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 THE 
 
 LAURENTIAN AND HURONIAN 
 
 SYSTEMS 
 
 i3sr THE RHia-ioisr nsroRTia: of 
 
 LAKE HURON 
 
 BY 
 
 ROBERT BELL, B.A. Sc, M.D., LL.D., 
 
 Assutant Director of the Oeological ihtrvey. 
 
 (FROM THE REPORT OP THE BUREAU OF MIXE5I, O.VTARIO). 
 
 PRINTED BY ORDER OF THE LEGISLATIVE ASSEMBLY. 
 
 TO RON TO f 
 PRINTED BY WARWICK A SONS, 88 AND 70 FRONT STRBIST WEST. 
 
 IS92. 
 
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 THE 
 
 LAURENTIAK MP HURONIAN 
 
 SYSTEMS 
 
 I3Sr TDEiE REG-IOIT ^STORO?!! OF 
 
 lAKE HURON 
 
 BY 
 
 ROBERT BELL, B.A. Sc, M.D., LL.D., 
 
 Asddaid Uirector of the Geological Survey. 
 
 (FROM THE REl'ORT OF THi: BUREAU OF MINES, ONTARIO). 
 
 PRINTED BY ORDER OF T H Pj LEGISLATIVE ASSEMBLY. 
 
 TORONTO : 
 Pb'Mted bt Warwiok & Sons, 68 and 70 Front Stb*bt Wkbt, Tobonto, 
 
 1892. 
 

 «*1 
 
 ( ^ 9) 
 
 ■yi I 
 
 <:4 
 
THE LAURILNTIAN AND HURON IAN SYSTEMS 
 NORTH OF LAKIi HURON. 
 
 liy Dr. ttobiTt Cell, Assistant Director nf tiie GtMlogical Survey ot Canada. 
 
 This paper is intended to give a brief account of the geology of the country 
 represented on the accompanying map extending from lake Huron northward to lake 
 Temiscaming and from lake Nipissing westward to the Spanish river. It will aim at 
 giving a summary of the various reports of the Geological Survey referring to thnt region 
 in the light of the most recent views in regard to the rocks of the district, and will cover 
 ground already described by the writer in the annual reports of the Survey for 1865 and 
 1866, 1875 to 1877 and from 1887 to 1890, by the lute Mr. Alexander Murray of the 
 same service in the reports of 1847 to 1857, and by reports made at various times by 
 officers of the Department of Grown Lands. 
 
 The geological coloring of the map is compiled by the Director of Surveys 
 in ihe Department of Grown Lands from the niiips and descriptions of Mr. Murray, 
 the geological map of the Basin of Moose liivi r, 1883, and that of the Sudbury 
 Mining District, 1890, by the writer, and also the ma])S accompanying Sir William 
 Logan's (irology of Ganada, 1863, as well as from the descriptions contained in the various 
 reports above referred to. As these reports and maps are not very accessible to tl;e pub- 
 lic, and some of them are out of print, it is felt that a s'lort summary of their contents, 
 with suitable explanations, arrangeul in convenient form tor reference and illustrated 
 with a geological map, would be found useful at the present time. The colors used are 
 made to harmonize with those at present adopted by the Geological Survey. The topo- 
 graphy is compiled from the surveys of the Department of Crown Lands and of the 
 Geological Survey. 
 
 With the exception of the larger islands'on lake Huron, and possibly a tract in the 
 Sudbury district, the area represented on this map is occupied almos*^ exclusively by 
 rocks of the Laurentian and Huronian systems. Descriptions of these rocks in general 
 and of their relations to each other by the writer are contained in the Section devoted to 
 Geology in the Report of the Royal Commission on the Mineral Resources of Ontario, 
 1890. But it is now proposed to give a more detailed and local account of the rocks 
 belonging to these systems which are met v/ith in the area represented on the map. 
 
 THE LAURENTIAN SYSTEM. 
 
 The Laurentian system may be divided into an upper and a lower formation. The 
 latter consists almost entirely of primitive or fundamental gneiss, wiiich is supposed by 
 many geologists to have been originally of an igneous nature, but to have undergone altera- 
 tion which has produced its more or less foliated character. The upper Laurentian 
 appears to consist of metamorphosed sedimentary strata to some extent at lenst, while the 
 Huronian rock" are undoubtedly largely sedimentary, but mingled with a varying propor- 
 tion of igneous rocks, both of which have undergone more or less metamorphism. 
 
 Mbtamokphism. 
 
