stub. L o c a l l y , because the southwesterly-plunging drag-fold pattern i s superimposed on the more general pattern of southerly-plunging f o l d s , i t appears that the f i n a l increments of move-ment occurred on the minor lode segments and, perhaps also the main Ruth segment. - 2 1 -A l t h o u g h t h e l o d e - f a u l t i n t e r s e c t i o n a p p e a r s r a t h e r a b r u p t a t t h e w e s t e r l y e n d o f t h e R u t h s e g m e n t , m i n e r a l i z a t i o n h a s p e n e t r a t e d t o a d i s t a n c e w e l l w i t h i n t h e f a u l t z o n e . A l s o , t o m a i n t a i n t h e a p p a r e n t f a u l t - l o d e c o n t i n u i t y , s o u t h e a s t e r l y -d i p p i n g m i n e r a l i z e d s h e a r - f r a c t u r e s , w h i c h a p p e a r t o b e " l i n k s " f r o m t h e h a n g i n g w a l l o f t h e R u t h l o d e , e n t e r t h e l o n g c r o s s -c u t f r o m a n o r t h e a s t e r l y d i r e c t i o n . N e a r s t a . 3 2 0 , a m i n e r a l -i z e d s t r a n d o f t h e S t e w a r t f a u l t p r o d u c e d a f a i r t o n n a g e o f o r e . I n t h i s a r e a o n N o . 3 L e v e l d i s t i n c t s e g m e n t s o f t h e S t e w -a r t l o d e d o n o t a p p e a r . H o w e v e r , t h e c r o s s - s e c t i o n ( M a p N o . 3 ) s h o w s i t t o b e t o t h e n o r t h o f t h e " l a t e r a l " r u n n i n g w e s t o f s t a . 3 2 1 . A f e w f e e t n o r t h o f s t a . 3 2 0 , a f a u l t s t r a n d w i t h a c u r v e c o n c a v e t o t h e n o r t h w e s t , a n d d i p p i n g f r o m 6 5 - t o 3 5 d e -g r e e s n o r t h w e s t , m a y b e a s h e a r - l i n k f r o m t h e S t e w a r t f a u l t t o t h e S t e w a r t l o d e . A l o n g i t f r o m t h e s o u t h w e s t t h e c o n s e c u t i v e a p p e a r a n c e o f d r a g - f o l d s i n t h e b 2 a n d b ^ d i r e c t i o n s , s h o w i n g c l o c k w i s e t o c o u n t e r - c l o c k w i s e r o t a t i o n r e s p e c t i v e l y , s u g g e s t a b l e n d i n g o f t h e l o d e - a n d f a u l t m o v e m e n t s a l o n g t h i s s t r a n d . I n o t h e r w o r d s , a l o n g i t t h e r e i s a t r a n s i t i o n f r o m a n e a s t e r l y m o t i o n i n t h e g r o u n d s o u t h o f t h e l o d e t o a n u p w a r d m o t i o n , a r o u n d t h e c u r v e , i n t h e f o o t w a l l o f t h e S t e w a r t f a u l t z o n e . O n N o . 3 L e v e l , t h e r e a p p e a r s t o b e a m o r e h a r m o n i o u s m o v e m e n t f r o m t h e S t e w a r t l o d e t o f a u l t t h a n t h e r e i s f r o m t h e f a u l t t o t h e R u t h s e g m e n t . - 22 -On No.4 Level, the mineralization and old stopes within the westerly part of the workings are on the lower pro-ductive section of the Stewart lode. To the northeast of the o l d stopes west of sta. 415, there i s no trace of the wide, westerly-dipping f a u l t zone seen on the above l e v e l s . The only prominent structure, trending across the northeasterly exten-sion of the Stewart lode, i s a cross-fault that dips 43 degrees eastward, and which cuts the southwesterly crosscut from the Ruth lode near sta. 412. This f a u l t , and minor fractures to the west, represents the Stewart f a u l t zone on Ho. 4 Level. L o c a l l y p rather gently east-dipping beds with minor steep east-e r l y " r o l l s " , duplicate the symmetry of drag-folds that are overturned eastward and downward. Closer mapping, in bedding such as t h i s , would probably bring out s i g n i f i c a n t minor struc-tures. The corresponding inter-bed motion then, displaces beds to the east r e l a t i v e l y down and over adjacent beds to the west -e f f e c t i n g normal inter-bed displacement. L o g i c a l l y then, the Stewart f a u l t which has consistently proved to be a "bedding f a u l t " on higher l e v e l B was also developed aa a normal f a u l t within t h i s section of eaaterly-dipping bedding. On t h i s l e v e l , and within a corresponding part of the major recumbent f o l d , several smaller easterly-dipping f a u l t s are of the "normal" v a r i e t y . S i m i l a r l y , they have developed through inter-bed motion and are closely associated with minor bedding drag folds that are overturned to the east and northeast (Map 2-A). - 23 -The s t r u c t u r a l connection between the Stewart f a u l t and Ruth lode i s not c l e a r l y apparent on No. 4 Level. However, a mineralized branch that leaves the lode near Sec. B - B follows a curving westerly course towards the f a u l t and prob-ably bends south to join i t a short distance west of the cross-cut . The continuity of hanging wall movements from the Stewart lode - to f a u l t - to Ruth lode i s evident from the pattern of minor structures. On p a r a l l e l strands of the Stew-art lode southerly-plunging drag f o l d s , in bg with clockwise, rotation, together with horizontal s t r i a e in ag, indicate that the lode hanging wall has moved eastward with almost no down-ward component. At sta.' 413, drag folds within the lode, l y i n g in b2 with clockwise rotation, fan out to the southeast, Lying close to the_1ode-fault "corner", they strongly suggest a con-tinuous easterly to northerly hanging wall motion from the lode to the f a u l t . The crumpling within footwall beds that arch symmetrically around t h i s corner Beems i n accord with the l o c a l "swing" in ground movement. Evidence of the continuous east-e r l y movement of the hanging wall i s provided again by the pattern of minor structures. At 50 feet southwest of sta. 411, drag folds plunging 35 degrees southeast in bg, indicate a l o c a l upward and eastward hanging wall movement out of the - 24 -fault-lode "corner". Farther west, both drag folds and f a u l t s t r i a e , in bg with clockwise rotation and in a2 plunging east-ward, suggest the resumption of the eastward and downward hang-ing wall movement that i s usual within lodes of the mine area. On No. 5 Level at ata. 573, a narrow zone of f r a c t u r -ing and shearing, s t r i k i n g nearly north-south, cuts o f f the main Ruth lode to the west. Southward from th i s i n t e r s e c t i o n , footwall strands of the Stewart f a u l t bend westward to para-l l e l the strike of crumpled bedding l y i n g in the lode trend. Throughout the length of the crosscut to the southwest a wide belt of folded east-west s t r i k i n g shear-fractures and sharply-crumpled bedding forms the Stewart lode panel on No. 5 Level. Maps No's. 2 and 3 provide plan- and cross-sectional views of the widely-stranded pattern of the lode at t h i s l e v e l . The curving pattern of easterly movements of the hanging w a l l "ground" on No. 4 Level i s f a i t h f u l l y duplicated within the Stewart-Ruth t r a n s i t i o n on No. 5 Level. Within the buckled Btrands of the Stewart lode, numerous southerly and southeasterly-plunging drag f o l d s , in bg with clockwise rota-t i o n , plus f a u l t s t r i a e plunging m i l d l y eastward in &2t provide adequate proof of the easterly- and slightly-downward movement of the hanging w a l l . Between sta's. 576 and 571 within the "corner" of fault-lode intersections, s i m i l a r minor structures - 25 -show the easterly - to northerly - -to easterly course of the "hanging wal l " motion into, and out of the Stewart f a u l t . As on No. 4 Level, the resumption of the easterly movement on the Ruth lode i s attended by a small thrust component; proof of this being supplied by the southeasterly-plunging drag fo l d s at s t a . 572. In summarizing the above analysis of ground move-ments through the Stewart-Ruth l i n k i n g structures, i t seems necessary to q u a l i f y some impressions of the exact nature of the component movements. F i r s t , i t seems unlikely that the t o t a l hanging wall movement, perhaps amounting to a few hun-dreds of feet, could be e n t i r e l y transmitted around the tight "corners" of these fault-lode intersections. However, in the text, the frequent occurrence of linking-ehears that cut acrosB these intersections has been called to the attention. These generally appeared during the course of detailed mapping, but where they do not appear on the map, l o g i c almost demands that they be assumed present. Assuming t h e i r existence, i t i s easy to see that they must have transmitted the greater part of the s t r i k e - s l i p displacement from one lode segment to another or, in this case, from the Stewart- to the Ruth seg-ment. The lesser part of the movement, or the part that con-tinuously followed the course outlined by the c r o s s - f a u l t and lode segments, was evidently "in sympathy" with the major movement. - 26 -Wall Rock Types and Structures Throughout the Ruth and Stewart segments, bedding on both sides of the lodes, but not in close proximity to them, strikes with f a i r r e g u l a r i t y between north and north 30 degrees west. However, bedding dips vary greatly in de- . gree and direction between the upper and lower l e v e l s . On Ruth No, 2 Level dips are s l i g h t l y westward, interrupted only by gentle waves or r e s t r i c t e d sections with frequent large and small drag f o l d s . Towards No. 3 Level the beds generally steepen and, l o c a l l y , dip v e r t i c a l l y or r o l l over to steep easterly up-side-down. On No.4 Level the bedding dips, on the average, rather f l a t l y to the east, but i s complicated by strong f a u l t s which roughly p a r a l l e l the bedding. Frequent discordant panels, blocks, and wedges of bedding have been produced where these bedding f a u l t s have traversed sections of i r r e g u l a r bedding structure. The bedding structures mapped on No. 5 Level have been BO complicated by east- and west-dipping f a u l t s that only a general approximation of the un-fractured pattern is possible. However, the few f a i r l y ex-tensive sections that were not seriously disturbed by complex f a u l t i n g , suggest a section of gently east-dipping up-side-down beds that were rather closely folded and crumpled about steep a x i a l planes. In softer beds intra-bed motion associ-ated with d i f f e r e n t i a l inter-bed movements,^as developed drag folds that are generally overturned to the east. - 27 -At several places within the upper and lower lev e l s the rocks contain a s u f f i c i e n t number of minor structures to allow conclusive bedding w t o p M determinations. Within the l a t e r a l in the footwall of the Stewart workings, sandy sec-tions of bedding provide a few truncated cross-beds. In this working, and throughout Ruth No's 2 and 3 Levels, cross-bedding within these westerly-dipping sections shows that these beds are right-side-up. Where drag folds have develop-ed in softer beds of t h i s section, they are overturned to the west, thus substantiating the more conclusive evidence pro-vided by the few occurrences of cross-bedding. Brag fo l d s within the generally east-dipping section of beds below No,3 Level are invariably overturned to the east and, with the positi v e evidence provided by a few overturned truncated cross-beds, show this major part of the bedding section to be up-side-down. The correlation of the separate sections of bedding mapped on each l e v e l , shows the large bedding structure to be a recumbent f o l d . The existence of this recumbent a n t i c l i n a l f o l d , overturned to the west was deduced by Mr. Paul B i l l i n g -s ley as early as 1946, from the mapping of A.B. B u l l e r and R.S. Moehlman. This structure i s convex, or a n t i c l i n a l to the west, with a generalized a x i a l plane dipping at only a few degrees in t h i s d i r e c t i o n , and l y i n g generally a few feet be-low No. 3 l e v e l of the Huth segment (Map No's. 2A and 2B and 3). Superposition of the Hanging Wall Projection (2A) over the Fooitwall Projection (2B) shows a marked s i m i l a r i t y of bedding structures on both walls of the lode, p a r t i c u l a r l y in those sections above No. 4 Level. In addition, the trace of the a x i a l plane of the hanging wall structure l i e s only a few feet below that of the footwall structure. This suggests that the apparent displacement on the Ruth lode, even though accompanied by a large component of s t r i k e - s l i p motion, could not have been greatly over 100 f e e t . Broadly described, the wall rocks of the Ruth lode are rather thickly-bedded, hard, l o c a l l y s i l i c e o u s a r g i l l i t e s with minor thickly-bedded quartzites and t h i n , soft to cherty a r g i l l i t e s . Beds are considered thin i f only an inch or two in thickness; thick, i f about two feet or over; and medium, between s i x and eighteen inches. The apparent s i l i c i f i c a t i o n , or simple thermal a l t e r a t i o n of wall rocks, p a r t i c u l a r l y above No. 4 Level within the productive part of the lode, renders the d i s t i n c t i o n between true quartzites and s i l i c i f i e d a r g i l l -ites rather d i f f i c u l t . Generally, t y p i c a l quartzites have a c h a r a c t e r i s t i c a l l y granular texture and medium- to dark gray color; s i l i c i f i e d a r g i l l i t e s , as a r u l e , appear fine-grained to porcellaneous, are often uniformly pale, or pale-striped - 29 -where they contain cherty layers. To the west of the Ruth segment, and forming the easterly cross-section of beds of the Stewart segment, is a be l t of r e l a t i v e l y s o f t , thinly-bedded a r g i l l i t e s . Major inter-bed adjustments, accompanying the development of the recumbent bedding f o l d , produced the concordant fracture zone which is the Stewart f a u l t . Wall rocks forming the footwall of the Stewart lode, and which are well exposed in the cross-section provided by the footwall l a t e r a l on No. 2 Level (Map No.2), are t h i n - to medium-bedded hard and soft a r g i l l i t e s with lesser t h i c k quartzite. Several rather strong bedding f a u l t s and zones of intense drag f o l d i n g are present in sections of softer beds. This footwall section maintains a rather uniform character to the lowest levels of the mine. Hanging wall rocks of the Stewart segment, p a r t i c u -l a r l y below Stewart No. 5 Level, appear to be much softer and less competent than their footwall counterparts. They are generally thinly-bedded dark a r g i l l i t e s with only minor quartz-i t i c sections. L o c a l l y , these beds are highly contorted and sheared and, within the lower l e v e l s , the Stewart lode appears to have flattened l a r g e l y by-branching into p a r a l l e l i s m with - 3 0 -t h e w e a k h a n g i n g w a l l b e d d i n g . P o s s i b l y t h e h a n g i n g w a l l b e d s a b o v e S t e w a r t N o . 