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Leo eortoe. plonchos. toMoouK. etc.. pouvont Atro filmde i doe taua do r«duction diff«renu. Lersquo lo doeument est trop grend pour ttre reproduH on un soul elieh*. il est filmO * pertir do i'englo supdriour goucho. do gauche * droite. ot do hout en bos. en prenont lo nombre d'imogoe ndeesooiro. Leo diogrommee suivents Wustront lo mOthode. 1 2 3 - 1 2 3 4 5 6 MNKOOPV ■■O UI II U H TKT CHMTT (ANSI and no TEST CHART N.. 2) 1.1 ■L25 1*. |ZS lit |2i ■ 2j2 u Itt 5l« 1 |2jO !fj 1 IL8 1.4 A ("•) Mt-SM-ro. 'a ck.KLlZ(= CANADA DEPARTMENT OF MINES Hon. MAimi Buunx, Mnanu; R. G. McComnu., Dnrait Mtmnn. GEOLOGICAL SURVEY WauAM MclMMU, DimBcnNO Gbouxur. MEMOIR 119 No. 97, Geological SbUu Geology of Matachewan District, Northern Ontario BY H. G. Cooke OTTAWA J. ra LABBOQDSRIE TACHA PRINTER TO THE KINO'S MOST EXCELLENT HAJB8TY 19M No. 1783 .St -|ii(? ». ! CANADA DEPARTMENT OP MINES R« Gt McComnu, Durvrv Mmuih. G10LCX3ICAL SURVEY i Mmom iiTI Ne. 97, CMtooKAi. Sam Geology of Matachewan District, Northern Ontario •T H. G. Cooke a«»-i) OTTAWA J. M LABIOQCKBOC TAOBt nOMTBK TO TBI KINOt MOtT IXCBLUMT lUiB8TT No. 1783 OONTINTt. Pk< 1 I t t ■alsMlolBr. PHMOlilM Rliyvlite. ONrtytafl RlnraJSutaCi AmmMw r >* ' — rtlT . lUnMlogiMlf': «tka GliaiMtar of iOtontkMi . TiBM«faltoratiMi ModaofoMn mliiUtkMM I I • » 10 V li :« u u 14 14 14 M Ift 15 U M 17 Stnietunl iBtOTMl rhnhtai MHuMnUeflMt of folding HKlfMiltinc It TfmoftS^ }• Estoraal *• Ralatiaw to oUot and yovngBr forawtioM J* KiMkMriM » OMribttUoa » UtkoinfiMl ohMMtor S Goo^amnAte •>' jSSTT.!^ « 8bte M Caleafeouo raoks ** DMnetioabttwMBKiMkMMlCoiMUnriM » Simetara g Intorma 2 fSSSr^:::::;:::v:--::::::::. :■:;::::::::::::;::;::: | MntMBOnkie aSaeta oi iBtMIUd.' 81 Kstcnua 81 Hd^oMtooiderfiiiifa;;;;;.::::;:: S • BektiautoyaiiaiMrfatinstioas S _. .^•■B 94 DubeaedykM 88 ColMdtMnM 83 DinMbation - 33 Struotmml nktioDs 84 Internml 84 - /iks FoUing 84 , FniltiM: 84 ' • Extwmid.TTr. -^ • • 34 £ji. Relstiona to oUilt tamMaoM X Supatfieud depoaiti. . . 37 *!«»>°Mi« geology 38 Aabwto* 38 Fhiorite, bwite, uid irai iote. ..'.'.'.'.'. ?? Fhionte 41 B«ito, .[]'. ['.'.'. '.'.'. '.'.['. ■*! NBiedeniuui claim ^^ Yamnr depotit ** Iron on 41 Gold .'.'.'.'.'.'.'.'.'.'.'.] « Oijgiii of tii« Mataohewan gold oiM. . . , ^ Introductkm . 43 Geology : : : .43 Vofeanioa *5 PorjAyiy « PegmatitM *l Diabaaes *7 Structure *7 Deacriptiwi of the ore^odiM. 1* Davidaon type ™ Otisae type '.'.'.'.'.'. '.'.'.'.'.'. '.'..'. ■*' Summary and oonohuiona. JS oo Index 67 Illustrations. Map 1793. Matachewan,Timi8kamingdi8triet,Ont In n««v^ ^™*'f»™",™e<^biJt series, with an older imneneDlaSedmii^ ^7 I ^:^^ °J*h8°Wdeporits and vicinity, PoweUtoKpT^^ 44 ^^ISfl °^ «'»'™ 5379 «d53M,M«howii by work done Sp to October; "*■ ^'&b^"iS?i^t^th^J^"^«^ ** K TV.«^ -ii* 21^- ^*A *H« "■JO' ore-bodies and dykes discovered BO ^'^'^'^^'^^^'^^'^'^^e^'^i'^^body^S,,^,;^ • 51 FAOI 39 39 ao 81 31 33 33 83 83 Geology of Matichewan District, Northern , < Ontario. INTRODUCTION. ECONOMIC HISTORY. Matsehewan district reedved its name from the old Hudson's Bay Company's trading post, Fort Matachewan, a place of some historical interest. The district has Bprunj| into pnuninence in the last two years tluwugh the discovery in it (h homes of valuable gold ores. 8« "outhem ntrte «plo»tion was nuuie to iSte? «Ski.'^ Montrose township,. 'S Forrest mwle a survey of MS,tl!ft?** cojoniiation n>ad to t¥e wert ««triet8. His work served as a^eK h^ST^- w*""* "^ Nipissin^ run east and west. The last^ ♦k!^iz "*"? **"«•> township lin«ww»» J. now completely -u^XflfcS'.S^*" » WO ~ that ?h7Surj5 lakes and straams. Some *rfrfs*^^i?^ *°°°. «»°trol for survevs of tl^ , trial hne of the TiiiUsSShilSfNjSX^'^ ^.«ddedT*?li bj . !Ktge-rwtu^'-««l^^^^ of Mi„es «c;^S t"hX7CJSin"c2r i™'-.^ ^*»^o Bureau Hw work was detailed and incl3%f JS^' ^°r"' Alma, and Ba^n rtreams with the micrbmete" ISd or^'S PP1°« "^ *•"« "'"•"er lakeTaS the vanous geologic boundari^ SKuL 1^^"^' "'^ *•>« J««»ting of completed'the toTOmnh?i«!i •'"occupied the summers of 19i7-ii i,„ Kmberley, WwfSSi" S KSk"T'"« ?' '^' n"rthein hafves^ Powell township; BaSbSm^2^£"M***r"*''P«' *»»« western half 3 and the southern halves rfaSVer^d'Mlv*?^' *»? Hincks towiihipS- bounAtfy of the district examined tffSn'' ^^^P^- The southern ary of the detailed map of the Gow^nr.^ ""*•* *^« ""'t'^*™ boun™ W. H. Collins. The outlines of ♦h^^*** ??**' completed in 1911 bv the surveys of the to^wJL« IndS^S ^"""H"' '^^^^ ^l >n by micrometer and Drismatir^nnT^. "'^ surveys have been filled Lakes and ponds not on7Sj?Z^JTT.°l *^^ «)utesTtravd and compass traverses ixS^n^^Tn^ ^^f^^ }'y ?P'^ '^"^^ o^^e Sf?K*°°u''°"P*»«- A thorough eSSat&nw ^^^^^^ ^'^^ t^e aid of a on the shores of the lakes and stSs«7fK '°'^«°'»" ^^k exposures mtervemng country was detemin^Srh^i.'' *''* geological nature of the fPWed about a haW-mife apS™^ ^^- "*""" °' ^^ ^"d compass ?T^ye!^ Northern Oatario Railway In additicm to the anal uutppiiig, aoiae time wm given both in 1917 and 1018 to a detailed study of the gold-bearing deposits of Powell tonpiship, the geology «* direction at vanops anglee. ," J^f^f' ^ overlay the whole countw.a^ have been ertaUishedwhfflo^e Cobalt ««^ov^ y^^ ^^^^ of thwr that they were Bupenmpoeed on the unflw^ms ^^^^^ j^^, m sSuct^when the Cobalt »en«wM ""^J^^^g^which extends wuth Kks township, occumes a ^ ^ ^* 'S i occupied in the niid£e of g^ the head aKe^P^ ^j '«*r*f«i of the Kiask sediments m *5'k1?S there/ where the older rocks stand to structure may be observed herald t^«' j^^^^„^ the avera^ S^f •'£^0'? 'JS^ Srli- p^laciSly^evelopod features are now class under consideration There are sevem^o ^^^^^^ » ^,^1*- li them is the valley "fMistoikonUke,^^^^^ ^^ ^^ ^^ ^^^ a fault may be seen on the west snore lu « Toiol. Sorv.. Cm., Mem. 3S, « W. short disUtnee to the north of Bell kbuid. A eeeond ezuai^e is the valley ol Fa^lt Uke, Midlothiaa tovnihip. The narrow Uke oooupiee a part of the vaD^y developed on a fault block. The valley ia a narrow, stekp- walled depreuion that may be traced north for about half a mue, and aoutb for about the same distance. A southward projection of the lute of the valley passes into a steep-walled valley that extends north from the nwthwest bay of Lloyd lake, so that the two probably are parts of one fauU. Otbw fault valleys cut across the structure of the Cobalt series. Axaaag these may be instanced the deep valley in Yarrow township south oftlM 92^hain portage. The fault may be seen on Mistinikon lake and staikes away from the lake in a direction slightly north of east, passing through the narrow steep-walled lake at the east end of the 92-chain partake. Its extensimt farther eastward is not known. A prominent valley has developed in Montrose township along another fault of this type. The valley is occupied in part by the east-west part of the creek from Seven Indi lake. The fault is supposed to continue west- wurd thvoHgh the northern end ot Hutt lake, where the rocks have been highly sheared. The second main class of topographic forms, those resulting not from eroeiou of the bedrocks but from the varying arrangenient of the gladal drift, are of considerable importance outside of the limits of the Huronian areas. The forms are, of course, of as many kinds as there are types of drift, and will be discussed at more length under that head. At thu point only two features will be mentioned, lakes and plains. The lakes in the drift include most of the smaller lakes of the district. Those in Argyle and in the western part of Bannockbum and Doon town- ships are typical. The map shows their characteristically irregular shapes, wtach may be described as a series of expansions, with little uniformity in position or auangement, connected by narrow, usually shallow, necks. The other main topographic feature resulting from glacial action is the plain. Plains are common within the area under discussion. They are of two types, the firat the slightly rolUng sand plain formed by outwash from a temporary ice front, diversified by occasional kettle holes, eskers, and rock ridges, the second of somewhat later origin and formed by the silting up of glacial or post-glacial lakes. Plains of the first type are to be found in the northwest part of Montrose township, in southeastern Cleaver and the southern half of McNeil, and in the eastern part of Argyle, and smaller areas are numerous. The second type is much less common, and the result- ing plains are usually small. Ope large plain of this type is to be found in the northwestern part of Argyle township, extending some distance across the western boundary into Hincks. Such plains very frequently have residual parts of the former lake still existing at their certres. Several small areas of this kind are to be found .in southwestern Cleaver. The outwash plains of the first type are frequently dry, and then are character- ized by Uttle vegetation except the banksian pine, commonly known a ia/'k pine. Wetter, low-lying parts have, however, become covered with a growth of sphagnum moss and now form flat muskegs often of large extent. Plains of the second type are almost invariably wet and covered with muskeg or swamp growth. DRAINAGE. «pooSittotto flSSne- of tlie drift covwr. Wbwo th^drifl b tUn, tSTw^M^HTuv limply » wriM of eunvatlm a£Midoiit, vwyim j" m MMmtodfram ewh other by Wrim of loek « *w«»»5"« «!" f "JP drift to tUetor, m th»t stnuM h«ve »<* •^^'^^JS^^ftu^ T^ ^Sne. are well i«ded, me«id«iBf ehwuiol. of fairly W^jj w«wj«« uTIbMiit eweS at i)u> headwatera where the itreaiw a» too "mU to taTe^SL^;^ below the Irrel of the Wtebo^^ SSS^taS; ue alao abwsnt, e«eept where ridges otnOLmm^'^^^^n^otUu^ boulden have ijcumulaied. Dunean Whlte««h. •"l^jgj^^rtt: with their various branchea, whieh drain the major part of the diatrict weet of Montreal river, are aU of this type. . . „ *_.< jl,^ The townsWps situated between the west branch crfMontre^w and Niven's baaeSie aw not drained by any OM lame rtj«m,^ ntherinc ground of a number of streams. The ^ght <'l}f^V^ ffioSftlSwea, in a «,rtheasteriy directwA, V'««^k*'^„!!£^*^ Mid^hian, across the southeaat comer of Montrose, ihenorthw«t corner of Bannockbum, and the southeast comer of Arorle. Th*^*™^^*"*** Sutteart of thi Height of Land is aU dr«n5l by creeks tributary to MoiSeal river. Thrprindpal of these is Dunoan credc, dwgmgt^ neater oart of Doon and Bannookbum townships, the northwestern SS?r o&ShuS? and the adjacent p«rt of Montio«. Itemotiw^ the head of Duncan lake. Another good-sised creek u Powell cieek, ;WchlSp?L iS^Montreal river near the north end of PoweU t«sn^ It" rains the northes^tem part of Bannockbum ««<**»»« .~'***»*"*^PS of Aj^e, and forms thelJMt route for entering the district from Montreal "^* The part of Matachewan district northwest of the Height of Land is broken bfa secondarj- divide which runs in a direction sUiftly north of wMt M^ tbTnortbem part of Montrose townsWp. ^The streams to the JSth^fTis cS^dTdrain to Hudson bay through Nighthawk nver, one of fbemSitribuSB of the Moose. They include the various branches o White&h Tad Nighthawk creeks, which run north in practically pamUel com«r6 to 8 mites apart, as far as Nighthawk lake, «*« *hicli bo J dK!«e To the south of the divide the creeks drain to the west mto GWriver, Caching Hudson bay through Mattagami f«»d Moose rivers. Th^a?e tw main creeks also in this part. The one nsee m Mjdlothum Slrfl"ws nort?