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Slocan ores Gillanders, Earle Burdette 1926

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sioc/w ones 6y £Mlf BUROET7T GKUWDatS 0 Thmtt sviMnttUfd for the Dt>yr** Of HMTTft of am mth* QcrpartmmT GfOLOCY S L 0 C A H O R E S b y EARLE BURDETTE GILLAHDERS A Thesis submitted for the Degree of MASTER OF ARTS in the Department o f G E O L O G Y . The University of British Columbia, APRIL, 1926 I T A B L E 0 ? C O K T S K T S . LIST OF ILLPSTRATIOBS. IITRODPCTIQK. 1 . Object of the Study. 2 . Location of the Slooan. 5 . A c c e s s i b i l i t y . 4 . Acknowledgments. SUMMARY ASP CQHOLUSIOfiS. QEHBRAL TOPOGRAPHY OF THE SLOCAN. 1 . General Descr ipt ion and f a c t o r s Inf luencing Present Topography: a. Description. b. Streams. c. Glaciation. d. De l tas and Terraces . e . Animals and Trees . 2 . Physiographic History of the Slocan. GEfiSRAL GEOLOGY OP THE SLOCAH. 1. Geological Column. 2. Description of Formations. FISSURE SYSTEM OP SLOOAK. 1. General—Geology of the Veins. 2. Strikes, Dips, and Origin of the Fissures. II. Til. KIBSRALOQY Of SLOOAM ORBS. 1. Methods of Polishing. £. Minerals and Descriptions. 0. Relation of Minerals to Baoh Other: a. Assooiations. b. Paragenesis. 4. Deformation: a. Time of deformation. b. Textures produced. T i l l . BBLATIOB OP MINERALS TO THB BATHOLITH. 1. f i rs t Period of Mineralisation. 2. Second Period of Mineralisation. IX. RSLATIOH OP MIKERALS TO DEPTH. X- 1fTt^T<P "* TAS0B8 T 0 PBPTH. 1 . Zonal Arrangement. 2 . Secondary Enrichment. XI. BIBLIOGRAPHY. o o O o o - - -I l l LIST Off ILLUSTRATIONS 1. Pioture showing peaks Page 5. 2. Greenstone Peaks S. Idaho Peaks 4 . Texas Peak 5. Sunset Ridge 6. Glacial Lake V. Carpenter Creek S. Lyle Creek 9. Hew Denver 10. Plate I. 11. • II. IE. • III. JJJ. n IT. 14. " T. 16, " TI. 16. " Til. 17. Geological Map 18. Topographical Map To n i i n II II ti face M it n I? n n n n n i? u i t ii n i i it n i t H It It In Pocket 6. 7. 8 . 9 . 1 1 . I S . 1 4 . 1 5 . 5 6 . 60 . 6 1 . 62 . 60 . 70 . 7 1 . • 0 O 0 0 0 O 0 IY. I N T R O D U C T I O N . 1. Objects of the Study. She writer had the pleasure of spending the summer of 1985 as assistant to Dr. C. E. Cairnes, of the Canadian Geological Surrey. The work included both the general and eoonomic geology of the Slooan map area. It was at this time that the writer became interested in the ores of this district, and was very glad of the opportu-nity of studying them more closely in the preparation of a Master's thesis. It is the purpose of the writer first to des-cribe the general topography of the district, and discuss the physiographieal history of the area. The general geology will also be given, and the fissure system and the origin of the faults will be considered. Over one hundred polished sections of the ores have been made and studied closely under the microscope, and the mineralogy and various characteristics of each mineral will be given, and, as far as possible, their relations to each other. Conclusions will also be drawn as to the relation of minerals to bathollth and depth, and the relation of values to the minerals and depth. It is thought that sufficient sections were studied to give a reliable V general idea of the mineralization and association of the minerals. However, to work out an accurate idea of the values to depth would require a systematic sampling of the mines and access to the mines' assay results. 2. Location of the Sloean Map Area. The Sloean map area comprises an area of twelve by twenty-five miles, situated in the Selkirk Range of Mountains. It lies between the Sloean Lake on the West, and the Purcell Trenoh—in which Kootenay Lake lies—on the Bast. The Northern boundary is about one and a half miles North of Schroeder Creek, which flows into Kooten&y Lake. The Southern boundary is about one mile South of Kaslo on the last and four miles South of Silverton on the West. The principal towns in the district are Kaslo on Kootenay Lake, Sew Denver and Silverton on Sloean Sice, and Sandon, situated in the heart of the area en the South fork of Carpenter Creek. 5. Accessibility. The Sloean district is reached from Belson by boat to Kaslo, or by rail to Sloean City and then by boat to Silverton, Kew Denver, or Bosebury; from the main line of the Canadian Pacific Bailway via Revelstoke, Arrowhead, VI. and Hakusp and from Bakusp by the Kaslo-Makusp branoh of the Canadian Pacific Railway, which runs through the area; from the Crow's Best branch of the same railway via Kelson and Procter. The area itself is well supplied with wagon roads to different mines, and trails everywhere, which makes travelling comparatively easy. The topography of the oountry is characterized by fairly level and contin-uous ridges, which extend above timber lined and form a natural thoroughfare for our field work. 4. Acknowledgments. The writer is greatly indebted to Br. C. B. Oairnes, of the Canadian Geological Survey, whose loan of specimens made the paper possible. He was found to be always willing to give assistance, which has been ap-preciated. This opportunity is also taken to thank the staff of the Bepartment of Geology at the University of British Columbia, especially Bean Brock, Br. Schofield, and Br. Burwash, for help at different times. Mr. frelelgh 1*. Osborne is also thanked for some hints as to grinding and polishing. - 1 -S U M M A R Y and C Q H Q L U S I Q H S . 1. It was found that the topography obtains its charac-ter, (such as sharp jagged peaks in the granite), from the underlying rocks. It is thought, however, that the main features of the topography are due to structures es-pecially sheer zones, along which the drainage has out down. Evidences of regional glaciation were not promi-nent in the area, although this factor may have helped that of peneplanation to give the peaks their similar elevations. Valley and mountain glaciers have been very aetlve in the area. 2. Since this papier is more concerned with the ores of the area, the physiographical history is given only briefly, as follows: There is a period of sedimentation until about Middle Jurassic time. Then the Juraside Revolution took place, and our history changed to one of eriision, which is believed to have reduced the land surface to a peneplain in Early Tertiary time. This old land sur-face was again raised in the Eocene by the Baramide Revolution, and the present topography has been carved from it. - £ -2. the latest interpretation by Bancroft of the geolo-gical history is as given on page z* of this paper. 4. She fissure system In the Siocan is thought to he mainly due to the stresses set up during the erogenic movements of the Juraside Revolution, which preceded the intrusion of the Kelson granodlorite. 5. Both native silver (secondary) and gold in the area as well as native arsenic just outside of the area.occur. 6. The galena is closely associated with the high grade silver minerals, freibergite and pyrargyrite. It is generally gneissic, and in places a peculiar fine grained variety ("yonngite or black ore") has been formed. The sphalerite is also observed to be fine grained. f. There is believed to have been an overlapping of deposition between the sphalerite and chalcopyrite, the ohalcopyrite being deposited contemporaneous with and la-ter than the blende. 8. The ruby silver is thought to be> mainly of super gene origin. 9. The paragenesis of the oommon minerals in the ores is: pyrite, siderite, sphalerite, chalcopyrite, (overlaps with the blende), tetrahedrite and - 2 -freibergite, galena, ruby silver, ealeite, ehaleoeite (secondary). 10. It is believed by the writer that the ores in the Slocan were deformed during the Laramide Revolution. This has developed, commonly, the gneissie and breceiated texture in the ores. It was also responsible less com-monly for the formation of exoeedingly fine grained lead and zinc ores. 11. There is a rough zonal arrangement of the minerals on this northerly flank of the batholith. It was found that there is a decrease of pyrite with an increase of galena and sphalerite, and a gradation from quartz, through siderite to ealeite, out from the batholith. IE. The minerals vary with depth. It is found that: a. Quartz, blende, and pyrite become more plentiful with depth, with a lessening in amount of the galena and siderite. b. Freibergite becomes less with depth pre-sumably due to the decrease of galena. c. Ruby silver is more abundant in the up-per portions of the veins, due to se-condary enrichment. The argentite and native silver are also secondary. 13. Silver values are largely associated with galena, due to the inclusions of high grade silver minerals, freibergite and ruby silver, in it. Thus the values decrease with depth as the lead ore and freibergite de creases and as the secondary ruby silver becomes less. o o o 0 o o o - 5 -GEKERAL TOPOGRAPHY of the S L O C A H . Description and Factors Influencing Topography. a. Description. The Slocan country is one of high relief, with the peaks and ridges rising at least four thousand feet above the valleys. These ridges and peaks vary little in eleva-tion, and when one stands on a summit and looks around him, he cannot hut think that once these peaks represented parts of an al-most level surface. Showing Peaks. Hence the present topography is the result of dissection of a relatively level surface - 6 -or peneplain which has been uplifted. The topography is related largely to the underlying rook and probably to a great extent to the structure. The under-lying rook is the factor that lends the cha-racter to tthe individual peaks, but the struc-ture is the factor that has given the topo-graphy its major aspeots. There are three principal varieties of rook in the area: intrusive granodiorite, Slocan series of slates, and the Kaslo schists. These all have somewhat characteristic topography. That of the granite and Kaslo schist areas is si-milar enough to allow them to be considered together* They are normally very rugged, and present precipitous ascents on practically all sides* They also have been more resistant to erosion, and so we have lit. Carlyle, 8,600 feet. Greenstone Peaks. - 7 -and highest peak in the area, in the gra-nites, and lit. Jardine, 8,500 feet, in the greenstones. The peaks made up of the Slocan series generally present a more gra-dual flowing ascent than the granite or greenstone peaks. In the oase of Idaho peak there is a gradual slope on all sides, giving it the appearance of a pyramid. Idaho Peak. Shey are not often symmetrical, however, but as a rule have uniform slopes on three sides with a fourth side that is broken off sharply, - 8 -often presenting a sheer wall with a long slope at the bottom. Texas Peak. This steep face is often present on the flortfc-East side. It is well exemplified in the ridge running in a Borth-Westerly direction between Sandon and Selkirk peaks, and also In Seco and Texas Peaks. In these, the South side has a gradual slope, but the northerly side is vary precipitous. The steep slope is not always on the Morth