5 L e v e l , a n d a d j a c e n t t o t h e s t e e p e r s e c t i o n o f t h e l o d e , w e r e c o m p a r a t i v e l y m o r e c o m p e t e n t . N u m e r o u s s h e e t s , s i l l s a n d d y k e s o f q u a r t z - f e l d s p a r p o r p h y r y a r e p r e s e n t w i t h i n t h e w a l l r o c k s a d j a c e n t t o t h e l a d e . I t i s e v i d e n t t h a t t h e m a j o r i t y o f t h e s e s m a l l i n t r u s i o n s o c c u r w i t h i n t h e R u t h s e g m e n t , a n d a r e p r a c t i c a l l y a b s e n t i n r o c k s a d j a c e n t t o t h e S t e w a r t l o d e . P o s s i b l y , t h e m o r e b r i t t l e , c o m p e t e n t c h a r a c t e r o f t h e w a l l r o c k s a d j a c e n t t o t h e R u t h l o d e p e r m i t t e d t h e d e v e l o p m e n t o f d e e p , o p e n f i s s u r e s w h i c h w o u l d a l l o w r e l a t i v e l y e a s y i n t r u s i o n o f t h e m e l t s . N u m e r o u s s t r o n g p o r p h y r y s h e e t s , a p p r o x i m a t e l y p a r a l l e l i n g t h e b e d d i n g o f t h e t h i c k h a r d a r g i l l i t e s , l i e w i t h i n t h e h a n g i n g w a l l b e d s e x p o s e d i n t h e o u t e r p a r t o f N o . 4 L e v e l . O n M a p 2 A t h e s e s h e e t s a r e s e e n t o t h i c k e n c o n s i d e r a b l y w i t h i n t h e a x i a l r e g i o n o f t h e m i n e f o l d , i n d i c a t i n g t h a t t h i s s e c t i o n o f t h e s t r u c t u r e p r o v i d e d a m a x i m u m o f o p e n s p a c e . T h i s f e a t u r e , i n i t s e l f , p r o v i d e s f a i r e v i d e n c e f o r t h e l o c a t i o n o f t h e a x i a l p l a n e o f t h e m i n e f o l d . O n N o . 4 L e v e l , b e d d i n g f a u l t s p a r a l l e l t h e t w o m a j o r s h e e t s . M o v e m e n t h a s c a u s e d s o m e b r e c c i a t i o n , a n d l o c a l l y t h e d e v e l o p m e n t o f c r o s s - j o i n t s i n t h e p o r p h y r y , i n -d i c a t i n g t h a t f o l d i n g a n d i n t e r - b e d m o v e m e n t s c o n t i n u e d f o r s o m e t i m e a f t e r t h e i n t r u s i o n a n d s o l i d i f i c a t i o n o f t h e p o r -p h y r y m e l t s . - 3 1 -By the method o u t l i n e d e a r l i e r i n the t e x t , the symmetry and s p a t i a l d i s t r i b u t i o n of bedding drag f o l d s were c l o s e l y B t u d i e d with the object of p r o v i n g or d i s p r o v i n g the bedding s t r u c t u r e i n f e r r e d . Drag f o l d s of anomalous symmetry; namely, those overturned up-dip, were r a r e , and were found t o be i n accord w i t h l o c a l i n t e r - b e d movements once the p o s i t i o n of these beds w i t h i n the s t r u c t u r e was e s t a b l i s h e d . At t h i s p o i n t , i t should be mentioned that Slocan drag f o l d s provide r e l i a b l e i n d i c a t i o n s of normal or i n v e r t e d s e c t i o n s of bedding and, p o s s i b l y , of the plunge of the major f o l d axes, but do not provide c o n s i s t e n t i n d i c a t i o n s of the a t t i t u d e s of major a x i a l p l a n e s . The heterogeneous composition of Slocan s e d i -mentary fo r m a t i o n s , and the consequent d i s s i m i l a r i t y i n the development of bedding drag foldB, prevents t h e i r use i n t h i s c o n n e c t i o n . P o s s i b l y , drag f o l d s i n assemblages of t h i n l y -bedded, s o f t a r g i l l i t e s l y i n g between t h i c k , r e l a t i v e l y comp-et e n t q u a r t z i t i c beds, would be b e s t s u i t e d ; but a good number of drag f o l d s should be d i s t r i b u t e d throughout the bedding s e c t i o n i n order to provide an accurate average of the v a r i e d a t t i t u d e s of t h e i r a x i a l p l a n e s . L i n e a t i o n symbols f o r bedding drag f o l d axes (bi) and the corresponding s t r i a e produced by i n t e r - b e d motion ( a i ) are p l o t t e d on Map No. 2. The a s s o c i a t i o n of the drag f o l d p a t t e r n s - 3 2 -c h a r a c t e r i s t i c o f t h e m a j o r e a s t e r l y - a n d w e s t e r l y - d i p p i n g s e c t i o n s o f " b e d d i n g f o r m i n g t h e m i n e f o l d i s b e s t s e e n o n M a p s 2A a n d 2B. I n a n d a b o v e N o . 3 L e v e l o f t h e R u t h w o r k i n g s , a n d i n t h e S t e w a r t w o r k i n g s w i t h i n t h i s v e r t i c a l r a n g e , d r a g f o l d s o c c u r r i n g i n w e s t e r l y - d i p p i n g b e d s a r e u n i v e r s a l l y o v e r t u r n e d t o t h e w e s t , s h o w i n g t h a t h i g h e r b e d s h a v e m o v e d w e s t w a r d a n d d o w n w a r d w i t h r e s p e c t t o r e l a t i v e l y l o w e r b e d s , o r t o w a r d s t h e o v e r t u r n e d a n t i c l i n a l a x i s . T h i s i s t h e m o v e m e n t p a t t e r n a s s o c i a t e d w i t h t h e r i g h t - s i d e - u p , w e s t e r l y - d i p p i n g l i m b o f a m a j o r r e c u m b e n t f o l d d e v e l o p e d b y f l e x u r e - s l i p f o l d i n g . H e n c e a l l s e c t i o n s o f b e d s c o n t a i n i n g b ^ l i n e a t i o n s , w i t h c o u n t e r -c l o c k w i s e r o t a t i o n , b e l o n g t o t h e m a j o r w e s t e r l y - d i p p i n g s e c -t i o n o f u p r i g h t b e d d i n g a b o v e t h e a x i a l p l a n e o f t h e m i n e f o l d . A s s u c h d r a g f o l d s w e r e f o u n d w i t h i n N o . 3 L e v e l b e d d -i n g t h e a x i a l p l a n e m u s t l i e s o m e w h a t b e l o w t h i s l e v e l . T h e p a t t e r n o f b e d d i n g d r a g - f o l d s w i t h i n a s e c t i o n o f h a n g i n g w a l l b e d s e x p o s e d i n t h e e a s t e r l y p a r t o f N o . 4 L e v e l i s s h o w n o n M a p 2 - A . W i t h o u t e x c e p t i o n f o l d s a r e o v e r -t u r n e d e a s t w a r d a n d d o w n - d i p , w i t h c l o c k w i s e r o t a t i o n a b o u t a x e s i n b i . I n a d d i t i o n , b e n t e n d s o f b e d d i n g c o n t a c t i n g b e d d i n g f a u l t s , d r a g f o l d e d s c h i s t o s i t y , a n d g e n t l y - d i p p i n g s h e a r c l e a v a g e i n t h e s e b e d d i n g f a u l t s , a l l s u g g e s t t h a t - 33 -structurally-lower beds moved westward toward the major f o l d axis; with respect to higher adjacent beds. This section of beds, then, belongs to the larger, overturned easterly-dipping section forming the under limb of the recumbent mine f o l d . Brag folds of t h i s symmetry are to be found i n the westerly part of Ho.4 Level and throughout Ho. 5 Level, showing that these workings l i e within the under limb of the mine f o l d , and that the major a x i a l plane i s c e r t a i n l y between Ho'a 3 and 4 Levels of the Ruth workings. The average plunge of a l l b i - l i n e a t i o n s shown on Map Ho, 2 would appear to be about 5 degrees southerly. S l i c k -snsides on bedding f a u l t s , or a i - l i n e a t i o n s , pitch within 10 degrees north of the respective d i p - l i n e s . Hence, i t appears that the axis of the recumbent mine f o l d plunges very gently to the south. Old Ruth Lode The productive part of the lode, from a short d i s -tance below Ho. 3 Level to the outcrop, i s a steep f i s s u r e s t r i k i n g about north 75 degrees east and dipping steeply, a l -most v e r t i c a l l y , to the south. The structure, here, is a reg-ular fracture with rather smooth and d i s t i n c t walls; having a f i l l i n g of broken- to crushed wall rocks or, formerly, banded veins of galena and sphalerite. Appreciable amounts of soft - 34 -graphitic gouge and schistose material, which are usually associated with shear-lodes, are conspicuously absent within the upper section of the vein. Below the productive section, from the f i r s t sub-level above No. 4, the lode f l a t t e n s rather suddenly to a dip of about 60 degrees south, which i t holds through No. 5 Level. The lode becomes a zone of sub-parallel shear-fractures, forming a braided structure in which one strand i s most clearly-defined and best mineralized. The lode f i l l i n g i s usually one of schistose, sheared w a l l rocks, black g r a p h i t i c - to pale bleached gouge with lesser amounts of cleanly-brecciated wall rocks in quartz-carbonate gangue. Veining and disseminated ore minerals are generally associ-ated with the l a t t e r type of lode f i l l i n g . From a description in Mem. 184 by C E . Cairnes, and the writer's own notes, the main strand of the lode pinches and swells from an average width of about 4 feet. Minor strands l o c a l l y widen the lode. Above No. 3 Level the vein f i l l i n g was largely clean galena and minor sphalerite with associated quartz-carbonate gangue. From No. 3 Level to a short distance below No. 4 Level, the ore reportedly contain-ed more zinc blende and l e s s clean galena. The lode where i t i s now exposed on No. 5 Level, contains a small amount of zinc blende in a gangue of brecciated wall rocks cemented by an abundance of gangue minerals. The gangue i s p r i n c i p a l l y - 3 5 -yellow carbonates with stringers and lenses of medium-grained white quartz containing much p y r i t e . The unminaralized sections on No. 5 Level are frequently nothing more than a single " t i g h t " shear or zone of sinuous shear strands, which contrast strongly with the wide, well-defined f i s s u r e of the upper l e v e l s . The following leve 1-by-level descriptions of the de-ta i l e d geology of the Old Ruth Lode are baBed on Maps No. 2 , - 2 A , - 2 B , and - 3 , and supplemented by the writer's f i e l d notes. No. 1 Level Throughout t h i s l e v e l the lode has a regular, but locally-sinuous trend and dips v e r t i c a l l y . Ore was mined above and below the l e v e l from the p o r t a l to the Stewart f a u l t . According to Mr. J.G. Black of Sandon, a minor vein within the port a l area diverged down-dip from the hanging wall of the lode. Its approximate position i s shown on Map No. 2 . L i t t l e i s known about the downward extension of this vein; possibly i t exists as a simple hanging wall " s p l i t " with l i t t l e d i s -placement of i t s walls, or as a link-v e i n between the main lode and an undiscovered steeper lode strand l y i n g to the south of i t . Within the main raise between No's 1 and - 2 Levels, gently south-dipping fractures, according to Mr.Black, pass through the vein and effect small normal displacements. These would appear to be ge n e t i c a l l y related to sim i l a r f r a c -tures mapped below the second sub-level above No. 4 , as shown - 36 -on Sec. B-B of Map l o . 