*St to Moose lake, and west t Grassy river The other, ofabout equal sise, rises in Lioyd lake and flows southwest to the Grassy. At the foot of mount Sinchur Ues Sinclair lake, one of those bodies of water pecuUar to glaciated regions, in that it possesses more than one rutfet-^This take h^ directly on the Height of Land and hs^ th^^ o"t»«t»- Sne to mitefish creek, the waters of which eventuaUy ""h Hud«>n bay ?he othOTs to different branches of Duncan creek whose waters find their way finally to the gulf of St. Lawrence. WATB»«OWBM. flhDftU wstMHDOwvn midit be dev d oped At wreml |dMM within tlie I. Ob WfaiteiUi ereek, In Annrle townriiip, tlwra an two falli Mwh with • lerel diffn«ii«e of mat 16 i««t,Midlnr the erection of miitaMe duns ■tonfle reeenroin of conrideniUe eiee eould be erented. The mnid »t the outlet of U6jd lake in Midlothitt^ township hM a fnU of 25 to 80 feet, and ik» high liilb whieh aumnind Llojrd lain would pennit of the itorafe of atanoet any derired amount ol water. The outlets of Montrose, Auten, and Midlothian lakes are also eharaeteriaed by rapids of rise sufficient to develop smne wateriwwer, but the country round the outlets in so low and flat that the necessary dams woukl be very expensire. On Nif^thawk ereek, about a mile mlow Austen lake, the creek flows throuf^ a deep A dam at this point would back up the water on Austen lake as I as might be desired. FLORA AND FAUNA. Matachewan district is well forested. The deep covering of drift has been very favourable to the growth of good-rised trees, more especially in the dryer areas. The excesrive mouture of the muskeg-fovered parts is commonly a great deterrent to growth, so that thev are covered onlv l^ sparse growtu of stunted spruce and tamarack. The sandy nature of the sml in the dryer areas has resulted in the growth of an unusual proportion of good-€ised jack pine, suitable for tie timbers. The best timber of this tjme was se«i along the banks of Whitefish creek, in Bannockbum, Argyle, a^ McNeil townships. In more clayey soils, good-rised spruce and balsam are charactenstically found. Inmvidual trees of red and white pne are scattered throu^^ut the area, more particulariy near Niven's One, but there are not enough of them to add any value to the timber estimates. The white pines are commonly found as large individuals up to 3 feet or more in diameter, towering over the rest of the forest growth. Tliey are cleariy the remains of an eariier forest growth destroyed by fire many years ago. A white inne 33 inches in diameter inride the bark, felled in cutting the Midlothian-Montrose township line, showed 215 annual rings, whereas the avenge large trees of the forest growth in the vicinity do not exceed 150. It is clear that the pines must have been good-sised trees, 6 or 8 inches in diameter, when the others began their growth; and the uniformity that exists in the sise of the surrounding timber indicates that all of these trees began their growth about the same time. The occurrence of rare individuals of white spruce as larg$ as the pines themselves shows that it is not impossible for these trees to ijttain a large size when pro' ted from fire. It, therefore, appears evident that the large pines are the . inants of an earlier forest groww, the survivors of a fire that took plact tbout one hundred and twenty-five years ago. That the funes are more resistant to fire than the spruces, jack pines, balsams, etc., is easily seen in recently burned parts of the district, where the white apd red pines stand green and vigorous, whereas every other tree has been killed. As the greater number of bush fires are ground fires, except when urged by high winds, the cause of the resistivity of the pines would appear to be due either to their deeper — iOa to— ihar \H$attib0tii tooOat or to a hMvier pvoleettvo oomlaf of boifc ob tho rooto aad kmw tronk tlukD oihw trwt poMMk avdy nuOl ozoeptiooi, boworer, tin dirtiiot under oouUmtfm b kU SS? wSS. fSTSs top of* iiiih hill, mieh " "w«»iSsSr^^^ ^wly Been that fiiwi hare been nomeioua «m1 of pwiodio oceurrenoe. Former burned areM cm» eHily be dtattofuWiedfroni sueh » vMtage point, either by their unnUer »verine_powth o! timber, or by the prepoodeiwioe in them of biroh and poplar, "fte latter trees ooaamonly. appear Mg on a burned area, and affwd aiheHer to %«?'?»"««« •^^•^^iJ'SL'f they Ineieaae b rtrength imolher out their hosts and prvrant the fiowtei of new incBviduals. ., „ _s Cycbnic storms ooeasionaUy destroy the forest nowth loeaUy, mowtof down aU twos. One arta of considerable sise that^ beM» thus affected lies in the centre of Hincks township, to the south rf the caiwe route. Travel in this area is difficult. Another area, very much smaller, is erossed by the 88-chain portafle east of Midlothian lake. ^ Whoe the drift contains a cowiderable proportion of el» there is apt to occur a heavy undergrowth of pound maple and hasel bushes, w^cta increase eonsideibly the difficulties of travel through the oountw. Undei^ KTOwtb of this kind is particularly thick over much of Powell townrtuft the northern parts of Yarrow and Doon, and the southeastern part of Sannockbum townships. \rildanimab are BtiU fairly plentifuL Moose are eepeciaUy numerous, and red deer and bear are occasionally seen. Caribou appear to be numer- ous in Argyle and MoNeU townships. Great numbers of beaver are trapped annuaUy, but the other fur-bearing anunals are »«du^ becoming extinct. The most abundant fish are pike, pickerel, w»d whitefish. Lake trout may be caught in Matachewan and Midlothian lakes, and brook trout in Wbit^h creek. GENERAL GEOLOGY. OUTLINE. The geology is that of Tinriskaming district in general and may be summarised in the following table: Reoent Pluvistile Mid laciartrine wclimeBto. VneanJonMur (InfeRrxl.) Qliteial. t^nniiwl and ground morune, eaken and kames, owtwaA plains. .jf}- .INMm .ObbaU wmim, Oawptzdik fotBMtioB BmMHUo intnuhr«% puiite, and qrenite. /tUnMJM eeniod. KMc MriM, eon^aiMiste, arkoM, ilate. VtHfOlrfoflHttg. Kwiwtiaffl RkgroUte, HKMte, ImmH, tab^ pwidotite. KEEWATIN (T). DItTBIBITTICm. The rockfl grouped under this head, are chiefly voleanke and include baaalto, andeaitea, and riiyolitei. with their associated tuffs. A number ot OBall bodiea of peridotite or pyroxenite, intrusive into the bvas, are abo groupadr somewhat improperly, with the lavas. The voleanics underlie about half of Matachewan area, with thar greatest development ia ita northern half. They occupy the fpreater part of Ahna, Baden, and Argyle townships, and Urge parts of Cairo, Powell, Bannoekbum, Mont- roae, and Hincks townships. At least five peridotite masses occur around the northern end of Lloyd lake, in Midlothian township. Others are found in the vicinity o( Ilahn lake, in Bannoekbum townwip. One or two were seen in the south end of Argyle township, near mile 3) of the Bannockbum-A^le line, and anothw in Powell township on the west shore of lake Mistinikon, a short distance north of the boundary of the Cobalt series. Burrows, in bis report, meidtions another on Whiskeyjack creek, one mile north of Fox rapids on Montreal river. This was not seen by the writer. Rhyolite is found mainly in Midlothian, Montrose, and Bannoekbum townships. In Midlothian township practically all the basement voleanics consist of rhyolite. A little of the southwest comer of Montrose township is underlain by rhyolite which is also found north of Boyer lake in the eastern part of the township. The rhyolite of Bannoekbum township is part of the same mass. Small amounts also occur on the east shore of Mistinikon lake north of the boundary of the Cobait series east of Bell island. Rhyolite breccias and cherts, or cherty tuffs associated with rhyolite flows, are particularly numerous in the rhyolite area in Midlothian town- ship. They are not prominent in Montrose township. Two considerable fooBdiatk* ■MM of riaUw cterls iran tontmA oa «k« Mil tkan of Mtaliiyimi Uk», oM to Ymiow tovMyp at tk* aortk mhImI of tht BoHlwnNMi* bdhr ol BMtt*. tkt othw to FvmU lovaridp at the miiwm wiilMlf «ilt MHkoMMIUMd. AHMdIbedyolMtotiiftiliaiN Bhidto of FMran towMtop, Ml ototoM 5t7» aad fMO ol «lM QoM MtoM CuivMgr. Tho iMMtoilir of tho mm oadortoto bjr tiw bMHM te oooopM by MMkimi umI bMidts, wHh mm •dBbtwo of toll of •omopoBdtag MMpoiitkNi. TImm w«« aot Mvamtod to tho iiM4»|itoc. UTaOI.OOI0AI. CUAMkCTUm. P$ridttik$. Tho peridotitM on of oooiiblo MMinoretol importoBM, itoM M b ootw ol good qoaUty hM been fooMl to hmo of them. ng time interval iridch has succeeded the formation of botii, yet the quarts disb ss e s are comparatively only slightly altered. The peridotites were examined carefully to determine their relations to the rhyolites. At three jriaces knife-edge contacts were found where the original grain was still easily visible on the weathered nurfaces in spite of the alterations undergone by the peridotite; and at each of these jntaets a strong chilled edpe 6 inches t-^ a foot in width was observed in the peridotite. The peridotite is, therefore, intrusive into the rhyolite. Two or three of the mssses were carefully mapped. They proved to be lenticular in slmpe, with the Ipnger axis varying from one tu four times as long as the shorter. The long axis in general is narallel to the iitrike of the rhyolites, so tbit the masses usually are laceoliibio in nature: in other places, as in the forked mass on the creek between Lloyd and Rhyolite lakes, the intrusives cut across 4he bedding of the rhyolites. The peridotites have never been found in direct contact with the Kiask series, so that their relations to it are not known. The relations observed on Rahn lake suggest that they are older than the Kiatk series. The Kiask basal conglomerate here rests on an irregular erosion surface of rhyolite which, if projected a few feet,, would cut the intrusive mass of peridotite. However, as the peridotite has been faulted into its present position, the inference is not a good one, although the fault appears to have been small. RhyoUte. Hie basement volcanics of Midlothian and a part of Montrose town- ships are very fresh, light grey rhyolites, with associated breccias, tuffs, and cherty tuffs. The best exposures are seen on Lloyd lake, especially in the north arm. The rock is predominantly massive and fine-grained, in many places highly amygdaloidal. Over large areas the rock is v. iry slightly altered, in strong contrast to the other member of the old volcanic complex. This at first suggests that the rhyolite must be much younger than the other volcanics, but no other evidence supporting the conclusion was obtainable, though carefully sought. The rhyolite strongly resembles It flOBfOfBMbljr Um riwoBU of MtlMm QiMbM, dMstftwl bgr tkt wri(«;> i Willi Um i& voImbIm oI th« wfloB. Md kttnA aMmo^JIm • vskMiM wt ■ wUt oa rtiwIly »h^. ^Fw^tkt.PWf**. *fe?*^v'-T rliyottte is wwiridmd m • BMBbtf of Um old ysM» mbdIm. fHtbout MV Botoblo btte »ad yriaito. Querto, tUMlto, nrrite, iiBd^blorito i M OMi pn r. Tte wmpodtkm of tiMw ehcrty iMb iboWi olMtfty tiMt they H« bMiuw fli flat Mb, eMB«it«d by eb«nkd Mdiamt fnm MtittioiM dvw off bv Um rbyoUtM, mm! probftbly pMrtly altemi by tbkit lolutioiM. Tb* bwkfed ttniotttM M|»ntM tbraa from tbe rbyoUtM, wbkh tb^ often ■troiigly neemble otberwiM. In ndditUm to tbe breedM and eberty tuifi, » leriee of welUbedded tiiit u« found between tbe rhyoUte nnd tbe Kinek eeriee, to tbe loutb and ■otttbmet of Midlotbinn bdte. Tbey loenlly attnin tbiekneMee of 300 to 800 feet. Tbey vuy in eompoaitkm from oberty tuffs to eUtee and arkoeee of oBv^uarter mm. grain, and an entire^ oompoeed of rbyolite frapnenta imd duet, usually badly altned. Tbe alteration is of tbe some type as tbat wbieb tbe rbyolite bas itself undentone, i.e., oarixmation and seridtisatira, and is inesumably due to tbe same cause. Tbo tuffs, tbeiefore, must bave been kid down rapidly and soon after tbe rbyolite. Tbe well bedded nature xA tbe tuffs indicates tbat the rhydite was extruded into water. Varying amounts of siderite and other carbonatee in well developed crystals are present in tbe tuffs. Carbonates may form as much as 70 per cent of the rock, but commonly not over 25 per cent. They bave been developed in situ, by the replacement of tbe feldspar and seridte of the tuff. Under the microscope, tbe carbonate is sebti to be full of inclusions of quarts, which were not affected by the soluticms which altered the nther constituents, and which, therefore, remr.^n unaltered and retain in the caldte crystals the pattern tbat they had in the original rock. AndetitM and BtuaUt. The andesites and basalts are prevailingly rocka of fine to medliiiu grain, and a dark green colour. The andeuites are w :ewhat lighter in colour than the basalts, and frequently contain wh': phenocrysts of feldspar up to 1 mm. diameter. The name " jreenstonea," commonly applied to these rocks, is expressive of their general appearance. The roclu formerlpr consisted of hombiende c pyroxene and plagio- clase, with accessory ibnenite. Metasomatic alteration has largely des- tioyed the original constituents, replacing the (dagiodase with albite and oligoclase albite, the ferromagneKian miner lis with chlorite, and the ilmenite with leucoxene; develop^ug at the same time more or less sericite and calcite. The alteration, however, has not destroyed the original structures and textures. Pillow texture is one of the commonest of these, and is found in many places. It is well developed on Hutt lake and may be seen on lake Kitchimine. It was found in Yarrow township on the shore of Mistinikon lake, in Powell township near the gold deposits, and in Cairo township near the end of the portage past the long rapio of Montreal river. Spherulitic textures occur in the northwest part of Bannockburu tnai-i) 14 towndiiD V«iolitle textuw. «e found on Aiirten and Mt^^« ^» bSS. •» cSon in the soothem part of Argyte towMhip. Wd original textuiea. MINKBALOOICAL ALTBRATION. CharaeUr of AUeration. The basement volcanic have aU undergone metasomatic alteration. their feld»^ and some formation o^«»»dual quartz. {J«^XTand and »eri)entine in varying quantities or wholly lacking. Time of AUeration. M F Wil8on» has shown that in the northern Quebec region the Cm., Mem. 39, 1M4, p» 84-W. M. m57r. a.. Am. 0*.l. 82, 1908. ».«-«• t G«ol. Snrv., w — , — -^ „ ■ > Dewey and Flett, Oeol. Mac Cooke, H. C, Geol. Surv., Can., Mem. »«. 