side, hut it is thought that the slope is steeper if the trend of the ridge is parallel to the strike of the strata, than if it is at right angles to the sedimentation. These ridges - 9 -are often flat on top, and covered with grass and mountain plants, as are also the more gentle slopes. A few of the peaks are surrounded by steep slopes on all sides, and have a very serrated and saw-toothed crest. The elevation in the area ranges from 1,750 feet, the height of Sloean and Kootenay Lakes, to 8,670 feet, the elevation of Mt. Carlyle. b. Steams, Since this is an uplifted and dis-sected peneplain, it is, naturally, the ao-tion of the streams that has developed this present topography to a large extent. It is thought that these streams hear some relation to the underlying structure. It is evident - 10. -in the Slocan that there are two main direc-tions of faulting, one Hortheast-Southwest, the other Uorthwest-Southeast. If the map is studied, it will he noticed that the main drainage has a Morthwest-Southeast and fiortheast-Southwest trend. It is thought that these very probably follow zones of weakness or sheer zones. It is also rather interesting to note that the four main creeks of the area, namely, Carpenter and Seaton Creaks, Four-Mile or Silverton Creek, Kaslo Creek and Mansfield Creek, form a rough pa-rallelogram, and the remainder of Carpenter Creek is roughly parallel to the Eorthwest-Southeast sides. The influence of the rock types is shown by the way the lower part of Kaslo Creek follows the Kaslo schists. Of course, all the drainage is not localized by these faults, since we have small creeks flowing down from a large hill like Beco Mountain, with a very steep gradient. These streams pay no attention to structure. How-ever, it must be remembered that these minor streams are small factors in the pesent topography. • 11. -Evidences of exceptionally intense glaoiation are lacking in the area. Bo gla-cier erratics or striated bedrock were found on the peaks. Brock (n1) has noted much re-gional glaoiation in the district. There has been extensive mountain and valley glaoiation. The mountain glaoiation is probably best ex-emplified on Dago Creek, which flows down from Mt. Carlyle, having its source in the small gla-cier that still remains there. On Dago Creek there is a series of glacier oirques containing small lakes with rock-rimmed margins (pater nofcer type.) Glacial Lake. nl Brook, R. W., Geol. Surv. Can. Summ. Rept., 1899. - 12, -There are four of these lakes on Dago Creek, and above the upper one is the remnant of the glacier. Cirques also occur singly as in Eeco Mountain, where there is a small' glaoier remnant left. These glacier cirques usually occur below sharp peaks or di-vides, and are narrow and surrounded by steep walls. The basins below the baoader divides, or cols, on the other hand, are bounded by more gentle slopes, have broader floors, and as a rule are carpeted with a luxuriant growth of grass and flowering mountain plants. These basins make Ideal camping places, affording good feed for the horses, and easy access to work on the summits. The summits are the ideal places to work in this area, on account of the almost con-tinuous exposure of the rooks. In the basin of Tvd.ve-Mile Creek there are a few long lakes occupying steps in the basin floor. This is a common thing in valley glaoiation. Truncated spurs are also noted in the area, especially in Carpenter Creek above Sandon. - IS. -Here the valley is modified to present the broad "U" type. This valley glaciation has also de-veloped hanging valleys. These are developed by the glacier broadening and. deepening the main valley, thus truncating the mouths of the tributary valleys, and leaving them in a hanging attitude. On Carpenter Creek these tributary valleys have not cut down to enter the main stream at grade, but enter it with a very steep gradient. In a good many of the streams, how-ever, there is a large, broad basin at the head, but nearer the mouth they have cut down, or graded themselves, forming a box-shaped canon at the mouth. This is well shown in Eossiter, Twelve-Mile, Lyle, and Carptanter - 14. -Creeks. Lyle Creek. The best example is the Denver Canon ©n Carpenter Greek, just above Hew Denver. Deltas and Terraces. Another feature in the topography is the terraces. One terrace fellows along the sides of Easlo Creek, being especially well marked in the vicinity of Eossiter Creek. When this is traced eastward, it is seen to join with the upper terrace at Kaslo, which is un-doubtedly the old Kaslo Biver delta. Similar, although smaller terraces occur around Silverton, Carpenter, and Wilson Creeks. The terraces are - 15. -made tip of roughly bedded gravels with inter-beds of sandy material. Thus it appears at one time the streams were about two hundred feet higher, since that is the lavel of the terraces. The streams have since cut down through these old terraces, and are now engaged in build-ing a delta at the present lake level. It is on these lower deltas that the towns of Silverton, Bew Denver, and Hosebury on Slocan Lake, and Kaslo on Kootenay Lake are built. In faot, these are the only level spots in the area on which to build a town. Sandon, the one town in the interior part of the area, was so limited for space for the town site that Carpenter Creek was made to flow/ in a covered flume, the roof of which forms the main and practically only street of the town. - 16. -•• Life. The country is not heavily wooded, except in isolated patches, where good timber is found. The prinoipal tees are larch, Douglas Fir, and several species of pine. The deltas of the country are far-famed for their fruit, a Kaslo man winning first prize at Wembley for his cherries. The principal animals native to the district are the Virginia and mule deer, porcu-pine, marmot, (whistler or ground-hog), marten, skunk, weasel, gopher, chipmunk, beaver, red squirrel, black, cinnamon, and grizzly bear. There are also many birds, such as partridge, blue and willow grouse, ducks, hawks, bluejays, whisky jacks or camp robbers, ptarmigan, as well as many smaller species. Pish do not seem to be very plentiful in Slocan and Kootenay Lakes, but small rainbow trout are numerous in Fish and Bear Lakes. Z. Physiographies! History of the Slocan: Schofield (n1) gives a history of the Selkirk a* Schofield, S. J., Geol. Surv. Can. Mem. 117, 1918. - 17. -and Rocky Mountains. It is upon this foundation that the writer will build up the physiographical history of the Slooan. The following sedimentary and igneous forma-tions occur in the area: Quarternary Mesozoic Palaeozoic Recent ani Pleistocene. Unconformity Upper Jurassic Intrusive Contact. Jurassic Intrusive Contact. Jurassic Disoonf ormity. Upper Carboniferous. Conformity Carboniferous or Pre-Carboniferous. Stream and Glacial Basic dykes. Aplite " Helson grandio-rite. Kaslo Schists. Milford Series Slocan series. Ainsworth series. The ages given the formations in the preceding table are those assigned to them by M. P. Bancroft (n1). By this table we see that the physiographical history dates back to Palaeozoic and very probably to Pre-Carbo-niferous times. The Ainsworth represent the oldest series of rocks in the area. They consist of mica schists, quartzites, and silieious limestones, and so are undout-edly of marine sedimentary origin. Thus we have as our n1 M. P. Bancroft, Seol. Sur. Can., Summ. Rept. 1919, p.39B - 18. -first record in the area, that of marine sedimentation. The next record in the history is the Slocan series. These are a series of quartzite, fossiliferous limestones, slates, and argillites. They have been placed in the Carboniferous, probably Pennsylvanian by fossils found by Banoroft, both in the area and in its Northern exten-sion into the Bardeau. Bancroft also reports a confor-mable contact between the Slocan and Ainsworth series, and so the Slocan series represents a continuation of the stable marine conditions that existed during the deposi-tion of the Ainsworth. At the end of the deposition of the Slocan series, however, we have a break in the sedimentation, and the whole Triassic period is missing in the area. It Is probably due to a beginning of the orogenie move-ments that characterized middle Mesozoic time. At any rate, the disturbance was not intense, and only a dis-conformity is found between the Slooan series and the Mllford series, which followed. The Milford is a small series, and consists of carbonaceous limestones and quartzites. They have been pftaced in the Jurassic by fossil; evidence found by Bancroft in the Southern Bardeau. This is the last sedimentation recorded in the - 19. -Sloean area, except for a little that took place during PleiBtooene and recent timet, and is still going on. facet later deposits are only in streams and deltas. Since the Jurassic sedimentation, the factors which give us our present topography have been active. These factors commenced to operate in Jurassic time. It was at this time that the orogenic movements, pre-ceding the intrusion of the Kelson or West Kootenay betholith, threw up the sediments, that had accumulated throughout the previous periods, into folds forming the Selkirk range of mountains. The earliest intrusion, according to Bancroft (n1), is that of very basic rook known as the Kaslo schists. This rook invades both the 81oean and Milford series of sediments. The Kaslo schists were seen by Bancroft to be out by the Nelson granodiorite in the Sardeau. Since the basic magmas are usually the first to be intruded, the Kaslo schists may be a differentiate of the Kelson granodiorite. The Helson granodiorite cutting the Slocan series is considered to be of Upper Jurassic age, and probably rune through into the Lower Cretaceous. This is the intrusion that filled the core of the newly formed a 1 Bancroft, M.F., Geol. Surv. Can., Summ. Kept. HIS, p.39B - so. -Selkirk Mountains. With the last stages of this intru-sion, we have the dykes intruded, and veins formed in the fissures which were developed at the time of folding of the sediments. The middle and Upper Mesozoie repre-sents a long period of deformation and intrusion. Thus with this movement we have our. history-changed from one of sedimentation to erosion. The pro-ducts derived from the erosion of the different rocks in the Selkirk Mountains formed a great thickness of sedi-ments in the great basin from which the Rooky Mountains evolved. Among these sediments we first find granodio-rite pebbles in the conglomerates in Upper Blairmore, which is part ©f Upper Cretaee©us time. This erosion went ©n Rigorously until early Tertiary time, when the eld land surface was reduced to a peneplain. This condi-tion is shown by the brackish and freshwater sedimenta-tion at this time in the Rocky Mountain.basin. In the locene, we get the beginning of the Saramide Revolution which built the Rocky Mountains; and uplifted the peneplaned Selkirk range. This revolution had the intrusion of the Valhalla granite associated with it. There is probably a small stock or so of Tallialla granite