3. The consecutive small normal dis-placements of the vein across this upper zone of fractures may be responsible f o r i t s apparent steep northerly dip above No. 2 Level. No. 2 Level On this l e v e l the lode has a broad, gently-sinuous trend and dips between 60 degrees south and v e r t i c a l . Small-er, less steeply-dipping hanging wall strands apparently d i -verge from the lode above the l e v e l and, down-dip, tend to bend into pa r a l l e l i s m with the l o c a l f l a t - l y i n g wall rocks. The main strand of the lode, at t h i s level", intersects gently-dipping thickly-bedded a r g i l l i t e s , s i l i c e o u s a r g i l l i t e s , and minor quartzites and porphyry. Both walls of the lode are cleanly-defined, and the adjacent wall rocks show few signs of deformation which might be related to an early intense shearing stress which might have produced major displacements of the lode walls. Near sta. 211, footwall beds dipping gent-ly to the east are bent to steep [southerly dips at the lode footwall, suggesting that the hanging wall moved down with respect to the footwall. At other places on the l e v e l steeply southerly-dipping bedding-warps adjacent to both walls of the lode also suggest a prominent component of normal displacement. Within the southerly crosscut bet?;een 209 and 210, a minor - 37 -hanging-wall strand of the lode provides excellent evidence of a normal displacement. Both the hanging wall, and cleavage p a r a l l e l to i t , are involved in a drag fold overturned down-dip to the south about a horizontal axis; this f o l d consti-tutes a b3-lineation having clockwise rotation, looking east. The lode, within this gently wavy, westerly-dipping section of thick beds, could owe i t s steep dip to a tendency of the i n i t i a l fractures to cut squarely across hard, b r i t t l e beds. The other tendency, that i s towards a deflection into the plane of weaker, less coherent sections of bedding i s shown by a hanging wall strand dipping at 30 degrees 'to the south. Where the downward extension was located in a cross-cut 40 feet below No. 2 Level, i t had, at least l o c a l l y , de-creased in dip to become e s s e n t i a l l y a bedding f a u l t . Up-dip, i t blankets a steeper lode strand, but both structures have been mineralized. Consequently, both the gently- and steeply-dipping fractures may have been developed under the same set of stresses. Between No's 2 and 3 Levels, in the main ra i s e , up-turned beds and several v e r t i c a l l y - d i p p i n g gash fractures over the hanging wall of the lode, l o c a l l y confirm previous evidence of the normal displacement (Sec. B-B). Another i l l u s -t ration of the tendency for lode strands to branch off into the hanging wall i s shown by Sec. C-C, in the main raise 40 feet above No. 3 Level. Here, the hanging wall branch is - 38 -is formed by a continuation of a southerly-dipping section of the lode below No. 2 l e v e l ; the l o c a l steepening of the other fracture, however, i s probably due to the presence of a sec-tion of thick, b r i t t l e s i l i c e o u s a r g i l l i t e s forming the wall rocks at this section of the lode. No. 3 Level Throughout No. 3 Level the trend of the lode i s markedly consistent. However, there i s a gentle bend between 308 and 314 which shows up on higher levels and in the 2nd sub-level below. Reportedly, the strongest part of the ore-body was located on t h i s gentle nose in the lode . P r a c t i c a l l y no evidence of the character of the lode matter remains with-in t h i s l e v e l . However, the walls and wall rocks of the lode could be observed, in .untimbered .sections . Again, minor structures a l l point to a normal di s -placement. On the hanging wall and footwall, bedding, for the most part, squarely intersects the walls, thus in d i c a t i n g that strong shearing stresses and large displacements were absent during the formation of the lode. At 310, where a westerly warping of the hanging wall beds might be construed as e v i -dence of a strong easterly movement of the hanging wa l l , well defined s t r i a e plunge d i r e c t l y down-dip. These l i e in the a3 d i r e c t i o n , and in conjunction with a l o c a l up-warping of beds - 39 -i n t o p a r a l l e l i s m with the lode, p o i n t to a r e l a t i v e l y downward movement of the hanging w a l l . S i m i l a r f o o t w a l l s t r i a e at 311 support t h i s i n f e r e n c e . Within upwarped hanging w a l l beds at 314, s m a l l drag f o l d s plunge w e s t e r l y at 15 degrees; r o t a t i o n about b j i s clockwise, l o o k i n g east, and the hanging w a l l bedding has e v i d e n t l y moved d i f f e r e n t i a l l y i n accordance with the normal displacement on the l o d e . S i l i c i f i c a t i o n of the w a l l rocks i s f r e q u e n t . The porphyry bodies i n t e r s e c t e d between 308 and 310 have been bleached and softened by hydrothermal s o l u t i o n s . More intense a l t e r a t i o n of the bleached porphyry at 316 has produced abun-dant disseminated p a l e brown s e r i c i t e , which, i n t u r n , has been s t r o n g l y s i l i c i f i e d where the porphyry i s c l o s e l y veined by q u a r t z . In the c r o s s c u t near 314, t h i c k a r g i l l i t e s are s i m i l a r l y s e r i c i t i z e d and s i l i c i f i e d . Below No. 3 L e v e l the lode m a i n t a i n s i t s steep d i p through a s e c t i o n of t h i c k hard beds w i t h i n the a x i a l r e g i o n of the mine f o l d . However, at the 1st Sub-Level i n the main r a i s e , a part of the lode branches i n t o the hanging w a l l beds (Sec.'B-B), while the other p a r t continues with a steep d i p to No. 4 L e v e l . W i t h i n t h i s l a t t e r branch, drag f o l d s w i t h h o r i z o n t a l axes l i e i n b3, about which clockwise r o t a t i o n , l o o k i n g eastward, has taken p l a c e . The f o l d s , a long w i t h the - 40 -lode f i l l i n g , have he en mineralized by sphalerite, sparse galena, and p y r i t e . Within the v e r t i c a l r a i s e shown on C-C, the productive steep section of the lode, i s apparently deflec-ted, or cut off, by less steeply-dipping lode strands. These strands were observed within both crosscuts below the 2nd Sub Level and possibly correlate rather c l o s e l y with the strong branch dipping 60 degrees south in the No. 4 Level crosscut. Comparison of B-B and C-C suggests that the less steeply-dipping lode strands are closely related in attitude and in t h e i r effect of r e s t r i c t i n g mineralization on the Ruth lode at depth. The r e l a t i o n s h i p between certain groups of fractures forming the Ruth lode w i l l be pointed out in the following section. No. 4 Level Throughout No. 4 Level the lode remains within the thick hard a r g i l l i t e s , quartzites, and thin s i l i c e o u s a r g i l l -ites dipping eastward below No. 3 Level. However, the lode i s a more widely-stranded zone of sinuous shear-fractures, and intervening and bounding w a l l rocks have been larg e l y warped into the lode trend. The deformation of the wall rock bedding, and the sheared character of the material f i l l i n g lode strands, suggest higher shearing stresses and greater displacements than in the steep upper section of the lode. Evidence of the east-ward and s l i g h t l y downward movement of the hanging wall i s - 4 1 -p l e n t i f u l . Between the main raise and 411 the footwall strand of the lode has a well-developed shear cleavage which angles easterly across the lode from footwall to hanging wall. The trace of cleavage planes upon the lode walls constitute a b2-li n e a t i o n plunging with the walls at south 30 degrees west; rotation about bg i s counter-clockwise and i s related to an easterly and downward hanging wall movement. Closer to the revise, f i n e striae on the footwall, and l y i n g in ag, plunge at 34 degrees easterly, thus confirming the inferred hanging wall motion. A few feet east of the main rais e strong grooves plunge at 10 degrees to the east, and are also ag-lineations. Corresponding to these, the intersection of strong, closed shear fractures with both walls plunges almost d i r e c t l y down-dip. These l i e in bg, and the cleavage planes are oriented to conform again with the easterly and s l i g h t l y downward move-ment of the hanging w a l l . Within the crosscut north of 410, i s the apparent continuation of the strong lode strand obser-ved at the foot of the main r a i s e . Comparison of the minor lode structures at both places, suggests that a strong s t r i k e -s l i p displacement has been succeeded by a milder downward movement of the hanging w a l l . Although normal f a u l t i n g appears to favour only the steeper fractures of a composite lode, i t appears that i t may be superimposed upon strands de-veloped primarily by s t r i k e - s l i p shearing, and probably o b l i t -erates minor structures related to the e a r l i e r motion. - 42 -From the p o r t a l to the footwall of the "Silversmith" fa u l t zone, i n d i v i d u a l segments of the lode show evidence of an eastward and very s l i g h t l y downward hanging wall movement. With t h i s , i t appears that the major component of displacement on the Ruth lode was that which involved the apparent easterly and downward hanging wall movement. No. 5 Level The geology of thi s l e v e l of the old Ruth mine i s taken from maps by B.B. Mayo, J.Lamb, A.TS. B u l l e r and R.S. Moehlman. Within the sho.rt section of the lode that is ex-posed, the pattern of minor drag folds and movement striae point to an eastward and s l i g h t l y downward apparent displace-ment of the hanging w a l l . Steep, southerly-plunging crumples, within the thickly-bedded a r g i l l i t e s that trend roughly para-l l e l with the lode, also may be related to a strong easterly movement of the hanging wall. The lode on this l e v e l has a markedly sinuous trend through the folded wall rocks. The lode f i l l i n g of soft gouge and wall rock breccia contained only small lenses of ore. In general, the "hanging wall motion" is similar to that deduced on No. 4 Level, without the presence of lode strands which show evidence of normal displacements. Within the sof t , crumpled beds of No. 5 Level, the lode zone has probably widened to include thicker sections of less-sheared wall rock between weaker lode strands. - 43 -Stewart Lode and Ruth Fault The detailed geology in a l l presently-accessible workings is shown on Map No. 2. Fortunately the general patt-ern of the f a u l t s and lode within the productive upper levels was available from an old plan compiled by H.A. Rose. The geology of Stewart No. 5 Level and the Stewart segment of Ruth No. 5 Level was mapped by E.B. Mayo and J.Lamb. That of 4150 Level, and other inaccessible sections, was taken from mapping by AM. B u l l e r and R.S. Moehlman. The presently-accessible sections were re-studied by the writer. The Stewart lode, l y i n g between the Stewart and Ruth f a u l t s , forms a mildly-crumpled nose with a general southerly plunge. This nose is most pronounced where i t contains the main ore shoot between the outcrop and Stewart No. 4 Level. With depth, the dip of the lode sharply decreases from about 65 degrees south, above No. 2 Level, to an average of 45 de-grees south through a l l the workings below No. 2 Level (Map No. 3). Where the lode intersects thinner and more p l a s t i c beds in the lower workings, i t i s a much wider zone of weak lode strands, separated by considerable thicknesses of contor-ted, but unfractured wall rocks. Between these rather f l a t and barren shear-fractures occasional steeply-dipping fractures are mineralized and, l o c a l l y , formed workable ore shoots. With-in the steep nose formed by the lode in the upper l e v e l s , the - 44 -w e s t e r l y l i m b was t h e more i n t e n s e l y m i n e r a l i z e d . T h i s ore s h o o t h a s b e e n d e s c r i b e d a s an a g g r e g a t e o f s m a l l o v e r l a p p i n g l e n s e s of c l e a n g a l e n a and m i n o r z i n c b l e n d e c o n t a i n e d i n s h e a r e d b e d s w i t h i n w h i c h a c c o m p a n y i n g q u a r t z - c a r b o n a t e gangue m i n e r a l i z a t i o n was r e l a t i v e l y s p a r s e . The l o d e , w i t h i t s g e n -e r a l l y g r a p h i t i c - t o g ougy f i l l i n g , a p p a r e n t l y was d e v e l o p e d m a i n l y b y f o l d i n g and s h e a r i n g r a t h e r t h a n b y f r a c t u r i n g and b r e c c i a t i o n . The s o f t , i n c o m p e t e n t S t e w a r t w a l l r o c k s w o u l d l e n d t h e m s e l v e s t o the f o r m e r t y p e of f a i l u r e r a t h e r t h a n t o t h e l a t t e r , w h i c h i s v e r y a p p a r e n t w i t h i n t h e r e l a t i v e l y b r i t t l e w a l l r o c k s o f t h e O l d R u t h L o d e . S t e w a r t Ho. 4 L e v e l W i t h i n t h i s l e v e l o n l y a c e n t r a l s e c t i o n o f t h e l o d e may be s t u d i e d . The w e s t e r l y s e c t i o n , w h i c h b e n d s n o r t h e r l y t o j o i n t h e R u t h f a u l t , i s now i n a c c e s s i b l e ; t o w a r d s t h e e a s t , u n d e r g r o u n d e x p l o r a t i o n was s t o p p e d a t l e a s t 100 f e e t s h o r t of i t s i n t e r s e c t i o n w i t h t h e S t e w a r t f a u l t . The a p p r o x i m a t e s t r i k e of t h e l o d e on No. 4 L e v e l i s e a s t - w e s t and t h e d i p a b o u t 45 d e g r e e s t o t h e s o u t h . W i t h i n t h e e x p o s e d s e c t i o n , m i n e r a l i -z a t i o n i s s t r o n g e s t where t h e l o d e a r c h e s t o t h e s o u t h b e f o r e a s s u m i n g a f i n a l n o r t h w e s t e r l y s t r i k e t o j o i n t h e R u t h f a u l t . H e r e , a zone of c l o s e l y - s p a c e d s h e a r - f r a c t u r e s c o n t a i n i n g f r o m a f e w i n c h e s t o s e v e r a l f e e t of h i g h l y - s h e a r e d , f o l d e d and c r u s h e d g r a p h i t i c w a l l r o c k s f o r m s t h e l o d e . B e d d i n g , i n b o t h - 45 -the footwall and hanging wall, has been deflected from i t s usual northwesterly trend into close p a r a l l e l i s m with the lode. Brag-folded shear cleavage within the lode, and grooves or striae on shear surfaces are s u