1917, p. IM- SB on eqiuklly good groimda, and may, thweffure, be taken aa fairly well proteil. Tbe aame oonelusiona may be conaidered to apply to the lavas of Mataehe- waa area, whieh are almoit identical in their nature and the eonditiona of thdr eztruaion vith the lavaa of oorthem Quebec. They afford a aatia- f aetory exjdanation of the vaiying extent to which the different rocks have bem altered. The pyroxenites or peridotites, the youngest rooks of the complex, have suffered the moat intense alteration; the basalts and ande- ntes, the oldest rdcks, thou|;h badly altered, are much less so than the pyroxenites; and the rhyohtes, of intermediate age, are comparatively shghtijr affected. Any agent acting uniformly on all the rocks, such as meteoric water, would have produced much more uniform effects in spite of the differences in the compoeition of the rocks. MODK OF OBIOIN. The lavas of Matache«•■'; to the south passes through the northwest part of Lloyd lake, which i.rire runs north, then passes on into a somewhat wider, steep-walled valley occupied farther to the south by another long, narrow, north-and-.::outh bay of Lloyd lake. It seems probable, therefore, that this whole depression may be one fault. Its age is post-Kiask. In Montrose township ^ prominent fault has upthrust the rocks on its north side, and brought the basalts of the older volcanic series into contact with the arkoses of the Kiask series. The age of this fault is, therefore, also post-Kiask. It does not appear to have displaced the Cobalt series to the east, and is thus of pre-Cobalt age. The fault is supposed to extend eastward through the north end of Hutt lake, where the older volcanics are intensely sheared. The fault strikes nearly east in its eastern part, and supposedly swings to northeast in its western part. A mmOI fwK ■tiikiiig north iO dMNM wert i- found oa lUbn W», under " Faulting of the CJoDalt senes. w;^{„5w„„ i-w- in oritvoroduced in this way is always parallel to the becding. Fa^k^ral^ produced schistosity along the relatively narrow ban J of th^tK^s.^'sJch schistosity is paraM to the stnke of the fault, and. therefore, need have no relation to the bedding. mu * L •>.,.♦ «f thp arpft aooears to have been somewhat more in- characteristic. The rfayditM have •offered eepeeialhr little. Sbew loiiee Are ranhr ia them. On Fftolt lake they are ■beared at the baae of the K3adE ■eriee, where the Kiadc eoaglomerate has slid over them during fol^ng; and aiao along the fault lones to the north and south of Fault lake. Shear- ing converte the rhydite into a aericitie Mhiit. The andesites and baaalts are converted by ebearing into chlorite ■chifts, which in thdr moat achiatoee forms are dark green, highly fissile rocks .with riossy, micaceous cleavage surfaces. Schists of this type may be seen on Mistiiukon lalce along the faulted sone north of Bell ialandf, near the gold deposits in Powell township, and in other places. Time ef Folding. The time at Which the folding of the volcanics took idaoe will be discuned more fully in the description of the Kiask series. The subject mav be dismissed here, therefore, with the statement that the folding oooutrea after the deposition of the Kiask series, so far as the evi- dmce at hand indicates. External. Relationt to Older and Younger Formationa. The basement volcanics are the oldest rocks of the region, as their name implies. They are overlain by the Kiask series of sediments with unconformity, as is shown by the ■ occurrence of debris of all the volcanics in the Kiask rocks. The uncon- formity, which will be discussed more fully under the Kiask series, ap^ars to be one of erosion mainly. No evidence has been obtained up to the present to indicate that the volcanics were folded before the Kiask series was laid down. They have been intruded by the great batholitha of granite, and large portions of them have been dissolved and digested during the process. KIASK SERIES. OISTBIBUnON. The name Kiask series has been given by the writer to a series of sedi- ments first found by McMillan^ in Midlothian township, and called by him Tlmiskaming series. As, however, there is little lithologieal or other resemblance between these rocks and the Timiskaming series as described by Miller and Knight around Cobalt, Kirkland lake, etc., the writer con- siders it best to apply a local name until the stratigraphic relations shall have been fully worked out. The largest area of Kiask sediments is found in the northern half of Midlothian -nd the southern half of Montrose townships. This area will be termed the Midlothian area; it includes about 16 square miles and extends from Niven's line on the west to the boundary of the Cobalt series in the eastern part of the township. On the east side of the belt of Cobalt series the Kiask series again outcrops, occupjring the southwestern comer of Bannockbum township &nA passing over into Lfoon and Montrose. In this area, hereafter termed the Bannockbum area, there are about 10 square miles. Some small, isolated patches of ^ ".l conglomerate are found in the neighbourhood of Rahn lake, evident, outliers of the Bannockbum >"Oeolpgy o( the ares alooc the Timiakuniiig and Northern Ontario Railway trial line between Qowganda and Porcupine '. Toronto, 1913. 90 A thiid ana of ftbottt ft tqaan Boile oocon on Mbtiaiktm U)m About ft mile south of the mouth ol Powell ereek. LITBOI.OOICAL CHABACTBB. The Kiftflk series ineludes conglomerftte, ftrkose or greywfteke, ftad slate members. Aherfttion of some of the uppef u^oses has produced types rather highly calcareous. Conglomerate. The basal conglomerate of the Kiask series varies a great deal in thickness and composition from place to place. On Kahn lake, in Bannock- bum township, where only erosion remnants of the basal conglomerate are seen, it is composed of the debris of a white granite cemented together with a small amount of black argillaceous matrix. At this point it hes directly on the surface of a rhyoUte, and occasional pebbles of rhyolite and other Keewatin rocks are present. At the west end of Boyer lake, in eastern Montrose, the conglomerate again lies directly on the rhyolite. This locality is the only one where red granite pebbles were observed in the conglomerate. The pebbled throu^- ■ out a thickness of several feet at the base were largely of red granite and coarse pegmatite with red feldspar; above this the red granite was replaced by the more characteristic white granite debris. The layer of conglomerate is rather thin, in the neighbourhood of 25 to 30 feet^ and is overlain by a few feet of a pebbly argillite identical with the slate conglomerate of the Cobalt series. Over this lies a fine-grained, rather soft greywacke which will be described later. In the western part of Midlothian township, along Niven's line, there are about 300 feet of interbedded conglomerate and coaise arkose. It increases rapidly in thickness to the east and in the neighbourhood of Fault lake, about 3,000 feet of conglomerate appears to have been piled up. To the southeast of Fault lake the conglomerate thins again, and south of Midlothian lake there is only a coarse grit in places with an occasional pebble. The basal part around Fault lake is a heavy granite conglomerate, so completely made up of granite debris that on badly weathered surfaces the outlines of the pebbles are lost and the rock in places might be taken for a white granite. White, subangular granite boulders of all sises up to 1 foot in diameter form approximately 95 per cent of the rock. The remainder consists of various coloured cherty tuffs, rhyolite, and serpentine. The granite varies in composition from syenite to types with about 15 per cent of quartz. The grain of most of the pebbles is very coarse. There is little matrix, and what occurs is apt to be rather quartsose. The white granite part of the conglomerate around Fault lake is about 200 feet thick. At this horizon its character changes abruptly, and there appears the more characteristic greenish-grey conglomerate of the Kiask series, as seen around Midlothian lake. It is beautifully exposed between Fault lake and Midlothian lake, by a recent fire which has swept the surface free of vegetable debris. Although it still contains granite pebbles and boulders up to 1 foot or more in diameter, such pebbles constitute only at **""* 5J*' o«>t of the totol IMM, iiuteMl of 95 per cent m in the lower hori- m. The renwioder are of the ancient greewtonei, or volcwiica, Sincu- •lilodaSdSert lirf!"*** '"P**^"® to find one of the rhyoUtie or 4he The pebbjea of the crajslomente are neither noticeably ancular nor noticeably weU-rounded. The granites are fairly well rounded, tie green- •tones rounded or elhptical. None of the greenstone pebbles are notiroably sheared, but they are all altered metaK>niatically, suggesting that such alteration had taken place before the formation of the conglomerate. The nutrix of the t. enstone conglomerate is greenstone dust, which m i^ces mkes the outhnes of the pebbles difficult to distinguish on freshly A few beds of conglomerate also occur interbedded with the arkoses of the senes. They are rarely over 6 feet in thickness or thereabouts, and are mostly found toward the base of the arkose horizon. The pebbles in some of these are fairly well rounded or subangular, in others quite sha^J angled. The composition of these conglomerates differs from both of the vaneties already described, in that both pebbles and matrix consist almost entirely of debns from the rhyolites and cherty tuffs. In this thev resemble the arkoses with which they are interbedded. Arkote. Arkose or pit overlies the conglomerate. On Midlothian lake the gnte have a thickness of about 6,000 feet. They are all steel^jrey rocks, uniformly hard, fresh, and well bedded. The beds are 6 inchw to 3 or 4 feet m thickness, and are marked by differences in grain rather than in colour. For this reason the bedding is difficult to detect on any but clean, wave-washed surfaces, except in the places where the difference in wain of adjoining beds is considerable. The grain of the coarsest grits b about ^ mm., that of the finest grained massive types 05 mm. a ^® composition of the arkoses is very similar to that of a rhyolite tuff, fragments of rocks and minerals, many of them sharp angled and even chisel-edged, but never more than slightly worn, constitute a larger or smaUer part, and are embedded in a fine-grained matrix. The fraements of the coarser vaneties are of rhyolite and cherty tuff, and, rarely, a bit of some other rock; together with chips of individual minerals, such as quartz, albite-ohgoclase, and magnetite. A thin section cut from an average bed of medium grain contained about 30 per cent of such fragments, the matrix of this rock consisted of about 50 per cent of chlorite, and the remainder mostly feldspar. Quartz, sericite, and magnetite were also present in minor amount. In other beds the matrix is largely sericite and •"loun. The sericite appears to be a primary constituent, and not formed by secondary alteration. Generally a Uttle secondary carbonate and pynte is present. Slate. tv/ijAi^-^"^, ?^ ^^?^ ^^*^ *'^°"* ^0 ^^«t t^icJ' "es on the west shore of Midlothian lake. A similar band crosses Niven's line at mile 82 • 60 chains uther bands cross the northern boundary of the township at three or four -I WfewMB MV*M '''*" vA and Nivoi'f Mm. TIm altttM m« tm7 SSS!r bT^imSbrTo tbt «y* they o.« UMk or ««kb. InA- S«vH« MU to MNHiit of • fiii»«rahi»^ &A»cris of ehloritt, >0BMttmM oTtUf BOWidmMi. d^ebptaf appMWitljr at th« «amMiM "' i ehlortte, bwnf«)l»oed,MidiBaybeiMnwHhintheealciteonrt -""fS^ in the Hote namber uid guaml •macement h they 4^.-«» outrtde ttte e^. PMt of thii ewboMte ie iWerfte, pwt cdclte or do» iiite. Aho- cether it fomu about 26 per Oent of the rook. In ■ome ''•^^^^^'^ Sloito cryrtale we rinuneSwith magnetite grains, in others with nnuooyite fibSTwlSX* ««e. «• arranged nan^^ which t'ley Ue. Thw wtmld eeem almort; to haw been purtied artde by tlie crystal during growth. Cobarsous Rodu. , Above the sUte layers, principally in the southern part <£ Momtrose township, a number of IWbt^Joloured soft rocks were found interbeddod wuTthe more characteristic grits and arkoses. Buui^ under the mieroMope these were found to have been «««nt»»"/ J*'" *^« •««;^ and gritsV but the material that composes them either had a better chance to dMompose than that of the ordinary arkose before being laid down in Its present porftion. or the orighial teirture was looser for some nMaa,iLvA permitted more rapid secondary alteration to go on. At wnr "J^Jhese locks have been coarsely fragmental grits, but are now badly altered to mbcturee of chlorite, kaolin, sericite. and caleite. Around Sinclair lake there is a fine-grained, moderately hard neywacke, a most monotonous light grey mud rock with little or no appearance of bedding. It covers a large part of the Bannockbum area on Moount of the flat-bedded structure of the area. It is seen under the microscope to be a typical greywacke of this senes. Shwp angular frag- mento ofminerals up to 0-2 mm. in length constitute about 40 per cent of it. Roughly three-quarters of these fragmente are quarts, the remainder mostly oligoclase. Thw are embedded in a very fine-gramed matrix of kaolin ^th a little epidote and sericite. DISTINCTION B»TWBBN KIABK AND COBALT 8M»8. Distinction between the Kiask series and the Cobalt series is difficult in places. especiaUy in the Bannockbum area, where the Kiask series lies flat The only distinction possible, where similarity m structure occurs, is based on the petrographic differences between the rocks of the two series. The Cobalt series in this vicinity is vepr largely composed of debris of reddish granite and syenites. The congtemerates are fiUed with red Kranite pebbles, the arkoses are red with abundance of red felds^ itraiM. the quartsites and black slates contoin mterbanded reddish beds, Mid. even where outerops of black slate are not large enough to expose the red(iirii beds grains of red feldspar can be observed on aUnost any freshly '*^ l*f*.