in the Borthern part of the Slocan map area. When the old Mesozoie land surface was uplifted in Eocene - 21. -time, the streams were rejuvenated and cut down in their old beds to give the; youthful topography that now exists in the Selkirks. Schofield (n1), in considering the origin of the Purcell Trench, states that it bears no relation to structure, and is the result of an antecedent river during Tertiary and Quaternary time. In the Sloeanthe writer thinks the drainage is largely influenced by structure. This cannot be compared with the Purcell Trench, which runs approximately Borth and South, and bears no relation to the Bortheast-Southwest and Borthwest-Southeast fis-sures of the Slocan. The Purcell Trench also appears to bear no relation to the structure or trend of strata. la the Sloean the writer considers the fissures are the chief factors influencing the drainage. These fissures were formed during the folding of the sediments in the Jurassic. These streams may have been antecedent to the uplift, and were before localized by these zones of weakness. n 1 S. J. Schofield, Geol. Surv. Can. Mem. 117, p. 60. - 22. -Table of Physiographica! History, Pleistocene and Recent. —Erosion—small streams and glacier deposits. Tertiary —Eocen® Erosion—uplift of peneplain —Early Tertiary Erosion—peneplanation. Mesozoic Cretaceous(Upper)—Erosion—inroofing of batho-lith maturity. Cretaceous(Lower)—Erosion—youth to maturity. Upper Jurassic —Erosion—intrusion of Kelson granodiorite. Jurassic —Erosion—orogenic movements of the Juraside Bevolution. Jurassic —Sedimentation—probable beginning of -—Triassic —Quiescence—orogenic movements Palaeozoic—-Carboniferous—Sedimentation—stable marine conditions. —Pre-Carboniferous—Sedimentation—stable marine conditions. - - - . ••« o o 0 o o - - - - -«• E J5 • •» GEBERAL GEOLOGY of t h e S L O C A U . 1 . Geo log ica l Column of S locan ; J t a l K l l B B i a - B t o e n t and n « t « t o o « . - - g j 2 u i d d S S i i t . . UNCONFORMITY. (—Upper J u r a s s i c — b a s i c dykes ) ( — a p l i t e " ) l ong pe r iod ( —Nelson g r a m d i o r i t e . ) of Meaogolo—4— ) deformat ion ( INTRUSIVE CONTACT. ) and i — J u r a s s i c —Kaslo s c h i s t s ) i n t r u s i o n INTRUSIVE CONTACT. i—Jurassic —Milford S e r i e s DISCONFORMITY. (—Upper Carbon i fe rous—Slocan S e r i e s Pa l aeozo ic ( CONFORMABLE CONTACT. (—Carboni ferous or ( P re -Carboni fe rous—Ainswor th S e r i e s . Base unexposed. 2 . D e s c r i p t i o n and C o r r e l a t i o n of Format ions : Ainsworth S e r i e s — P a l a e o z o i c . The name Ainsworth was g iven t h e s e s e r i e s t o r e p l a c e the name Shuswap used by Bawson to denote t r e -Cambr ian r o c k s i n B r i t i s h Columbia. They a re shown i n a ye l low co lour on - 24. -the accompanying Geological map by Drysdale. The series consists of mioa schists, ouartzites, silioeous limestones, with their hard bands of hornblende and garnetiferous mioa schists. Bancroft estimates the thickness of the Ainsworth series exceeds ten thousand feet in the Slocan map area. The base of the series is not exposed in the area. This series is in conformable contact with the Slocan series, and together they form a monoclinal structure. They have a northwesterly trend with about a 45° dip to the South-west. Since this series conformably underlies the Slocan series, which are of Carboniferous age (fossils), they are considered to be Carboniferous or Pre-Carboniferous also. At any rate, these rocks are not of Beltisn age, as thought by Dawson, LeRoy, and Drysdale. Slocan Series—Palaeozoic. The Slocan series is nade up of quartzites, impure dark and finely crystalline grey fossiliferous limestones, slates, and argillites. In a few places contact metamorphism has been sufficient to form andalusite and mioa - £5. -schists. All of these rocks are noted to be carbonaceous. These rocks occupy most of the map area, filling in to the South and West of the Kaslo schists. They are shown as blue on the accompanying geological map. There appears to be more limestone in the Sastern part of the area. Drysdale estimates a complete thickness of fifteen thousand feet of all of this series represented in the area* On account of the intensely folded nature of the sediments, however, much work should be done to make a reliable estimate of the thickness. This series overlies conformably the Ainsworth series. Its lowest member is a fos-siliferous limestone band that rests on the schistose mica quartz ite of the Ainsworth. Drysdale considered the Kaslo schists to be of volcanic origin, and to underly conformably the Slocan series, as shown in the accompanying geo-logical map>. Thus, to make his structure work, he postulated a fault between the Slocan and Ainsworth series. Bancroft, after rather de-tailed work in the area, cnnckided that the fault does not exist; that the Kaslo schists are of •» 86. >• Plutonic origin, thus cutting out the necessity for a fault; and that the Ainsworth conformably underlies the Slooan series. The Slocan series hare been placed in the Carboniferous, probably Pennsylvania)! age, by fossils collected in different parts of the area, and in the Bardeau. Milford Series—Mesozoic. The name Hllford, after Milford Peak, was first used by LeRoy, denoting the rocks in the syncline along the Blue Ridge. They are shown on the geological map as blue between the Kaelo schists (green), and Ainsworth series, (yellow). This series is made up principally of quartzites and limestones, and resemble very much the rocks of the Slocan series. The series is also characterized by the occurrence of flinty auartzite or cherts. Bancroft found fossils in this series in the Southern Bardwau Mountains. They consis-ted of fragments of Belemnites, and the horizon is thought to be of Jurassic age. The time break between the Slocan and Milford series is represented by a disconformity. - £7. -Jurassic Igneous Bocks; Kaslo Schists. This formation is considered by-Bancroft to be of intrusive origin, and to constitute a batholith in shape and mode of occurrence. It is considered to be a differen-tiation product of the magmas that were intruded in the West Kootenay during Jurassic time, pro-bably running through into the lower Cretaceous. The Kaslo schists do not extend far South of the Slocan map area, but broaden out to the Kortii, and are of considerable extent in the Eardeau. It has intruded both the Slocan and Milford series. According to Bancroft, the eontact is definitely that of a batholith, aad is not con-formable with the Slocan series, as Drysdale thought it was. fhe contact is characterized by a contact breccia, mistaken by Drysdale for a. squeezed conglomerate. On the Eastern side, many apophyses have been given off into the rocks of the Milford series. The rocks at the contacts are also said to be altered by haat and pressure. The Kaslo schists are made up of a complex or basic igneous material such as - £8. -intrusive hRccia , serpentine, augite and horn-blende gorphyrites, diorite and gabbro. Besides these the mass contains much seminentary rock, which Bancroft considers to be roof pendants. The schists are of Jurassic age. They cut the Milford series holding Jurassic fossils, and are cut by the Kelson granodiorite in the Bardwau, which is cnnsidered to be Upper Jurassic. Kelson Granodiorite. Just the fiorth Part of this extensive West Kootenay batholith extends into the Slocan country. . There are also a number of smaller batholiths (as by Kew Denver) in the area. This rock is shown as red on the accompanying geolo-gical map. Most of the stocks; are thought to belong to the main batholith, and join at depth. The rock grades form a granite through grano-diorite to a quartz diorite. There is also a marked difference in texture betwwen the different masses. The main mass of the intrusive in the Southern part of the area is characterized by immense feldspar phenoerysts. These do not oecur in the stocks. This is probably due to a - 29. -more rapid cooling. The stock near Hew Denver seems to have a greater proportion of salic mi-nerals than the main mass. The stock at Rose-berry is much more acidic than the one at Hew Denver. This rock in the Northern part of the area is closer to the mass of Valhalla Granite in the Gardeau, and so it is probably associ-ated with the Baramide rather than the Jurasside Revolution. There are a few roof remnants observed near the periphery of the main mass of grano-diorite in the Southern pert of the sheet. The oontaet metamorfhism has not been intense, altering the slates to andalusite and mica schists for short distances, and the limestones to crystalline varieties. There has been much more metamor-phi am in the Ainsworth series, and it iet probably due to their greater depth. There has been a lot of minor intru-sion in the Slocan. These represent the latter stages of the Jurassic igneous activity to a large extent. However, there appears to have been some pre-folding intrusion. There are many sills folded with the strata* They are probably - 80. -similar in age to the Kaslo schists. The first dykes associated with the intrusion of the main mass of the Kelson grano-diorite are aplitic in character, These were followed by an intrusion of lamprophyric dykes. The lamprophyric dykes in the area were noticed to occur cutting both sedimentaries and granite. Most of the ore deposits in the granite occur associated with a lamprophyric dyke. The ©re veins are noted to out the dykes, and so they represent the last of the Jurassic period of igneous activity. The fallowing is the possible order of the Jurassic igneous activity: 1. Kaslo schists. 2. Pre-folding dykes—mainly aplitic sills. 2. folding. 4. Intrusion of Kelson granodiorite. 5. Post granite dykes—aplite and lamprophyre. 6. Mineralization. The Kelson granodiorite is thought to be intruded during Upper Jurassic time, and pro-bably continued through into Lower Cretaceous time. The only other formations in the area * 9k» -•r« tbo«« of s e e e e » e l l i s t » l gr«r«lt ef Fl«i«toe«n« ant R«e*nt *£«. Tfc»«« *r« • • In ly o o o 0 o o e - 32. -FISSURE SYSTEM of t h e S L O G A N . It would probably give a better idea of the veins if the mineralogy was considered before the fis-sure sytem. However, the fissures antedated the minera-lization, and it is thought best to keep the historical sequence. To fill in the lack of the mineralogy, a short geological description of the veins will be given. !