CIHM Microfiche Series (Monographs) ICMH Collection de microfiches (monographles) Canadian Institute for Historical IMicroreproductions / Institut Canadian de microreproductions historiques Technical and Bibliographic Notes / Notes techniques et bibliographiques The Institute has attempted to obtain the best original copy available for filming. Features of this copy which may be bibliographically unique, which may alter any of the images in the reproduction, or which may significantly change the usual method of filming are checked below. Coloured covers / Couverture de couleur □ Covers damaged / Couverture endommag^e □ Covers restored and/or laminated / Couverture restaur^ et/ou pelliculde I Cover title missing / Le titre de couverture manque I I Coloured maps / Cartes g6ographiques en couleur I I Coloured ink (i.e. other than blue or black) / Encre de couleur (i.e. autre que bleue ou noire) Coloured plates and/or illustrations / Planches et/ou illustrations en couleur D D D D Bound with other material / Reli6 avec d'autres documents Only edition available / Seule Edition disponible Tight binding may cause shadows or distortion along interior margin / La reliure serr^ peut causer de I'ombre ou de la distorsion le long de la marge interieure. Blank leaves added during restorations may appear within the text. Whenever possible, these have been omitted from filming / II se peut que certaines pages blanches ajout6es lors d'une restauration apparaissent dans le texte, mais, lorsque cela 6tait possible, ces pages n'ont pas ^t^ film^s. Additional comments / Commentaires suppl^mentaires: Various pagings. This Kent it filmed at the reduction ratio checlced balow / Ca document eat f ilm« au taux de rMuction indiqu* ci-deaaoua. L'Institut a microfilm6 le meilleur exemplaire qu'il lui a 6\6 possible de se procurer. Les details de cet exem- plaire qui sont peut-dtre uniques du point de vue bibli- ographique, qui peuvent modifier une image reproduite, ou qui peuvent exiger une modification d?*"- la m6tho- de nomriale de filmage sont indiqu^s ci-des jous. I I Coloured pages / Pages de couleur I I Pages damaged / Pages endommag6es D Pages restored and/or laminated / Pages restaurtes et/ou pellicul^es Q Pages discoloured, stained or foxed / Pages dteolor^s, tachet^es ou piqu^es I I Pages detached / Pages d6tach6es ^yj Showthrough / Transparence I I Quality of print varies / a D Quality in^gale de I'impression Includes supplementary material / Comprend du materiel suppl^mentaire Pages wholly or partially obscured by errata slips, tissues, etc., have been refilmed to ensure he best possible image / Les pages totalement ou partiellement obscurcies par un feuillet d'errata, une pelure, etc., ont 6t6 film6es ^ nouveau de fa?on ^ obtenir la meilleure image possible. Opposing pages with varying colouration or discolourations are filmed twice to ensure the best possible image / Les pages s'opposant ayant des colorations variables ou des decolorations sont film^es deux fois afin d'obtenir la meilleure image possible. lOx 14x 18x 22x 26x 30x 7 12x 16x 20x 24x 28x 32x The copy filmed here ha* been reprodixed thanks to the generosity of: York Univeriity Toronto Scott Library The Images appearing here are the best quality possible considering the condition and legibility of the original copy and in keeping with the filming contract specifications. Original copies in printed paper covers are filmed beginning with the front cover and ending on the last page with a printed or illustrated Impres- sion or the back cover when appropriate. All other original copies are filmed beginning on the first page with a printed or illustrated impres- sion, and ending on the last page with a printed or illustrated Impression. The last recorded frame on each microfiche shall contain the symbol — ^ (meaning "CON- TINUED"), or the symbol V (meaning "END I, whichever applies. Maps, plates, charts, etc., may be filmed at different reduction ratios. Those too large to be entirely included in one exposure are filmed beginning In the upper left hand corner, left to right and top to bottom, as many frames as required. The following diagrams Illustrate the method: L'exemplaire film* fut reproduit gr«ce i la gAn*rosit* de: York Univeriity Toronto Scott Library Les images suivantes ont «t« reprodultes avec le plus grand soin, compte tenu de la condition et de la nettet* de l'exemplaire film*, et en conformit* avec les conditions du contrat de fllmage. Les exemplalres orlglnaux dont la couverture en papier est lmprim«e sont fllm*s en commen?ant par le premier plat et en terminknt solt par la dernlAre page qui comporte une empreinte d'Impresslon ou d'illustration, solt par le second plat, salon le cas. Tous les autres exemplalres orlglnaux sont fllmte en commen9ant par la premMre page qui comporte une empreinte d'Impresslon ou d'illustration et en termlnant par la dernl*re page qui comporte une telle empreinte. Un dee symboles sulvants apparaltra sur la dernl*re Image de cheque microfiche, selon le cas: le symbols — signlfle "A SUIVRE ", le symbols ▼ signlfle "FIN". Les cartes, planches, tableaux, etc., peuvent »tre fllmte A dee taux de reduction dIffArents. Lorsque le document est trop grand pour *tre reproduit en un seul cllch*, il est film* * partir de I'angle sup*rleur gauche, de gauche * droite. et de haut en bas, en prenant le nombre d'Images nteessaire. Les diagrammes sulvants illustrent la m*thode. 1 2 3 MICTOCOrV KtSOlUTION TfST CHART lANSI onj ISO TEST CHART No 2) ^ ^PLIED IIVMGE 165J Ea?t Mam Street Rochester, Ne« rork U609 USA ('16) «82 - 0300 - Pttone (716) 288- 5989 - Fom CANADA DEPARTMENT OF MINES Hon. LouiB Codwihi, Minister; A. P. Low. Deptfty MinUtor GEOLOGICAL SURVEY R. W. Bbock, Director. c MEMOIR 19 No. 26. Gi£OLOQICAL SERIES Mother Lode and Sunset Mines, Boundary District, B.C. BT O. E. LeRoy VORK OTTAWA aovssNiiBNT ptasTma bubkao 1913 '.'..J. . - I -^ J 1 "• " V- r*^ ■••'*'^. -"*. *' • "■ •», " *■—. \ 1- •> *c ■V . ' •, 1-' "^ " .''■ '» •y/v- , ' ;■ ' ;i;v ■'-T" ' :.,^-Vu^- Vr/' :V^iV". |- ' ■ ■■>■"- ^^^feDr . ) - I CANADA DEPARTMENT OF MINES Hon. Leva CooMHi. MiaUtor; A. P. Low, Dnuty UmUtm, GEOLOGICAL SURVEY R- W. Broi'k, Dirrrtor. Qi MEMOIR 19 No. 26, QEOLOQICAL SERIES Mother Lode and Sunset Mines, Boundary District, B.C. »r O. E. LeRoy OTTAWA OOVKRNUBNT PRIN1..(0 Bl'RKAU IBIS N.. UM. CONTENTS. CHAPTER I, Introiturtinii (icni ml •tnti'mcBt. ,. ....''' f l.'lil >v.,rk itnil nrknowledffmrnta nltuntion Hinlory Prvviuua work nn'l Ijibliojcrnphy., . CHAPIEK n. Ocnrnl I'tmrnrtor of I S General giiiloKy UcniriU (l< .rription ut (ornmtioM I'nl:ii,/i,ic: ■ ' • Mi'wijoic •■••■ Tcriiiirj- . '.'.'.'.'.'. •.'iiutcrniirv .'.....,..' 'I ilili' i>f r>rinatinnfi. ( oiiipHnif ly. ul,|. , Oiwlwooil an.i I'hoonij '.'..". ? lJi'taili'lr)tfy ■ ■ Jii^piroiils f'hirta Tull> '.'.'.'.['.'.". Brooklyn fonimtion IntHxIuciiun , ...... I- r)i^.tril)Ution and structure. . il Litl.ol.iKy }J Ci 1 iiiical roiiipoaition }5 Quarti |»)rpliyrite '.'.'.'..'.'. 13 13 13 13 13 13 14 U 15 1« 17 Mt'sojoic luni ou» rork.f Intnnliiction Grunodioriti-^roup l)i the Brooklyn 11 formation. Tho rork in concidcrnbly nltertd ami to nome rxtrnt h:is Hhiired in the Hilifificntion wliicli hu^ [ifToit.Ml thi- formnlions it intrudes. The time of intruxion in placed proviHionully as upper I'aluHjzoic, hut nuiy be Muiozoic thougli eurli«'r than the grunodioritc of Jurassic (?) age. MESOZOIC. The granodiorite of Jurassie (?) age outcrops at neveral points and occurs in undergn-und workingM, an dyke.s and inatises seem- ingly connected will: a l.irger mass underlying the whole district. It is widc-spreud thruugliout the district and large areas outcrop in the vicinity of Deadwood (Imr. 2, p. 21). It ran-es in compowi- tion from granite to HKmzonite, granodiorite being the prevailing type. Hornblende porphyrites in a few dykes and small masses also intrude the ohler rocks. Owing to the few exposures they are not seen cutting the granodiorite, but it is pussible that they belong to ♦he Phoenix volcanic group of Daly, which is referred to late Alesozoic. They arc so placed here provisionally. TERTIARY. The Tertiary is represented by a series of intrusivcs ranging from olivine basalts to pulaskite porphyry. They occur in dykes and .