f f i c i e n t l y well developed to provide a movement pattern. At two separate sections minor drag folds plunge southwesterly and are overturned to the southeast; related movement striae plunge southeasterly between 30 and 40 degrees. This i s the usual pattern of bg and &2 l i n -eations so related as to provide conclusive evidence of the eastward and downward hanging wall motion. Within a small lode strand l y i n g in the footwall of the main structure minor drag folds are overturned d i r e c t l y down-dip, so that fold axes l i e in b3 with clockwise r o t a t i o n , looking eastward . This single observation of drag folds related to normal displacement on the Stewart lode indicates that l o c a l , late normal displacements followed the strike s l i p component of displacement which was mainly responsible for the development of the structure. A clue to the character of the footwall bedding with-in the upper productive section of the lode is provided by ex-posures within the footwall crosscut. Here, a small section of westerly-dipping a r g i l l i t e s should, in part, suggest the presence of b r i t t l e beds within the upper workings. From the i r s i m i l a r i t y to rocks within the Huth segment, i t i s l i k e l y that the upward steepening and, possibly, greater shattering of the - 46 -wall rocks produced more favourable conditions for mineral deposition within the upper section of the lode. On Stewart No. 3 Level the lode is apparently offset to the l e f t on a n o r t h e r l y - s t r i k i n g f a u l t l y i n g to the west of the r a i s e . Two strands of the displaced lode cuts across the top of the r a i s e . The absence of lode structures within the southerly part of No. 4 Level and the presence of a d i s t i n c t strand traversing the raise at t h i s l e v e l , suggests a similar displacement to the west of the r a i s e . Apparently the cross-f a u l t f l a t t e n s in dip below No. 3 Level and intersects No. 4 Level at a closely-timbered section within the crosscuts to the south of the westerly part of the lode. Stewart No. 5 Level Only small pockets of ore have been mined in raises above the l e v e l . On this l e v e l the lode follows a sinuous east-west trend that contrasts with i t s arcuate course in the levels above. As on No. 4 Level, the lode traverses rather soft a r g i l l i t e s in which shear strands s p l i t and converge with r o l l i n g attitudes, to form a pattern of closely-sinuous shears lacing a gougy- to fragmental graphitic f i l l i n g . Quartz-carbonate gangue mineralization i s even sparser than on the l e v e l above. - 47 -At 70 feet west of the main r a i s e , minor drag f o l d s within beds adjacent to the hanging wall of the lode plunge at 25 degrees to the southwest. Rotation about these axes in bg is clockwise, suggesting downward and eastward r e l a t i v e hang-ing wall displacement. Within the lode, close to the Ruth f a u l t , bg lineations were developed under the same clockwise rotation stress; nearby striae in &2 complete the pattern of lineations produced by an eastward and downward hanging wall movement. Southwesterly-dipping footwall beds turn sharply eastward with southerly dips at the footwall of the lode. The symmetry of this drag pattern i s completed by hanging wall beds which bend to a westerly strike and southerly dip at the hang-ing wall of the lode. The general axes of bedding curvature plunges to the southwest or, l i k e the minor drag f o l d axes, in b2. S i m i l a r l y , rotation is clockwise. Consequently minor structures provide conclusive evidence of the eastward and down-ward "hanging wall motion". At i t s west end, the lode bends sharply northward to join the Ruth f a u l t . Undoubtedly, the Ruth f a u l t , l i k e the Stewart f a u l t , developed from a localized intense inter-bed adjustment to large scale f o l d i n g . Consequently i t should be, mainly, a normal f a u l t on which the hanging wall has moved down-dip to the west. This motion is confirmed by the pattern of minor slickensides on f a u l t surfaces close to i t s intersection - 4 8 -with the lode, These, plunging d i r e c t l y down the dip, are c l e a r l y lineations in a]_, and which have developed under a normal displacement. Close "by, however, the axes of drag folds within the schistose f i l l i n g plunge at 48 degrees to the northwest. With counter-clockwise rotation about t h e i r axes these lineations suggest a southerly component of movement on at least some elements of the f a u l t zone. This movement, in-turn, was probably influenced by movements on the nearby lode, and suggests that s t r i k e - s l i p components of movement were con-tinuous from south to east around the in t e r s e c t i o n . As on other fault-lode intersections late easterly hanging wall move-ments on the lode apparently continued af t e r cross f a u l t i n g was e s s e n t i a l l y completed. Old Ruth No. 3 Level As was pointed out in the section describing the Stewart f a u l t , no recognizable strand of the Stewart lode could be traced f a r on No. 3 Level. Also, i t appears, from cross-sectional projections on Map No. 3, and the presence of f a u l t strands curving westerly from the Stewart f a u l t several feet north of sta. 320 (Map No. 2), that the lode should l i e only a few feet to the north of the l a t e r a l driven at south 75 degrees west from sta. 321. -,49 -Old Ruth No. 4 Level Cross-section A-A indicates how the lode zone may widen "below Old Ruth No. 3 Level. Accompanying this downward s p l i t t i n g of the lode into wider-s,paced shear-fractures, there i s a tendency for the through-going strands to f l a t t e n within the soft hanging wall a r g i l l i t e s of the lower l e v e l s . However, concurrent with this spreading-out and f l a t t e n i n g of the lode zone, i s the tendency for steep open veins to develop between indi v i d u a l strands. It was these fractures, having an appar-ent "gash" relationship to the main zone, that carried the bulk of the ore below Old Ruth No.2 Level. Naturally the ver-t i c a l extent of these ore shoots would be closely limited be-tween f l a t t e r lode strands. On Old Ruth No. 4 Level the two main ore shoots (Map No, 2) developed on such steep veins l y i n g towards the footwall of the lode zone. From what evidence of r e l a t i v e displacements that i s supplied by minor structures, i t appears that the hanging walls of i n d i v i d u a l lode strands moved eastward with l i t t l e , i f any, normal component of displacement. Most distant from the Stew-art f a u l t zone, footwall grooves at sta. 416 trend almost hor-i z o n t a l l y eastward. These represent a2 lineations and indicate a, pure s t r i k e - s l i p , eastward displacement of the hanging wall of this r e l a t i v e l y steep strand of the lode. Eastward, and close to the intersection of the lode with the Stewart f a u l t , - 50 -drag-fold axes in bg plunge to the south and southeast consec-u t i v e l y , indicating that a part of the general eastward hang-ing wall movement has curved northeasterly around the "corner 1 1 towards the Old Ruth Lode, v i a the Stewart f a u l t zone. Throughout the length of the lode on t h i s l e v e l there i s a marked swing of the hanging wall bedding from i t s usual northwesterly trends to an east-west trend where i t approaches the lode. This counter-clockwise drag pattern o f f -ers a d d i t i o n a l confirmation of the r e l a t i v e eastward movement of the hanging wall ground. At the west end of No. 4 Level, the workings en-countered a broad zone of intensely-fractured and sheared sed-iments. This f a u l t zone, which i s evidently the only i n t e r -section of the Ruth f a u l t made below No. 2 Level, forms the westerly l i m i t of the Stewart lode in No's 4 and 5 Levels. The lode-fault intersection is now inaccessible. Old Ruth 4150 Level No data pertaining to minor structures, which would supply evidence of lode displacementBj are available from geo-l o g i c a l plans of t h i s l e v e l . However, the pattern of counter-clockwise bedding drag close to the lode zone confirms the inference of an easterly movement of the hanging wall ground. As on No. 4 Level, mineralization d e f i n i t e l y favours the steep-er, r e s t r i c t e d strands of the lode. The "hanging wall d r i f t " emphasizes the spread of the lode zone at this l e v e l . Old Ruth No. 5 Level Careful detailed mapping on t h i s l e v e l has produced much information of wall-rock structures and deformation. As may be seen by the spread, sinuous pattern of the lode strands on Map No.2, and the cross-sectional spread of the lode shown on Map No. 3, a strong lode movement has been distributed over a much greater width of wall rocks than is usual in the higher productive sections. Consequently, the soft a r g i l l i t e s of No. 5 Level exhibit a more i n t r i c a t e and l e s s - e a s i l y deciphered pattern of foldi n g than where the lode is a more constricted zone of fra c t u r i n g and shearing. On No. 5 Level, several strands of the lode show a strong tendency to follow warped, irr e g u l a r bedding planes, and to be involved in the same close bedding contortions that were developed by the r e l a t i v e l y east-ward movement of hanging wall ground. Bedding adjacent to stations 588 and 589 is t i g h t l y crumpled with f o l d axes plunging s l i g h t l y southward. Rotation about these axes, in bg, is clockwise. In addition, striae on the surfaces of inter-bed " s l i p s " , and most evidently in ag, indicate the easterly and s l i g h t l y downward movement of hang-ing wall ground. At the end of the crosscut south of 587, the symmetry and attitude of minor drag f o l d s suggests an easterly to northerly hanging wall movement on l o c a l , similarly-curved - 52 -lode strands. Within weak and strong lode strands observed between 586 and 576, numerous drag fo l d s with axes plunging southerly in bg, and related ag-striae on lode- and inter-bed shear planes, a l l point to a general eastward and downward movement of the hanging wall ground. At sta. 576, drag fo l d s plunging down to the southeast, and presumably lying with axes normal to the direction of d i f f e r e n t i a l movement, suggest that a small component of thrust has attended the easterly- to northerly swing of ground movement from the lode to the Stew-art f a u l t . Summary Old Ruth-Stewart The major bedding structure of the mine area i s a rather sharply-folded recumbent a n t i c l i n e , convex to the southwest, and with i t s a x i a l plane dipping s l i g h t l y in that d i r e c t i o n . The a x i a l plane l i e s a few feet below No. 3 Level within the Old Ruth segment. Localized inter-bed adjustments accompanying folding have produced three major bedding f a u l t zones. Bounding the Old Ruth segment are the "Silversmith" and Stewart f a u l t s , while farther to the west the Ruth f a u l t delimits the Stewart segment in t h i s d i r e c t i o n . Thickly-bedded a r g i l l i t e s , q u a r t z i t i c a r g i l l i t e s , and quartzites com-prise the r e l a t i v e l y firm, b r i t t l e assemblage of wall rocks within the Old Ruth segment. Thinner-bedded a r g i l l i t e s below Stewart No. 4 Level, with a r e s t r i c t e d section of q u a r t z i t i c a r g i l l i t e s , p r o b a b l y in the footwall of the lode above th i s level,comprise the generally incompetent wall rocks of the Stewart segment. The Stewart- and Old Ruth lodes are linked through a northerly swing of strands from the Stewart lode to the Ruth f a u l t , followed by an easterly bend of elements of the Stew-art f a u l t to j o i n the Old Ruth lode. Restricted sections of the f a u l t , close to the lodes, have been veined by ore miner-a l s , showing the pre-ore age of the f a u l t . Also, were the Stewart f a u l t of poat-ore age, the normal displacements char-a c t e r i z i n g i t s upper westerly-dipping part would have caused right-hand offsets, rather than the present apparent l e f t -hand o f f s e t . In addition, i t appears that the lodes have developed rather independently on either side of the Stewart f a u l t zone. The Stewart lode i s a broad zone of f r a c t u r i n g and shearing, dipping at about 45 degrees to the south; the Ruth lode is a well-defined steeply-dipping f i s s u r e f i l l e d with brecciated b r i t t l e wall rocks and, formerly, with ore miner-als above the second sub-level above No. 4. Below the f i r s t sub-level above No. 4, the lode has a somewhat f l a t t e r dip and widens to a broad zone of fractures and shears, enclosing deformed softer beds in the lower l e v e l s . Important orebodies were r e s t r i c t e d to the upper steep sections of the Stewart and Old Ruth lodes. The attitude and symmetry of drag f o l d s , shear clea-vage , and buckled wall rocks shov/s that there has been a gener-a l downward and eastward r e l a t i v e movement along the lodes of the hanging wall ground. At least a small f r a c t i o n of th i s movement has been continuous from the Stewart to the Old Ruth lode v i a the Stewart f a u l t zone• On the Old Ruth lode the main easterly and downward