• General—Geology of the Veins: There are three chief types of deposits in the Siocan map area noted by previous writers. The writer will add a fourth to these. a. Fissure veins in the Granoftiorite. These veins are small. They are largpLy fissure filling, but there has been some replace-ment, and in many eases they have the appearance of a shear zone. They are mineralized chiefly by argentiferous galena, freibergite, sphalerite,v ehalcopyrite, and pyrite, and native and ruby silver with a quartz ganguei. They do not differ much from the deposits in the Siocan slates, save far smaller proportions of lead and zinc ore - 32. -and a greater percentage of the high grade silver minerals. Their chief difference from the Slocan slate deposits is that they have a quartz gangue while the others have a siderite gangue. They are similar to the veins in the Stocan slates in that the ore occurs in shoots. These veins are, on the whole, small, no doubt due to the compe-tency of the granite mass at the time ot differen-tial stress. b. Metasomatic Replacement of Limestone Bands in the Slocan Series. This type is represented in the area by the G«fc-Province and Luoky Jim mines. They are formed by replacement out along the limestone bands where they are interseeted by fissures. The predominant mineral is zinc blende with which is associated galena, pyrite, pyrrholite, quartz and siderite. These deposits are low in silver values. The sequence of mineral deposition in these corresponds to deposits in the shear zones in the Slocan series. c. Deposits in Shear Zones in Slocan Series. These deposits are formed both by fissure filling and replacement. These veins have been - 34. -deformed since their original deposition, and give the gneissic ani brecciated structure. The shear zones vary in thickness from a few feet up to fifty feet. The filling in these zones consists of galena, sphalerite and frelbergite, chalcopyrite, pyrite, pyrrholite, ruby silver(in the upper levels of same mines), The chief gangue is light coloured siderite, but some caloite and quartz is present. Besides this there is much brecciated country rock, large horses of slate in the veins are common. The walls are generally well defined, and often highly slickensi&ed. The ore occurs as shoots in the veins. These shoots generally have a pronounced rake. They may have been localized in several ways; i. By the intersection of cross fissures, ii. By dykes forming an impervious wall, iii. By carbonaceous slates or argillites forming an impervious layer. iv. By the precipitating Action of the carbonaceous material in the rocks. %low (n1) ascribes the shearing of one wall of the vein past the other in faming the shoots that are arranged &n echelon. The intershoot n 1 W.L.uglow, Eoon. Seol. Vol. 1£, 1917, p. 650. - 56. -portions of the rein consists of breociated country rook with mineralization in the form of siderite and small specks of sulphide. The reins in the Slocan series have strike northeast and ere characterized by a steep dip. Most of the reins dip steeply to the Southeast. The reins in the granite (a.) strike Bortheast also, and hare a steep dip either to the Borthwest or Southeast. This location of the shear zones might suggest their oontinuation into the granite-mass. The similar mineralization in types a., b., and c , certainly links them to the same source. 4. Fissure (auarts) Tains in the Slocan Series: These reins are found in the northern part of the area. The McAllister is the moat important deposit of this type. These are an en-tirely different type of rein. They are charac-terized by a quartz gangue holding mainly argentiferous tetrahedrite with small amounts of argentite. These reins are thought to be of later age than the main mass of the Slocan deposits, and are associated with the Saramlde Eerolution and intrusion of the Valhalla granite, which is about four miles to the North. It is •ery possible that the stock near the McAllister and Silver Glance mines is of lalhalla granite. Shis conclusion that these veins are associated with the Laramide is supported by the facts that: i. They have a decidedly different mineralization than these connec-ted with the Nelson granodiorite. ii. There has been no deformation in these veins. The deformation of the other veins presumably took place during the karamide Bevolu-tlon. t. Strikes. Pice, and Origin of Fissures; It will be readily noticed on examination of the geological map prepared by Drysdale that the fissures trend la two general directions. One set of these frac-tures strike Northeast-Southwest, and the other group strikes Korthwest-Southeast. Furthermore, it will be noticed that the Northeast-Southwest set of fissures carry the bulk of the productive ore deposits. This system is characterized by very steep dips. The greater number of the veins have a Southeast dip. The dips of the unmineralized Northeasterly fissures is not known. The Northwest-Southeasterly system is also characterized by steep dips, both to the North and South. - 57. -This direction of fissuring corresponds in a general way to the strike of the sediments, but cuts across the dip of them. It is characterized by the intrusion of dykes along these fissures* The dykes are earlier than the mineralization, and in many places the veins cut them. These dykes have probably in places localized the ore shoots in the veins. A few veins occur along the Horthwest-Southeast fissures, but are very unimportant economically. It is very probable that there has been a number of factors present in causing the shear zones. The most important factor is thought to be the stresses that were set up during the exogenic movements preceding the intrusion of the Helson granodiorite. At this time the sediments in the Slocan map area were thrown up in folds running in a direction a little West of Kofcth. That is;, there was a great horizontal shortening fr©m West to last. Thus the stress that deformed the sedi-mentary rocks in the area was a congressional stress. When the Slocan series had become tightly folded, they became more competent, and since they could not fold any more, they found relief in rupture. This rupture, produced the bulk of the fissures in the Slocan. This formation can be explained by the strain ellipsoid idea — 58 • — for a non-rotational compressional stress: nofin-H \N£ST >. Stress Axes. (HP-- greatest. SB'—lis an. AA.' —least. Eft sT Strain Axes. AA'—greatest. BB1—mean. CC —least. In applying the strain ellipsoid to these fis-sures, it mast be remembered that they were formed during an orogenio epoch, when there was considerable stress from below, as well as lateral stress. This stress from below will give the elongation of the strain ellipsoid vertical and produce the fissures, as shown in the block diagram. Schofield (n1) postulates a pressure from the West. Thus if you denote your non-rotation pressure by an arrow from the West as shown on the block diagram, ac-cording to the strain ellipsoid we shall get Hortheast-nl S. J. Schofield, Bull.Trans.Can.Inst, of Min.fc Met., Vol. 1925, p. - 39. -Southwest and Horthwest-Southeast fissures produced. This idea for the formation of the fissures is strongly supported by the fact that there has been a very marked horizontal shortening as well as uplift in the area. There has been much igneous intrusion in the Sloean district. The main West Kootenay batholith ex-tends into the Southern part of the area, and there are a number of stocks and numerous dykes throughout the area. This suggests not an exceptionally great depth of se-diments. Consequently, they would become quite heated at the time of intrusion. Then on contraction due to cooling, they would crack. This factor may be of some importance in the district, especially near the con-tacts of the main batholith and stocks. Especially the fissures in the granite might very well be developed tensionally, due to contraction by cooling. However, the few veins occurring in the granite in the Sloean have a general northeast trend, and are probably due to a regional stress. The question arises as to why only the Hortheasterly fissures carry ore shoots of eommereial im-portance? This may be explained in a number of ways: 1. Bateman (nM, after a detailed study of . . . . . . . . . . . . . . . n 1 A.M.Bateman, Beon. Geol. Yol.XX., 19£5, p. 557. - 40. -several of the mines in the district, concluded that the Northwest fault fissures are much more discontinuous, both horizontally and vertically, than the Northeast fissures. £. It will be noticed from the map that the northeasterly trending fissures are nearly at right angles to the granite. The Northwesterly fissures tend to flow around the granite with the sediments, and so would probably not out it. 5. Many of the Northwest fissures are fcarma-tional dips or nearly so. This would tend to a sliding along the bedding planes, producing gauge rather than a shear aoross the bedding planes producing a breccia. It is obvious, then, that the Northwest fissures would be much more impervious to mineral bearing solutions. Thus it Is i thought that the Slocan sediments have undergone strain (Northwest-Southeast and Northeast-Southwest fissures) to a non-rotational stress from the West of Southwest. It is observed that only the North-easterly fissures carry ore deposits. - 41. -MIKERALQGY of the SLOG AH ORES. 1. Method of Polishing; She sections studied were polished on the University lap. She coarse grinding was done on a steel plate with #180 emery powder. It was founa that the beat results were secured if the emery were not too wet when applied, and if the specimen were worked from the centre to the circumference of the lap. Considerable pressure should be applied, and the specimen rotated to prevent deep scratches appearing in one direotion. She next grinding with the #805 emery can be done in the same manner as the first, on a steel plate, or by hand on a glass plate. She latter has several advantages. In the first place, if the steel laps are worn, as the University ones are, you cannot secure a perfectly flat surface with-out the use of the glass plate. A flat surface is neces-sary for a uniform polish. She glass plate iB better also for cutting down relief between two such minerals as quarts and galena. It also prevents the formation of large pits in a mineral like galena, because the grinding is slower and gentler, and naturally does not tear the surface along cleavage lines so severely. Finally, grinding on the glass plate is as rapid as changing steel «• 4£. m plates. The final polishing Is done on a cloth-covered lap* The hardness of the mineral determines the polish to be used. If the mineral is hard, lite pyrite, it is best to use chromevlm oxide on a linen lap. If the mi-nerals are soft, like galena and sphalerite, a good po-lish may be obtained with rouge on a broadcloth lap. If you have both hafcd and soft minerals in one specimen.it is better to use the chromium oxide before going on to use the final polish with rouge. The polishes should be used in the form of a thick paste, and run until quite dry for best results. Considerable pressure should be applied, but the time of polishing should be brief, as it develops toe much relief between hard and soft mine-rals. About thirty seconds on the rouge wheel will suf-fice for galena. 2. Minerals and Descriptions; The following minerals occur in the Slocan: a. Hatlve Metals; Arsenic--As. fiafcive arsenic is reported to oc-cur in the I». H. mine near Silverton. According to the owner, Mr. A. B. Pingland, the native arsenic is found in kidney-like forms associated with calcite. fiative arsenic is tin-white on fresh fracture, and tarnishes dull grey. Mo specimens of L. H. ore were - 43. -examined. 