-ills, and theonh'r of intrusion, commencing with tlie Idcst, is i)li\ine basalt, aupte purpliyrite, monzonitr^^ porphyry. and pulaskite porphyry. They are referred to the Miocene and are probably intrusive equivalents of the lavas of thr >rUhvay volcanic uroup, which latter is (hvclopcd in the immediate vicinity though just beyond the bordirs of this particular area (Fig. 2, p. 21). QUATERNARY. The Cordillera ice sheet covered the whole area, the general direction of movement being S. 18° E. The drift is modified and consists of clays, sands, and gr.'ivcls with rounded bouhh'rs, distributed as a mantle of varying thickness over the greater part of the area. 12 TABLE OF FORMATIONS. For purposes of comparison a tabular arrangement of the rock formations at Phoenix and Dead wood is given, following the table of formations for Dead wood. Quaternary. Glacial and Kcrcnt . . Modified drift, ctays, sanda, gravels. Tertiary Mioccner Pulaskite porphyry. (alkali syenite porphyry). IJ>yke8 and sills. Honzon:te porphyry. Dyker and sills. Auidte porphyrite. Dykes. Olivine basalt. Dykes. Mesozoir Hornblende porphyrite. Dykes and masses. Jurassic? Granodiorite. T Quartz porphyrite. Paleozoic, Carboniferous? Attwood aeries, Brooklyn formation. Ciyatalline limestone. Knob Hill group. Tufif and ash rock more or leasailicified, chert, jasperoid. Sniall leniies of argillito and limeatone. Group m part is silicified limestone of the Brooklyn formation. COMPARATIVE TABLE OF FORMATIONS. Period. Dead wood. Phocniz. Miocene I^ilaskito porphyry Pulaskite porphyry. Monzonitc porphyry Augite porphyrite Augite porphyrite. Olivine basull ( )ii„„„,.„„ Midway volcanic group(LavnK) '"*-"""' ■. ,i ■ ■ , , , ^^Pttle River formation. Jurii.^sic ('ftrl>oniferou.i I'ri>("arl)oniferouH Hornblende porphyrite (iranodiorite group Syenite and syenite porphyri'. Quartz porphyrite.. ,, , , , Rawhide formation. lirooklyn formation Brooklyn formation. Knob Hill group Knob Hill group. 13 DETAILED DESCRIPTION OF FORMATIONS. PALEOZOIC. Knob Hill Group. INTRODUCTION. tuffs, together with small residual masses or lenses of argillite and crystallme limestone. The rocks belonging properly to the group were, in the main, originally tuffs of varying texture usually extremely fine grained. These have been altered wholly or m part to such hi^ghly siliceous types as cherts and jasperoids. Part of the jasperoid at least is replaced limestone of the Brooklyn formation, but has been arbitrarily included in the Knob Hill on account of its intimate association with the roi" s of that group. Other residual masses of limestone and of argiUite may possibly belong to the Brooklyn and Rawhide formations' infolded in the tuffs, but any decision to be regarded as final must await more work in other fields where the relations are nriore clearly shown. In the Phoenix area the jasperoid zone is sharply marked off from that of the cherts, but at Deadwood there is a gradual transition between the two, and in mapping, the boundaries have been somewhat arbitrarily drawn, dividing zones of jasperoid-tuffs from those of chert-tuffs. The age of the group is Palaeozoic without any definite position being assigned though it is probable that no great time interval lapsed between the deposition of the Knob Hill tuffs and the Brooklyn limestones. DISTRIBUTION AND STRUCTURE. Tuese jasperoids, cherts, and tuffs probably underlie the whole fhl ,rVT- lu' J^«P^^«''J« 'I'-e usually at a higher horizon than the cherts. The rocks arc massive, rarely banded, and the several umts occur as irregular lens-like masses, overlapping M emdr^o.' ?i ^-°«^'°«' '"d Ore Deposits of Phocnii. Geol. Surv.. C.n., 1911 3938— i2 14 or dovotailinp; into one another sharply, or by pradual transi- tions. They are much jointod and shcarcul in several directions, the trend varying from N. 3° 11. to N. 08° E. with dips ranging from 70° to 90°. It is probable that faulting has been general, with possibly little displacement, but no data rcfiarding the latter question could be gathered on account of the general similarity of the rocks. Locally along zones of shearing small areas of schists have been developed in the chert-tuff zone. Along some of the later fractures which were avenues for the Tertiary igneous intrusives, vertical and horizontal zonis of brecciation occur, the fragments in part being cemented by the igneous rock. Finer friction breccias occur in fault planes noted underground. LITH Vl.OGY. J asperoids.— The jaspcroids are grey or greenish grey in colour, and consist of oval, rounded, oblong, and subangular pebble-like individuals of grey or brownish grey chert embedded in a matrix of calcite, quartz, and chlorite. They weather to a light rusty grey colour with the chert individuals standing out in high relief (Plate IIIa) and often simulate in character a con- glomerate or breccia. Veinlets of quartz and calcite fill joint and other planes which commonly traverse the rock. The individuals of chert vary from those of microscojiic size up to others an inch or more in diameter, and on the whole the rock is much fim - rained than the type occurring at Phoenix. The matrix varies Irom an almost purely calcareous one, to a dense quartz-chlorite type in which the chert individuals can only be discerned with difficulty. In minute shear zones pyrite and chlorite are usually associated, and the former in crystals and grains is rarely absent from the main body of the rock. Microscopically the chert individuals are seen to consist of aggregates of niicrocrystalline or cryptocrystalline (juartz up to 13 mm. in diameter, the individual grains having either smooth or interlocking borders. The grains show slight strain shadows, and a development of catadastic structure in some of the larger ones. The matrix varies depending on the origin of the jasperoid. If it is derived from a tuff the matrix is composed of compact kaolin felts in which lie fragments of feldspar, grains I'r.MF n- 1 A Limoatonc in part replaced l.y silica, rcprpscnts a transitional typo bctii hnifstonr and ja.six'ruid . B. Limestone (1), in part replaced by cpidotp (c) and quartz (a) 3938-p. 14 ' 15 of quartz, calcite, in small amounts, and ragged plates and fibres of chlorite. If, however, the rock was originally a lime- stone, th' matrix is largely calcite with numerous grains of quartz, and shreds of chlorite. Trcmolite, epidote, garnet, magnetite, and chlorite are present in the matrix of some of those types associated with the ore bodies, and are believed to be later metasomatic replacements of part of the calcite matrix, in the zone of contact metamorpiiism. The calcite is both clear and tuibid, occurring in mosaics of grains or in sponge-like masses enclosing chlorite and tremolite. The tremolite and chlorite usually occur in sheaf-like and radiate clusters, and in minute acicular forms. The former is colourless with a marked parting parallel to the base, and the latter is pale green. The chlorite also fills a few minute shear planes Pale yellow, turbid epidote and colourless, clear zoisite occur in granular aggregates, or in single grains, either in the calcite or along the contact of quartz veinlcts. Pale brown garnet has similar associations, as also have the grains and crystals of mag- netite and pyrite. The jasperoid is traversed by a reticulating system of quartz veinlcts with a width up to ' nun. Three or more periods of vein filling exist, each period being separated from the succeed- ing one by periods of minute faulting (Plate IV B). The fractures and minute fault planes Acre ai)parently the channels along which the .siliceous solutions travelled during the period of replacement, and many of the veinlcts are of tadpole form, and terminate in rounded individuals of chert. In some types the pro.(>se.«, of silicification have progressed more uniformly through the rock, and replaced it more exten- .sively, giving gradual twinsitions between jasperoids and chert in which there are few distinct individuals of the latter. Cherts.— The cherts are grey, bluish, lifiht greenish, dense grained siliceous rocks K(>nerally massive though occasional' r bandedin various tones of grey. When locallv sheared they arc cemented into qunrtz schists. They are finely jointc(' a-' "frac- tured, with faulting and slight displacements. The p. .es are filled with white quartz and occasionally with calcite. They are brittle and have a conchoidal fracture. Near the ore bodies the cherts arc dotted with flecks and grains of yellowish green 3938 — 2^ 16 epidote. In the banded types narrow lensea or leaves of pyrite have been deposited parallel to the banding. In appearance they vary from a typical chert to a massive lode quartz or fine grained dense quartzite. They weather from light grey to almost white with ru3ty patches and streaks due to the decom- position of the pyrite content. In the main they arc derived from tuffs though some may have been originally argillites. Under the microscope they are seen to be composed of grains of microcrystalline quartz from 015 to 0-2 mm. in diametsr, with smooth or interlocking borders, passing gradually into vague areas of cryptocrystalline quartz which are usually turbid from dark opaque (carbonaceous ?) films surrounding individual grains or aggregates. As in the case of the jasperoids, the cherts ar' traversed by a similar system of quartz