hanging wall motion was apparently transmitted by the f l a t t e r f r a c t u r e - 3 h e a r zone below, and per-haps cutting off, the steep upper section. The productive-steep upper section may have developed as a major fracture in "gash" r e l a t i o n s h i p to the lower section, as a consequence of general late normal displacements; or i t may have formed or i g -i n a l l y as an oblique-slip fracture zone, followed by a strong late normal displacement which erased minor structures devel-oped by the e a r l i e r lode movement. Steeply-dipping sections of the lode are evidently favourable to ore-deposition. The upper section of the Old Ruth lode apparently owes i t s permeability to the presence of open fractures or a rather coarse breccia f i l l i n g . Breccia-t i o n was apparently a consequence of the r e l a t i v e downward movement of the hanging wall across the ends of b r i t t l e , f l a t -l y i n g , closely-folded beds over the second sub-level above No. 4 . With i t s longest dimension along the strike of the lode, the orebody is elongate across the line of r e l a t i v e displacement - 55 -o r t h e l o n g a x i s l i e s i n t h e b 3 - d i r e c t i o n . E x p a n s i o n i n t h i s d i r e c t i o n w a s a p p a r e n t l y f a v o u r e d b y t h e g r e a t e r l a t e r a l e x -t e n t o f t h e s e c t i o n o f b r i t t l e , f l a t l y - b e d d e d w a l l r o c k s , a n d b y s m a l l v a r i a t i o n s o f d i p w h i c h w o u l d c r e a t e o p e n s p a c e s o f g r e a t e s t e x t e n t a l o n g t h e s t r i k e o f t h e l o d e . I n a d d i t i o n t o t h e s t e e p d i p o f t h e u p p e r p a r t o f t h e S t e w a r t l o d e , o t h e r f a v o u r a b l e o r e - f o r m i n g f a c t o r s a r e p r e s e n t : A b r i t t l e s e c t i o n o f b e d s o c c u p i e s t h e f o o t w a l l o f t h e u p p e r s e c t i o n ; t h e l o d e f o r m s a p r o n o u n c e d s o u t h e r l y p l u n g i n g n o s e w i t h i n t h e u p p e r l e v e l s o n l y ; t h e n o s e i s f u r t h -e r c o m p l i c a t e d b y s o u t h e r l y - p l u n g i n g c r e n u l a t i o n s d e v e l o p e d b y l o c a l s i n u o s i t i e s i n t h e s t r i k e o f t h e l o d e . I t i s p r o b a b l e t h a t o r e c h a n n e l s w o u l d b e h e l d o p e n d u r i n g t h e p e r i o d o f m i n -e r a l i z a t i o n , a n d t h a t m a j o r p l u n g i n g o p e n s p a c e s , a s " o r e t r a p s " , w o u l d r e s u l t f r o m t h e e a s t e r l y - a n d d o w n w a r d h a n g i n g w a l l m o v e m e n t a c r o s s t h e n o s e . L i k e t h e O l d R u t h l o d e , t h e S t e w a r t l o d e c o n t a i n s o n l y s m a l l o r e b o d i e s w i t h i n i t s l o w e r , w i d e r , a n d f l a t t e r s e c t i o n s . H e r e , m i n e r a l i z a t i o n w a s a p p a r -e n t l y l o c a l i z e d t o s h o r t Bteep " g a s h " f r a c t u r e s b e t w e e n t h e f l a t t e r , m o r e - c o n t i n u o u s s h e a r s t r a n d s o f t h e l o d e . W i t h i n t h e O l d R u t h - S t e w a r t s e c t i o n o f t h e m i n e a r e a , a s e l s e w h e r e i n t h e S l o c a n , s t r u c t u r a l c o n t r o l s o f m i n e r a l i z a -t i o n c a n n o t b e t o o c l o s e l y t y p e d . T h e y e x i s t w h e r e t h e m o s t f a v o u r a b l e c o m b i n a t i o n s o f r o c k t y p e s , b e d d i n g a t t i t u d e s , - 5 6 -f r a c t u r i n g a n d b r e c c i a t i o n , a n d r e l a t i v e d i s p l a c e m e n t s o f t h e l o d e w a l l s c o o r d i n a t e t o d e v e l o p m a j o r c o n t r o l l i n g s t r u c t u r e s . MASCOT-HOES SECTION Prom a point on Old Ruth No. 2 Level, 200 feet west of the Ruth f a u l t , which cuts off the Stewart lode to the west, a long crosscut was driven 600 feet to the south. This cross-cut was. stopped in a wide northeasterly-trending shear zone, and which i s presumably the Hope lode. The lowest productive l e v e l of the Hope mine i s about 250 feet above Old Ruth No.2 Level, or in about the same horizon as the top of the Stewart orebody. In i t s north-south position, the Hope lode l i e s be-tween projections of the Old Ruth and Silversmith lodes. The Hope lode was productive over 4 main l e v e l s ; the lowest, No. 4, i s at an elevation of about 47 50 f e e t ; the upper adi t i s at an elevation of 5260 f e e t . No. 5 -Level was not successful in the search f o r downward extensions of the orebody. To the east, the lode i s cut off, or deflected south-ward at the northwesterly-trending Lone Star f a u l t , This f a u l t l i e s only about 100 feet west of the Ruth f a u l t , where i s was observed on Old Ruth No. 2 Level and in the New Ruth 501 l a t e r a l . To the west, probably following small offsets on cross-faults, the Hope lode seems continuous with the Mascot lode. - 57 -- 58 -The upper productive part of the Hope lode cuts a generally hard, competent assemblage of calcareous a r g i l l i t e s and quartzites, and massive quartzites, from east to west across the sedimentary section. The few outcrops that could be found (Map Ho. l) show that at least the upper sections of wall rock dip to the southwest. As the Hope workings are now inaccessible, the detailed cross-sectional bedding structure throughout the l e v e l s has not been established. Apparently no major porphyry bodies were encountered in- the mine workings, but at depth the lode appears to dip towards the footwall of the West Silversmith "plug". Also, a small northeasterly-trending porphyry dike outcrops southeast of the Mascot tunnels, and about 300 feet in the hanging wall of the lode. This may be an offshoot from the West Silversmith d r i f t (Maps Ho. 1 and 4). C E . Cairnes, in the G.S.C Mem. 184, provides an extreme-l y good description of the underground geology of the Hope lode which i s quoted in the following paragraph. "The Hope lode d i f f e r s in structure and mineralization from the Ruth lode. It is a productive zone, rather than a well-marked f i s s u r e . This zone has a general east s t r i k e , dips to the Bouth at angles varying from 25 to 40 degrees, and in i t s productive parts varies in width from less than a foot to about 40 f e e t . It has been formed by a combination of f r a c -turing and shearing, factors which vary in r e l a t i v e importance - 59 -a c c o r d i n g to the nature of the rocks t r a v e r s e d and the angle a t which the zone encounters them. In g e n e r a l the Bteeper-d i p p i n g p a r t s of the lode are the more r e g u l a r and b e t t e r de-f i n e d and are c o i n c i d e n t with the i n t e r s e c t i o n of the more com-petent rock members, p a r t i c u l a r l y where the lode cuts most ad-, r u p t l y a c r o s s them. Where the lode dips a t a low angle and tends to f o l l o w the bedding of the sediments, the rocks are much broken, the channels f o l l o w e d by the m i n e r a l i z i n g s o l u -t i o n s are i r r e g u l a r , and the w a l l s of the lode are i l l - d e f i n e d and r e q u i r e much c r o s s c u t t i n g t o f u l l y explore them. Much of the old workings have, by reason of the broken nature of the ground, caved and are a c c e s s i b l e with d i f f i c u l t y i f at a l l . The p r i n c i p a l p r o d u c t i v e area was i n the eastern s e c t i o n of the mine workings and extended from the surface t o a l i t t l e below Ho. 4 l e v e l . I t had a maximum, length on No . 2 l e v e l of about 550 f e e t and pitched to the eas t , out of the h i l l . The lode f i l l -i n g c o n s i s t e d of crushed rock, c a l c i t e , s i d e r i t e , q u a r t z , and ore. A f e a t u r e of the lode was the l a r g e bands or l e n s e s , up to 3-1/2 f e e t t h i c k , of c o a r s e l y c r y s t a l l i n e c a l c i t e that l a y c h i e f l y next to, or near, the hanging-wall and were u n d e r l a i n by ore p a r t l y cemented by c a l c i t e . The ore shoots were i r r e g -u l a r i n form, p i n c h i n g , s w e l l i n g , and i n p l a c e s a b r u p t l y term-i n a t i n g at t h e i r g r e a t e s t t h i c k n e s s a g a i n s t a c r o s s - f i s s u r e . They c o n s i s t e d of galena or blende or mixtures of the two. These lenses were strung out i n l i n e , or overlapped or were - 60 -arranged in echelon. In general they favoured the hanging-wall hut also occurred on or near the foot-wall or w e l l with-in the body of the lode . They varied in thickness from a fr a c t i o n of an inch to 2-1/2 feet and averaged, probably, about 100 feet in length. Cross f i s s u r e s were encountered in places and in part proved productive but were small, the large being a fis s u r e following the bedding on No. 1 l e v e l and running into the footwall." A prominent feature of the northea s t e r l y - s t r i k i n g lode holding the Hope orebody is the temporary swing to the southeast along a northwesterly-trending, west-dipping f a u l t . This "jog" i s very close to the apparent "center of gravity" of mineralization. I f this l o c a l deflection of the lode i s compared to that'around the New Ruth orebodies (Map No.4} some s t r i k i n g s i m i l a r i t i e s are apparent. In both cases ore-bodies are adjacent to the curving intersection of the lode and a transverse f a u l t zone. Also, in both cases, t h i s i n t e r -section has produced trough and nose structures, plunging Steepler to the southwest. In other words, f o c i of deformation which are capable of producing excellent channels for r i s i n g ore solutions, have been produced. Direct evidence of the nature of ground movement along the Hope lode i s lacking, but these may be inferred as sim i l a r to those on the Old Ruth and New Ruth lodes. Some - 61 -evidence, s u p p l i e d by m u l l i o n s on the f o o t w a l l of the s t r u c -ture i n the Mascot workings, s u b s t a n t i a t e the i n f e r e n c e that the hanging w a l l moved down and to the e a s t . Under t h i s d i s -placement the tendency towards the development of southwesterly r plunging drag s t r u c t u r e s should be most pronounced. P o s s i b l y i t was s t r u c t u r e s o f t h i s , p a t t e r n , , i n a d d i t i o n t o the other s t r u c t u r e s noted by C a i r n e s , t h a t l o c a l i z e d m i n e r a l i z a t i o n and produced the i n t e r r u p t e d , l e n t i c u l a r , c i s c o n t i n u o u s , or over-l a p p i n g ore shoots on the Hope l o d e . I t i s u n f o r t u n a t e that the h a b i t s of i n d i v i d u a l ore shoots are not d e s c r i b e d . Some d e t a i l e d knowledge of these would h e l p to prove or disprove the above assumptions. NEW RUTH SECTION Introduct ion The westward extension of the r i c h lode structures from the Silversmith mine forms the main structures of the New Ruth section (Map No. 4). Both the New Ruth "Footwall" and "Hanging Wall" lodes extend westward to the Ruth f a u l t . Beyond the Ruth f a u l t is a s i n g l e , tightly-curved structure. Following sharp bends to the northwest and southwest in going through the Ruth f a u l t , i t continues to the Lone Star f a u l t , and is here referred to as the'New Ruth West lode, or simply the West lode. At a time when the orebodies of the Old Ruth section i-of the mine were nearly depleted, the Ruth-Hope Mining Company turned to the exploration of the westward extension of the Silversmith lode into their ground. At 1150 feet from the por-t a l of Ruth No, 5 l e v e l , a crosscut was driven almost due south for a distance of about 2700 feet to intersect the extension of the Silversmith lode. The southerly part of the long crosscut and pattern of subsequent exploratory workings are shown on lap No. 4. The 501 l a t e r a l , driven by the Kelowna Exploration Company, under the geological direction of Mr. Paul B i l l i n g s l e y , - 62 -- 63 -is also shown. It was located to test more westerly extensions of the Silversmith lode. It was thought possible that these would l i e in the footwall of the West lode, or in the footwall of the West Silversmith porphyry exposed in the westerly hang-ing wall d r i f t . In 1946, R.S. Moehlman and A.E. B u l l e r carried out the e a r l i e s t 40-scale mapping done i s these workings by the Kelowna Exploration Company. Later in the year the writer mapped parts of 501 l a t e r a l and the old workings along the Lone Star f a u l t and West Silversmith lode. In 1947 Br. E.B. Mayo mapped much of the 501 l a t e r a l to the east of, and within the porphyry.and extended h i s detailed studies of minor structures along the Lone Star f a u l t and West Silversmith lode. As a re-s u l t of his studies he confirmed Mr. B i l l i n g s l e y ' s inferences of the nature of lode displacements, and contributed new data of lode movements, f a u l t displacements, and the mechanics of intrusion of the porphyry. These studies are summarized in his "Structural Study on Ruth 501 L a t e r a l and West Silversmith Lode". The writer has drawn upon a l l of the above studies, p a r t i c u l a r l y the l a t t e r , in writing t h i s section of the thesis. In addition, valuable