2. Gold—An. fiative gold was found by the wri-ter in a specimen from the Phoenix claim, near Retallack, and is- reported to occur in visible amounts in the L. H. mine. In the 1. H., the gold occurs in quartz associated with pyrite, pyrrholite, and arsenopyrite. In the Phoenix claim, the gold occurs free in quartz that also contains bright pyrite cubes. This is the only deposit of this type in the Slocan, and is situated in the Kaslo schists. The vein strikes Borth 40° West, and dips steeply South-West. The gold was seen as microscopic particles in the quartz. 8» Silver—Ag. fiative silver in the Slocan mines is of relatively small amount. It is said to occur in the ore in wire, leaf, and shatty forms. It was found by the writer in small microscopic masses imbedded in argentite, and in one instance in galena. This was in a specimen from the upper levels of the Hewitt mine. It is also reported from the Van Roi, Richmond-Eureka, Rambler-Cariboo, Flint, Granite King, and Utica mines. In the Hewitt mine, both the argen-tite and native silver are deposited along cracks in the ore, and are considered to be secondary. Native - 44. -silver is found in the joint planes of th® rock below the ore shoots in the Utica mine, and is no doubt of secondary origin. Silver is also said to occur in the blende, but more often in galena, (nl) b. Metallic Mineral8 (predominating). 4. Galena—fbs. Galena is very widespread in the area, occurring in practically every mine except a couple of quartz-freibergite veins and one quartz-pyrite-gold vein in the northern part of the area. The lead very often occurs as lenses in the vein, ill varieties of galena are seen,from a coarse cube variety to steel galena. Much of the galena is what has been described by V. L. Uglow (n2.) as gneissic galena. This is produced by a deformation in the vein after the primary ore deposition. Much of the so-called steel galena has been produced in this way. Deformation has even gene farther than that, and has produced an almost amorphous variety of ore, prin-cipally galena, which is locally called "youngite". These fine-grained lead ores will be discussed later under ore tefttures. n£ Report of the Zinc Commission, p. 228. n* W. L. Uglow, Boon. Geol. Val. 12, 1917, p. 643. - 45. -She galena of the diatriot is supposed to be In itself argentiferous, as shown by analyses in the %>ort of the Sino Commission. Galena generally always contains small specks of frelberglte in it, as well as ohaloopyrite, and in the rioh ores it seems to be the main host of ruby silver. Galena is, then, thought to derive its principal values from its in-clusions of freibergite and ruby silver. 5. Sphalerite--(Zinc Blende)~ZnS. The sphalerite in the Slocan ocours massive, and orystal forms are very rare. However, crystals are seen to protrude into vuggy spaces in the massive zinc ore of the lucky Jim and Texas properties. Also some very nearly pure and amorphous zinc ocours in the district. The writer believes this ore was formed in the same manner as the "youngite". She zinc blende is present in practically every mine in the Slooan, generally associated with siderite and galena. The Cork-Province and Lucky Jim mines, which are formed by metasomatic replace-ment along limestone bands, are the best examples of massive zinc ore. The zino blende itself is re-latively pure, and oontains very little manganese. It is characterized by minute specks of ohaloopyrite - 46. -•eattered all through it. Silver values derived from lino ore are thought to he due to a fine sprinkling of galena or grey oopper or both through it. In the Utioa mine, the blende carries exceptionally high values, it is seen to contain many minute re inlets of ruby silver. 6. Tctrajhedri;ue--Tane1^ freibergite (Cu.Afi^ SbgSjy The tetrahedrite of the area is definitely shown to be the freibergite variety by an analysis on page 258 of the ftport of the Zino Commission. The freibergite la found mainly In large and small masses in the galena. It is less often found associated with sphalerite. It is massive, and has a steel grey co-lour. In the dry ores, it forms masses and reticu-lating veinlets In the quartz. In these dry ore veins, such as the McAllister and Silver Glance, it often has argentite associated with it. c. Subordinate Metalllo Minerals; 7, Angles!te—PbSO/. Anglesite is very rare in the area, and was not seen by the writer. However, it la said to occur in the area as aystals in small cavities, and also associated with oerussite in the Wellington Mine. - 47. -8• Argeptlte (Silver Glance)—Ag«>8. Argen-tite occurs principally in the dry ore veins of the Slooan, associated with freiberglte and quartz. This argentite is of hypogene origin. It was also noted by the writer in the upper levels of the Hewitt mine. Here it occurs as plates along fractures in the ore, and has very small specks of native silver Imbedded In it. Both the argentite and native silver are thought to be supergene. 9. Arsenoiayrlte—FeAeS. Arsenopyrite is of frery limited extent in the district. It occurs in the liueky Jim, Antoine, Silversmith, and 1. H. mines* The L. H. is the only place where it is present in any quantity. In theAntoine and Silver-smith it is found associated with quartz, siderite, and country rock, and generally has its orystal form. 10. Azurite (Blue copper Carbonate)— % Cu QOp.Cu(QH)p. This mineral is not of widespread occurrence, and is found only in small amounts. It occurs in the oxidized portion of the veins, and results from the decomposition of ohal-copyrite or freiberglte. It was most noticeable in a specimen of oxidized ore from the Beaver claim. 11. Cerrusite—-White Lead Ore—PbGOy. Gerrusite is quite plentiful in some of the mines, such as the - 48. -Wellington, Beaver, and a prospect called the Raibow, situated near the Utica Mine. It usually occurs mixed with impurities in a clayey gauge. 18. Chalcocite—Copper Glance—CuS?. Chalcocite was found by the writer in the Van Roi, Eagle, Mammoth, Standard, Apex, Whitewater, Flint, and McAllister Mines. It is in relatively small amounts. It is secondary to both chalcopyrite and tetrahedrite. It was seen veining grey copper and sphalerite, and also seen to replace calcite and galena. Senerally, however, it forms a layer aroiafl the chalcopyrite and grey copper. Another very cha-racteristic form is its occurrence along on both sides of ealcite veinlets cutting the grey copper. This was well shown in the McAllister ore. It is also seen to occur the same way around a calcite veinlet in the galena. In this case, the galena seemed to be replaced. IS. Chalcopyrite—Copper Pyrites—CuffeSg. Chalcopyrite is widespread in the Sloean mines, but is never in great amounts. It is found principally with the sphalerite, but also with galena and tetra-hedrite. It is older than the tetrahedrite,and ga-lena. It occurs as residual masses in the galena. - 49. -With the sphalerite it adopts the form of minute specks haphazardly arranged in the blende, or as small specks arranged along straight lines, or as minute veinlets cutting the blende, from this fact, it is thought that the chalcopyrite is in part con-temporaneous with, and in part later than, the sphalerite. The chalcopyrite is not argentiferous, and the ore is said to be lower grade when it is present. 14. Covellite—CuS. This mineral is rather rare in the district, but was seen to occur in the Mommoth, Beaver, and Kuth mines. Its occurrence is similar to that of chalcocite, and is thought to be a further enrichment from chalcocite. The mineral is seeondary, and generally associated with chalcocite. 15. Jamesonite—Sulphantimonide of Lead— 2PbS.Sb9Sg;. This mineral was not seen by the writer, but is stated to occur in the area. 16. Limonite—2ffepQg.gHg0. Limonite is usually present in the oxidized zone of the different veins. It is derived from the oxidation of the iron pyrites in the ore. In the Beaver some limonite in erystal form was seen. It appeared to be a pseudomorph of limonite after platy marcasite crystals. - 50. -17. Malachite—Green Copper Carbonate— 0u0oy.0u(OH)p,.This mineral is found in the oxidized portions of some veins. It takes the form of coatings and small concentric masses. It is associated with azurite, and derived from the decom-position of the primary copper minerals. 18. Manganese oxides (wad or Pyrolusite and Manganite). This mineral is found in small streaks and masses filling oracks in siderite and quartz. These are probably derived from the manganese content in the siderite. Wad also occurs in quite large bodies along the North side of Kaslo Creek. Here it has been de-posited in bogs. 19. Melanterite—FeSo4.7HpO. A white coating thought mainly to be melanterite on account of its greenish tint is found on the walls of many of the old workings. It is derived from the oxidation of the pyrite. 20. Proustite—Ruby Silver--Ag?AsSR. This mineral is stated to occur in the area by A, M. Bateman. It is not readily distinguished from py-rargyrite when in small masses under the microscope. The writer belives the ruby silver in the Antolne to be proustite by colour and chemical tests. This - 61. -belief is also substantiated by the occurrence of arsenopyrite in the Antoine ore. This mineral, however, is very rare in the area, the antimony variety being predominant, and associated with the antimony variety of grey copper. 21. Pyrargyrite—Ruby Silver—AggSbS^. Thi s mineral is quite widespread in the area. It is most abundant in the Van Eoi and Hewitt and other pro-perties near the granite. It occurs in the Metallic, Ifacky Thought, Jackson, Fisher Maiden, Utica, Richmond-Eureka, Mountain Con, Idaho, Silversmith, Bosun, Rambler-Cariboo, Standard, Comstoelc-Virginia. It is moat abundant in the upper parts of the veins. The ruby silver is found as streaks or films in the fraotures in the lead and zino ore. In most cases it is associated with the lead ore and occurs in the galena as small masses or as small veinlets following the cleavage planes of the galena. It is also seen to vein sphalerite, tetrahedrite, stibite and quartz. In some cases, such as the Utica, the blende seems to carry more silver than the lead. This acoounts for the exceptionally high silver values in the Utica zinc ores. In the Hewitt mine, there is a good deal of ruby silver associated with stibnite, - 52. -In this case the small Veinlets occur running paral-lel with the needle-like crystals of the stibnite. The ruby silver is best developed in the Hewitt mine, where it often is found as clusters of beautiful crystals associated with calcite in vuggy spaces in the quartzose ore. The crystals, when held up to the light, are a ruby red odour. 22. Pyrrhotite—ffe^.