- ^ .^^ '"^ (» ^ eoDtrary ooataiu pntetioiUly MMdiddMi. lUddidiBMiitepebblMwweobMrvwIintlMeoni^uuKmte at tba ww( end on Boy«r uJu, but in no othor loeaHty. The nuwt ptOn*- «ii^ MMwh failed to tvmi raddfadi bedi or crafau of nd tMgpu in the loeki at any othar pla«e, or in any horiwrn of tha aorica. amvcTuu. Inkmal. Stntitmphy. In the Midlothian area the Kiaak aeries oonsieta of conglomerate at the baae, overlain by a band of date, then by thick beds of aricose or grit. The conglomerate varies both in thickn«M and composi- tion from place to place. Around Fault Uke the base consists of about 200 feet of the heavy, white, granite con^omerate nreviously described, ffioveriain by 2,000 to 3,000 feet of greenstone conglomerate. The con- merate thins to the east and to ' s west. On Niven's line the total olmess is only about 300 feet, anu all the exposed rocic is greenstone conglomerate, so that the granite conglomerate is either quite thin or altogether lacking. Between the south end of Midlothian lake and Lloyd lake the conglomerate is also only 200 to 300 feet thick, and in one place is almost altogether replaced by a coarse grit. Directly overlying the conglomerate a bed of black argillite or slate was observed on Midlothian lake, on Niven's line, and on the Midlothian- Montroae boundary. This bed is about 60 feet in thickness. It was not traced through the area, but its location above the conglomerate in both cases and its uniformity of tluckness renders it probable that it is continuous between these points. Beds of arkose or grit interroferoed toward the base with beds of conglomerate overlie the slates. The beds of conglomerate are few and avera^ about 6 feet in thickness. The grits vary in texture from coarse matenal carrying small pebbles the size of a pea to very fine-grained greywackes or sandstones. At least 6,000 feet of these arkoses are exposed on Midlothian lake. The total thickness is not known, owing to the lack of BufScient good outcrops for structure determinations. The arkose and its interbedded conglomerates are composed almost entirely of material drawn from the underlsring rhyolites and their associated beds of cherty tuflfs. The relation of the carbonated arkosee found in Montrose township on both sides of Midlothian creek, to the arkoses of Midlothian lake, is not known, as the exposures were not good enough for structure determinations. They were concluded, however, to overlie them, since such carbonated phases were not found anywhere on Midlothian lake above the con- glomerate. In the Bannockbum area the succession differs somewhat from that of the Midlothian area. The base, which has l»een seen on Boyer lake, Rahn lake, and north of Sinclair lake, is a white granite conglomerate, about 30 feet in thickness. At the west end of Boyer lake the lower 5 or 6 feet of the conglomerate contains many pebbles of granite and pegmatite containing red feldspars instead of white. Such a condition was not ob- served elsewhere. The pebbles of the granite conglomerate are embedded la ft natrix of bUok •rgUUte, and on Bovtr kUu the mm» ariUUto OMfnriBg ■Mtttand pebbiM of gnnite fcmat a bad • few fMt In tbiekuMi ovtriyteg tba eoacloBwtstc. Ita awwarano fa Idaatleal with tha alaW congl om c f att of tbaC^iat aerlea. OrMvlBg tba argUHta band fa found tba noaotuioaa unbaddad giajrwacke deaofbad on par 23. Ita tbickneja waa not deto^ minabla owing to ita ilat^ying ■traetura and Na iadi of baddiag. On tba ■otith alda trfBoyar lain, bowarar, it ifaaa into a hill about ISO faat Ugh, w that ita thieknoai muat ba at leaat ISO faat. If a uniform dip of 10 degraaa ba aMumad for it betwean Bovar laka and Sinelair laka, tha thiokneai is at laaat 1,300 feat. The true thickneaa probably lies between theee extremes. Like tha arkoae of the Midkithian area, the greywacka is oompoaed almost entirely of rhyolite debris. On tha eastern M» of the Bannoekbum area D. J. Fisher observed eonsiderable thicknesses of flat-lying black sfates apnareutly overiying the greywacke. These slates contained no grains of red feldspar or bands of reddish material such as are abnost invariably found in the slates of the Cobalt series in this district. They were, therefore, mapped as part of tha Kiaak series. The relatitm between the formations of the Midlothian and Bannock- bum areas may be rendered clearer by the following diagram: ArkiMD with mrbontod bMltr Slate IlidlothiM MM Arkoae •ad eoi«lom«nt< ± 6,000 leet aivywarke ± 1,300 iMt Baaaoekbura area \ BUtotOfMt Slate 6 bet . CoBglomente 300-3,000 (eet CoBclomerate SO^SO leet 1 Folding. The Midlothian area has been tightly folded, so that the rocks now arc all on edge, with almost vertical dips. The strikes follow closely the boundaries against the rhyolite. At the nose of the fold, near the distri t line, the general strike of the beds on the soutuem limb of the fold is south 75 dej^rees east, that of the northern limb is about north 20 degrees east. The axis of the fold, lying midway between the two, strikes north 65 to 70 degrees east, and, since the syncline narrows to the west, is plunging steeply to the east. As the dips are about the same on both limbs of the fold, the axial plane is vertical. The south side of the area of Kiask series, which has been carefully mapped, shows two pronounced bends to the south, one to the west of Midlothian lake, the other at the northeast comer of Lloyd lake. The strikes of the rocks here follow closely the curves of the contact, so that these are concluded to be drag folds on the flanks of the main syncline. The axes of these secondary folds strike north 35 degrees east and north 70 degrees feast, indicating that the folding has been of the normal type. The KiMk MfiM Um •Imott flat in the Bannookbuni mm. Thk geullMUjr BMkM it difleult to diitiiifuiih from the Cobdt miIm, whm ■farilM w«k typM, rarb m the anilUtee, are under eonaidentioB. The ^^f^y ^^^^.Vnponnmi on the eMtera side of the ana, when then JCJ^'Ti;.53*SJf ?[ •^J"**^ P»rt of theae an clearly Cotalt •erie.Ta. K5!'J5f!£^'!lZ!*'' ^J^ ?l?5!r ^J*** ■"'' ^ feWapar Rraina oharaeter- jH'^^ltr^i: 2i***f •»!'"'*« •»«'• «w> «u''^' mtomIm, and have been mapped with the Kiaak. However, the determination ia doubtful in |Maeee. 1 ]?**u?vP'^5l •''0'" that the Pvinoekbum ana ia an anticline the axis of which strikea north 10 degrees ^eat and ia plunging to the south at ■ '^J •**? *"•" *"• formation diaappean below the Cobalt aeries on the Bou^. The NOBounced synclinal bend in the boundary of the formation ?^iJ**T.j ^ probably the croaaing of the principal axis of the \iid- lotblan fold. The Bannockbum fold ia, therefon, a pronounced anticl'nal croM fold, if we conaider north 66 degreea eaat as the principal axia of f d- ing; and the flatneaa of the strata in the Bannockbum ana ia probably due to the counteracUng influencea of the ayncUnal folding and anticlinn' croaa folding at thi« p^int. •.i.^i**?l***^^*il° down-faulted urea the beda an all steeply dippina, with a stnke Bouth 66 degrees east and dip 6« degrees north. Mttamorj^ieEffecU qf Folding. The effects of folding on the rocks of the Klaek aeriea have been aurpriaingly slight. Appanntly they acted as 1™!^^*' *<""P*^°* "nit" even when folding was seven as in the Mi*^. Tinu of Folding. The folding of the Kiask series evidently took place befon the deposition of the Cobalt series, as that series is comparatively unmetamon>ho8ed in this vicinity. It also probably occurred before the intrusion of the great batholiths of granite, as these are nowhere sheared. 1 he folding movement may, therefore, be stated as post-Kiask and nre- granitic or pre-batholithic. FauUing. Faults are rather common. A block fault with a north- south strike passes through Fault lake and weathering along the fault has produced a valley of some length, of which the lake occupies a part. The northern boundap^ of the Midlothian area is a fault, with a general east- west strike. It baa brought the Kiask series against the basalts of the volcanic series. The fault has not apparently affected the band of Huron- '*A *!. .t T,Vj?"? ." Pi^bably, therefore, pre-Huronian. The boundaries ot both the Midlothian and Bannockbum areas against the band of Cobalt series that runs through Montrose township are faults. As will later be showi m the discussion of the Cobalt series, this band forms a downfaulted block m the northern part of Montrose township, the displacement of which decreases toward the south. The eastern boundary of the Bannockbum .irp.a seems to be also a fault hne or a senes of them. The members of the Cobalt series in contact tba imr mwihtw of tbc OowiMd* tomaUkm. mm » coalMt mbdm Im r «1 «nt|it by f Mttting. «l wtmrMSBUrUMtiMl wHb tboM obMmd on IfkUpUiiMi Idn. No S^tfcSiMrclmly thoi» oHw^ M^ be MM in lA iMrt two pUcM m tbe lake Mort. BskmaL RdaHoiu io A» Kmmkn. The KiMk wriM Um unoonfonublyttiKm tb« roH«M of the widMt TdeMic. At the pwMiit time It tanottoowii whether the unconfonnity ie erodowa only, or both etnieturjl wjd ««w»n»»- The KiMk beeal e(mglomer»te, wherever found, Uee on rhycriite. in t&e MkllothUn are* » cwrful etudy failed to show any dWeiMce ta rtri» <« S^Stween the .MUment. and the underiylng Ay«f *••. New Rjibntato, w&ere the baeal eonglomerate lie. tot and le prei«.t onhr to «»» P^{g* or eroeion remnante, the moat careful examtoav on failed to y*«*™»^~ itrueture of the rhyoUte. From the faeU determined around y^lifc however, and the faet that, aa the map ehowe, the eonglomerate everywhere teets on rhyoUte, H ia concluded that there can be no pronounced structural JSSiSrorSty brtween the two: m, that t»W,~« «^*»7' ^^^ZTi^iiSS elae foldinf to the rhyoUte has been only eli^t before the aedimente were laid down . . There can be no doubt, however, aa to the erpdon^ natwe of the unco^SiT^beSreen the toaek eerie, and the Keewato. The upper Kiaak oonriomerate i. largely made up of fragment, from the tower volcanic,^ bawdt. and andedte. commonly grouped towther »• green- atone.: wherea. the upper bed. are compoeed Uurgely of debri. from the A^U member of thefower wrie.. Rb"oli^ cbBle., though to MiaUer nSenrare al» to be found to aU horiK)i». down to the bawl con- glomerate. . ^ . , , . . . The rhyoUte i. intruded on the wuth diore of Rahn lake by a dyke of Mfpentiniied peridotite rtriking north 30 denee. west and dipptog JteeW wuthwedT It i. ah» intruded by a l*"^ ^^t^'T^.S'bbro wLcB hM not been Mrpentiniwd. The wuth diore of the lake w ao»if about 20 feet high, overhanging romewhat to place., and pawtog at the top into a rteep .Spe that flatten, rapidly into the ^^"^^ «^J^f 'f*^' .i^U this surface, on the steepnrioping edge, and on the face of the cWf itoetf to one place down to the waters edge, are to be seen patehes of thf Kiaak basal conglomerate, varying from a few mches to a few feet m ttoctaess. It is clew that it murt have been laid down on a very »«>JP>1",««*»^ aooroachmg that of the present; and it is equaUy clear that the irre- aularity must have been one of erodon, since the old surface cuts across not only the rhyoUte but also the gabbro intrusive into the riiyohte. The penod betwwn the extrusion of the rhyohte and the deposition of the KiMk series must have been suffi iently long, therefore, to permit of the totrusion and cooling of the totrusive, and for erosion to cut away the rhyoUte and expose it. •r Tkt wurw d ^ matto pt/bhUt ia tiM bMd XkMk ,i,i.m bM^toowB. N«Mhr liU of tha gnahM of tbt diHrUl boataiajnoNor niff^.-'^'^i^ *. •»»(»•, vhHo malto wm found At Um north ond of haro boon Um khivm ct supply. * ' o u-??'!?!?" *•• *** ^"ft* *'^- T>>« eon*^ of Um KImIc and Ui« CoImH MriM WM not dimUy obMnred at any pi^t Howtvw. Umto oaa bo no doubt Uiat Um Cobdt Mriei it Um youBgor and Uoa uneo^onn- ♦•^"P^J *** *4r^ l5t»MMidk,Ud«.ar^ulrKladi««iJirrt!SSr tUtad and aooM of iU aOftwr lavan have boon mora or !