information concerning the geology of the now-inaccessible workings on the lodes was taken from old plans by H.A. Rose . - 64 -Rock Types and Structures In 501 l a t e r a l , to the east of the porphyry, i s an assembljage of rather thinly-bedded hard f i s s i l e a r g i l l i t e s , inter-bedded by thicker argillaceous quartzites. Beds follow the normal northwesterly s t r i k e , and dip moderately to the southwest. Where they approach the footwall of the Silversmith lode zone, beds show l o c a l easterly deflections of s t r i k e ; close to the footwall the bedding bends uniformly to an east-e r l y strike and southerly dip, in sub-parallelism with the plane of the lode. This effect of drag by lode displacements i s also seen within beds forming the hanging wall of the West Silversmith lode. Mineralization and Orebodies The mineralization of a l l members or extensions of the Silversmith lode is rather s i m i l a r . The major ore miner-als are galena, sphalerite, grey copper, and argentite. Ore minerals found in minor amounts include chalcopyrite, the ruby s i l v e r s , native s i l v e r , and "oxidation" products such as anglesite, cerargyrite, and smithsonite. The chief gangue minerals are quartz, c a l c i t e , and s i d e r i t e . A l l , or only a few of the above minerals may occur in a single deposit. Individual orebodies generally occur either a,s crude lenses, or as regular tabular bodies of ore and gangue miner-a l s , with a brecciated, and often, roughly-banded structure. - 65 -The l e n s - l i k e f o r m s a r e f r e q u e n t l y s i t u a t e d w i t h i n f o l d e d s e c -t i o n s o f t h e l o d e . They may he s t r u n g o u t i n l i n e , o v e r l a p p i n g , o r e n - e c h e l o n i n a r r a n g e m e n t . Where g a l e n a and s p h a l e r i t e a r e p r e s e n t , m a s s e s of t h e l a t t e r a r e f r e q u e n t l y v e i n e d b y g a l e n a . Where t h e gangue i s o f the u s u a l q u a r t z - c a r b o n a t e v a r i e t y , c a l -c i t e u s u a l l y v e i n s q u a r t z , and i s , i n t u r n , v e i n e d b y s i d e r i t e . Where a b u n d a n t " y e l l o w and b r o w n c a r b o n a t e s " a r e p r e s e n t , much d i s s e m i n a t e d p y r i t e w i l l u s u a l l y be f o u n d i n t h e g a n g u e . . M i n o r r e v e r s a l s o f the n o r m a l s e q u e n c e of m i n e r a l d e p o s i t i o n may be due t o r e - s o l u t i o n and c o n s e q u e n t r e - d e p o s i t i o n , o r t h e f r a c t u r -i n g of " y o u n g e r " m i n e r a l s and m e c h a n i c a l f l o w a g e of " o l d e r " m i n e r a l s i n t o t h e open s p a c e s . M i n o r c r o s s - f r a c t u r e s w i t h i n a n o r e b o d y h a v e d i f f e r i n g e f f e c t s on t h e c o n t i n u i t y of v e i n s t r u c t u r e s . M o s t f r e q u e n t l y , t h e v e i n or v e i n l e t i s o n l y o f f -s e t b y a s m a l l amount; o c c a s i o n a l l y , t h e c h a r a c t e r of m i n e r a l -i z a t i o n a n d t h e s t r u c t u r e o f t h e v e i n v a r i e s a c r o s s t h e c r o s s -f r a c t u r e . E v i d e n t l y b o t h p r e - and p o s t - m i n e r a l m i n o r c r o s s -f r a c t u r e s o c c u r i n l o d e s . A t s e v e r a l p l a c e s e v i d e n c e of " l a t e " q u a r t z i n d i c a t e s t h a t more t h a n one g e n e r a t i o n of i n d i v i d u a l gangue m i n e r a l s a r e p r e s e n t . S i l v e r s m i t h Lode The S i l v e r s m i t h l o d e e n t e r s t h e New R u t h a r e a a s two d i s t i n c t members. These a r e t h e h a n g i n g w a l l a n d f o o t w a l l l o d e s . E a c h i s ; a w i d e zone of s h e a r i n g a n d s l i p p i n g , s e p a r a t e d b y a - 66 -panel of r e l a t i v e l y undeformed massive rocks, and which is over 100 feet thick on No. 5 l e v e l . The hanging wall lode l i e s along the sheared footwall contact of the main Silversmith por-phyry plug. The footwall lode l i e s in sheared a r g i l l i t e s and quartzites and well below the footwall of the porphyry. Fre-quently the hanging wall of thi s lode l i e s under thin porphyry sheets which are most l i k e l y footwall leaves from, the main body. Generally, the lodes that have developed adjacent to a strong body of porphyry are characterized by the development of fracture structures, with the ore minerals f i l l i n g f i s s u r e s and gashes or cementing a brecciated f i l l i n g along with a quartz and carbonate gangue. Those sections of a lode that l i e en-t i r e l y within the sediments are characterized by the develop-ment of shear and fold structures, and orebodies are generally lens-shaped with sharp walls of sheared graphitic material. However, l a t e r movement and mineralization have caused some brecciation and re-cementation of these bodies. Ruth Fault Two main northwesterly-trending f a u l t zones interrupt the lodes along t h e i r courses across the mine area. These are the Ruth fa u l t and the lone Star f a u l t . The Ruth f a u l t which is the stronger, s t r i k e s about north 15 degrees west and dips a l i t t l e over 70 degrees southwest. It appears to be a through-going f a u l t zone, with minor footwall or hanging wall strands - 67 -dipping at f l a t t e r angles, and which swing sharply to j o i n the lodes at fault-lode intersections. It i s f i l l e d with strong-ly-sheared and crumpled g r a p h i t i c material, i n d i v i d u a l crump-les often indicating the direction of f i n a l displacement. A few stringers and lenses of quartz are found in the f a u l t where i t crosses 501 l a t e r a l . Lone Star Fault The Lone Star f a u l t , a weaker structure, varies from a broad zone of moderately-sheared g r a p h i t i c a r g i l l i t e , where i t follows the eastern footwall of the West Silversmith porph-yry, to a narrow zone of intensely-sheared g r a p h i t i c a r g i l l -ites and quartzites southward to i t s intersection with the West lode. It strikes roughly p a r a l l e l to the Ruth f a u l t but has a more ir r e g u l a r course where i t curves to follow bumps and bays on the porphyry footwall. Under the porphyry i t dips rather f l a t l y and in sympathy with i t . South of the West Silversmith lode, where i t becomes a more d i s t i n c t i v e structure, the Lone Star f a u l t dips about 60 degrees to the southwest. Just north of the West lode a strong element of the Lone Star f a u l t bends sharply in a tight arc through a southeasterly and, f i n a l l y , a northeasterly direction to merge with the West lode. Probably only a minor strand of the Lone Star f a u l t continues southeastward past the west end of the West lode . In the other di r e c t i o n , on i t s northwestward course, the Lone Star f a u l t s p l i t s on the southeast corner of the West Silversmith porphyry. - 68 -A strand from the hanging w a l l of the f a u l t curves, through a tight arc, to a southwesterly course, to j o i n the West S i l v e r -smith lode on the hanging wa l l of the West Silversmith plug.. Along the Xione Star f a u l t are frequent " s q u i r t s " of gangue material and porphyry (?). The porphyry, often concor-dantly f i l l i n g drag structures in the f a u l t zone, i s closely fractured and strongly veined and replaced by quartz-carbonate vein matter. Occasionally, a l i t t l e sphalerite i s associated with the carbonates of t h i s vein matter. The course of the Lone Star f a u l t northwestward, beyond 501 l a t e r a l , i s uncer-t a i n . Judging from i t s usual behaviour the f a u l t could easily swing to a westerly trend to j o i n the Hope lode in the footwall of the plug. West Silversmith Lode The West Silversmith "lode" i s a rather broad, poor-ly-defined zone of sheared and closely-broken gr a p h i t i c a r g i l l -i t e s . From the southeast nose of the porphyry, where footwall elements of i t come from the Lone Star f a u l t zone, i t has been traced for 400 feet to the west. Along i t s course i t closely follows the southward-dipping hanging w a l l contact of the West Silversmith porphyry. The general trend and char a c t e r i s t i c s of the structure have been deduced from data provided by diamond d r i l l hole intersections, and the f i n e r d e t a i l s from direct observations in the old mine workings. The structure contours - 69 -on Map No. 4 were sketched in by a correlation of d r i l l hole intersections. The actual trend of the porphyry body beyond „the west face of the old No. 5 Level workings has not been es-tablished. However, diamond d r i l l holes directed from 501 l a t e r a l , and penetrating the hanging w a l l of the porphyry plug, have provided intersections which were plotted on both plan and section. Thus, i t was possible to project the porphyry contact downward to the No. 5 Level and to i n f e r the s t r i k e on horizons above the No. 5 Level. Carbonate veins and replace-ments follow the footwall f o r a short distance west of the Lone Star f a u l t . Only minor amounts of dark brown sphalerite were found in the lode, closely associated with quartz-carbonate gangue. -Cross-Fault One other structure i s s i g n i f i c a n t enough to warrant at least a b r i e f description. This i s the acutely-angling f a u l t l i n k between the Ruth and Lone Star f a u l t s , herein re-ferred to as the Cross-f a,ult. This structure follows a f l a t l y -arcuate st r i k e of north 45 degrees west where i t departs from the hanging wall of the Ruth f a u l t to north 30 degrees west where i t approaches footwall elements of the Lone Star f a u l t on No. 5 Level. I t s presence was indicated vaguely on old plans but considerable diamond d r i l l i n g was accomplished from the 501 l a t e r a l before the structure was f i n a l l y established. - 70 -In i t s central sections i t seems to consist of several closely-spaced shear strands, that may merge into one zone of crushed graphitic material. Cross-sections show that i t generally dips at a f l a t t e r angle than either the Ruth or tone Star f a u l t s , hence i t forms a "roof" which would rather quickly l i m i t the upward extensions, above No. 5 Level, of possible lode struc-tures in the footwall of the New Ruth West lode and l y i n g to the south of 501 l a t e r a l . A few d r i l l - h o l e intersections, namely on R - l , R-2, R-4 (?)', R-15 and R-16, indicate that lenses of both porphyry and quartz or quartz-carbonate with s i g n i f i c a n t amounts of brown sphalerite l o c a l l y f i l l the struc-ture. This, and the similar occurrence of ore minerals on the Lone Star f a u l t suggests that mineralization has again extended from the lodes into the northwesterly-trending f a u l t zones. West Silversmith Porphyry This i r r e g u l a r body of porphyry, indicated on old plans and intersected in Ruth 501 l a t e r a l , i s limited by the Hope and. West Silversmith lodes in a north-south d i r e c t i o n and by the Lone Star f a u l t to the east. Its v e r t i c a l and westerly extent are unknown. The i r r e g u l a r hanging wall probably dips between 45 and 60 degrees southerly. The easterly footwall, generally conforming to the Lone Star f a u l t , dips between 20 and 30 degree's to the southwest. The shape of the northeast-e r l y footwall and the "forced" curvature of bedding and s l i p planes on the hanging wall of the Lone Star f a u l t suggests that - 71 -the body was, to some degree, f o r c e f u l l y intruded. The rock may be c l a s s i f i e d as a feldspar porphyry. It has the t y p i c a l "birds-eye" texture of the main Silversmith stock and is most probably an offshoot from the main stock. Marginal flow lay-ers, formed by the planar arrangement of the feldspar pheno-crysts, are approximately concordant with the periphery of the porphyry body. These and other structures w i l l be described and discussed l a t e r in the text. Minor Structures and Movement Patterns  Buth F a u l t : The only exposure of t h i s major f a u l t i s at i t s i n -tersection with the 501 l a t e r a l (A of Map No. 4). The zone includes a width of about 60 feet of intensely-sheared graph-i t i c a r g i l l i t e s and quartzites. "Movement structures", such as drag folds and shear cleavage, are best developed over' the sharply-defined footwall. Drag-fold axes plunge, on the aver-age, at 40 degrees to the southwest; rotation about b i i s counterclockwise, looking north. Consequently, the r e l a t i v e displacement of the hanging wall i s in a i , normal to b i , and i s downward and s l i g h t l y to the northwest. Shear cleavage, s t r i k i n g northeasterly and dipping noRthwesterly at a lesser angle than the dip of the f a u l t , has developed i n accord with t h i s direction of movement. West Silversmith lode : In the face, at the west end of the old d r i f t , drag folds and "gash" fractures are well developed within l e s s -sheared " r i b s " of the lode. Brag f o l d axes plunge at a slight angle to the southwest, and are overturned to the southeast (H) for a clockwise rotation about bg. The "gashes", s t r i k i n g southwesterly and dipping northwesterly, l i e close to the plane b-c. The attitude of