veinlets of three or more generations (Plate IV B). They have a radiat- ing or parallel arrangement, and may swell out into lenses 2-4 wide and • 7 mm. in length with individual grains up to • 6 mm. in diameter. Others occur as thread-like lenticular forms, pinch- ing out in both directions along the length of the minute fracture. Calcite in tiny grains is distributed interstitially through the quartz; pyrite is usually present in grains and crystals often surrounded by a narrow rim of limonitc; and near the ore bodies, grains and aggregates of turbid epidote are sparingly developed through the rock. Tuffs. — The tuffs are fine-grained, dense, compact rocks and in colour a dark grey usually with a greenish tinge. They are finely jointed and fractured, the planes being filled with quartz and occasionally calcite. Though generally massive, fine banded types occur in alternating yellowish green and dark green tones. They weather to a rusty grey with a finely spotted surface. Quartz, chlorite, feldspar, and pyrite are individual minerals which can be distinguished in some of the coarser types. The principal varieties are quartz-chlorite tuff, chlorite tuff, and quartz-feldspar tuff. Microscopically, they consist of frag- ments or individuals of twinned and untwinned turbid feldspar and grains of clear quartz up to O-IS mm. in diameter, in a matrix of microcrystalline and cryptocrystalline quartz, shreds 17 of kaolin, felty aggregates of pale green chlorite, vague and turbid areas of calcite and epidotc, and grains and crystals of pyrite and magnetite. The thin sections ali show additions of secondary silica to a greater or less (- tent, indicating that the rocks are in the nature of transitional 'ypes between tuffs and cherts rather than true unaltered tuffs. Veinlets of quartz similar in character to those described under jasperDids and cherts traverse most of the thin sections examined (Plate IV B). The jasperoids, cherts, and tuffs, in the vicinity and adjacent to the mineral zone or zone in which lime silicates have been developed, contain epidote, zoisite, garnet, tremolite, actinolite, and magnetite in trifling amounts. These minerals are more abundantly developed where the matrix was originally largely calcite and was, therefore, favouralile to replacement by lime-silicates. Veinlets of calcite of a later period fill fractures which cross the quartz veinlets. The origin of the large quantity of silica necessary to convert the tuffs and associated rocks to jasperoid and cherts, is not quite clear. It may have been derived from some intrusive magma possibly a deep seated body of which the quartz porphyrites are offshoots. Brooklyn Formation. INTRODUCTION. The Brooklj'n formation is the lower member of the Attwood series correlated by Daly with the Carboniferous, from its similarity to the rocks of that age occurring in the Rossland mountains. In the map-area the formation consists wholly of crystalline limestone, which, as elsewhere in the district, is apparently devoid of fossils. It has been in part replaced by silica giving ro;''- of the jasperoid type, and in part replaced by lime silicates in a zone of contact motamorphism, or mineralized zone, which contains the important bodies of low grade copper ore (Plate III A and B.) DISTRIBUTION AND STRUCTURE. The main exposure of limestone occurs north of the Mother Lode mine, while a larger area lies to the east of the Marguerite 18 mine, the western border of which appears on the map. Minor outfropa occur at different points as residual masses lying in the jasperoid and the mineralized zones. The limestone has been associated with the rocks of the Knol Hill grou)) in the various earth movements experienced since their deposition, and the main contacts where they could be seen appear to be faults, the limestone being block faulted down into the tufaceoi;.- rocks, the faults in two instances being sharp planes boundinj, the mii\eralizcd zone. A similar fault occurs underground at the north end of the Mother Lode ore body and the plane is followed by a dyke of augitc porphyrite. The limestone is massive with the bedding planes obliterated. Irregu- lar jointing causes the rock to break into rough angular frag- ments. Near thi' ore bodies the rock is sheared and breaks into tlat lens-like fragments coated with a thin fdm of chlorite. LITHOLOGY. The limestone is compact and crystalline throughout and varies from medium to fine grained. The colour varies from grey to pure white, the lighter types often having greenish or bluish casts. The grey limestone in some localities may pass sharply into the white, which on a fine scale gives a mottled appearance to the rock. The white limestone is less compact, and usually has a saccliaroidal texture. The rock is traversed by an intricate system of minor planes of weakness now filled by veiulcts of white calcite. Pyrite is usually present in minute crystals and grains but generally is in very trifling amount. Microscopically the rock consists of clear and turbid grains of calcite with smooth and interlocking borders In mosaic arrangement. Evidences of strain arc apparent in the uneven extinction and curved planes of twinning and cleavage. Small aggregates of microcrystalline and chalccdonic quartz are of frequent occurrence even in the purest types of rock and are developed interstitially to the calcite individuals, or tend to replace the calcite along cleavage planes. Locally this replace- ment of calcite by quartz unUer favourable conditions has con- tinued until the limestone is wholly replaced, thus giving a jasperoid, oc a rock having the appearance of a fine quartzite. In an intermediate stage, the rock, transitional between lime- 19 stone and jaspcroid, i-onHista of oval and rounded, oblong urains of light and dark Rny thcrt rniljodcUd in a matrix of light grey crystalline limeatoni-. On the wcathiTcd surface the individual grains stand out in high relief and simulate in ai)pear:tiiee a line conglomerate. Further action in some cases causes the grains to anastomose and form irregular areas of solid chert an inch or !uorc in diameter, and in <'oiuplete replacement a chert is the result in which tlie orifiiiial oval forms c;in oidy be discerned on a polished surface or microscopically (Plate III A). In piitces !i banding occurs where the jasperoid alternates with limestone, tlie replacement by silica following more favour- alile bands in the original rock. This is further ace tuateil by the jasperoid being of dilVcrcnl grain in ditlVrent bands. Near the ore botlies and along the border of the mineral zone, th-.- limestone shows a spotted replacement by actinolite, garnet, cpidote, etc., which have formi'd in little n' -ts interstitial to the grains of calcite, or along the cleavage planes of that mineral. The mineral zone is composed e;>sentially of lime silicates which have replaci'd the limestone metasomatically. To prevent needless repetition a description of this zone is omitted here and appears under economic geology. CIIF.MICAIi COMPO.SITION. .\nalys( s of the grey and white limestones were made by Mr. M. F. Connor of the Mines Hranch and appear below. I ir Til In>oIuI)lf 0;;2 OCO (140 (Ixidcsot iron :in(l :.luinir,iuin 1111) I'O 02(1 r;lli'iuiil (':ir!ii int.' a'l-Sti ',lli:i.-, 'J7-C7 Mzp^n. jiicii ciirliurKiti' l-'M> i ■ l.i 1-40 InditcniiinuJ, \vut( r. I'tn 2 4ii i:;.' 0:i:! 10000 lOOQO 10000 I. Wliitcfrystallinr linii-lunc. Mi'.rnU' riti' i.iinc. II. Wliili'cry^ V . 1 f 7T ■ r » ^ " ■- ► 4 .' > ► K X it r. if-. .H K \ u if. , « r »; w ;; >; K K » It i; ,- * « « >: : , U V K Mother iedt Sunitt »Mar$u»rita K" i _ »■ ^ . ■• » •» V 1 "' * I. ^ H < -i ^ W -iv «' .•* I. ^ «: I. '•^ ^-^ J , .►»*:» 'r^ -iiy-' . (- 4 <• -I '■^J •'►'• ► -' *• -1 < I. Oru finia gd Oranodtarite Iv Artiary 2av hy ()r)nim. in »\zo. In tne uran^toid types the fonn is UMialiy poor am" irreifiilar. Tiie plaKJoclasc is occasionally twinned according to tlie all.ite law and a few individuals have the neUlitionrJ rarlsl)ad t winnins;. Zonal structure is (,f rather rare ocf urnncc. The ijlaniodase phenocrysts are often surrounded hy a thin crust of clear untwiniicd feldspar with a crenulate outf-r hordrr. Strain shadowswith incipient «ranidation are coiunioii. Chlorite and iinionite traverse many of the individuals alnuk fracture an(; cleavaKC planes. The mineral alters to kai>lin, turl.id acurcKales of epidote, and carhonat. .