«•• aebiatificd^ fokUng tnovemeata. The Cobalt awiet dinetly to the eaat U«a uniformly flat, and ia UDmetamorphowd. A time intorvaJ of folding and aubeequent eroakm muat, therafore, have intervened betweeb the eloae of Um depoai- tfon ^ Um Kiaak aeriea and the commencement of the depositbn ofthe vobalt r~*'" Malumt to Iha OraniU Intnui»t$. At no point waa tiM Kiaak aeriea found in eontaot with any of the graniUo intruaivea, ao that Uw rebtion between them cumot be ceitalnly Itnown. On EUaabeth Uke, however, the Kiaak aeriea la cut by many veinlets, moat of which are quarts, but one of peKmatite waa obaerved. The presence of this veinlet indicates (bat tnen ia a body of mtrusive granite magma not far away. The Kiaak series is, ther^ora, tentatively pUtoed in the geologic column as older tt«a n h ?^**° intruMves, until aome mora satiafactory proof of age can be Mona or obioim and HiaroRT. The nature of the Kiaak series, as outlined in the imceding mves IS so remarkable aa to make it diflScult to outline a mode of origin Tor it which will satisfy all the facts. Briefly summarised, these facts are as follows: The basal oougloirerate in the Midlothian area is a granite con- glomerate with only about 6 per ceat of other constituents. Above this tnere is a heavy greenstone conglomerate, with not more than 10 or 15 per cent of other constituents. The overlying beds of grit and arkose, mingled with occasional beds of conglomerate, are chiefly composed of rhyolite- debns. Any theory of origin, to be fully satisfactory, must explain where tnese three kinds of mateiial came from, and why they were carried in and laid down in the order mentioned. The sediments of the Midiothian area consist of granite conglomerate at the base, overlain in turn by greenstone conglomerate and by arkose with occasional beds of rhyolite conglomerate. The total thickness of the conglomerates is apparently 2,000 to 3,000 feet around Fault lake, thinning to about 300 feet both in the eastern and western ends of the area The thickness of the arkoses and grits appears to be at least 6,000 feet. In the i^nnockbum area, only 6 miles from Fault lake, the basal granite con- g omerate is 30 to 50 feet in thickness, the greenstone conglomerate is altogether lacking, and the overlying beds are not coarse grits but fine tnat-t 38 erevwacke passing upward into slate. The total thickness of the *onnation rS? veiVmuA less. Any theory of origin must account for th«« Ili!a5abl7clwnge8 in the chiiracter and thickness of the sediments withm a distance of a few miles. The nature of the Kiask sediments indicates that they were accumu- lated raoidly and did not undergo much wear between their source and the phSSSr deposition; and tLt the rocks of whose fragments they are SJS^ underwent rapid mechanical disintegration «°accompamed by cheSl decomposition through the ordinary procesfles o^.^^**^*"5f- Rapid accumulation is indicated by the angularity of the Pebbles in the coSomerate, by the characteristic occurrence of shaip a^^K^^ f nd ch sel S in the fragments of the grits and arkoses, and probably by the SSdVSltu^f the greywacke of the B.^^^i^u™ a'l*:^^;^^^ beddina in muda is characteristic of deposits that have accumulated Sr veS rapidly or else in very shallow water. Rapid dis; tegration of the parent Vocks is indicated by the "nif«™ «'l'«'«-»>'^«.il3S of the sediments from the coarsest to the finest. When disintegration Secure uSv nonnal present day conditions, vegetation keeps the detritus freKSg lushed a A until the action of the weather has ™tted th« ™«^s more or less completely, with formation of such products as kaolm, Kte inToxides, and quartz. These are mechanically separated dunng eroS a™d are deposited in separate beds as sandstones and clays wKm the lime md magnesia, which are earned off as soluble WoarWtes are precipitated by various means as limestones. In the Ki^kTrSs the ro^C^^*^ compo^d of the fresh or slightly altered detritus S The parent rocks, instead ^ being sandstones, clays, and hmestones; no tKhe disintepation of the original rocks must ^aye ^cen closdy followed by the removal of the disintegrated material. We can infer, therefore, with some certainty, that vegetation was Uckmg and, smce a Sw Ivingland would not fimiish coarse detritus rapidly, tluit the area from which the sediments came was hilly, perhaps mountainous. We have, therefore, a series showing evidences of rapid accumulation without much weathering of the original rocks; ^with wide variations i^ apparent thickness ^thin short distances; and with the peculiarity oT being composed of granite debris at the base, of greenstone debm m the middlefand of rhyolite debris in the upper horizons. The firet quality, Ts indicated in the preceding paragraph, impl es a hilly or mountainous counter, bare of ve^tation, supplying the sediments. The vanations in ■ thXess are characteristic of deposits formed by torrential streams descending from a mountainous country. A mountainous hmteriand is thus implied from two linos of evidence. Incidentally deposits formed by torrential streams frequently possess an onginal depositional dip. If this was the case in the Midlothian area, the real thickness of the s.^- ments will be much less than the apparent thickness, whichis calculated on the assumption that the beds were ongii Hy laid down flat, ine third quality mentioned above, that of the peculiar separation of the rock materials composing the Kiask sediments, is more difficult to «cp am. Threxplanation may be, perhaps, that a gradual uphft of the hmteriand was going on, exposing new rocks to erosion. ^ x. , i i a The great thickness of the conglomerate beds around Fault lake, and the rapid decrease in the thickness to Uie east and west, suggi.st that tbe I 29 MBition occupied now by the lake must have been originally the mouth of the torrentia stream which carried down the sediments. As the heavy beds of conglomerate are on the south side of the Midlothian area, the stream would appear to have flowed from the south and the supiiwed range of mountains from which it brought the sediments would also, therefore, lie to the south. ' Under this theory the Kiask series is a series of localised origin, since the inatenal>: vsl^th r",rapo8ed it must have come from the basin probabFy of a single v. ge> Htream If H is of the same age as any of the other ancient series of sj imonts found ir aorthem Ontario, such as the Timiskaming of Kirkland '.k. a relation till unproved— the two need not have the same or a simila omnosition, I at the composition will vary with the variations of the' rocks ?reot river basins. MINERALIZATION. As the Kiask series is probably older than the granite intrusives of the region, there appears to be no reason that it should not be mineralized in places. However, the writer has not observed any notable mineraiiza- *'"!!* "*u*°^ P*"°*' '° fact the rocks are so massive and unaltered that at Mght they create an unfavourable impression on the prospector's mind The only tendency observed toward mineralization was on Elizabeth lake" wher there are a number of veinlets of quartz. At some other places an impression of mineralization is given by the rusted appearance of the rocks but upon examination this is seen to be due to the weathering of secondarv iron carbonate. •' AGK. The Kiask series lies on the eroded surface of the rhyolites, the youngest rocks of the volcanic series, and is, therefore, younger than the rhyolites As shown on page 32 this series is probably intruded by, and, therefore older than, the granites. In the discussion of the age of the granites (page 33) it is shown that the Kiask series was folded, probably elevated to form a mountain range, and eroded to base levol before the Cobalt series was deposited on it. The Kiask series is, therefore, very much older than the (obalt series. GRANITES Distribution. Granite form.s a considerable proportion of the rocks in the eastern part of Matachewan area, but only a small proportion in the western A small mass IS found near the centre of Hincks township, underlying a portion of the Cobalt band there. Dykes, probably offshoots from this mass, are found here and there to the southeast. Another mass of Kranite n(M^ -f wu*-!'"2 ?*.^.°^ ^'^*^^'" township, a third in the eastern part of McNeil near Whitefish lake, and a fourth crosses the Powell-Bannockburn i)oundar>'. In the eastern part of the area the condition is different. A ' WIU ■■ J J i* so large part of Kimberley and Yarrow townshipji is underlain ^ »«?>*«; anotheTmaas underUea about 30 square miles of the eastern part of Cairo and Alma, and a third, good-eiied body is found in the northern part of Baden township, extending eastward into Alma. In addition there ww several small bodies in the southern part of Powell township in the neigh- bourhood of the gold discoveries. LITHOLbGICAIi CHABACTBES. There is a considerable variation in the composition of thc«e various granitic intrusives, together with certain similarities. W. H. ^o'toS; « describing the^anites of the Gowganda area to the soutn, has divided them into two main classes according to whether the ferromagnesian mineral present is biotite or hornblende. On this basis of classification all the Kranites of Matachewan area will fall into one class, as all are horn- blende granites with syenitic phases. The cntenon, however, is apoor one, since the presence of mica or of hornblende seems to have been a function of the original wetness or dryness of the magma 'and micaceous phases or homblendic phases might, therefore, occur .n different parts of the same batholith. Certain writers have used gneissic textures as a cn- terion for the separation of granites, with the implication that t^pse body's possessing the gneissic textures must be older than bodies without such textures. This, however, would be irue only when- the gneissic textures were produced by regional deformation acting on a mass of sohd granite. The imeissic textures commonly found in granites have been clearly shown* to be not the result of deformation, but merely flow textures developed during the solidification of the granite mass, so that they may have developed in any intrusive in which movement occurred under proper conditiWs of viscosity, and cannot, therefore, be taken as a cnte""" f »««• A G Burrows* has recently advanced the idea that strong resemblances in chemical composition are indicative of identity of intrusion, and has used the idea to correlate two bodies both of which possess unusually high pereentages of potash. The conception appears to be a good one, its main objection in practice being that it requires a slow and expensive chemical analysis before any conclusions can be drawn. The converse of the propo- STannot, however, be accepted as true, namely that gTr^nlZi'^ composition are of different ages or even come from different sources Sanalyses of the granites of the HaUburton area, which Adams and Barlow by a careful detailed study have shown to be of a single age and souree, show rather wide variations in their chemical compositions. How- ever. Burrow's suggestion of using some chance excess of one of the rarer constituents-in this case potash-as a criterion for comparison, is a good onrand is the best means yet offered of classifying and grouping granites by ntemal evidence. It is along the lines suggested and used by Derby who found that he could classify his granites with a high degree of certainty by measuring the relative proportions of their heavy residual minerals, the garnet, rircon, titanite, etc. TGeol. Surv., Cm., Mem. 33, 1913, p. 43. , _, .t > irt -« in-ut » BoWN: L.. Joir. of Oeol.. iusyisment to vol. 23. No. 8, W". W- «-*^ • bSsSiI;, a. d.. Kept. Ont. B«i««. of MU«, "• "If • W- «^*"- • Adam* •nd BmIow, QvA. Sunr.. Cm- Mem. 6, 1910. pp. 82-62. n Up to the present time, however, no satisfactory means of seoaratiM in! f„« w^'S**^"'*^ sedimentary horizons which may be use^for the f^r off' ^^T *® ^"'^ f «™°**« ''^^"'y 'yi°K I'eneath a sedimentary l^nnni^ -r*" *!• " ?"«•««>«'?*«. »»at they intrude the older volcanic complex and are overiaid by the Cobalt series. They are alL therefore, assumed to be of the one age until proof shall be adduced for tncir separation. Nearly all of the granites of the districi are rather syenitic types containing small amounts rarely more than 2 to 3 per cent of free quartz The quartz content is variable, however, within the same mass, so that in S^if't V^Tk""^" """^u "l";*^ quartzose, in other places there ^11 be none visib.e to the eye. The ferromagnesian mineral present is commonly f™Ll!l r ^''k-P^ .'