these fractures, being normal to the pla,ne and l i n e of lode displacement, shows them to be more closely related to simple tension in ag rather than to the type of shearing stress which develops fractures that dip into the direction of movement. By drag-fold symmetry the l o c a l hanging-wall motion was eastward and s l i g h t l y downward. Twenty feet from the face (J), on the southside of the d r i f t , a small shear joins the lode acutely from the south-east. Brag folds in the sheared gouge have horizontal axes and are overturned to the southwest. Evidently, crowding of the hanging-wall block into the junction of the lode and lone Star f a u l t , has been relieved by a southwesterly slump of ground over fault-lode shear-links. F o r t y - s i x feet from the west face (K) drag folds in the wall and back are oriented and overturned for the downward hanging-wall movement to the southeast. F i f t y - e i g h t feet from the west face (L) grooves on the hanging wall of the porphyry plunge steeply to the southeast. Close by, drag folds plunge to the southwest, with axes oriented at right angles to the grooves. Hence both a£- and bg-lineations, the l a t t e r with clockwise rotation, confirm the r e l a t i v e southeasterly-and-downward hanging-wall movement along the West Silversmith lode. Lone Star F a u l t : This zone i s continuously exposed f o r over 300 feet, except f o r a short section that s k i r t s the southeast nose of the porphyry "plug". A few feet east of the porphyry body (C), the f a u l t crosses 501 l a t e r a l as a widely-stranded structure, in which i n d i v i d u a l "shear strands." enclose wider sections of crushed and broken b r i t t l e a r g i l l i t e s . Above the steep foot-wall are f l a t t e r strands which dip rather concordantly with the contact of the porphyry. Brag folds overturned to the south-west, with grooves also plunging in this d i r e c t i o n , are orient-ed f o r a r e l a t i v e downward and s l i g h t l y northward displacement of the hanging w a l l . A similar displacement on the Cross f a u l t , exposed within 501 l a t e r a l only a few feet to the east, i s recorded by minor drag fo l d s and s t r i a e . South of 501 l a t e r a l , where the Lone Star f a u l t s k i r t s the porphyry, drag folds recording anomalous lode movements probably originated from slumping of the porphyry plug. These unique variations from the general movement pattern do not appear to be of s u f f i c i e n t importance to warrant a detailed analysis in t h i s thesis. - 74 -Drag f o l d s i n the f a u l t , c l o s e to i t s i n t e r s e c t i o n with the West S i l v e r s m i t h lode (§), are i r r e g u l a r l y squeezed w i t h i n the " c o r n e r " . Small b o d i e s of porphyry ( ? ) , i n j e c t e d i n t o the buckled g r a p h i t i c f i l l i n g have been s t r o n g l y replaced by quartz and c a l c i t e . These have not been s e r i o u s l y deformed by lode movements. L o c a l l y drag f o l d s w i t h i n the f a u l t have been d e f l e c t e d from t h e i r u s u a l f l a t , n o r t h w e s t e r l y trend to plunge towards the trough formed by the f a u l t - l o d e i n t e r s e c t i o n . A l s o , t h e i r symmetry i s such as to show a d e f l e c t i o n of the downward movement of the f a u l t hanging w a l l to one more n e a r l y i n the d i r e c t i o n of that of the l o d e . At S, drag f o l d s w i t h i n the f a u l t plunge at 43 degrees westward and are overturned to the south; l o c a l l y these may be considered as b g - l i n e a t i o n s w i t h clockwise r o t a t i o n . Thus, immediately south of the corner, the e a s t e r l y component of movement of the lode hanging w a l l has turned southward to p a r a l l e l the s t r i k e of the f a u l t . At U, the c h a r a c t e r i s t i c normal displacement of the Lone S t a r f a u l t again becomes e v i d e n t . Here, minor drag f o l d s , w ith s p o t t y f i l l i n g s of c a l c i t e , plunge g e n t l y a t about n o r t h 70 degrees west. R e l a t e d grooves and s t r i a e , most probably formed i n the l i n e of displacement, plunge at 56 degrees south-e r l y . Consequently, the hanging w a l l may be i n f e r r e d to have moved s t e e p l y downward and southward. - 75 -Over the porphyry (?) lens forming the f o o t w a l l of the f a u l t a few f e e t south of R, minor drag f o l d s have d e v e l -oped w i t h i n the sheared g r a p h i t i c f i l l i n g . Axes of these plunge d i r e c t l y down the dip of the f a u l t and p a r a l l e l t o pronounced " r o l l s " on the f o o t w a l l . B e i n g overturned to the south, r o t a t i o n about these b g - l i n e a t i o n s i s c l o c k w i s e . E v i -d e n t l y the hanging w a l l of the f a u l t , on approaching the West lode, shows evidence of s t r i k e - s l i p displacements comparable to those on the l o d e s . Very l i k e l y t h i s motion i s r e p r e s e n t -a t i v e of the movement on s h e a r - l i n k s which converge with the hanging w a l l of the f a u l t from the northwest. Small bodies of porphyry (?) which conformably f i l l the expanded s e c t i o n s of minor drag f o l d s could have been i n j e c t e d a t approximately the same time as the f o o t w a l l l e n s . The m a t e r i a l forming these i n j e c t e d bodies has been s t r o n g l y r e p l a c e d by y e l l o w c a l c i t e , w ith only a suggestion of the o r i g i n a l p o r p h y r i t i c t o g r a n i -t o i d texture remaining. Quartz, f i l l i n g f r a c t u r e s i s the a l -tered porphyry, i s n o t a b l y undeformed, so was e v i d e n t l y i n t r o -duced d u r i n g the c l o s i n g stages of ground movement. At the i n t e r s e c t i o n of the Lone S t a r f a u l t and West lode the f a u l t f i l l i n g i s c l o s e l y buckled and dr a g - f o l d e d on s t e e p l y - p l u n g i n g axes. The l i n e a t i o n s i n b2 shows clockwise r o t a t i o n . At t h i s p o i n t i t appears t h a t "hanging w a l l motion" i s southward and eastward around the "corner" of the f a u l t -lode i n t e r s e c t i o n . Probably, a l t h o u g h the displacement on the - 76 -West lode cannot "be determined because of the i n a c c e s s i b i l i t y of the workings, the r e l a t i v e hanging w a l l displacement on the West lode was downward to the east, l i k e that on the West S i l v e r s m i t h l o d e . West S i l v e r s m i t h Porphyry The rock comprising t h i s body has a l i g h t - and dark-speckled appearance. Abundant f e l d s p a r , and minor quartz phen-o c r y s t s are set i n a dense :ground mass of purplish-brown femic m i n e r a l s . O c c a s i o n a l s m a l l rounded i n c l u s i o n s , composed almost wholly of f i n e - g r a i n e d femic m i n e r a l s , occur throughout the body. These may represent p a r t l y - r e s o r b e d b a s i c segregations or h i g h l y - a l t e r e d i n c l u s i o n s of w a l l rock. Frequent sharp-w a l l e d dikes of cinammon-brown lamprophyre cut the main i n t r u -s i v e . Phenocrysts and dark i n c l u s i o n s form, r a t h e r obscure l a y e r s . W i t h i n these f l o w - l a y e r s , f l o w - l i n e s have been pro-duced by alignment of the phenocrysts and i n c l u s i o n s i n l o c a l l y p r e f e r r e d d i r e c t i o n s . The p a t t e r n of f l o w - l a y e r s and flow-l i n e s , from d e t a i l e d mapping by B r . E.B. Mayo, i s shown by c o n v e n t i o n a l s t r i k e - a n d - d i p symbols and arrows, r e s p e c t i v e l y , on Map No. 4. To quote from h i s i n t e r p r e t a t i o n of the s t r u c -t u r e : "The p l a n a r s t r u c t u r e conforms roughly with the c o n t a c t s , so f a r as these are known. The arrangement of the l a y e r s in the western p a r t of 501 l a t e r a l suggests a pronounced northward - 77 -"bulge in the footwall of the porphyry... . The l i n e a t i o n i n -dicates that the porphyry has moved upward at a low angle from the southwest. The f a c t that the primary planar structure conforms roughly to the contacts and seems to r e f l e c t the shape of the i n t r u s i o n . . . i s considered conclusive proof that the porphyry i s not a block, faulted off a larger mass." The main S i l v e r -smith Stock, shown on the east side of Map No. 4 might, with-out the benefit of information gained by the study of flow structures, be considered as the larger mass from which the West Silversmith "plug" was faulted to the north across the Ruth and tone Star f a u l t s . Space for, the West Silversmith plug may have been provided by a general opening of the ground, possibly accompanying actual fracturing as expressed by the adjacent lode and f a u l t , and by some assimilation and thrust-ing aside of the wall rocks. - 78 -PETROGRAPHIC FEATURES OF THE WEST SILVERSMITH PLUG (a) Megascopic: The body of the porphyry, l o c a l l y , i s cut by small f i s s u r e s . Bleaching of the porphyry adjacent to them forms the only v i s i b l e type of a l t e r a t i o n . .;These bleached zones, contain-ing a few grains of pyrite^ have sharply-defined margins so that they appear as thin s i l i c e o u s veins. The brown lampro-phyre dikes, where intersected or bordered by f i s s u r e s , are s i m i l a r l y bleached. The most highly-altered sections of the porphyry are those marginal areas which are bordered by the West Silversmith lode or the Lone Star f a u l t . Simple bleach-ing i s common adjacent to both structures, but carbonate a l t e r -ation favours the walls of the lode. At the southeast corner of the porphyry "plug", and in the footwall of the lode, the porphyry has been completely replaced by c a l c i t e and a l i t t l e s i d e r i t e over a depth of several f e e t . Within t h i s carbonate s h e l l are a few specks of brown sphalerite. Specimens of altered porphyry were derived from the contact zones of the plug, from i n t e r n a l l y - a l t e r e d sections, and from altered lenses within the f a u l t s and lodes. Speci-mens No's 3 and 8 represent inclusions and lamprophyric bodies - 79 -w i t h i n the p o r p h y r y . D e s c r i p t i o n s of these s l i d e s do not appear h e r e ; the l a t t e r was examined by M r . J . W . Young i n c o n n e c t i o n w i t h h i s s tudy of the age r e l a t i o n s h i p s of ore and lamprophyre i n t r u s i v e s . Of t h i s s u i t e , even a p p a r e n t l y " fre sh" specimens proved t o be s t r o n g l y a l t e r e d when viewed by the m i c r o s c o p e . C o n s e q u e n t l y , p o s i t i v e i d e n t i f i c a t i o n of many c o n s t i t u e n t m i n -e r a l s were i m p o s s i b l e . However, a few l e s s - a l t e r e d areas w i t h -i n the s l i d e s p e r m i t t e d a r e a s o n a b l y c l o s e e s t imate of the c o m p o s i t i o n of the o r i g i n a l , u n a l t e r e d r o c k . (b) M i c r o s c o p i c : Specimens 1, 2 , and 9: ! These are from specimens; of the " f r e s h " p o r p h y r y , taken i n 501 l a t e r a l and w e l l w i t h i n the i n t e r i o r of the " p l u g " . The r o c k has a w h i t e - s p e c k l e d a p p e a r a n c e , w i t h w e l l -formed f e l d s p a r p h e n o c r y s t s , up t o a l / 2 - i n c h i n l e n g t h , and set i n a very f i n e - g r a i n e d p u r p l i s h - b r o w n groundmass of dark m i n e r a l s . The p h e n o c r y s t s a r e , commonly, s l i g h t l y rounded -perhaps through s l i g h t r e s o r p t i o n by the c o o l i n g magma. E s s e n t i a l M i n e r a l s -( l ) P h e n o c r y s t s ( f o r m i n g up to 50 p e r c e n t of the s l i d e ) show: r e l i e f l e s s than b a l s a m ; b i r e f r i n g e n c e about f i r s t - o r d e r w h i t e ; 2V - 50 degrees , o p t i c a l l y n e g a t i v e ; s t r e a k y , patchy e x t i n c t i o n ; t w i n n i n g m a i n l y C a r l s b a d , wi th - 80 -occasional polysynthetic twinning. These are evidently crys-tals of sodic orthoclase. (2) Groundmass, shows: Mainly fine-grained quartz and feldspar which has a composition that is apparently simi-l a r to that of the phenocrysts. A cc e esory] Minerals : Brown "biotite as small bent plates; apatite as small crystals with roughly hexagonal cross-sections and marked r e l i e f ; sphene, with very high r e l i e f and high birefringence, and occasional acute rhombic cross-sections. A l t e r a t i o n : Feathery c h l o r i t e has replaced the b i o t i t e . The degree of replacement v a r i e s . The a l t e r a t i o n of patches of o r i g i n a l b i o t i t e , which are distant from minor f i s s u r e s tran-secting the s l i d e s , suggests that c h l o r i t i z a t i o n has been effec t i v e throughout the body of the rock, and not r e s t r i c t e d to fractures, which might appear to be responsible for l i m i t -ing the extent of a l t e r a t i o n while functioning as channels for late solutions. The feldspar phenocrysts have been strongly altered to fine-grained aggregate of s e r i c i t e , c l i n o z o i s i t e , and kao-l i n . C l i n o z o i s i t e , with p a r a l l e l extinction and v i v i