^. Pyrrhotite is not a common mineral in the area. It was seen by the writer to occur in the Van Boi, Lucky Thought, Jackson, Bisher Idaiden, Richmond-Eureka, Wonderful, Silversmith, Bosun, and Lucky Jim. It appears to be associated with quartz and blende, and is more plentiful in the lower levels. £3. Pyrite—Iron Pyrites—FeS«?. This mineral is very common, but is seldom found in large amounts. It is found t@ be practically always the oldest mineral present. It also occurs as perfect cubes, widely desseminated through the Slocan series. In one mine, the Phoenix, it is the only sul-phide in a quartz vein. Here it probably carries a little gold, although free gold was seen in the; quartz. In the silver-lead-zinc veins this mineral is - 53. -desseminated through the ore. It is seen t© in-crease in depth with the increase in quartz andl de-crease of the galena and siderite. Pyrite is also found to be most plentiful in properties in or around the granite. The presence of this mineral in the outcrop of the veins is probably a very important factor in the formation of the secondary charbonate ores. It was probably active in the formation of secondary ruby silver as well. It most commonly is fiound as small masses or grains in the other minerals, but in some places it is seen to form veins. In one instance the pyrite was seen to traverse the sphalerite. This would constitute a second genera-tion of pyrite after the blende. This second gene-ration of pyrite is thought to be very limited. In the Rambler-Cariboo the pyrite is supposed to be rich in silver. This is not due to the pyrite's carrying silver values itself, but to a fine inter-mixture of freibergite with it. 84. Rhodonite—MnSjOg. A vein carrying rhodonite occurs in the Kaslo Schists near Zwicky. The vein is irregular, ranging from a few inches to several feet of solid rhodonite. This type of deposit - 84, -Is probably the souroe of the bog manganese mentioaed before. The two deposits occur quite close together. 26. Btibnlte—SbgSy. Stibnite was found as-sociated with sphalerite ruby silver and quartz in ore from one of the lower levels of the Hewitt mine. It is characterized by its needle-like crystals, which have a radiating structure. It is noted to be traversed by small veinlets of pyrargyrite. 26. Smithsonite—ZnOOg. This mineral occurs as concretionary growths and coatings on the walls of old workings. It is especially well developed in the Freddy Lee mine, near Sandon, which is the oldest mint in the district. Here it attains a thickness of two or three inches. A specimen showing the concretionary struoture and general oharacter of this mineral was given to the University Ifciseum. Its most favourable place of deposition is where the water is draining from the old stopes. 27. ? mineral—plowoioes Pb.Ag.Sb.3. Bo con-clusive microchemical tests could be obtained for this mineral. It is thought to be boulangerite. It is associated with galena. - 55. -d. aGangue Minerals. 28. Barite—'BaSO^. The writer had none of this mineral in specimens that were examined. It, however, is seen in the field as a gangue with the lead ores on rare oceasions. £9. Galoite—CaCOpu Calcite is in general a minor gangue mineral in the area, although in some mines such as the Wakefield it forms practically the exclusive gangue mineral. It occurs as lenses with ore on the side of it, or as a gangue containing ore. It is also found in quartz vugs displaying perfect crystal form. In the Lucky Jlim mine it has been recrystallized from the limestone, and thus purified. 50. Kaolin—£HeO.AlaOg.&SiOg. This mineral is thought to help make up part of the gauge that occurs in some of the veins. 51. Quartz— SiQp. Quartz both the massive and crystalline forms and constitutes an important gangue, especially in the deposits close to or in the igneous rocks. In the general type of silver-lead deposits it increases in amount w£ th depth. In the dry ore veins it is practically the entire gangue mineral. - 66. -Quartz is very seldom seen in good crystal forms. These are best developed lining vugs in the Van Eoi and Hewitt. There is generally several generations of quartz shown. The last generation of quartz in the area was after the deformation of the ores, and is thought to he associated with the Laramide Revolution. 82. Siderite—FeCOg. Siderite is by far the most abundant gangue mineral in the area. It gener-ally takes the form of massive crystalline bands, and lenses, in the vein. It generally comes pretty early in the period of mineralization. It also con-tains ore as well as being interbanded with it. The mineral itself is generally light in colour, and has well developed cleavage. According to Argall, of the Zino Commission, pure aiderite car-ries no silver values. It is found to have a marked manganese content, and belongs to the variety known as mangano8iderite. This manganese gives the mineral a slight pinky colour. 5. Relations of Minerals to each Other; a. Associations. Before considering the paragenesls, it might be well to discuss the minerals that are very closely - 57. -associated to one another. Sphalerite and chalcopyrite: Chalcopyrite is found as patches in the galena. However, the common oc-* currence is with the blende. The sphalerite almost in-variably has chalcopyrite associated with it as small (microscopic) specks arranged in straight lines, or scattered haphazardly through it. The sphalerite is also seen to be traversed by minute veinlets of chalco-pyrite . Galena and zinc blende: Galena and zinc blende are closely associated, and are found in practically every specimen together. Galena and rich silver minerals: inother very close relation is that of th© rich silver bearing minerals, freibergite and ruby silver, with galena. These minerals are found almost entirely with the lead ore and exist only in minor quantities.in the other minerals. The freibergite occurs as masses in the galena. These masses vary from mierosoqpie size to those am inch or more in diameter, (as in the Silversmith). The ruby silver is seen to occur as small masses, but usually it veins the galena galena generally following the eleavage planes of the lead. Stibnite and ruby silver: Stibnite is rare in the ores, found only in the Hewitt Mine. Here it is PLATEI STiBNlTe PYRAR6YRITC A B. SPHf\L£FHTE CHfiLCOPYRtTE QUrtRTZ - 58. -invariably associated with ruby silver.which traverses it in small veinlets. (Plate I A) Besides these exceptionally close associations all the rest of the minerals are rather closely associ-ated, and it is seldom a specimen is examined that does not contain at least six minerals. Many specimens show ten minerals in rather intricate intergrowth. b. Paragenesis. The age relationships of the different minerals is based on inclusions of one mineral in the other, by the appearance of one mineral to replace the other, and by the traversing of one mineral by small veinlets of another. Ill this way, a general similarity as to the order of deposition of the common minerals was found to exist in the area. This general order will be discussed first, and then the rarer minerals will be fitted into it as best they ean. The list of commoner minerals in their order of deposition is given as a working basis: Pyrite, siderite, sphalerite, chaleopyrite (overlaps the sphalerite), tetrahedrite and freibergite, galena, ruby silver, ealcite, chalcooite (secondary).. Quartz, which is a eommon gangue mineral, - 59. -occurs in a number of generations, and cannot he fitted definitely into the table. In the Van Roi and Hewitt mines, the last generation of quartz came in after the deformation of the ores (Plate I B ) . This generation iB thought to have brought in the primary suby silver. These mines are near the granodiorite, and characterized by a quarts gangue before the deformation. The deposits farther from the granite are characterized by a siderite gangue, and although quartz iB usually present, it is small in amount. In most of these mines, the generation of quarts after the deformation, is lacking. These veins have been badly sheared since the original depo-sition, and a gaagy vein filling has been formed, which would be quite impervious to solutions. Ihere we haye a brecciated ore, there is generally this last quartz generation present. * Pyrite is the oldest metallic mineral in the great bulk of the deposits. It is found as irregular outlined grains in all the other minerals. These grains are thought to be replacement residuals. In the zinc ore of the American Bey mine, pyrite was seen to traverse the sphalerite as small veins. Thus, in some cases we have a second generation of pyrite following the deposi-tion of the sphalerite. PLffT£J[ A. /=>YRlT£ SIDE; RITE SPHALERITE GALE MR SPHALERITE CHQLCOPYRITE: B. - 60. -Siderite is the most common gangue mineral in the ores. It is of early generation, andusually follows the pyrite and quartz in the sequence. It is seen to re-place both the pyrite.and the quartz, but is usually residual to, or traversed by, the <Mrfae* sulphides and caloite. A second generation following the sphalerite has been seen in some of the specimens studies. Sphalerite is the oldest of the economic minerals. It is seen to replace siderite, quartz, and pyrite, but is replaced in turn by galena. (Plate II A) Sphalerite and chalcopyrlte are intricately associated. The ohalcopyrite is seen to occur in the sphalerite as; (Slats II B); 1. Small haphazardly arranged pin points. £. Small specks and lenses arranged in straight lines. These lines sometimes are seen to intersect. S. Small veinlets cutting the zinc blende. These vefcLets often intersect alLso. Sometimes, however, they seem to have no general direction. They are usually straight and often occur as a series parallel and another series at an angle to them. From these faots, it has been concluded that these minerals are in part contem-poraneous, but that the deposition of the chalcopyrlte has continued after all the zinc blende was deposited. That is, there has been an overlapping in deposition. At A. j SPHALERITE 1 | TETFMHEOfflTE \ | GALEm» \ \ PYf&ttYRlTE <,:?.& 0 '•" S-T ».-!•&!* .