- with (piart/. The horn- blende is pale green and yellowish srecn and occurs in good forms ill prismatic and basal sections, i.n av.Tane of the larj:er individual being 1 by O-A mm. in size. It more often is found in irrcKular individuals with frayed terminals. It is rarely fresh and has either been leached to paler lints or altere) ws a period of vigorous erosion and the mountain systems resuitmk from folding and uplifts during the later Mesozoic were reduced from the lofty alpine type to mature forms, the peaks and ridges having a broadly uniform elevation. The district is not regarded as having reached the final stage of a peneplain, but was merely reduced to moderate altitudes.' In Oligocene time the broader valleys wholly or in part became lake basins in which a series of sands, gravels, and clays were deposited, becoming by induration sandstones, conglomerates, and shales. In certain localities vegetation was sufficiently luxurious to cause the formation of lignitic shales with some beds of lignite coal. The forn\ation has been called the Kettle River formation and from the efTccts of later erosion now appears in isolated or detached areas throughout the district. The Miocene and possibly the later Oligocene was a period of wide-spread volcanic activity, during which time the district was covered by a series of lava flows aggregating a great thickness. The lavas consist of basalts, andesites, trachytes, and possibly more acid types. The oldest lavas are basalt and the youngest of the series is apparently an alkaline trachyte. They are known as the Midway Volcanic group, and are unconformable to the Kettle River formation. The unconformability indicates only a comparatively short period of erosion. The lavas are cut by their intrusive equivalents, olivine basalt, augite porphyrite, monzonite, and pulaskite porphyry, which occur as dykes, sills, and stocks. The period of lava flows was accompanied with 'Brock, R. W., Sum. Rep., Gm\. Surv., Can., 1902, pp. 93-94 A. Daly, R. A The .\ccor(iance of Summit levels among Alpine Mountains." Jour, of Geo!., vol' XIII, pp. 105-125. 26 and followed by earth movements, which produced warping and faultmg particularly apparent along the contacts of the lavas of the Midway Volcanic group and sediments of the Kettle River formation. The Midway Volcanic group is probably of the same age as the Volcanic group of Dawson occurring in the Kamloops area while the Kettle River formation corresponds to the Coldwater group. In the map-area no lavas are found though they occur in great development immediately to the west (Fig. 2, p. 21) The intru.sive equivalents, however, are well represented in dykes or sills of olivine basalt, augitc porphyrite, monzonite porphyry and pulaskite porphyry. In only one instance are they found cutting one another, the case being a sill of monzonite porphyry cut by a dyke of pulaskite porphyry (See general map). The several types are porphyritic and show well marked selvages or chilled borders an inch or so in width. The dykes are found generally throughout the underground workings, but do not increase in number with depth so quicklv here as elsewhere in the Boundary. The augite porphyrite was not noted as out- cropping at the surface, but two dykes, however, occur under- ground, one in the Mother Lode mine, and one in the Crown Sil- ver tunnel. Later movement al.^ng the dyke fissures has pro- duced minor faulting with brcciiation. LITIIOLOGY. Olmne Basnlt-This rock occurs in only one dyke having a length of 510 feet and a maximum width of 30 feet. It is a dark grey, almost black porphyritic rock in which laths of grev plagio- clase feldspar, phenocrysts of black pyroxene, and Vounded individuals of yellowish green olivine are eml^cdded in a dense fine grained base having the appearance of pitehstone. The rock weathers to a rusty grey with a pitted surface due to the removal of pyroxene and olivine individuals. Under the micro- scope^the rock is seen to be comparatively fresh and consists of 27 1 labradorite, : igitc, olivine apatite, and magnetite. Thelabra- dorite occurs in tabular, lath-shaped, and square individuals up to 3 mm. in length. They have no uniform orientation that would suggest fluidal structure but lie in all directions. Many show the stop-like outline indicating incomplete growth. Twinning is by the albitc law with occasionally the additional Carlsbad twinning. Many of the individuals have symmetri- cally arranged inclusions of the groundmass. The augitc is pale yellow or colourless. The large individuals are idiomorphic with sharp or rounded angles, and range in size up to 1 • 3 by • G mm. Some have irregular borders with enibay- ments indicating corrosion, and a tew are twinned polysyntheti- cally. The mineral is fresh with Init slight alteration to chlorite along cleavage and fracture jjlanes. It holds as inclusions a few grains of almost completely serpentinized olivine. The fresh olivine is colourless and occurs in rounded, irregular, and wedge-shaped individuals up to 3 mm. in diameter. The alteration to yellowish green serpentine follows the borders of the individuals and the numerous irregular cracks traversing them, with the fibres and plates of serpentine lying parallel to the cracks which they traverse. Many of the smaller grains are completely altered. The groundmass is in relatively larger amount than the ' ts of irregular individuals and minute of augite, fibres and plates of chlorite, , rains and crystals. Colourless apatite in slender crystals and roimded grains occurs as inclusions in the augit(>, olivine, and feldspar. phenocrysts and laths of plagiocla and a little magne ^ ;.(/i7c Porphijrile. — This type was on'y noted in two instances and then as dykes in the undcrgrourd workings of the Mother Lode and CrowTi Prince. The cb Ke in the Mother Lode mine follows for a distance the fault plane or contact between the ore body and the siliceous rocks of the Knob Hill group. The rock is much c' iposed and rather soft from shearing movements subsequent to its intrusion. It is dark grey in colour and consists of phenocrysts of black pyroxene in a finer grained mass of greenish grey feldspar, and minute black plates of biotite. The rock is lamprophyric in its general texture. 28 Microscopically the feldspar is seen to be both twinned and untwmned, but the alteration has been too great to permit of any satisfactory determination of its composition. The similar rock at Phoenix contained both orthoclase and acid labradorite. Many of the turbid laths contain a large amount of green ch.orite which has a certain symmetry in arrangement. The augite is pale yellow and sl^ows good forms in basal and prismatic sections. The size of the individuals ranges up to 1 mm. m diameter. It is less abundant than the feldspar but occurs in mdividuals of larger size. It is but slightly altered, chlorite being the secondary product. Biotite occurs in oblong forms and irregular plates of which many are allotriomorphic towards the feldspar. Magnetite in crystals and grains is in considerable amount, and is found in contact with individuals of augite and biotite or as inclusions in them. It al.o occurs in dust-like grams and aggregates in chlorite. The groundmass consists of laths of plagioclase, biotite, and pale green chlorite, the latter occupying angular interspaces between feldspars and being probably derived from the biotite. The rock is closely related to the augite porphyrite occurring at Phoenix, but is apparently more basic in character. An analysis of the Phoenix rock by Mr. M. F. Connor of the Mines Branch, is given below. According to the quantitative classifica- tion the porphyrite is shoshonose. ^^^■' 55-90 ^'^^ 15-.'S2 FejO, ,22 FeO ..22 M«?o ;:::::::;;;;;; 4.70 S'^^^ 5.79 N'^A^ 2-89 K2O 4.. 4c It^ '■'■■-'--- 1-40 S 0-14 St, 0-46 ^^^ 009 99. 3G 29 -: a U Momonite Porphyrij .—In hand specimens this rock is grey or greenish grey in colour and of porphyritic texture, with rosettes or irregular clusters of light grey feldspar, in a highly feldspathic trachytic or microgranitic groundmass in which minute laths of glassy feldspar may be discerned. The rock weathers to a pale rusty brown or dirty dull grey with a pitted surface, due to the removal of many of the phenocrysts of feldspar and the grp'ns of the dark (f.