°.tl>^<'"se of the gold-be£.nng intrusives in PoweU township n which it is mica. The ferromagnesian content is invariably small. Feldspar forms 90 to 95 per cent of almost any specimen of granite l-trhl^X'^»?jT w" ^ * tendency to the formation of porphyritic phases, with bright reddish feldspars up to one-half inch diameter embedded in a paler coloured, finer-grained groundmass. Burrows has pointed out that the granite mass on the east side of Cairo and Alma townships is very high in potash, as are also the small masses in Powell township around the gold deposits. It IS suspected from the similarities in general appearance and microscopic structure, that other bodies ure of much the same tVpe, particu- lariy those m the southern part of Yarrow township, in western Powell crossing into Bannockburn, and in the middle of Hincks. As the potash content would indicate, the granites are true granites, the feldspars being orthoclase and albite with the orthoclase in excess, and not granodiorites with mil'- tne-soda feldspar. STRUCTURAL RBLATIONS. Internal. In general the granites are perfectly massive. One good-sized dyke of white gramte, found in the southwest comer of Montrose township, was badly sheared and qmte schistose. This dyke will be referred to later! Ihe remamder of the gramtes, however, even when in the form of smaU dykes, show no shearing whatever. Gneissic textures are occasionaUy present, part. -iilarly toward the edges of the masses. These are primary flow texturee, formed by the movement of the granite magma while becoming'." us. The viscosity is producible in two ways: by ordinary coohng in «uich case the gnessic bands do not differ in composition from the rest of thrf magma, and the gneissic texture consists only in a parallel arrangement of the nucas or hornblendes of the granite; and by digestion of stoped-off lumps of older rocks, such as the older volcanics, in which nMh«5L§!i!r"'*^^!r *' ™Pl««d "?o™ prominent by the presence 2t.h ,^^^ 1°^ dipstion which vary from lenses of bade rock softened and stretched, to patches of highly micaceous and homblendic rock which as rannaeat a mature of digested baric rock and granite. The general lack of huge amounts of such textures in the Matachewan wamtes mdicates that they have not been of a comporition to digest the wder rocks readuy. This may have been due to a lack of water in thfe magma, as evidaaced by the fact that the common ferromagnesian mineral is hornblende instead of mica. A comparatively dry magma would presumably have been more viscous and, therefore, less active both physicaUy and chemically in >reaking up the rocks intruded. External. ROatims to Older FormaHoM. The granites intrude all the rocks of the old volcanic series. Proofs of intrusion are easy to obtain, as the volcanics may be found broken off by the granite at the contact and forming contact breccias which often form bands one-quarter to one mUe in widSi. Dykes of the granite break through the volcanics, particularly m Hincks and Powell townships, and show chilled edges against the older rocks. The relation of the granite to the Kiask series is not to be directly seen, as the two rocks are nowhere in contact, but it may be inferred. The Kiask swies has been strongly folded, whereas the gramtes nowhere show any signs of having been subjected to folding. The granites are prevailingly pink and red, but pmk and red gramte debns is found m the Kiask conglomerate in one place only. These granites could not, therefore, have been exposed when the Kiask was being teid do*^. A angle vemlet of pegmatite was found cutting the Kiask series on Ehzabeth lake, and as such must have had its origin ui some larger body of gramtic magma in the vicinity or not far below. For these three reasons the granites are ^(mcluded to be younger than the Kiask series. A possible exception is the granite dyke found in the southwest corner of Montrose. This dvke crosses the south end of the portage between Junction lake and Hutt lake, with a strike nearly east and west. As previously mentioned, it is highly schistose, and rather badly altered. It is rather an acid white granite, like the pebbles in the Kiask con- glomerate, and on account of its appearance and metamorphism it is considered to be possibly of pre-Kiask age. ReltUions to Younger Formatiohs. The granites are intnided by a series of basic dykes, of the composition of a diabase, many of which are characterized by large porphyritic crystals of labradonte feldspar. Suft- cient evidence of intrusion is furnished by the strongly chilled edges of the dvkcs* Both dykes and granite are overlain unconformably by the Cobalt series The basal conglomerate of the Cobalt series may be seen in places lying directly on the eroded surface of the gramtes or the dykes, and is lar^ly made up of the debris of the reddish syenitic gra: 'tes of the district. ▲OB. The granites of the region, with the exception of the schistose dyke described above, are thus younger than the Kiask series, but older tban the 33 CotMlt aeries and also older than certain diabase dyices. Further conaidera- tions fix the age someThat more closely. The deporition of the Kiask series was followed by folding movements « such intensity as to force the strata into ahnost vertical positions. Mountain-building always accompanies close folding, so. far as Imown, so that it may reasonably be assumed to have occurred here. Batholithio intrusion, where it occurs, appears also to accompany folding movements °l *" '°''°^ *^«™ closely. The granitic intrusions of Matacht^an area, therefore, probably accompanied or closely followed the folding of the Kiask series. The Cobalt ser'os was laid down on a penoolained siirface of much the same contour as the present surface, as has been generally recognized by all geologists working in northern Ontario and Quebec.> Its base rests in turn on the ancient volcanics, the Kiask series, the granites, and the diabase dykes that intrude the grani tes. The reduction of the mountamous area to base level, exposing and eroding the granite batholiths, must have required a very long time. The age of the granites of Matachewan area, on the above considera- tions, IS, therefore, placed as slightly later than laat of the Kiask series, and long enough before the deposition of the Cobalt series for a mountainous area to be reduced to base level. DIABASE DYKES. An interesting series of diabase dykes has been found in Matachewan area, occupying a place in the geologic column hitherto unfilled in this region, between the granite intrusives and the Cobalt series. The dykes are coarse quarta diabase, and in places are chai'acterized by the presence of very numerous phenocrysts of labradorite feldspar sometimes 2 or 3 inches in diameter. The feldspars have the waxy appear- "ice acquired through sericitization and kaolinization. Otherwise the dit .^fues appear nearly as fresh as the Nipissing diabase. They cut the granites in the western part of Yarrow township, and, according to Burrows, in the eastern part of Cairo township. Two or three were observed cutting the Kiask series on Midlothian lake. They are especially numerous around the gold deposits in Powell township, where they cut the small porphyry intrusives. On the Davidson claims in Powell township the Cobalt conglomerate may be seen lying on the eroded surface of one of the dykes and includinK boulders of it. The age of the dykes, as shown by the above facts, is later than the granites and earlier than the Cobalt series. The same considerations as were advanced in the case of the grarutes may be applied to the diabases, to show that the dykes are only a little Uter than the granites they intrude. In i^ot, the association of the diabase dykes with the granite masses strongly suggests that there may be a magmatic connexion between the two. COBALT SERIES. The Cobalt series has been studied by W. H. ColUns, and fully u. scribed by him in recent publications of the Geological Survey of ' CoUim, W. H., Geol. Surv., Can., Mem. 33, p. 61; Mem. 9S. o. 74. WilaoB. U. E.. Geol. Sunr.. Can.. Mem. 39, p. ». 1 hw memoir, p. 37. S4 CuumIa.* The writar will, tharafore, not enter on ui extended deeeription of the Cobftlt eeriee in Matachewan area. • CJolliM has divided the Cobalt series into the Gowganda and the Lorrain formations. The Qowganda formation includes the he-vy 1^1 conglomerate, the greywacke, arkose, and slate conglomerate of the series, and the Lorrain formation includes the Lorrain quartsite pnnoipaUy. The Lorrain formation has not been found in Matachewan area. DIBTRIBTmON. The Cobalt serioi is found mainly in the southern part of Matachewan area. Its northern boundary runs from the southwest corner of Mid- lothian township diagonally across to about mile 4 on the east hne and mto Doon then north for about 6 miles into the middle of Bannockbum town- ship: it then turns southwest to Montreal river near the southwist corner of Powell township, and is bounded by the east branch of the Montreal as far as the south boundary of the map. Another area occurs m the south- eastern part of Kimberley township. From the main mass of Cobalt series outlined above two long narrow tongues branch off in a direction north 15 degrees west. The smaller tongue starts from the shoulder in Bannockbum township and extends north mto Argyle townsblp. It is about 4 miles long and averages only about one- quarter of a mile wide. The larger tongue branches off from the mam mass in the eastern part of Midlothian township, and extends northward beyond the northern boundary of the map-area. Within the map-area it is about 18 miles in length, and varies in width from about 3 miles to somewhat less than one-half mile. Like all the Cobalt series these bands stand topographically high and form ridges which are among the moBt prominent topographic features of the region. Mount Sinclair, one of the highest points, lies toward the south end of the western ridge. BTBTICTURA.L REliATlONS. Internal. Folding. The Cobalt series in Matachewan district has been gently folded, and the strata thrown into open folds with dips rarely exceeding 20 degrees. The main axes of folding strike north 15 degrees west "J the western part Of the district to nearly north in the eastern part. These axes have controlled the trend of the valleys developed by erosional pro- cesses wherever the Cobalt series is or has been developed. In general, valleys are developed along the anticlines, and the synclinal remnants form the hills and ridges. Faulting. Faults of post-Cobalt age may be detected in several places. Most of them are strike faults and as such may have developed at the same time as the folding. In other places, however, the faults are not strike faults, and appear to be lines of weakness developed during pre- Cobalt time, along which further movement took place after the Cobalt was laid down. In one or two of them the scarps are so steep that it is Tg^I. Burr.. Can., Mem. W, W17, pp. fl»-84. Oeol. Surv.. Can., Hiu. BuU. No. 8, IBU. 8S diffiooH to avoid the oonoliuion that then haa been movement along them in raeent times. The most prominent faults are those bounding the long ridge of Ck>balt series that runs northward through Midlothian, Montrose, Hincks, Cleaver townships, and beyond the boundary of the map. This ridge is a graben or downfaulted block. The faults are of the hinge type. There is little or no displacement at the south end of the ridge, whereas near the northern boundary of Montrose the displacement is sufficient, on the east side, to have brought the slates of the Gowganda formation in direct contact with rhyoUte. The displacement appears to decrease again toward the north, and m Cleaver township the basal boulder conglomerates are again in contact with the older rocks on the east side of the ridge. Direc*. evidence indicative- of faulting was obtained at the point where Nighthawk creek crosses the narrow part of the ridge in the middle of Hincks township. There the strata along the water side of the ridge, which within a few chains lie almost flat, are tilted up to a dip of about 45 degrees east, with a north strike. Also on Maher lake, in the northeast comer of Midlothian town- ship, a narrow belt pf the Huronian strata are seen to be tilted up to about 35 degrees west with a strike north 5 degrees east, whereas the Cobalt series on each side are flat and undisturbed. This disturbance must be due to faulting, and as it is localized on the southward projection of the boundary of the band to the east of Sinclair lake, it would appear reasonable to consider it as the commencement of the eastern boundary fault. There may also have been some faulting along the northern part of the smaller branch of the Cobalt series that projects through Bannockburn into Argyle township. The normal boulder conglomerate is found at the base of the ridge in contact with the greenstones, but there is no great thickness of it visible, only 30 to 50 feet, whereas on Mistinikon lake to the east and in Midlothian to the southwest the boulder conglomerate is very thick, 300 feet at least. Farther to the south, on the Bannockbum-Doon line, the slates of the Cobalt series appear to be in contact with the Kiask series. It is very possible, therefore, that there may be a downfault of the Cobalt series along this line also. Collins has suggested that the line of Mistinikon lake is a fault, and has cited suggestive evidence in favour of this hypothesis.