-ic-.f-Cfr I | j QUARTZ \ | GALENA | | CALCITE B. 61. -first, the two minerals crystallized simultaneously, giring haphazardly arranged specks of ohaloopyrite. Hext there was a further deposition of ohaloopyrite occurring alone as masses (after replaced by galena), but more often replacing the blonde along its dodeoahedral clea-rages, giving the spooks arranged in interseoting and parallel straight lines, and the parallel and interseoting Toilets. The ohaloopyrite Is found as small residual masses Imbedded In tetrahedrite, thus proving it to bo younger than the grey copper. She freibergite occurs as rounded residual looking masses In the galena ore. In some cases these masses appear to be elongated, which might suggest their being younger in age than the galena. However, the evi-dence is much in favour of the grey copper's being the older, although they may be nearly the same age. The other two less common minerals are ruby silver and oaloite. fhe ouby silver is very often asso-ciated with galena, in which it oocurs as small masses or veinleta following the cubical cleavages of the galena. It is also seen to traverse tetrahedrite, quartz, and sphalerite (Plate III A) to form along a contact between galena and one of the other minerals. In the hand A GRLCfsa I I PYRFIFtGYKlTE 1 [ C0LC/TC fCilfcl'O :. ft. | | QUA&TZ \ 1 CGLCITe *• 68 • — speoimens it is seen to occur as films in cracks in the ore, and as crystals in quartz rugs (Hewitt mine). The occurrence along fractures in the cos, and following the contact of two minerals, and following the cubical cleavage of the galena, might very well be explained by secondary ruby silver being formed. The occurrence as masses in the galena, however, appears to be primary. Oalcite occurs in one or two mines such as the Wakefield as a gangue, taking the place of siderite. This oalcite is most certainly primary. However, another generation of calcite in many of the ores is thought to be of se-condary origin. It occurs as zig-sagging velnlets following the galena cleavages. It is seen to fill cracks In the quartz (Plate III B) and to have replaced the siderite out along its cleavage cracks, developing a lattice-like frame throughout the siderite. This calcite is also seen to replace ruby silver. (Plate IT A) In the tan Hoi, perfect crystals of calcite occur in the quartz vugs. (Plate I? B) Chalcocite is quite widely found in the ores. It is of supergene origin, and is always associated with chalcopyrite or freibergite. Its most common occurrence is to replace the primary copper minerals, chalcopyrite and freibergite, around its margin. It is also seen I I SPHALERITE STIBNITC QUARTZ A. | Gfll-ENA | | /9ff GENT ITE T ISRTIVE SILVER - 62. -replacing galena out from the main copper mass, and also to replace the lead along "both sides of a calcite veinlet. Of the other minerals found in the area, only four of them are of primary origin. Arsenopyrite was seen to occur in the Antoine, and also a very little in the Silversmith. This is thought to be the oldest sul-phide mineral coming in before the pyrite. Pyrrhotite is generally found to be early in the sequence, and is placed ;just before the sphalerite. Pyrrhotite is very rare in the suite of ores studied. It might be more plentiful in depth. Stibnite is found only in the Hewitt mine. In the specimen examined, it is seen to be younger than the sphalerite, and older than the ruby silver. It is seen to be veined by quarts (Plate Y A) and so it is very likely about the same age as the galena. The mineral from the Eewitt thought to be beulangerite is very intimately associated with the galena and freibergite. It appears to be younger than the galena, but on account of its close association with these other minerals, it is thought to be older than the deformation. If this mine-ral is beulangerite or some other similar lead sulphan-timanide, it is most probably that the stibnite is of - 64. -about the same age. On looking at the formula of boulangerite, (5PbS.2SbgSg), we see that this mineral is really a solid solution of galena and stibnite, and so we should expect th®se three minerals to be of about the same age. Since galena is argentiferous, probably all of them may be argentiferous. The main secondary minerals are native sil-ver, argentite, covellite, cerussite, malachite, and azurite, limonite and smithsonite. These minerals ooeur in small amounts in the ores, and are of little economic importance. A good deal off the ruby silver is thought to be secondary, and is of much, more economic significance. Argentite is noted to be foamed in flaky forms along cracks in the ore, and it holds microsco-pic specks; of native silver. (Plate Y B ) , Hative silver was also noted to occur in the galena (one instance), and in the freibergite. The covellite is associated with the ehalcooite and primary copper minerals, and is thought to be a further enrichment of the chalcocite. The other minerals—cerc&ssite, malachite, azurite, limonite and smithsonite, are mostly of superficial Arigin, and are constantly forming in the oxidized portions of the veins. - 65. -4. Deformation of Ores. a. Time of Deformation. Practically all the ores in the area have heen deformed. The question arises: When were these ores disturbed? There undoubtedly was a period of ennsiderable disturbance during the fcaramide Revolution. This Eevolution built the Eocky Mountains, and uplifted with minor folding the old Selkirk Range. This uplift may have been very gradual, but one should expect strong stresses set up during this process. This Revolution was also accompanied by intru-sion of the Yalhalla granite. It is natural that in this time of deformation the stress should find relief along the old shear zones,(now veins), thus deforming the ores. There is also a possibility that the deformation took place during the last stages of the Jurassic igneous activity. Lindgren (n*) in hisTfiineral Sepesits" says: "Crushing and brecoiation of the early minerals are extremely common; indeed but few veins are entirely free n 1 W. Lindgren, "Mineral Deposits", p. 166, 19 - 66. -"from it. Repeated opening of the fissures and deposition of new generations of vein material often take place, and the cementing ore may he enriched at the expense of the older gen©! rat ions". In some of the Slocan ores, we find a new genera-tion of quartz cementing the brecciated ore. However, there are, quartz veins associated with the Valhalla granite of the Baramide Revolution and it is thought that the new generation of quartz gangue could he better correlated with it than with the silver-lead-zinc mineralization of the Juraside igneous activity. It must also be remembered that in some of the veins in the Slooan slates, there was intense shearing, which would be mere likely due to the Laramide distur-bance than to the last movements of the Juraside Involution. Thus it is concluded that the ores were deformed at the time of the Juraside revo-lution, and the second period of mineralization was associated with the Valhalla granite. b. Textures developed. In practically all the Slocan deposits, there is a secondary texture developed. This - 67. « texture varies as to the kind of ore. In a quartzose ore, as in the Van Hoi and Hewitt, we get a breaking up or bracciatien of the ore. In this oase the ore has been cemented by quarts, and the angular fragments stand out very well. Most of the deposits did not present so compe-tent a mass, and so partly flowage (in galena) and partly brecoiation (in sphalerite and other harder minerals) took place. The result of the flowage of galena was the development of a gneis-sie texture. Carlyle (n1) was the first man to write about this texture. It and its origin are •try well described by Uglow (n2). He confined the result of the flowage of galena to the gneissic texture. The writer will show that steel or pseudo-steel galena and an almost amor-phous lead ore, (known locally as "youngite"), as well as an almost amorphous variety of spha-lerite, were formed by the deformation. Uglow concluded that the gneissic texture was produoed by the sliding of one wall of the vein past the a 1 W.A.Carlyle, Kept, of Minister of Mines, B.C., 1896,p.47 a 2 W.L.Uglow, Boon. Geol., Vol. 12, 1917, p. 643. 68. other. This eaused the vein to break in lenses, and the handing of the gneissie ore runs length-wise in the lenses. The fallowing drawing from Uglow's paper will explain the situation: re»- c/^-f-ormal'an M<?in coonTry roc/( He eoneluded that this teiture was formed by shearing, from the following data: 1. Walls are smooth, slickensided and slightly curved. 2. Ore occurs in lenses with en echelon arrangement. 3. There is a gauge of sheared coun-try rock. He also points out that the harder minerals such as sphalerite and tetrahedrite are arranged or drawn out in bands parallel to the gneissie structure. The galena is also seen to flow around these minerals, and fill in the intervening spaces. Uglow states that the stress was suf-ficient only to alter the galena by flawage and - 69. -the more competent minerals? by fraeture. This is oorreet in the great majority of oases, but where there has been a formation of "youngite" the stress has been sufficient to cause a flow and granulation of the Bine blende. Thus it is oonclided that the pseudo-steel galena and "youngite" and vexy fine grained zinc ore were formed by a severe flowing and granulation, followed by a reorystallization in an almost amorphous form. The writer advances the follow-ing arguments for this conclusion: i. The mines in which these extremely deformed ores occur present an extra amount of shearing in the vein itself. This is best shown in the Whitewater and Wellington Idines. Here the barren parts of the vein are extremely sheared, and are practically all in the form of a gauge, which presents much difficulty in mining. ii. The writer's attention was first drawn to this effect of shearing by some ore specimens seen in the field. In these, there was a gradation from a fairly coarse deformed cube texture, through diminishingly coarse gneissio texture to that of a very fine grained PLATEW COARSE neoiun Fl/Y£ A. QUARTZ SPHALERITE QftLEnfii ! i i i f . ip i'^lf DtflECT/ort OF B&MQirtG B. PYR/TE q(//9RTZ SPHALERITE MIXTURE OF GALEna (no STL Y) fi/vo BLENDE. - 70. -texture in which the gneissic structure- scarcely showed. Here the reerystallization to form new perfect cubes was not complete, "but it had the appearance of steel galena, (Plate YI A). iii. The sphalerite and even pyrite she® marked granulation under the microscope, and small bits of these are found scattered all through the galena. These have been evidently torn from the main mass, and during the flawage have become thoroughly mixed with th® lead ore. The main masses of sphalerite and pyrite themselves are drawn out in the form of sharp pointed lenses, ani in places are seen to flew around grains of quartz* (Plates YI B. and YII A ) . iv. lastly, this fact is proven by the existence, along certain lines in the ; youngite, of patches of carbonaceous material which shows marked slickensiding. ' '. '' * From the facts that the very fine grained zinc ore occurs only in veins where there has been the most extreme shearing; that it is almost invariably associated with "young^e'1 in the veins; and that it has quartz and 1 1 PYR/TE 1 QUARTZ A | | SPHALERITE | 1 rHXTUHE OFs GfiLEntf(MOSTLY) wo BLF/VDE: QUARTZ L 1 SPHRLERITE CRRBOHftCEOU /1/?T£*f?//1L - 71. -oarbonaoeou8 material drawn out or developed along parallel lines in the ore, (Plate VII By. the writer has concluded that this exceptional form of zinc ore has bean developed in the same manner as the gneissio galena and "youngite". - - - o o O o o - - -- 72. -EBLATIQH OF MINERALS to the B A I H O L I I H . 