-rric) constituent. The rock occurs as dykes and sills which present well marked chilled zones along their margins Microscopically the rock consists of soda orthodase and ohgoclase (Al„ A;, Al^V;), feldspar, augite, biotite, quartz, calcite, chlorite, apatite, and magnetite. The phenocrysts of soda orthodase are rounded, oblong, or square, in forms up to 2 -To by 1-.5 mm., and are occasionally twinned according to the Carlsbad law. They are very turbid and arc usually sur- rounded by a narrow zone (al)out 0- 1 mm. wide) of clear feldspar in optical continuity with the main individual. The oligoclase occurs in clusters of tabular and lath-like in.lividuals, the average size of which IS smaller than those of soda orthodase (up to 0-7 X 0-3 mm.;. They are all twinned according to the albite law and a few have the Carlsbad twinning. Thev are generally turbid from kaolin and carbonates (calcite?) and are surro nded by narrow zones of clear s„da orthodase. Strain shadows are common in both fdds]iars. Pale yellow augite occurs in rounded idiomorphic form- ip to 1-5 by 1 mm. in size. The mineral alters readily to chlorite and the greater part has been altered to aggregates of chlorite and calcite. Apatite and magn.'tite are in small amount- in some slides the latter occurs in filiform aggregates, the minute threads terminating in small lobes or possibly crystals. In this form it is either included in the feldspar, or forms l)orders about 0-1 mm. wide around phenocry.sts of soda orthodase, the filaments being arranged with the longer axis at right angles ti) th ■ margin of the phenocryst. The groundmass is about three times the volume of the phen- ocrysts and varies in texture. In some thin sections it consists of a trachytic mass of laths and irregular grains of plagioclase • 3 by 00 mm, a little clear untwinned feldspar, minute oblong forms (0-2 X 04 mm.) and plates of biotite allotriomorphic to the 3938—3 30 feldspar, and angular grains of clear quartz interstitial to the feldspar, the latter at times in relatively large amount. Chlorite and calcite are also present, the former being due to alteration of biotite. This type passes to one in which there are fewer laths of feldspar and more interlocking irregular grains, the tex- ture becoming coarser and microgranitic. The rock is more basic than the normal pulaskite and probably is closely related to, if not identical with monzonite. Pulaskite Porphyry.— The pulaskite porphyry (alkaline syenite porphyry or bird's-eye porphyry) is closely reL.led to the above described monzonite porphyry and is probably a slightly more acid phaseof the same magma. It is acompact, greyish, porphy- ritic rock consisting of phenocrysts of light grey feldspar with greenish cast embedded in a dense felsiticor microgranitic ground- mass which is highly feldspathic. The feldspars have a tendency to arrange themselves in rosette-like clusters. The weathering of the rock is characteristic, the border becoming a brownish grey, while the phenocrysts become pale brown or pink. Microscopically the texture of the rock is similar to the mon- zonite porphyry, and the mineral content is also similar with the exception that nearly all of the phenocrysts are soda orthoclase, the few of plapioclase being acid oligoc]a>c. The volume of the base is much greater than that of the phenocrysts. The biotite which occurs intcrstitially to the feldspar in the base, is in relatively small iimount and for the great par* is altered to chlorite. The greater portion of the base consists of soda orthoclase and oligoclase laths. Quartz occurs in very small amount. The analysis of the pulaskite porphyry occurring at Phoenix, made by Mr. M. F. Connor of the Mines Branch, is given below in column I,' and an analysis of the Rossland pulaskite by Dr. Dittrich, Heidelberg, is placed in column II.' The Phoenix rock according to the quantitative classification is monzonose and it is probable that the pulaskite at Deadwood belongs to the same type. 'LeRoy.O.E. •Brock, R. W., Goologyand Ore Deposits of Phopnir. Memoir No. 21. Sum. Rep., Geol. Surv., Can., 1902, p. 104 A. 31 S'02 57-3'' ^1=^» 17-27 ^'PaOs i.g2 t'e<-> 3..)4 ^^'k^> 2-08 ^'^^^ 4-24 Ni^sO 4..^ |J=^ 5.% .^.='^- 0-08 ''^*2 0-88 ^f^ CM •^^"•J 0-09 ^'^ O-OG liii is compos.d of the siliceous rocks of tiu. Knol. Hill (rroup .-.nd granodiorite. The contact between tiie liinc-toiie and Knol) Hill rocks is apparently due to Mock faulting rather than to a sharp folding, possibly a doui)le faulting', one approximately aldiig the strike of the ore body and a second across it as shown by the marked slip or crush zone from the 200 to the 40(» levels in the Mother Lode mine. By this faulting the limestone was lowered into the jasperoids, etc., of the Km)l. Hill group. Small lenses of limestone also appear at a couple of points well within the mineral zone. The zone is cut by Luter (T. rtiarv) dykes of augite porphyrite, monzoniti>, and pulaskite porphyry which are usually very irregular in size, strike, au\w* zonf is only a oronil patch, proJmt.ly not more than a fiw fret thick at ttic dcopcst point, lyinj? on the hiliccoun rocks of tht' Knob Hill group. CHARACTEK OF TIIK ORi: DODIKS. The ore hodicH arc irrcgiihir, h'ns-likf masses and vary widely in si/e .'iiid attitude, the latter dependinR piohaMy on the thick- ness and attitude of the original limestone. The ore hody of the Mother Lode stands almost vertical along the fault f.ace of the linie-t(.ne Mock where the vertical thickness of the mineral zont -^ proh.al ly the greatest. The Sun-et ore liodies .MTi' pra'tieally horizontal. The foot-wall is either limestone or the .siliceous rocks of the Knol. Hill Rroup, and is practically the commercial as well as Ihe structural foot, though in jdaces a hand of barren gnngue rock intervenes between the structural foot-wall and tlie ore l)ody proper. The lianging-wall is visually a commercial one, and the ore either insensibly becomes lower in grade, or the p:iy ore suildeulv terminates ahjng a gouge fdled fissure or ••slip." The ore bodies are traversed by a series of fissures, locally termed "slips." These run in all directicms and at all attitudes from vertical to horizontal. They vary 'n length from a few feel to a hundred or more fi'et, and in width from :i fraction of ;!ii iiicli to several inc hes. The smaller ones pass by gradual transitions into those of almost microscopic dimensions, ;u\d the whole form a reticulating system of a very intricate nature and of several ages. Faulting has been general, though u-ually with sni:dl displacements. The system is .Mnalogoii- to that described under jasp'Toids, and illustrated in Plate IV 15. The fissures, no doubt, have generally I)een caused by stresses set up during the process whereby tht limestone was being re- placed by the lime silicates. They nr,- also considered as being a most important factor in ore deposition, forming, as they did, the channels of circulation for ore-beariug solutions, which 3:> uradually passed from the trunk rlmnnds to the fim-r s.ries of (li->ttilnitnri('f, thus iHTiuitlinR ani'vcn imd widf-sprciil (icposi- tion of thfir mctiiilic ..,iitniiill amoun of chalcipyrite and pyrite. SIIkIu movcment-i uIour these pn-niineral fissures have taken place suh-ecpii'iit to thi' formation of the ore bodies, a^ evidenced by the many >lickcnsided >urfac(i. \Vrd({c-.,liiiped massc-^ or ribs of almost birren Kancue rock appear in all the ore b idles, and are usually obstat les to economic mining. DependinR on their im()ortan( ,- and po~iti(m, they are either stopcd or left standing. Tin' ore is so unifoiin in its h.w grade character that much admixture of barren gangue would quickly bring it below the shipping grade. CHARACTER OF THi; ORE. The ore is massive, rarely ban(UMl, and consists of chalcopyrite. fjyrite, and magnetite, which are hnely and uniformly distributed through the gangue minerals along fracture and cleavage j)lanes, and interstitially between individual grains. The gangue min- erals are actiiuilite, garnet (andradite), ei)idote, tremolite (rare), zoisite (rare), chlorite, calcilr, mui (juartz. The ch.ilcopyrite and pyrite are more closely associated with the (luartz and calcite which fill fraclur( ^ and interstitial spaces in and between the lime silicate minerals Occasionally masses of chalcopyrite are found, but these arr of relatively rare occurr'nce. Magnetite also occurs in irregular leus-like masses, both along the bonier of the main ore botlios and also .it various horizons through them. Azurite and malachite were found in the surface zone of oxidation. Arsen- opyrite, galena, zinc blende, and jiyrrhotite' have been noted in very small quantities. The average ore ranges from 1-1 to 1-3 per cent of copper, and the gold and silver values amount to about $1 per ton. 'Br-..-k, 11, W , ,s:ui,i, Rf^port, G-^j!. Su.-v-., C::n.. iooe, p. 11J.\. 