* The writer has obtained evidence strongly supporting this hypothesis, though modifying it somewhat. Mistinikon lake has been described as a zone of intense faulting in pre-Cobalt time. The evidence at hand goes to show that after the Cobalt series was deposited, further slight movement occurred along the old planes of weakness, jointing the Cobalt series so as to allow of rapid erosion along the fault planes, but without any great displacement of the rocks on either side. The southern end of the lake was the part seen and studied by Collins. To quote from the report cited above: " The lake is a narrow, straight body whose shores rise often prcipitously. The western shore is entirely Huronian, and the eastern entirely Laurentian or Keewatin. The contrast m this respect is particularly evident in a narrow ravine that extends southward from the little bay in the southeastern angle of the lake, for although the ravine is only a few chains in width at the bottom, the sides, ■ G«oI. Sonr., Can., Hem. 33, 1913, p. 18. noB^ctinc of mtiM on the eMt Mid flai4)riiig greywikcke on the wert, wre SSSfStttrit i. not ewy to expuS either the cWt or the eudden dSipSrIS trf U» Uurentbn gnek* weet of it, eieqit by conridennf it to oomcide with • fault i^ane." j . « ,„ ♦u- About 4i milee to the north of the b»y mentioned by CoUlne, the writer found the l««e fault de^sribed on page 18 cutting cherty tuffs. aThS iSth end it^-e. out into the lake. appar«tly P«»lf 1 with tne MM of rtw lake, and^TSe north it ewinga to the northeaet. At the p int SKre tS Xhain portage leave. Mirtinikon lake it ui again vi«j>le, rtS« iomewhat northTeaet, and apparently following a large va ley. fttSd SSbTSLi farther by direct i«in., but H^H^Jf ^^t°r"S eastwards into the lake at the other end of the QO^jhain portage. ThW Ukelw trend is directly athwart the strike of the Ooba" ""^i iflM ^anow cleft, the sides of which rise almost perpendicularly for 100 to IfiO fe^t Such B cleft cannot be explained except by faulting, probably of comparatively recent date. ,•„„., j On the west shore of the narrows about hatf a mile north of BeU 'stand another large fault cuts the volcanlcs (see page 18). As the Cobalt series to the southls not sheared. It is clear that the mam faulting is of pre^obalt *i ThV chanSl on the' west side of Bell Wan^owever, » a nam.w deft with high walls vertical In places, and is best explained by «««««* movement along the old fault plane. Other faults, as shown or. the map, S^ to 1^ seen ol the shores of kstlnikon take tothe north of th». Most of them have a strike In a general northward direction. It is clear, there- fore that thi take has been'Seveloped along the locus of an.anoient fauH or faults established before the Cobalt series was deposited. It seems probablfthat stresses have been relieved In recent time by f 8^* "jovement aloHK these old sones of weakness; and It does not seem unhkely, therefore, ?hat sucrslight movements may have taken place more than once since the de^sition of the Cobalt serfes, with an accumu atmg d-^P^^* °' the rocks on either side sufficient to satisfy the facts as described by " 'RelMionatoOJderFmmatimt. A study of the maps of the Mateohewan and GowKanda areas shows the profound unconformity with which the Cobalt S rests on the older fomatlons rf the region The base o^ the wrles rests In turn on the ancient deformed basalta and rhyohtes, on the Jefom^Ktask series, and upbn the granites which i^tnide them No further proof of unconformity Is necessary. A further exammation of the map brings out the fact that there Is rarely, if ever .iny marked bend In the boundary of the Cobalt series at the lines of contact of one of the older formations with another, as for example where a 8~nite is in contact with a greenstone. This Indicates that the surface.on which the Cobalt was tald down was a peneptamed one, since otherwise the harder r(2ik would have stood up as a ridge, on which the Cobalt series would be originaily thinner than on the softer rock. The mapping would show this conSltlon by a curve In the Cobalt contact at the crossing of the older contacts, as In Figure 1. The lack of such curves indicates the ongimd peneptalned nature of the surface. Peneptanation is also indicated by the Numerous Irregutarly-shaped erosion remnants of Cobalt »fnf ' /ojmd especially In the Gowganda map-area to the south. As therew very UtUe reUef in the region, it is evident that over large areas it has not taken S7 • gn«t depth of «roiioB to rameve tba Cobalt Mrie* from the old rarfMe, ■o that tho Ck>bdt wriM fonna merely a eomparatively thin scale on it. The old mrfaoe eannot, therefmv, be far below the prewnt peneplained •m^oe, and aooordin^y was a pene|dain of much the same contour as at present. r L / liA Greenstoi'3 ,'-' ' . . . 'Greehstone ' ' . I Figure 1. Diogranmuitical rqireaentation of the contact of a younnr ledimentary leriM. such ta the Cobalt scries, with an older unpeaeplained aiinaoe. The granite is suppoaed to have stood up from the greebstones aa a ridge. Relatumt to Younger Formationt. The only younger formation of the region is the Nipissing diabase. In the Gowganda area to the south the diabase intruded the Ck>balt series in large dylces and sills. None was found in Matachewan area, cutting the Cobalt series. NIPISSING DIABASE. As mentioned, no diabase was found in Matachewan area cutting the Cobalt series, and, therefore, definitely determinable as the Nipissing diabase. Dykes of quartz diabase are occasionally found cutting the volcanics, Kiask series, and raranites, however, and some of these may be the Nipissing diabase. Such dykes are very numerous in Kimberley township, and these are very probably Nipissing, and related to the large sill of diabase in the southern part of the township. For full description of the diabase the reader is referred to the reports of W. H. Collins.' > G««l. Sorv., Caa.. Mem. 33, 1»13, pp. 8»-M; Hem. W. 1917, pp. 84-101. i ; : guPERncuL DEPoerre. mp^SSd0podU Wl toto four gMMnI eU»M. IF?«1 "IS?^ J^SSS SSSmT^iMh pUtoi, and gUeul or port^flwUl Ww bedt and rtrwun Aa MWk of ground moraine, or boulder cUy oocure to tU northern part rf ySow tSd the «lj»c*nt •outhernpwrt of PoweU townrinp.. The B^ ground underlain by the Cobalt -rfc. In B«mookburn and Doon io^lto. is covered with a thto sheet of ground m«»toe. Another smll areaiieT in McNeil townAip to the wuth of Whltefifh lake- As the boulder cUy is to general a iTcher soil than t^e terminal moraines or the Swh plains. itsTecognition is assisted by the <»•"• K"'^^ °' *?f,*ti^° wUch it supp<^rte, to contrast to the tpareer growths «>n *5*o*5«.'^^- The forest wntairis a large proportion of deciduous trees. •^^'WlyJ"'^''! and to addition there ii an exceedingly thick undergrowth of ground maple, hasel, and alder. Terminal moraines are scattered thickly over the area. They arc not SZ^y found on top of the high Huronian areas^ *>"*J° "Tf^??? » hea^ accumulations of drift haVe been heaped apmst northward fac ng sloS. sSch accumulation has occun-ed against tile face of the Huroanvn • S hi Bannockbum and Powell townships. This would '•eem to ndicate that during the decline of gUcUtion, when the ice was thimimg and depositing heavy morames it did not override these elevations, which are oX 300 to 500 feet above the general level. Further evidence to the same effect was obtained by mapping the morainic belts m a lew P^<;«« where \ uld be done without too much expenditure of time. Although SacH . v. ,meP* to the district was to a direction about 10 degrees east of soutu. M shown by the direction of stria and of individual morames and eskers the belts of moraines on .the west side of the Huroman ndge fn the wStenT part of the district all »»ye ^northeast trend, as if they were lateral to a lobe of ice pushing down into the valley to the west of the ridM but not mounting over it. Similarlv the moraines to the ««i6t of the Huronian ridge haveli northwest trend. The wide valley of Duncan fr^ extendtog north into Bannockbum township is fi led with moraine S^ard «ie northern end and outwash sands and gravebi m the southern S^ato as if foUowed by a tongue of ice. The P™«f 1 'f°~«"«= ,^J* ^ns slightly east of north throu^ the chain of l?^*^^™™ ,*Jf™^ l*/^! in Doon toVnship to Argyle lake. Another monumc Jet runs slightly south of east across the southeast comer of Argyle and mto the north- Sem part of Powell. This belt appears from %mentory data to have TwesTwSi extension through Hincks. alon? the divide between the two brai Jhes of Whitefish creek, connecting with the be'* that crones tne narrow place to the Huronian band in the centre of the township. Its extension is supposed to indicate the normal position of the ice front where not influenced by the presence of Huroman ndges. Between these morainic belts, which represent stands of the ice border for longer or shorter periods of time, sand and gravel plams we foS cSLiSid of the materials carried out by.waters flowing from the meltiilg edgVof the ice sheet. Th««. outwash plains are frequen% pitted, the holes marking the spots where hirge blocks of ice were buned m the S0 MitWMh and btor melted. PL * of thii tvp» are eqMNsbUy promiiMnt to th« eoutbm pwto of Cleaver and MoNcil townahi|M; the greater part of Aigyle townaUp ia covered with outwaab. Smaller areaa of the tame type «re fouml In the aoutheaitem part of Hindu, the western half of Montroae, and the valley of Duncan creek. Olaolal uui poat-gkolal lake and itream depodta are comparatively nnaU In relative amount. A fbt iwamp with an ocoarional pond covere *°r, vl^}}*" ?ijf *° *••• northweet comer of Argyle and adjacent parte of McNeil and Hinoka townshlpa. It is clearly a glacial or rec«nt lake now ahnoat entbely filled in. Thie is the largest area of the kin^. found «a«iln the map-^rea, but there are several smaller ones to be seen at different jpkoes. The district la a good one In which to see the process of lake-filUng in aU Its stages. Austen Uke and Seven Inch lake, for Instance, are basins filled wfth soft mud covered only by a few Inches of water in many pboes. The shores of such lakes are frequently bordered by a belt of marsh plants and moss growing on the surface of this soft mud, forming a qualdnf bog dangerous and in places impossible to cross. The width of this belt mcreases year by year, and at the same time the solidity of the older parts increases with annual increments of growth, until the lake u reduced to a small pond or two in the midst of a ossy wet plain. This stage Is well shown on a former Uke in souti iteni Cleaver on the granite boundary nearly east of mile 98 on Niven's line. After this stage is reached trees commence to root in the muskeg, chiefly stunted tamarack and black spruce, and gradually spread until a' typical muskeg, covered with a moderately thick growth of small to medium sised trees, b formed. A large muskeg of this type occurs in northeastern Argyle. Stream deporits are of very small relative importance. They are mainly post-dacial terraces formed as the various streams of the area cut down through the drift deposits filling the valleys. A number of them notably those on Montreal river between Elk lake and Indian chute, are probably of glacial age. They are of such size and elevation above the present stream that they were clearly formed by a stream of much larger volume than the present, probably, therefore, when the natural drainage was aupnented by the waters of the melting glaciers and by drainage from areas which after the retreat of the ice took other channels. In this con- nenon it is notable that such stream terraces are found mainly in the valleys of south-flowing streams such as Montreal river and Duncan creek, but are not marked, within Matachewan area at least, on the streams flowing north, such as Whitefish and Nighthawk creeks. ECONOMIC GEOLOGY. ASBESTOS. Asbestos in small veins and stringers has been observed at several places withm the map-area, more particularly in the western part. It occurs m masses of basic gabbro and peridotite, which have been altered to serpentine. These bodies, where found, have been noted on the map. Only one deposit of possible commercial importance has as yet been dis- covered, on the south shore of Rahn lake in the western part" of Bannock- ■* i \ IM ■•»^~»^ ~°»S£l AuiSSU^rS^ of aU orifin.1 texture Mid tomtoi • •*^'JS^f^^^5Sl^ JaSSute wUina lU original gnmuUr from the fault ptone *»»• "^"^^P!!^ y, h uniuual feature is texture. ««i fbwrtoa ^•J»S. J^^SK?il eLrtore The charecter- pr««eiit at tWs plaoe. '""^ ^^^i^f^Sud ^ w"u rounded maawa lliirolive green, *»•»»"«»* "'^•'2^3^^ «» black, coiiriomer.t., lyini "J.^"*,:^. ho"? dirt J SJt Sere i. no coni»xioi. by the faulting that took place. .u. ^,*^«, of course, less than this. s:„r£r„rxre;i-;^K»i'r^r.on«t o, .h. ^d^u_ Specie, ot the .rt»..te were .ul,mltt.,l I. RH«|..e»Uhe 0„1^»J Miyto make this field economically valuable. 