d blue anomalous interference colours, frequently grows outward from - 81 -the nucleus of smaller feldspar phenocrysts. These phenocrysts show no twinning or zonal e x t i n c t i o n . C a l c i t e forms as ir r e g u l a r patches throughout the groundmass, or f i l l s small, discontinuous f i s s u r e s that have developed as tension cracks or "checks". These f i s s u r e s , with c a l c i t e f i l l i n g s , transect a l l minerals of the s l i d e . Patches of "bordering fine-grained minerals have "been replaced by c a l -c i t e . In specimen No. 9 c a l c i t e forms about 20 percent of the s l i d e . . Leucoxene, the opaque white a l t e r a t i o n product of ilmenite, occurs marginally with respect to grains of this mineral. B i o t i t e , possibly the second generation, follows minor fissures and develops outward from them by replacing (?) some of the groundmass minerals. It i s possible that i t s apparent development along these fissures is ac t u a l l y an i l l u -sion provided by the reverse development of f i s s u r e s in elong-ate patches of b i o t i t e . In contrast to much of the c h l o r i -tized b i o t i t e present i n the s l i d e s , the "veining" b i o t i t e show l i t t l e effect of a l t e r a t i o n . Summary: The rock i s probably a po r p h y r i t i c , s l i g h t l y sodic granite or granodiorite. From i t s p o r p h y r i t i c texture, i t - 82 -a p p e a r s t h a t c r y s t a l l i z a t i o n o f s u p e r - e u t e c t i c a m o u n t s o f t h e c o n s t i t u e n t f e l d s p a r m o l e c u l e w a s w e l l a d v a n c e d b e f o r e t h e m a g m a r o s e t o f o r m t h e p r e s e n t " p l u g " . A f t e r e m p l a c e m e n t t h e r e m a i n i n g , r e l a t i v e l y c o o l m o l t e n f r a c t i o n c r y s t a l l i z e d t o f o r m t h e f i n e - g r a i n e d g r o u n d m a s s o f q u a r t z , s o d i c o r t h o c l a s e , b i o t i t e , a n d m i n o r a c c e s s o r y m i n e r a l s . T h e a b s e n c e o f p e r l i -t i c c r a c k s , t h e l a c k o f e v i d e n c e o f m a r k e d d e v i t r i f i c a t i o n a d j a c e n t t o f i s s u r e s , a n d t h e a b s e n c e o f g l a s s y m a t e r i a l , i n -d i c a t e t h a t t h e f i n e l y - c r y s t a l l i n e g r o u n d m a s s w a s d e v e l o p e d b y t h e q u i c k s o l i d i f i c a t i o n o f . t h e r e l a t i v e l y c o o l m e l t c o n t a i n -i n g t h e p h e n o c r y s t s . T h e a l t e r a t i o n i s o f a r a t h e r c o m p l e x n a t u r e a n d , a s t h e t r u e c o m p o s i t i o n o f o r i g i n a l r o c k m i n e r a l s i s u n c e r t a i n , c a n n o t b e e x p l a i n e d e a s i l y o n t h e b a s i s o f t h e p r e s e n t c o n -s t i t u e n t s . H o w e v e r , s t r o n g s e r i c i t i z a t i o n a n d k a o l i n i z a t i o n o f t h e s o d i c o r t h o c l a s e h a v e o c c u r r e d . T h e c l i n o z o i s i t e c o u l d h a v e d e v e l o p e d f r o m t h e a l t e r a t i o n o f p l a g i o c l a s e f e l d s p a r . M u c h o f t h e c h l o r i t e p r e s e n t r e p r e s e n t s t h e d e u t e r i c a l t e r -a t i o n p r o d u c t o f b i o t i t e . T h e u n a l t e r e d v e i n i n g b i o t i t e , s e e n i n t h i n s e c t i o n N o . 9, w a s p r o b a b l y 1 i n t r o d u c e d a s a n e a r l y h y d r o t h e r r a a l m i n e r a l r e l a t e d t o l o d e m i n e r a l i z a t i o n . T h e " v e i n i n g " c a l c i t e i s p r o b a b l y t h e y o u n g e s t m i n e r a l i n t h e r o c k a n d m a y b e r e l a t e d t o l o d e m i n e r a l i z a t i o n a n d p o s s i b l y t o r e -s o l u t i o n a n d d e p o s i t i o n o f o l d e r c a l c i t e w i t h i n f i s s u r e s . T h e - 83 -"patchy" c a l c i t e may have originated from limey wall rocks which were assimilated by the magma. Specimen No. 4 This represents the bleached rock adjacent to a f l a t normal f a u l t within the porphyry. The width of the bleached zone suggests that a considerable volume of hydrothermal solu-tions passed along t h i s structure. Microscope: The feldspar of the slide has been i n -tensely s e r i c i t i z e d . Much of the o r i g i n a l fine-grained quartz has been coarsely r e c r y s t a l l i z e d and augmented by s i l i c e o u s solutions. In places quartz has penetrated fractures in the s e r i c i t i z e d feldspars, and partly or wholly replaced them. The f i n e l y - f e l t e d masses of s e r i c i t e are not confined to areas occupied by the former feldspars, but appear to have resulted from the d i f f u s i o n of potash-rich solutions throughout the rock. Specimen No • 5 i This i s a specimen of the porphyry close to the mar-gin of the plug. It was taken at one foot from i t s "frozen" contact with the bordering a r g i l l i t e s . Microscope: The rock has a similar mineral compo-s i t i o n as specimens from the i n t e r i o r of the "plug". However, coarse c a l c i t e and s e r i c i t e f i l l the many fi s s u r e s that cut - 84 -a l l rock-forming minerals. There i s no marked increase in the i n t e n s i t y of s e r i c i t i z a t i o n and k a o l i n i z a t i o n of feldspars. Veins of late c a l c i t e form the most prominent feature of the rock. Specimen Ho. 6 This slide represents the altered s h e l l of porphyry at a point three feet below the footwall of the West S i l v e r -smith lode. Microscope: Nearly a l l of the o r i g i n a l rock miner-als have been s e r i c i t i z e d . The o r i g i n a l fine-grained quartz has r e c r y s t a l l i z e d to form coarser-grained patches. Apatite, as rather coarse grains, i s more abundant here than in central parts of the "plug". A few small c a l c i t e v e i n l e t s cut a l l minerals of the s l i d e , but there i s much less c a l c i t e than could be expected so close to a strongly carbonatized section of the lode. B i o t i t e is absent. Its former presence i s suggested by ir r e g u l a r patches of feathery c h l o r i t e which con-tain small shreds of magnetite. Specimen Ho. 7 This sl i d e represents a deformed lens of altered por-phyry from within the Lone Star f a u l t . Microscope: The slide consists of a very fine-grained assemblage of quartz and s e r i c i t e , containing numerous small - 85 -grains of feldspar. The feldspar, with i t s strong zonal ex-t i n c t i o n , is probably more ca l c i c than that of the main "plug". The rock has a marked schistose structure, imparted by the f l a t t e n i n g and elongation of the feldspars and the f o l -i a t i o n of feathery flakes of s e r i c i t e . The feldspar grains have been warped; they show ir r e g u l a r extinction within curved, discontinuous twin-lamellae. The fine-grained quartz shows simi l a r fractures and strain shadows. The structures and composition of the constituent minerals indicates that the lens of porphyry was dynamically-metamorphosed a f t e r i t s s o l i d i f i c a t i o n within the f a u l t . A l t e r a t i o n by hydrothermal solutions i s expressed by v e i n l e t s of c a l c i t e containing small grains of p y r i t e . Sequence of Geological Events; New Ruth-Silversmith Areas. The h i s t o r y of the major bedding structures which were, most l i k e l y , well-developed previous to the formation of i n i t i a l lode fractures, i s not discussed here. 1. S t r i k e - s l i p f a u l t i n g along lode fractures, closely-timed with normal displacements on the northwesterly-trending f a u l t s . Possibly early hanging wall movements on lodes were easterly and northeasterly. 2. Continued normal displacements on normal f a u l t s ; co-incident with, or closely followed by downward and eastward displacements of ground above the hanging wall of the lodes. - 86 -M i n o r i n c r e m e n t s of t h i s l o d e movement p e r s i s t e d and c o n t i n u e d a r o u n d " c o r n e r s " of f a u l t - l o d e i n t e r s e c t i o n s . 3. I n t r u s i o n of t h e p o r p h y r y ( f o l l o w i n g an e a r l y s t a g e of 2.) i n t o m a j o r b e d d i n g s t r u c t u r e s and f r a c t u r e z o n e s . A d j a -c e n t w a l l r o c k s were b a k e d and h a r d e n e d . 4. C o n t i n u e d l o d e and f a u l t movements, w h i c h were a c c o m p a n i e d b y b r e c c i a t i o n o f b a k e d w a l l r o c k s a n d some m i l d d e f o r m a t i o n o f p o r p h y r y i n t r u s i v e s . P o s s i b l y m i n e r a l i z a t i o n of t h e l o d e s commenced w i t h i n t h i s p e r i o d . M i n e r a l i z a t i o n was e v i d e n t l y c o n c e n t r a t e d a t s e c t i o n s of b r i t t l e , b r e c c i a t e d w a l l r o c k s and c r u m p l e d s e c t i o n s o f t h e l o d e and b o r d e r i n g s e d i m e n t s . 5. P o s t - o r e n o r m a l f a u l t i n g , p r o d u c i n g s m a l l o f f s e t s of m i n e r a l i z e d s e c t i o n s o f t h e l o d e s where t h e y a r e t r a v e r s e d b y n o r t h w e s t e r l y - t r e n d i n g f a u l t s . - 87 -REFERENCES M a p s H . A . R o s e ; o l d p l a n s s h o w i n g g e o l o g y o f N e w R u t h a r e a . A . E . B u l l e r & R . S . M o e h l m a n : " R u t h N o . 5 l e v e l . " A . E . B u l l e r : g e o l o g i c a l s k e t c h s h e e t s O l d R u t h m i n e , p a r t i c u l a r y o f w e s t p a r t o f N o . 3 L e v e l , 4 1 5 0 S u b - L e v e l a n d r a i s e . R . S . M o e h l m a n : c o n t o u r e d p l a n s o f s t o p e s f r o m " P r o d u c t i o n o f N e w R u t h A r e a . " E . B . M a y o , J . L a m b , a n d W . S h a r p : M a p N o . 1 , " S u r f a c e G e o l o g y o f R u t h - H o p e a n d S i l v e r s m i t h A r e a s . " E . B . M a y o , J . L a m b , W . S h a r p , A . E . B u l l e r , a n d R . S . M o e h l m a n : " C o m p o s i t e F l a n o f O l d R u t h M i n e . " E . B . M a y o : " N e w R u t h A r e a . " P . B i l l i n g s l e y , A . E . B u l l e r : P r e l i m i n a r y m a p s , s e c t i o n s , e t c . o f O l d R u t h a n d N e w R u t h g e o l o g y . R e - p o r t s a n d P r i n t e d M a t t e r C . E . C a i r n e s : " S l o c a n M i n i n g C a m p , B r i t i s h C o l u m b i a . " G . S . C . M e m o i r 1 7 3 , 1 9 3 4 . " B e s c r i p t i o n s o f P r o p e r t i e s , S l o c a n M i n i n g C a m p , B r i t i s h C o l u m b i a . " G . S . C . M e m o i r 1 8 4 , 1 9 3 5 . E . B , M a y o : " S t r u c t u r a l S t u d y o n R u t h 5 0 1 L a t e r a l a n d W e s t S i l v e r s m i t h L o d e , " J a n u a r y , 1 9 4 8 . " S t r u c t u r a l G e o l o g y o f O l d R u t h M i n e , " 1 9 4 8 , I I 23OOOE N I 22oooe US I 1 1 ! I ! A) i s . i f <*5 I t is { \ II K \\ \ 23000 £ zzocoA 8 3 21 OOPE 21 OOP £ ZOOOOE /9QQQE 200O0E /9000E /8QOOE /7QOO£ /7000E /6000E /SOOOE X 70 38 19 No. 3 EL 4400 7 A/a 4 EL. 4247 5-io -~ - J L A/o.S - £L.399& ' 646?' TO Eb/rr^L MAP NO. 2 A SPREAD COMPOSITE PLAN 5HOW/NG GEOLOGY OF THE OLD RUTH MINE SANDON, B.C. Ceo/og/cal Mapp/ngr by Ke/ewna Exp/oraf/on Co. Sfa/rrc Compz/eaf by WAS. 5be*rp § Feb., /9SO. Scct/e: /in. =4-0 f+. V v_ Bec/a/ino ; gasf- ctnaf wesf-af/pp/no- . Fractures arno/fracture -Zones. M/nera//zoff'/on crna* sfopea'-ouf ore boo//es . /4rg////feSj or prec/om /nan f/y crra///etc eous . (puarfz/fes or prec/om in ofn f/y guarfz/'f/c. L/mes /ones or prec/o/n/nanf/y //mey. F'orphyry crna/ /ofmprop hyre. E> rc/ g - fo /c/ axes /w/ fb apparen f ro /a f/onj : Fau/f sfr/oe. n n A/o. 2 j 4494' A Z-A LONC/TUD/NAL PROJECT/ON HANC/NC WALL 6eoiocy OLD RUTH M/NE Sca/e /in. ^-40 ff Drawn by W.fii Snarp , /949 • No. / RUTH - 4584 ' No. Z -4494' No 3-4400' No. 4 -4Z47' \ ' \ \ ]/ . / No.S -399<>' 4 S 2>J . - -- . , . — \\\\\"--z^r . \ \ x x \ \ W \ \ \ \ \ — C ^ - V _ x x k X n  / B ZB IONO/TUD/NAL PROJECT/ON FOOTWALL GEOLOGY OLD RUTH M/NE Sca/e: /in.*40f£ Prawn by W.MS /949 • X X X 7~///s /cx7/-/~c>7c yc/r? 7~o eersT*' e>/~ jRr<\ SECTION C-C /?-/ 45 &4 ' 3 - 4 ; <t*73' E/<? E~ 7*~ip SfafiCP FkV. laTera/ E/oT- To sfeeyzr/y - ro//"Tp 7?- Z ; 44&4 7?-2, 4494 ' /oc sfeey* £-c///*s; Ore- fe/rs/an frcrcTures V c7/7e/ Arec/cf/rry c/r<T<f-//ref/cotfe /7<?rsrro/ c/ss/p/o-ce. \ Zoc/e ypro/>e?£/y o7fs~ef~ Zo /70/-ffr /////<? ev/'efe/rce of e^/errs/orr of S/*e*veT/-E I ZocZe Amwt Mo. 3 de* Hr-or/Tfrrps-7?-3 j <4400 ' ; 4400 \ \ \ \ \ \ J>Zo/?ec/ 0/7 ^fetrp? f/-trc~7%/-e \, at //o /60 ' To <r#s?~ of Sec. APPffOX. POS/ TZON OF A*/S OF RECUMB. FOLV AT SECTZON. Zoca/ Sector? of S-c///o J?ee/c//srp J <42*?7 Steep Jz-/TAK 7?r, f t 6en\ steep rVc/,rs on / srSo&-£.e-r. Afor/rro/ cZ/s/?Zercr/7re-/7t c?7^ rn/s St*c/~ of /aeZe S~/~r'/re -s/'jc e^/r/^/ereenre-nt or? J-trcr/rcf. Er/efenee ofxfr/Ae^ j - /^e» e/fsjp/. or? 'ff&fk Sfr-crrrc/; A>o-t ef. of c/'/z> - s/'/z> erf /JO -4247' 7? -7/SO ScT? Zer. ; 9 ' \ \ \ \ \ \ Eeporfe d ore \ \ \ \ \ \ \ vv V ft** £/• 3996 ' \ 9 SECTION A - A SECTION B-B. (J err. steej> £ - e/'/oi Sec 0-3. X /r-s; 3996' CROSS-SECT/o/\ DETAILS OF STEWART AND OLD RUTH LODES RUTH MINE, SANDON x x ScaZe - / / / ? . -4077 Feb., /5>50 No /&200JE ft /82oo/r 

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.831.1-0053506/manifest

Comment

Related Items