36 The character of the ore differs mineralogically only from that at Phoenix. At Phoenix, epidoteand garnet are predominant and actinolite of rare occurrence. The iron oxide generally distributed through the ore at Phoenix is hematite, the magne- tite there occurring only in distinct masses. Mineralogy . Only the minerals composing the mineralized zone and ore bodies will be considered under this heading. Arsonopyrite, galena, blende, and pyrrhotite referred to in earlier reports' of the area, were not noted by the writer. Metallic Minerals. Chnlcopyrite (sulphide of copper and iron)— Chalcopyrite is the most important and valuable of the metallic minerals and contains all the copper values, and practically all of the gold and silver as well. It occurs as solitary grains and aggregates up to 2-5 mm. in diameter, as narrow threads and streaks, and as minute elongated lenses up to 12 mm. in length, developed along cleavage, fracture, and shear planes in the gangue minerals (Plate V, B). It is also found associated with the calcite i^nd quartz which fill irregular areas in the u- tinolite, and actinohte-garnet types of gangue, and usually forms along the contact of the calcite or quartz with the lime silicates. It is usually associated with iron pyrite, which, in part, is contemporaneous with the chalcopyrite. It also sur- rounds grains and well formed crystals of magnetite, as well as filling minute fractures which traverse the latter mineral. It is also found in larger masses which are relatively pure, but these are of somewhat rare occurrence. Iron Pyrite (disulphide of iron) — Iron pyrite is closely associated with the chalcopyrite. It often occurs in gooa crystal forms, the cube and pyritohedron being the more common, and combinations of the cube and octahedron 'Brock, K. W., Sum. Report, Geol. Surv., Can., 1902, p. 1I9A. Pmtk V. A. Clarnct crystals in ralcite (40 diamotors). B. Chalcopyrite (blatk mineral) in actinolite (grey minoral) (40 diameter*) 3938— p. 36 37 being less so. The crystals vary in size up to a quarter of an inch in diameter. Microscopically they are found disseminated through the gangue minerals in sizes up to 0-1 mm. in diameter. The mineral has a wider range in deposition than the chalcopyrite, part of the pyrite being about the last of the minerals to crystallize. Magnetite (magnetic oxide of iron) — Magnetite occurs generally distributed, in grains and crystals, both solitary and in aggregates of octahedra, throughout the gangue minerals and favouring the contact between the lime sili- cates and the calcite or quartz. It also occurs as massive bands alternating with actinolite and garnet and as large irregu- lar lens-like masses of varying size at different horizons in the ore bodies. It has been formed earlier than the sulphides and is in part slightly later, and in part contemporaneous with the lime sili- cates. When massive the magnetite forms a dense crystalline aggregate, in which the sulphides are irregularly disseminated, occupying interstitial spaces between the grains, or filling minute zones of shear and brecciation. It is usually traversed by numerous seams of quartz and calcite. Narrow brecciatcd zones were noted, with the fragments of magnetite cemented with quartz or calcite. Limonite (hydrous sesquioxidc of iron)— Limonite, in brown and reddish tones, results from the decomposition of the sulphides. It often forms a coating on pyrite, and on chal- copyrite with malachite. It occurs generally throughout the ore bodies as thin films along joint and shear planes, and fills microscopic cracks in the garnet (Plate V, A) and cleavage planes in the actinolite. Malachite (green hydrous carbonate of copper) — Malachite of pale green colour and rather dull lustre occurs as botryoidal incrustations on chalcopyrite. Azurite probably occurs also but was not noted. The oxidized zone has in great part been mined, hence but relatively little of the secondary metallic minerals are now to be seen. 38 Non-Metallic Minerals. Actinolite (magnesium-calcium-iron-amphibole)— Actinolitc is the best developed and most widely distributed gangue mineral. It varies from pale green to greenish grey and is pleochroic in pale green, almost colourless and yellowish green tones. In places it occurs in columnar masses with fibres several inches in length, which show the eminent cleavage and the char- acteristic basal parting. It generally occurs in acicular and lath forms with frayed or ragged terminals, arranged either without any particular orientation, or in sheaf-like and radiate clusters forming felty masses which in the aggregate produce a gangue of considerable toughness. At times it appears intergrown with magnetite. The sulphides are deposited in it along the planes of cleavage and parting (Photo B, Plate V) and in minute shear planes. A black variety of hornblende associated with pyrite and calcite occurs in veins filling fissures in the massive actinolite. Along some of the larger shear zones the actinolite has been converted into a substance resembling "mountain leatlier" consisting of series of interlacing flat thin leaves and fibres, pale grey in colour but lacking the quality of toughness. Tremolite (lime-magnesia silicate)— Tremolite was only noted microscopically and is of rare occurrence. It is colourless and forms sheaf-like aggregates associated with other gangue minerals. Garnet (andradite-lime Iron silicate)— Garnet occurs both massive and in crystals. A test analysis by M. F. Connor of the Mines Branch, showed distinctly that the variety was andradite. The colour is reddish brown, pale brown, and honey yellow with usually a resinous lustre. The crystals present the rhombic dodecahedron and combinations of it with the tetragonal trisoctahedron, and have formed freely towards or along the borders of the calcite filled areas (Photo A Plate V). Microscopically the massive garnet is pale yell v and occurs in aggregates of rounded polygonal forms traversed by numerous cracks. In all the slides examined it was seen to be quite isotropic. The crystals vary up to 2 mm. in diameter and 39 have developed freely towards the calcite and quartz. The massive garnet has been finely breeciated locally by later move- ments, and the angular fragments are cemented together by quartz or calcite. In some instances the brecciation has pro- duced a finely comminute name of the New Dominion Copper Company, in which the British Columbia Copper Company has the controlling interest. The principal mines operated by the British Columbia Copper Company in 1910 were the Mother Lode at Deadwood, the Oro Denoro at Summit, the Jackpot in Wellington camp, and the Rawhide at Phoenix. The Lone Star and Napoleon mines in the State of Washington are also being developed and will shortly add very materially to the general ore production. The ore from the Napoleon and Jackpot supplies the deficiency f sulphur which exists in the normal low grade copper bodies, ypical of the Boundary district. 45 hJhLr"'.*"^'!.?^ **"" '"'"P""^ " "'*"»**''' »t Anaconda and Jr't Zr *1 ""^ *''"'' '° ^""'^^ "^ "'•--'^y demand*. The arHt furnace wm blown m on February 18, 1901, and the second one wa. .nstallcd in 1902. At pro.ont 'the smeltery conrts o three furnnces wh.ch treu. from 1800 to 2400 tons per day with a maximum capacity of 2G(H) tons. During the early yvlrs the mate wa. .hipped direct, but in Vm a bJcu.. rLTng plan was msta Ic^ to convert the matte to blister copper. The p r consists of 2 converter stands with 7 horizontal shells and Is a capacity of between 40 and .50 tons of matte in 24 hours. The verted to bltster copper about 993 per cent pure and carrying the gold and silver values. The blister copper is shipped to New Jersey for complete refinement at Bonlr T^Z n "'''* f ^"-""^hout. being derived from the plant The enJ^ f* ' °" ""' ^"°*'^°'»y "^'^^ «°™'- «5 miles distant The coke supply is procured from the International Coal a^d Coke Company at Coleman, Alberta. About 120 men Tre usually employed at the smeltery. The smeltery r .Boundary u^uTlte^e^rm^Zr^--^^--'---^ MOTHER LODE MINE. Location. urZf ^"u*"? ^"'^f '"'"' '' ''*"^**^d °" *»>« ^'^^t Side of Dead- wood creek at an elevation of 3450 feet above sea-level It is spur of the Canadian Pacific railway about 3J miles long. Production. The mine is the second in importance in the Boundary dis- trict and ranks next to the Knob Hill-lronsides mine at Phoent t_o2^14,481 tons of ore smelted. The recovered values amount 20, imf^pVn.im^''''''''^ ^°'"»' «°"^«'« «""k., Eng. ^ tlin. Jour.. Mar 3938—4 46 to 37,648,2^'! I iinds of copper; 93,024-2 ounces of g.tld; and 336,S80a oiir.'t of wilver. The iiv< rngo value jM-r ton tliust iimouhts to !>< ».s pounds of copper, 041 ounces of gold, and 0-167 ounces of ^ I. r. / ' lojmtnt and Equipment. The mi 500 foot le 200 foot If i.