41 FLUORITE, BARITE, AND IRON ORE. Kte^ (topoirito of fluorito, bMite, mmI btuwtito an found in (he eMt«ni ^.y**"****".*?*- The* luive not b««n eumfaMd by the writw. foilowhic d«wri|>tk>na m from the report on the utm by A. O. Burrows. rbvoniTC. " Fli«>rit« (fluorqwr) hM been found in unaU quantity in a number of quart! vein* in Cairo and Alma townahipe, but none of the depouta exam- ined la of commercial value. Owinf to the widetipread occurrence of the mineral, it ia powifaJe that prMpeetinc might retult in the finding of eco- nooiio depoeita. The mineral k of a deep purple colour, occurring in amall manea in tiM quarti or in the w^ rocic adjacent to the veins. It i« alao present in the Biederman barite vein. One occurrence where the fluorite is m the quarts is on the Harvey claim, No. 18286, west of the road frwa Fox rapids north to the Craig claims. This vein is about 7 mohes wide, stniies north 78 degrees east, and has been traced several hundred feet. Some pieces of fluorite, 2 inches across, were taken from the vem. All the showings of fluorite are in the syenite." BARITZ. " Veins containing barite occur in several parts of the area. These are generally small, but two deposits have been found which would be of ronunercial value were they nearer railway transpoitatlon. These are the Biederman deposit in Cairo township, and a deposit near Yarrow la Ice in Yarrow township, Biedtrtnan Claim. The claim (15042) is situated on the west shore of Browning lake, in the north part of Cairo township. The country rock i« a red syenite in which there is a barite vein with strike north 65 degrees west and dip 80 degrees north. The deposit can be observed about 100 feet from the shore of the lake where a shallow shaft has been sunk at a point where the vein has been concealed by drift to the east. Here there is a width of 15 feet, and the barite can be traced westerly for 100 feet, decreasing to a width of 7 feet. Beyond this there is drift followed by an exposure of barite about 30 feet in length and 3 feet wide at the east end and 2 feet wide at the west end. The barite is for the most part white in colour and of goon ore was observed in smaU quartz veins in the vicuuty of Yarrow towJ^J ° tKS roc^ that encloses the veins is conglomerate and Srite of Se Cobait series that dips gently to the east at 10 to 15 degrees." GOLD. Gold discoveries have been made at several points in Powell, Cairo, Ahna «id Kn townrfups.^ The I^bs importent of these were not SrHr^^,\V4v-^^^ ^eo-vSSe1 in Powell township. , ^ v « The deposits occur on the north side of Davidson creek, abo«t haK- way betwo^SThl Tut and west branches of Montreal nver. Davidsons S^ov^JT was^e in a small mass of red syenite porphyry and thatof oK was Tt^ndent volcanics close to a.similar mass of POfPhypr tS c]!Lt up tS the time of writing remain the only ones on which important bodies of ore have been proved. 43 the ™S^*Si 7°'\7°* "^ vigoroudy on the Davidaon clafans durin. eily dlte °* "^^ continued and mining commenced atVn the S^^l**'„f^^^n'*.*^^^";l'*~'' '''^^s i» *e autumn of 1917 and OBIGIN OF THE MATACHEWAN GOLD ORES. Introduction. ttth^^L.^T' ^^- °*?^' '^r' '"^ the'^vicixdty weS &y develop bl dt,SKl°' ^'^•'^*'-' t»^«y '^e™ -ot ex4med closelfl^d'^m^S:? 44 45 Qeclogy. on the Davidron Md ml2 P^Jl n, * °^^- ^"^^^ the intrusiona and suggest that thev and dSS^i^ th- )S2i~ i *°® *T° "f" *»°"fi«*e»»c«a8ing distance boundary drawn about 1 onn^L* ftL *l j exceptions all lie within a ' Oi.t. Bureaa of Mines, Rept. 27, 1918, p. ffl7. pyroxMW with » nuU amoimt pear very fnah in tha hand q)Mim«n, but und«r the mioroeoope tiw feklqwr i« wen to be bMily altered to intwrowth of kaolhi and lerieite or paragonite. In place* the dylm are highly porphyritio, with ^enoeryets y * *^°«'» "'"^ ^^^y ^ picked up in a parallel trench 50 or 100 feet distant, indicates a simikr shape for these ' Spun, U.S. Geol. Bunr., Prof. Paper 65, p. 114. 80 dw. DriOiBg it M nvMBt bring eondaetokl with tht obiMt (rf tattbc tht hypoth^ thftt tb* lentieulw outerqM an ooly tbt msuUM vipnmo n ol on diooto whkh nwy have m oaaddmMn dowliwMd extemkn. The riM of the (n»-bodiea vuiet greatly. SnuOl bodiee • few iiwhee or feet in vridth are numeroua, and the largest so far found is about 75 feet in width. The large bodies lie with their long axes approximately parallel to the bedding planes of the tuffs, and may eventually prove to have some relation to the secondary folding. The position of the smallest bodies, •1 AmUte^/hat ts lO • ••• • UnaHored oountryrock Mered but not m'noralizecf tone • • • •••••I ,' \' \\ Altered and fn/nena//zed xone • • ■ • .- • ./ • • *. •• / J J .■■■ • V..--. • . • • • *' - • . • . • ; • ' •' . • . " • • . » • • • • • • « . _ • • • . • . Pegmatite i^in Altered and nvnenalized zone • ■ '0 ' •.•••■ ; Altered but not mineralized zone Unaltered country rock Rr«5. «««^i"««r«^J«ij,^,,,,^^,^,.^ tlKiM in nnenl lew thM » foot In wkHh, ^kMt not t»Ma to h»T« be«i iSlirfto«fS^b!ldS« but by Joint orw^ '"^ TbJintenud •trurtow of the ore4iodlee of the Oti«e type it tatereetlnf , •ndSSSySSSSw thdr origin. ^Figure 6 ehow. on • l«r|e «i»Te Sm JSTK-body .bout 12 feet in width, ocoumngm trench No. 1. At the o«itre theie le • body of ~therrilioeou.pefm.tlto about 8fwt in -ni»kni..«iHKl mltmm tha treneh. On ewjh «de of thie vein there le . aSirfwtVridB OT^the north side. iHie latenttion, which wiU be dewsribed ^r« fXK. conrirti nminly of clcitiwUcn, the ininer.liiation is a SSliSSn, iS' p^rin».lly Laerou.. An ouierjone of rock ,»Jer^ EffSS^Si^rM, Ihmk. thi .Itered wd minemliiwd wne; tlus « 6 fc«t wide on thTnorth ^de, and slightly lew thw . .oot on the louth. The U^t Sev idtered roct grsdeTintb the dwk green country rock fairly Srff^Jut wXutW^ boundary line. The gradatlonal wne u ?JSdr*^^h ortw?Vwidth. fhe line of contact i. wavy, and frequently embayed in a highly Irregular manner. The etructure described U characteristic of aU the ore-bodies m the Bchist. altSugh it is sometime, rendered more oompex by *»» 5»t™«on of twi ormore vehtf of pegmatite within each other's .one of influence, « £ re^tion may be^ured by an insufficient development wUch ^mSed^ow without the central pegmatite. Variations occur m the 3StiSn of^e^tral dyke or veirthTwidth of toth inner and outer ^^rf JteStion, and the ktent of the emrichment of thinner .one ^d JKSraff in bith. The data bo far «5cured are i»t »"ffi««°Vt° 'i**^'; ^SewUtion between theM variations, but enough work has been done to^icate that the composition and sise of the centi^l dyke or vein are tL SpiJgoverning factors, and there is also a possibihty that some of th^SSy^ksmiy have been more easily altered than others. The data bearing on possible differences in susceptibility to alteration in tiie cSirnl^ rockStre rathCT scanty. All of the volcanics are seen under ihe microwobe to be very simihir in composition^ their differences bemg S^ SXrela .ve ^portions of the constituent minerals I one SIk U mow suweptible to alteration than another, it nnot be due to SffwSic^ iJ^compcSition. and the cause must be sougb Pjy""^ d^J^^- ences, such as terture. The tuffaceous types, the rhyc, : and basalt tuffs, Sibtwilyhad originally a more open texture thai U'J massive basalts, Sd whe^Lwed tSrleLr competency resulted in vheir becoming more itoTthan the massive rocks. Both their origmal texture and their SSr Bubsequent schistosity would make them '""'X^^S^ Fi«v^ 5" tions and allow of a larger degree of alteration. As shown on Jbigure 4, S'of throre-bodiesiSe loosed in the rhyoUte tuffs and the basalt Sffs which (Sectiy underUe them. However, the fortuitous location of £Ss nS^ the irtrusive make, it impossib e to conclude definite^ that the localisation of tne ore4>oat Ml ia^ i» wkltb. On Moh lido ^ (1) The ore 'i' t- ha' the dylw « vei n eir 31& B^aUsatiot -. n ur. r»tion < . wJated to the else and the eompo^- Smof^ecwtrairt «. li -^ ''°«*^ f**^*^ •^JS^ft !i*^ hlvA hMr . XI Istd ^.v ^" „-^titeB, whereas the effects of the :siLS's.*^'iu. -: ■ .< f.^^^^^uT^tr'^sS'^rwdr boon ■licht. Tbf -siam ■-•^ ntnininf 23 to 60 per cent of lewepar SSar to Lve pro, iced t» e uu t powerful minersli-tkm wi^to«*»<«; SK thfaS be^ qual ■^•'. ■'.T.t of alteration and »J««f"^^ roughly proportion.* to I'uc mc of ; I >e dyke or vein. (4) The »old content oftBedyke^d vcm-forming solutions was also dependent on tbelr «wnpo- Stion The pyrito deposited by the dykes of red nor^yry oont^ vew "ow values. S^j po^hyry dyU < arry more 8«>»d^tlSjiu J^ values within the .lykes themselves, but not apparently ^ mmeraUw ge 8um)undtog rocks very W«hly. Pegmatites appear to have owried the rawdmum of gold, which tEey d.-po«.ted a« auriferous PST*** ,^0*^. J» J»^ veinsand in t& altered waU rocks; whereas the solutions forming the pure quarts veins csjried little gold. The only primary »'«*'»t».°'^- J}.^ gSnl^ ma'gnetite originaUy present in the altered ^^tf »^»»'>"?* uo to 5 ner cent is converted into sulphide, fonninfc a few «^^"P^ 0-5 mm.' diameter instead of a multitude of small grams, FoaaDiy, aiso, isi,::3r£,'ttS ^'Sjr.r~ v'^^?'^""^ Summary and Cimclutiofu, tltt> i^OTuorf •rtJKT.'; tI."^Tr' *?. ""' """ '•' "optioo. of the dSerentuLrSf L^f Tteffi^i'"L'^/*'" •*? P"^"'*- ^'twm Were at fi«t nch m mlica, aoda. and alumina, which^iyrtalliwd oat ftitt to fom tha iMterW ol pefin^t. vetafc Tl» le^^ ^«L2t»i^ 1^ the Kdtttkxu idbtfively enridied in Ufflw. ewboa aogode, an MdcHe ud auriferous pyrite. There ia Httle direct evidence to oonneot the gold of the I>»^idw5 propiS^^e porphyry, «ccept the faet that 2«,^ ""^^^^ Sh^ the intruilve ma». However, the proof «iat the neUnfabounnc Iff ^ch towtromrfiioaUy identical i^ the D«vidjon porphyry, SSS^lSd rMiSrSE^luB-on faievitaWe that the gold of tiiebaviion SSStf^mXT^ W«tic conrtituen^ The diffeientlation haa here S&^tS^pSTto the rtage in wMch the imneral oowti^ of Selnagmatio solutionB are rihea and gold, and these are depoated as quarts with native gold. INDEX. ^OBM, meaiuaf. Aaut toinulup. . . AwUdtM........ ATM. A^ijie.;.;.;: •AAestoi.V.'.'".;" Aiuten UJte ^•••en towiuhip BuHe Bwnett, H. A.;.; ; BMalta ~ ", Robert ...'.'.'.'.[['. 1 barite veiii _ . cUim „ * w.w ;■■• "Owning lake Baa mountain Bnmnw, A. O. ! ! ! ««"««•>, JS. M. . . . Cairo township ClJfiMeous rock* Cherty tuffi C«*i*««ri«B " Jdii^'Si*' ^«n«i»n beiWeei". „ raatwu to older fannationn CoUina, W. H fo^^^ef foraMJooa...'.'.'. Cckndfy^uiia'daiBm. '.'.'.'..'.'. CoB^merate". . . ^'•''*'°P««t Coip«»y. '. '. '. Craig dainw Davidaon cluinu. j5^^tj^ofor>bodie.. ttabawa. Urainjfe Duncan creek. ...... ^Mbethlake Eftlake Exploration, hiitory of.'.".'.'. . <7 ...1,41, rAOB 3 42 13 1 38 31 10 4 ... 1,42 19 41 3 13 2 41 41 ■ ■ . 20, 23 41 ■2i 90, 41, 42 2 1,41,42 22 12 3, 16, 33 22 36 • 37 1,2,30,33,37 47, 49 43 20 41 33, 43, 40 1 49 .6,; 47 27 S 3 M KMdtUn »,17,90 Ftailto 17.25.M Waxam 7 Jte!"::'v::::::::::::::::::::::::::::::::;::::::::::::::::::;::::::::: ''^ fluoriU 41 »pMi •. 16,34,84 " BwtamanUe cffMti 9S * timeol l»,as VtocMtflna 8 FoRMt, A. O S G. Ocokfy, eeonomie 39 " lenaral g " gM weM 45 (SmmI dqMiitt 89 » drat 6 " •*»» 88 Gold 1,43,49 " otm, MaUdiewMi, oriKia of 48 Gkiw^ukda fonoatkn 84 GfanitM 38 " rristiona to older formationa 83 " rdstions to younger (ormatioiui. . .'.' ^ 83 Qnmy river 6 Qreenstonee 18 Grey porphyry 83 H. Halfniik lake 13 Harvey daim ' 41 Harvie,R 40 Hri^t of Land 8 Hirtoiy 37 " eeoDomie 1 Hopkins, P. E : 43 Hntt lake S, 18 I. Ircn on '. 41, 42 K- Kame lake 38 Kaolin 10 Keewatin 9 Kiaak aedimenti 4 " wsriee 11, 19, 24 " " and Ckibak seriee, distinction between 23 " " relations to the Cobalt series 27 " " « M granite intrusives 37 " KeewiUin 30 Kimbertey towndiip g Kitehimine lake 13 L. I/A Brosse daims 43 Ltkcs 5 Leaeoiene 10 V tfctaatlaa *««*«*r^diiri«:;::; ." JK:::: -• tOWMhip. g«^riJ5r:::;;.- MontRMatowB^fat. MopwaomitaSlT..." ■ ri*» Otiae daima ^ s~7.v;:: S Ouaean.. lake Oata BWunt , I 9 ••• M •••• a,i». •••■' 10,48 18 19 ... ao 1 39 X 18, 85 1 22 4 « 6 « 37 3 • • 15, 27 48 1 49 47 0,10 8 47 « 1 %''W» JE...'"' 40 11,20,89 9, U 12 12 .11.13 10 2 0,22 21 IUb '^r'.'t' • 'V ,.,..•.. mtaumtpmm T. UwniRKHdMwUMniODtafionBw^r u MriM Vi*V ▼. * W. MmM.B toirdqMMtt Y. ' lake '1 10 3,8 4& 41 41 I ,->.' -=!' "' 1 HH ^^^^IH^^H 1 ! 1 ^^^^^^^^^^^^^^^^^^^^^^^ 1 T LEr«ia> >• Z I RECCNT H I GLACIAL spiirt&rutd: »■■■ » £& KEWCCNAWANM HURONIAN GU ■n z < s ^*tmm ^A nqrsm s i' r. AflL^^H^ A 4 ?^^. ^ w- MirtHi^ Han AifrHuw I fc wii m M i pnTMu lt0.i>?Comi«u~Oe>uTT MiNnrm. MIKVty VVkltlM* Mf l«HM. DimCTlNa 0 hi \.. \ , '^ K-- >\. .' , '..--,^- &- I L\iyv ^wet,m%.fj t^-., cr; m t j iii ii j ii Ikirua^KI / ►cUc\ i ■ ^> ' } n^ : i .--J \^' A z s/igh«to t^i 1 ^IMBMiitaMMii ^tm-'Otmrn' / \^-^ "^ ^ '", 1± '^I'j-^ i-y \ o -N 1RI&' ^": wr xam^ •Ote- A TIMSKAMING DISTRICT Scale, ojkso • MUC TO I INCH vm js^ims^- TtlMSKAAMNS DtSTHICT ( WILC T» t mi