1. first Period of Mineralization. This is the period when the important ore de-posits of the country were formed. Bateman (n1) points out that there is a zonal arrangement of the minerals around the batholith. The study of the distribution of the ores both in the field ani by means of polished surfaces seems to bear out this faot. It was also found that there was a somewhat similar arrangement with rela-tion to depth. The relation of the minerals to the ba-tholith will be taken up first, and their relation to depth compared with it. The relation of the minerals to the batholith may be discussed under four heads. Of course, all of these minerals are derived from the igneous emanations given off fram the batholith, and it is their position with reference to the granite that is considered here. a. The lead-zinc minerals, galena and sphalerite, are of wide spread occurrence in the Sloean map area. They are found in every vein with the n1 A.M.Bateman, Scon. Geol. Vol. XX., 1925, p. 565. - 73. -exception of several quartz-tetrahedrite-silver veins and one quarta-pyrite-gold vein. The galena and sphalerite are found to be quite scarce in the deposits in the granodlorite itself, or those very close to the periphery of the batholith. Here they are associated with high grade silver mine-rals, and limited in occurrence. The ore is quartzose and so is a dry ore. As you go out from the batholith, the percentage of galena and blende is noted to become greater. Thus in most of the deposits in the Slocan slates, the galena and sphalerite form the bulk of the mine-ral content. Hence the percentage of lead and zinc increases as we go from the granite. b. gvrlte is found disseminated through the other minerals. It is noted in much greater abundance in the veins in the granodlorite and veins in or near the stocks, than in the deposits in the Slocan slates. It occurs quite abundantly in the Hint, Victoria (partly in a granite stock near Sandon), and in the Rambler-Cariboo, which is also near a stock. In deposits like the Silversmith, Standard and Bosun, it is of very minor occurrence. Thus it appears that pyrite - 74. -deoreases as the occurrence is farther from the batholith. e. Zonal gradation is probably b®st shown in the gangue vinerals. The veins cutting the granite or those situated close to the intrusive, are characterized by a quartz gangue. The general mass of the deposits out from the granodiorite and occurring in the Slocan series have very little quartz as gangue mineral. Whatever quartz does occur is of very early origin. Siderite has taken the place of the quartz as the main gangue mineral. In a few fissures such as the Wakefield and the Canadian, it is found that the main gangue is ealcite. On further examination of the geological map, it will be noticed that these veins occur close together in the central part of an area which has no stocks and wherce very few dykes were found to exist* In other words, these veins are probably the farthest of any in the area from a granite contact. The occurrence of this oalcite gangue also suggests a deeper basin of sediments in this particular region, thus giving a slightly lower temperature, which would be more favourable for the deposition of - 76. -caloite. Thus it is found that the relation of this generation of minerals to thebatholith may be summed up very briefly. It is found that as you go out from the batholith, there is a decrease of pyrite, with an increase in galena and blende, and a gradation from quartz, through siderite, to caloite. It was also condbided that the occurrence of a massive caloite gangue represented a lower temperature and so the veins probably are the farthest from the in-trusive contact. *• ttaaat Period of Bjneraliztion. fhiR p»riod of mineralization is much later than the first period, and is associated with the Laramide Revolution and intrusion of the Valhalla granite. We find that the otogenic movements prior to the Valhalla granite intrusion opened the old fissures, causing a deformation of the ore either by brecciation or flawage. Then the mineralizing solutions from the newly intruded magma found their way up into some of the old fissures. The best example of this second period of mineralization in the area is the formation of quartz-tetrahedrite-silver veins. These are represented by the McAllister and Silver Glance - 76. -in the northern part of the Slocan map area and by a number of similar veins in the granite of the Slocan mining division South of the area. These two occurren-ces represent a high intermediate temperature, and are quite close to the source of the mineralizing solutions. However, in the main mineralized area in the Slocan, the Valhalla intrusion must have been buried to a consi-derable depth. The secondary mineralization of the silver-lead-zinc veins consisted chiefly of quartz. This quartz is shown best in the Van Boi ana Hewitt mines, where it cements the breooiated ore and exhibits comb and vuggy structure suggesting a much lower temperature than the quartz-tetrahedrite-silver veins. There may have been a little ruby silver introduced during this period of mineralization. Thus we see that the minera-lization from the Valhalla represents emanations from below, and not radially from the batholith. - - - 0 0 O 0 0 - - -- 77. -KBLATIQH Of TEE MINERALS TO DEPTH Bo great depths hare been attained In any of the mines in the Slooan, and so no very radical changes are apparent. Also it must be remembered to work out a detailed account of the relation of the minerals to depth would require a much more complete suite of ores than were available or could be studied in one winter. However, it appears that there is a general arrange-ment of the minerals with relation to depth in most of the properties. Pyrite is seen to become more abundant as depth is gained. This is well shown in the Cork mine. With the increase in pprite there is also a tendency for the gangue to ehange from siderite to quartz. In the case of the Wakefield and Canadian mines, where there is a oaloite gangue, it is very probable that if suffi-cient depth waa obtained that there would be a gradation from oaloite through siderite to quartz. It has also been noted by Argall (n1) that the zino ore becomes more abundant in depth and that galena diminishes. The field and microscopic experience with the ores seems to bear out this statement. We have n1 Argall, Report of Zinc Commission, Mines Branch, Can. 1918, p. 168. - 78. -all the massive zinc deposits such as the Cork and lucky Jim at fairly low elevations. Mines such as the Silver-smith, which have a large galena content, also occur at fairly low elevations. On studying the geological map, it is seen that the mines situated high up are generally associated with many dykes and stocks. This point is well illustrated on Reco Mountain and also on Idaho Peak. Thus it would appear that the periphery of the intrusive was much higher in elevationAthan in points by the Slocan Star and Bosun. This would tend to give all the veins a more even temperature and a similar mineralization. It was found by the writer that the high grade silver minerals are moat abundant in the upper portions of the vein. This applies most particularly to ruby sil-ver, when it is present. The extra amount of freibergite found in the upper portion of the veins is thought to be due largely to associations. As has been mentioned before, the galena is usually more in the upper parts of the veins. This association reason would also apply to whatever primary ruby silver there is. However, there is onljr one mine, the Hewitt, where the writer has found ruby silver at depth. This ruby silver is very probably of jaypogene origin, and belongs to the second period of mineralization. There is nothing to show that the second *&** Uw r*%$ 9t\+*T it • tut*-* »- * *•:?'•' »;, *-f*;*?.-*• «tr« ** i# •Mfrntery •wrt*h»*f* . f*">•.!.* * * **** f» «s • - »**-r. f |.i *. is - 80. -THE BBLATIQH OF YALDE5 TO DEPTH Before going on to consider the relation of values to depth, it might be well to consider the rela-tion of the values to the different minerals. The tet-rahedrite of the Slooan country has been proven to be the argentiferous variety freibergite. The galena of the district is said to be argentiferous in iteelf. Ho entectios of galena and argentite were seen in the spe-cimens examined. However, it is practically impossible to get a piece of galena that has no small specks of freibergite in it. These small specks of high grade silver minerals are thought to be responsible for most of the high silver values in lead ore. Galena is prac-tically always found finely intermixed with the zinc blende. It is thought that the mixture of galena and tetrahedrite in the blende explains the silver content of the zinc blende. In the upper parts of the veins ruby silver is seen to be associated with all the ear-lier minerals, but most particularly with the 1Bad. 1. Zonal Explanation. The values in the mines in the Slocan are known to be higher in the upper than in the lower levels. This can be partly explained by the zonal arrangement. - 81. -That is, ve have seen in the relation of minerals to depth that the galena decreased with depth, with the increase of zinc, pyrite and quartz. These last three are comparatively low grade minerals. In faot, only the zinc carries any silver. The galena, on the other hand, is a high grade silver mineral, and usually con-tains other high grade silver minerals such as grey copper. The grey copper is present in the galena at depth, (as shown in the Silversmith), hut the propor-tion of galena is smaller at depth than in the upper part of the veins. Hence it is obvious why the values should he higher in the upper portions of the veins. t . Secondary Enrichment. The process of secondary enrichment is thought to he responsible for the most marked changes in va-lues with depth on the veins. Ruby silver, from its occurrence in the ores and position in the veins, was considered to be in the main a mineral of supergeno origin. We also find argentite only in the upper por-tions of the veins, and the native silver is generally associated with it. The argentite was seen to occur as plates in cracks in the ore. These minerals are de-finitely of supergene origin. These conclusions are sup ported by the occurrence of other secondary minerals, - 88. -auoh as ohalooolta and ooralllta. That It la oanoludad that tha fonoation of pyrargyrlta, argantita, and na-Xirm allvar by supargana prooaaaaa la raapoaslbla for •moh of tha lnoraaaa Lc valuas In tha uppar parts of sons of tha slnaa. Ha no a tha daoraaa* of raluaa with daplh la thought to ha ana to: 1. tonal arrangsaaot of tha clnarala. 11. Ssooadary aarlohaanv. B I B L I O G R A P H Y . Argal l , P h i l i p — Report of Zinc Commission, Mines Branch, Can., 1912. Bancroft, M. E., — Geological Survey Canada, Summary Report, 1919 and 1917. Bateman, A. M., — Econ. Geol., Vol. XI., 1925. Brook, R. W., — Geol. Surv.. Can., Summary Report, 1899. Bastin, E. S., and Laney, F. B., — U. S. G. S., Prof. Paper 104. Clarke, P. W., — Data of Geoohemistry, 1980. Davy, W. M., and yarnham, 0. M., —liiorosoopio Determination of Opaque Minerals", 1920. Drysdale, C. W., — Geol. Surv. Can., Summary Report, 1916. Leroy, 0. B., -- Geol* Surv. Can., Summary Report, 1910. lindgren, Waldeman,— "Mineral Deposits", 1919. Murdook, Joseph, — "Microscopic Determination of Opaque Minerals", 1916. Uglow, W. L., — Econ. Geol., Vol. XII., 1917. Waldschmidt, W. A.,— Econ. Geol., Vol. XX., 1926. o o o 0 o o o 


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