^ Above the o'' f" mine ia d« m'-. hole" (PI. 1 fompartnur ' hoisting ore, been eonstru ■d I., i ;'.ncl out", ' I'd by a four conipiirtment I'haft to ilic 'U at 60, 200, :}(M), iiiid 400 f(>et ; t f • (iO ai„ ) conne tt-d with the surfao by tunnels. I to tl • tvTi ,.j,t p„int ,„j the outcrop, the •' ■ ' . -irrics forminR a large "glory ' ' '■: niap). The shaft is a vertical 4 mpiirtments of whiiii are used f«r ne for iiiM lud one manwuy. Ore pockets hav« ' fl Iw'' >^ • " ^^ -•!, and all ore won in the mine is raised in -ton skips. tiorse haulage is used on the GO anil 200 foot levels, and electri liimlage on the 300 and 400. Thi mine is ligh'id throughout by electricity. From the upper hins !it the shaft jwcket head, the ore is dropped to Blak. crushers, ind after crushing is carried on a belt conveyer to the shipping bins which have a capacity of 2000 tons. These are situated near the terminus of the spur lino, and the ore is hauled to the smeltery in :>0 to 50 ton cars. Air is furnished by two compress- ors, one Rand and one Ingersol-Sargent, with an aggregate capacity of 70 drills. Electricity as motive power is used throughout with the exception of the haulage on the 00 and 200 foot levels. About 235 men are employed at llie mine. Methods of Mining. Parallel drifts are run in the direction of the strike of the ore body, one being at or near the foot-wall, and the series are connected by cross-cuts. Raises with chutes are put up about every 35 feet, commencing in or near ore and connectinp; with one another at intervals, and also with the level immediately above. The method of sloping is that of the (.illar and room. The raises from the several levels were originally driven in spiral forms, but recently the method has been changed to a straight 47 1!^ 1 ,T^%«"*""^ i^fi™ «nd requires little or no timhrinK iH-j oncl the chut,^. while the number of pillar, left for «upp<,rH dcj>end on the local eharaeter of the in.m.Hliate groun.f with refcrenee to the attitude of the f.Hsure. or -.lipV' The ",r ace ore is «till LeinR won from n nerie. of cuarries forming the loTKc "glory hoi.." (Plate I a,.,! Plate IV A) The ore driflZT "'"'" '? ""' *^" ""'^ 2(K) foot l..vel.. Diamond dnilmg ha. m .. • past l.m. extensively us,d to do the initial prospectmgand to outline the general dimensions of tl. ore Geological Rilatiom and Character of the Or ';,„ y. There is apparently but one or. bo.ly, though of irregular form, when examine.l m detad. In . .rtain sections of the work- mgH where two or more bodies wer. develop,.!, it was foun.i by later work that they were eonneet, J with tl. main ore bodv the separating masses being ribs or irregular wedges of low^r' grade ore, or almost I rren gangue. Along the outerop the ore bo.ly has a length of about 1,100 feet (see general m.,,). The length, however, diminishes with M-pth and on the 4..0 foot level is a liMe less than 250 feet ... *, i", ^:^r ^'""^ '" '" ""' '^^ maximum, with an aver: ag.' ot about 40 f..et. The thickness of ,)„. ore is m.nlified bv the number of lean wedges or ribs which may occur nucrbanded with It. As an example, a cross section at one point on the 60 fo<)t level gay.., starting at the foot-wall, ore !() feet, waste 40 ,. jet ore 30. wast,- 18 ore 82, waste 27, ore 5-u total of 107 feot of „r.- and 85 fe.-t of lean or barren gangu, The general contmuity of the ore body is brok.-n by an upward truncated cone-shap.-l mass (body) of lean and barn-n gangue wuch extends from the base of the mineral ,.one ulmos- ro the bO foot level. The vertical ran^e from the highest point on the outcrop to the lowest dev.Iop.-d portion of the or,- bjdv amounts to about C50 feet. ' The general strike is N. :in= E., with a ,.urv. to to ea^t ^t the north end of th, ore bo.ly. Tlu- ,lip is to -h,. south.-^st and vanes from 45° to 70», steepening with .lepth until the lowe; half of the ore body is practically vertical Section A-p. gener-d map.) ** '"i.n 393s— 4i 48 The foot-wall is crystalline limestone and the ore is cither in close contact with it, or is separated by a narrow band of the gangue minerals (section A-R, general map). The contact of ore or gangue with the limestone ia usually quite sharp, and the limestone wall often presents an irregular angular or broken surface without a distinct foot-wall fissure. The hanging or east wall is, on the whole, a commercial one and consists of the usual gangue minerals, or partly epidotizcd ancl mineralized granodiorite. Along the south boundary, which is marked by a fault from the 200 to 400 foot levels, the ore body is in contact with the rocks of the Knob Hill group. The system of fissurcis, of several ages, which traverse the ore body in all directions and at all attitudes, has been an important factor in the distribution of the ore. Along the borders of some the ore is noticeably of slightly higher grade than the aver- age, but gradually fades out into normal ore. Subsequent to its formation, the ore body has been cut by dykes of pulaskitc porphyry. They vary from a few inches to over 20 feet in thickness, and are found at all levels from the surface to the 500 foot level. A main dyke on the 200 foot level extends along the length of the ore body and dips into the foot-wall. On account of its low dip it has been a serious obstacle in mining. The ore along the borders of these dykes is of higher grade than the average. This may be a concentration, due to a mineral- izing action set up by the intrusion, or the dykes may have followed some of the more important prc-mineral fissures, which have higher grade ore along these walls, as noted above! One dyke of augite porphyrite occurs at the north end of the ore body along the contact between ore and country rock on the levels following u fault fi.ssure. Later movements have crushed and altered it to a great extent. The thickness varies up to 25 feet and it dips south at about 55°. Character of the Ore. The ore consisi? of chalcopyrite, pyrite, and magnetite as grains, aggregates, and thread-like streaks and lenses, sparsely, though uniformly distributed through a gangue composed of varying proportions of actinolite, garnet, epidote, calcite, and 49 quartz. Chalcopyritn also occurs in larRor and purer massos, but these arc relatively rare. Magnetite occurs in irregular mass..s and l.-nses of consi.l.rable size, ..,,,(1 often can bo mined separately from the general ore: they are found both along the bord.r and at various horizons in the ore body. With the variation of gangue three types of ore can be differ- entiated: a siliceous where the lime-silicates predominate, a calcareous rich ni calcite, and a ferruginous composed largely of magnetite. ^ Analyses of these types give the following results:— f'ilica Alunijnfi Iron oiiili' Liiiic iin^l iiiaf^ncHia. yiliotiu.i (iilcaridui Fcrnntinous 27 -.i;! 44 23 7-4C. IB 03 20 10 I'itl 12 00 34 00 SI 13 10 •26* •British Columbia Mining H.conI, May 1902, p. 173. Through the courtesy of the British Columbia Copper Com- pany the writer is enabled to r»ublish the following analysis by Mr. Frederic Kefftr, the consulting engineer of the Company. AVEBAGE OBE OF THE MOTHER LODE MINE. Alumina Allcalculatff SILVER MINE. The Crown Silver mine lies to the east of the Mot' er Lode on the eastern edge of the Mother Lode zone. The development consists of a vertical shaft 250 feet deep with levels at 150 and 250 feet. A tunnrl 86 feet below the collar of the shaft was driven in a westerly direction for about 300 feet, mostly in min- eral zone. No ore was encountered, the mineral zone carrying but trifling amounts of chalcopyrite. From the material on the dump it is evident that part of the lower shaft workings are in granodiorite THE QUEBEC COPPER COMPANY, LIMITED. THE MARGUERITE MINE. The Marguerite mine is situated near the eastern border of the map-area and is about 4000 feet ea^t nf fV,„ /t *u T ? mine. It is owned by the Quebec Copp: CompanT The ' body or bodies have been developed by a sSli f t ^ 100 foot level wh^e twi o e bodf" '""'"''"' °""""'^ *° '''' 22 feet thick respecthdy A^st ITZlT:^ ^^^"'^ good returns in copper, gold anS silver F .. "'' ^''"° on the dump it is a^par'en^ tttron^d^iab/r^ wl^r fn a barren mass of grancdiorite ° 53 INDEX. Actinolite f*"*- Anaoondu, smelter at. .'.'.",.'. 38, 48, 51, 52 Analysis, auuife inrphyrito.. *• 45 I' limestones '." ' ' 28 Mother Lode ore ... 19 1^' Pii'nskitcporpliyry....'..^]. 49 Roiwlanu pulaskite 31 31 Bibliography Boundary Falls, smeltery at dismantieHl Mines Co. 8 -- „ 45 Boyd, W. H., topoiiraphioal work i)y 43 British Columbia Copper Co 3 ., ", a'-knowled^ments. '' *? rlaimsheldby « Rropt R w ownersofMotlicrLode... ^ arockRW.,rcTOnnai89ance survey by * Brooklyn formation * 5 17 Calcite Chalcopyrite ''■'■'.'■'......'. "^ Mareuerite mine. .... ...... ^^ Mother Lode ore . Sunset mine ore Chlorite Climate C.O.D.elaim Connor, M. F., analysis, auKiteporFhyrite... '..'.;. „ " limestones ' f I'j .. I... ." Pulaskiiennrpbyrv. uopper, Deadwooil mineral zone _" '"rcelyprodured in Boundary district low (trade. Brooklyn formation MiirEuerilemine " Mother Lodeore. ...'..'. ^^ produced at Mother Lode. __ smeltery at Anaconda Sunset mineore... Crown Silver claim ;; ;; ." located.'.'.'.. ;;::::::;::;;:;;;;; mine 39, 48, 52 3S 52 48 51 39 8 43 28 19 31 1 32 1 17 52 49 45 45 SI 43 4 51 Daly Dr. R. A., gcoloRical examination by. Ucadwood mineral zone ^^ ""iinE camp, situation of... n-i. ■ u ^ '"■'"'"'•< "in of mini sat Uittrieh, Dr.. analysi.^ Rossland pulaskite Dominion Copper Co wu^mhim;. Don.Iulisclaim Drysdale, C.W., .ireal iteolony by . '.'.'.'.'.'.,', S 32 3 S 31 43 43 3 54 Ea«t, John, Sunset claim located by CitniTia mine, copper producer Epidote Paoi. 4 1 .39, 48 Flora Florence claim . 8 48 6 Garnet Geoloty, economic.,..! !.......,'..'.' ' 38, 40, S2 " Kcncral 32 " Mother Lode mine '0 Sunaetmine 47 Gold, Boundary diatrict M " discovery o( in Boundary creek • discovery of in Rowland 3 ^ Marguerite mine 8 ' Mother Lode ore 82 " production of at Mother Lode *• Sunset mineore 46 Gold Drop mine, copper producer... *• G«at&o^"'^!.'i™'""«' Smelting, and PoWerCo-. ! ! ! . . ! { Green wood, where 8i timted !........ !..^.''" 3* 3 a Hogg, W. L., purchaser of Sunset group „ I Iceland spar found in Mother Lode mine Ingram, Wm., Crown Silver claim located by '? Iron pynte ' 4 Irrigation necessary for agriculture " 7 J Jackpot mine operated by B. C. Copper Co. Jasperoids ft^' -^yi ^ 14 K Keffer, Frederic, analyses Mother Lode ore ,. Kettle River formation... *» Knob Hill group 28 Knob Hill-Ironsides mine, copper producer *? Limestones, analyses of Limonite Lone Star mine 10 37 43 S5 ■ McCormick, Wtn.. Mother Lode located by ''*°*: Magnetite ' 4 " Marguerite mine.... '^ " Mother I^core M " Sunset mine ore ... *8 Malachite H Marguerite mine, anal^aexot limestone. . ..^ ! ?I ' ' location, etc Jj " lone M Meaosoiu, detailed de.tcriptiun of.. S Metallic minerals w Midway volcanic group 3fl Monarch mine, conpcrproducer 28, 29 Montreal and Boston Co. • Montrealand Boundary Creek Mining Co!.' ^ J? Mother Lode, analysisof limestotic. TJ ' " B.C. Copper Co., holders of....! J? copper producer *f ' " equipment, etc • history of *? " located « .'.' operated by B.C. Copper Co. i? production of , " " »one '-'■'■''■'■'■'■'■'■'■'■''■'■'''':^.':::::::::::::::::. ■ 33 N Napoleon mine New Dominion Copper Co. ..............'..'.'.'.',■■ . ™ Non-metallic minerals ** O Offspringclaim Ore bodies, origin of ™ Oro Denoro mine, copper producer , operatedby B.C. Copper Co.. '.'.'...'..'.'...■.■.■.■.'.■'. '.'■."'■■■'■■ 43 P PaliMsoic. detailed description of... ,, Primrose claim 'J Pyrite, Marguerite mine ™ " Mother Lodeore ■.■..'.'.'.'.'.'..■.'.■.■.■.■.■.■.■.'.■.■.■.'.■. « Q Quarts Quaternary 39, 48, S2 Quebec Copper Co., owners Marguerite mine. . 52 B Rawhide mine, copper producer D '1 J "a- °pe™*<'d*)yB.c.copper Co.. !!;.:.:.:;. X Kossland, discovery of gold-copper depositjj at 3 S St. Lawrence rone Silver, Boundary district '• M Silver, Miir urrlti- mine ^*''"- " MiilliiT LinlO'iru , 88 " priKlui-tionutMuthori^ilo'.'. *• Jjiowolioo mini , .-(ipiMT pr.i.lm-pr <• »l indiirU I'vritic .smeltinir Co 1 Sunll. pwtT iliiim 43 Bunsi'i claim loiated <3 " itrouj) ."...',..., • * " mini', production, etc.. *3 lone JO 33 T Tenbr.-vck claim Tertiar.v, 'Ictailol d'gcription r,( ♦> Timi'e''r*'"' "'"'""''*• *'»"»ef Lode located by .'.■.■.■.■. '.'.'.'.'.'.'.'.'.['..'.'.'.'. ^ Toponraphy It Tremolitc f7 38 W War Eaffle mine, copner producer Weir, John, bonded Motiier Lode mine. ' 4, 43 B Zoigitr 39 CLASSIFIED LIST OF RECENT REPORTS OF GEOLOGICAL SURVEY. Since 1910, reports issued by the Geological Survey have been called memoirs and have been numbered Memoir 1, Memoir 2, etc. Owing to delays incidental to the publishing of reports and their accompanying maps, not all of the reports have been called memoirs, and the memoirs have not been issued in the order of their assigned numbers, and, therefore, the following list has been prepared to prevent any misconceptions arising on this account. Memoirs and Reports Published During 1910. REPORTS. CoUina. No. 1058. "'P"K.. The Edn.,.n,on coal field. A.berta-by D B M..0.H 9. ^o^9.^0c.,o,.a.l Serie.. Bi«hor„ coal baain, A.ben.-by G. S^ Ontario-by J. W Goldthwait ^'P'^S'nK in southweatcrn MiMoia I}. Mmom IS. MiMom l«. m So. ll.C.olooiral Scrtr, In*rt« (rom the Tcrtii. ry Ikkadrnonlta .J tha V. ;,'^/" "'■ '" '»<»-hy Anion Han.,. Tho ei-a\ngy anil om ilpcMU of Phocni. Boumlary .Ii-tr„t. British C.lun.biu-bv O. K. L^lov* •^'"«""' kK """"■" P-^vincc—by Heinrich Rie' an.i 'loTph ^"r 'J- 'f''''''%'-^l ■'<'"■'<■ Roport „f tho CommiH^ion appoint.d to invp^t will- Turtle mountain, I r.nl<. AllnTtn. 1(111 "P""'""" "> Andrrw r""'!" «^ "• " v"^.'"' """'""yof «t<-..pr.M-k lake, Ontarir-l.y laki', l>ntariu— by Charles D. Walrott. MiHoiR 18. Memoir 31. Memoib 17. Mrmoir 35. MiMoiK 33. Meuuir 38. Memoirs Published up to Oct. 15, 1913. ME.\tOIRS-OK(>[.()GICAL SKRIES. '^ Yo'ui^™'"""''' ""^"'"- ""«'"'"' 'l'»'"'^<. ^''W nrunswick-by G. A. %. D'.OUr'^i"" *''■""'• ^^""•"" •'""''•'• ■*'"•'"'■ Territory-by ■'^'u";-disSt"i';iT'';;i^'V^^ by Morlr^y i:.' m^l^ "'''"'"'"« "'^'•""'"' "' '''""i"'- ™unty, Qun._ ■'^'ilAn^'?; «'<;"'"fli™i .Smf». RcoonnBissiinnc olc.nK the National Tranv contin.ntal railway in Houthrrn (jiK.bri— by .Ir.hn A Dross™ -by W^'n^Tollin^"'' '^'"' ""''"'^ "' <^=^«>-""«J« Mini-8 Divi^on No SI a.uUmcal .S.T.f«. Goolotty of ttic Xorlh Aitiorican CordillorH at the forty-ninth parallel-by Reginald Aldworih Dal^>- Part T Memoirs in Press, Oct. 15, 1913. Memoir l'J. ^°- »'• <'>«'?""'' *">». Clay an.l shale dcpo.,it, of the western Mr«n.n t? P'";,"'J,'^^»<' art, ")-l'yH.mrich Hies and Joseph Keele Memoir 37. ^^.J?, 6t„/<,e,ca/ .Series, l, rtions of Atlio district B^C.-by J). D. Memoir 23. ^'^^/^'^'j-OJ^^'/ertV, Geclo«- of the coast and inlands between tho BfSJrolt ^''"'" Charlotte sound. B.C.-by J. Austen MiMoni 40. MtiiatB S3. liuioiB IB. MiMoia at. MlMuM 38. MiMoiii 30. MlMOIB U. MiMoiB 30. liiiiow an. UaiKMB M. Wilx.n. G»iilu^itfal Strift. B.f.-by C. H Ufitniliral Stnn. ( 'iinii'l»--by W Tul.meMi Mining dirtrlrt. B.C.-by C C»nn«ll Ciold Held* oJ Nov. 8«oti«-by W. Mnlmlm ZZi'" '"°^** "* '"• -o'th""" P~vilL. of ....... ._^.,, n. niBirnmi. •■ ™. «« .1/ 1 267/ '. til '\^j r;/ ■^. ii-tu.'n ,4,'.fu,.-..'f..j (•w| '•mu.'f. I t.;,j4.n , ■■tfff/H4i./^l*t, i'i.'i"— |i' i.>tiiii>iii|!n.ii|f.ii,.H,ii|s s ..inr.i^ sum;,! '■lnMi|. 'iMi^ 1.....K,. I 'tji't '/.If'.,,. stMu.., /„„./ / -|.iiiiii| •II' 'N "II I'll "- llfiK ' l\ Itl.MIIIIM.itrtl I|||M s .^ nt...O-M> \\ ■I'llll Jepartmrnt of iQuvs OCOIOOICAL SURVCV HoMV'''''eMn£MAN Minister; A PLow DcputyMimistsr; RW Shock. OinccTon TOPOGRAPHY mil ' '»'IJ.-.-rtl ' -•iMinU'/ir . .1,,,/ t 'tiff t 'nuuihtnttuii MAP 29 A ■>,;il,-.i'i,4,il,^l,.l,,Hf, DEADWOOD IIHITISH t IHJ MBIA »• -J_J~ , ScttJp 41^1 XMU MoirM mil 400 nCT tC 1 INCH «iSTw; BRITISH COLUMBIA t! m/imoueniTt • Jk"* v«i^l H«Mii« -y SHCAT HOPfS ^ I.ECEM) i iiliuiv < ultitrv HiM'N iitit wfU tku> d I ribwurk Itailwavii Trjulp I I'HUIW HV*-, KIi-vhIhlI tmiuwavK htiaft bouti**N - ! HeliH* Tuttaptu DnvB I)*^tn'*.^iiiii ■ miiMiti-x Kl MLXES TOPOGRAPHY WMBOYD '^ rn^f^ru 1910 t c r SHCftKc, 1910 -«.„. ■ » IVMl-ll 1(1,,,.. fi V^ Kill ^ Cff£At rtn.\ 3 ^sr.v^iiirr yiiyvi^, OOD |il,IMIil.\ GEOLOGY j O £ LEhOY fiunouic C H^ DRYSDdLl ^/fC4, topqgraphI A i T ^HC 'iPAfiO MICROCOfY *l$OlUTION TIST CHAIT lANSI and ISO TEST CHART No 21 1.0 I.I [f Hi 1.8 _jj /APPLIED IfVMGE Inc S^ '653 Eas! Ma.n Sireet B^S Rochester. New I'ork 1*609 USA '^Si (716} 482 - 0300 - Phone ^K (716) 288- 5989 -To. o N o _i ' t StI-IK'tlll'ill M«>flinii ?*«-iiIt» hHII>il riu*l v..f-m ECONOMIC GEOLOGY >• ft < o < h X ui u 5 N o (A U 2 UI z bJ U o LKC.KM) ( Ihv. Hiijiti , ^'l HV(*i M(iii/t>iiii(> iHnriihyiT (llivtlii* Iki.smIi \Uatih\i»ntlv iKir|ihvriif 'rfHii*»flioritp 11 QiiHTtz p o r pb r y rite (Uacinl Htriap ttiinit of JRtms OGICAL SURVEY NisTER A Plow. DeputyMinister. Brock . irector SUHStT r-r-Q M>>i-tiiiii iiltiiiit line A B ml 'lu*! vn-Tu^il. MM) l«^i |.> 1 im-li 3&C'0 *' 3*00 i 3200 BRITISH COLUMBIA 1 1 I.KC. KM) riilim-c CiiliniT r- 1 illuKlslltll Wllllll'ti.'K-.l W:itcf i.-uiks j Hallways . . ■1 "~~ Ti-nils -J '1 Ntiir •livifinw/ivh - - - • fill Wl:l-U MiiiHral iu< 11 tuiu*-uts Klev;iii'4l ti:uiiw.-ivs Hrtils£**M SllHit lUMt»«l*K Sbai>K ruiiiN'N IV,.,i..-.l- V;'mh n-oiii-s..., tt-jrli ini> rniiiit'ii? ll| K.-licf i iltllniii-s \H \\t VS|-li. -Mlll.-tl J. Mill'- Itimjih ••luiWitl^tlPltftllH ! i 't-illl«*«ll()l'tt( A_J VnHiT* jmrjiljvnti' N ■ o U4 " in l/)ui ■] 4,^ .1/ ■■nn/iHt ni*iiii'H'rftht.t< KlltUl flill fZl'VMIp Kiiolj Hill c^Hiii MftihiT l.oilf rtrp ImnH' SmuIhiIs — I C'lacinl HtJ-ine '"-' 1 fft-olo^r^ti li(Miii(liU'>* (Vold^'ical ImiuuiIhiv r . O. S<*ufH'aJ . ' h^oifniftfier tirui ( 'hi*'t' Uruufihtsmiui . S. 1 i. Alexaii(ii»r.««t/ (> E.Pnufhonjiu*'. DniuafUnmfn. MAP .i( Sftii4:<'i * nuJf.-4 to I ifir/i MiJFlWAl LODE AN] DEADW BRITISH CO ftoo 400 iwo aoo tuo Scalp Krv' Meirts 400 FEET TC - --^X ' ' •^ 1^ o^^ ■ -"i^::^''^*^^'^'' -""^^ >/> MAP i O A ;adwood ISU rOLirMBIA Scale, woo GEOLOGY C £ LEnOY. CCONOUIC, 1310 C W OHYSOALE. AimL! 19-0 TOPOGRAPHY *l HBOYD in CH*ROC 1910 WE LAW SON 1910 AC r SHEPPARO. 1910 TrH il I* Nlllir 'l'Hm»/ITs .i..lV tl* W'.ti. Ki'-viiii .1 n Hna\;. Mi;iH ho'iN "■tlf UU- tJi' \ p ^ nt !»■■ ■Ill -■ s Wilt 1 ((.">■ tint 1. -Ill H" K.-lirt SlmttK I'tllttlflH Phmmf<*l.-i 1 ntf,onx M^'m.'f X" W