 By this term is meant those changes in rocks which have been produced by 
 pressure and heat, and possibly electricity, acting slowly or through a very long 
 time, and producing molecular or chemical interchanges in their constituents, and 
 causing them to become in a greater or less degree crystalline. The original com- 
 position of some rocks is more favorable to metamorphism than that of others 
 
With a change of conditions, rocks may undergo a second or further metamor- 
 phisiu. Th(3 element of time being very important in l)ringing about metamori)hism 
 it follows that the older rockH are the more subject tliey have been to have undergone 
 this process. The more ancient rocks have necosHarily been those most liable to disturbance 
 from these changes wh'ch have always been going on in the crust of the earth, so that they 
 have been moved from their original positions and have been tilted, crushed and cont'^rted 
 more than the newer ones, almost in direct proportion to their age. The very fact of 
 strata standing at hiqh angles to the horizon appears to be connected with the metamor- 
 phic processes, and rocks which are locally disturbed, as in certain mountain chains, are 
 found to be metamorphosed, while the same strata in continuation are not changed 
 where they are found nearly horizontal. Great outflows of igneous matter have also in 
 many instances had the etiect of altering rocks locally. 
 
 A crushing and disturbing force due to the constant shrinking of the earth and act- 
 ing horizontally at the surface has been going on in its crust from the earliest times. The 
 effect of this force may bo seen, not only on the large scale, in the tilting, folding up and 
 faulting of the older rocks, but also in their microscopic structure, thin sections of them 
 vpi y often aflbrding the clearest evidence of their having been subjected to intense 
 pressure, forcing asunder solid grains, grinding them against each other or crushing them 
 to small particles. Another effect of the intense lateral pressure referred to has been to 
 produce in rocks a schistose or a slaty cleavage at right angles to the direction of the force. 
 In the crystalline schists this has been effected by the crushing force, aid<?d often by a 
 shearing movement, causing the component particles to move slowly around till their 
 greater diameters assumed positions at right angles to the direction of this force. In the 
 schistose rocks the cleavage planes of such minerals as possess cleavage have been made to 
 corre.spond with the directions of the mechanical arrangement of the other particles, so 
 that in cro.ss section the whol- texture has a i)arallclism of its grains, giving it a lami- 
 nated appearance. Dioritic schists have proba])ly been originally massive diorites, and 
 have had their cleavage structure developed in the manner just indicated. Many geologists 
 believe that some kind of gneiss have been formed out of massive granite in the same way. 
 
 These | recesses involve an enormou.s lapse of time, so that a crystalline and schistose 
 condition is prima facie evid' nee of antiquity. Indeed if we exclude those cases of 
 local metiuuoiphism wbicli have been referred to, it may be said in a general way, the 
 more crystalline and altered rocks h»v ; uecome the more ancient they may be presumed 
 to be. 
 
 Notwithstanding the apparent stability of the rocks in this part of the world, far 
 removed as they are from volcanic activity, there exists nevertheless within them a state 
 of perpetual unrest. Unceasing changes are going on in the arrangement of their con- 
 stituents as illustrated by crystal enlargement, pseudomorphism and decomposition in a 
 petrological sense. 
 
 Besides the constant internal changes taking place in the rocks there is restless 
 action or movement on a large scale throughout the whole body of the earth. One of the 
 primary causes of this movement is the constant shifting of the matter on the surface by 
 the action of air and water or ice. The earth is not a rigid solid, but obeys hydrostatic laws. 
 When a certain weight of matter has been transferred from one part ';o another its effect 
 is to sink down the part to which it has been transported, while there will be a tendency 
 to rise to a corresponding degree at the point which has been relieved of this burden. 
 These oscillations were probably more frequent and rapid in the earlier geological ages 
 than they are now, but they will continue to go on to a greater or less extent as long as 
 air and water exist to transport matter and disturb the equilibrium of the earth. 
 
 Divisions of thk System, 
 
 The lower division of the Laurentian system is characterized by monotonous uni- 
 formity in the nature of its rocks, which consist of gray and red gneiss, usually much 
 bent or disturbed, and having generally only a ruUely foliated structure and a solid or 
 massive character. Its felspar is almost entirely orthoclase, whereas the other speciea 
 
arc aiiuiulaiit in tlic upin'i' (li\i,si()ii. 'riicic is u ytiicial iiliscnct! of i.roiioiiiic iiiiinrals, iiiul 
 the nutiilier of iniiiiTal spcoifH is .small aa eoniparcd with th« lattf-r. Thtt upper diviHioii 
 is of a more i'()iii|ilcx or (liMV'riMiti-.tcil cliarai'tcr, or coinpriHcs a f^Tcatcr vitrifdy of rocks 
 and mini'ials. It posscHst's more rc;;uiarily in its Htratitication and incliidfs j^rr-at liandfil 
 niassi'H of ciystaiiint! linii'stoncs, vitrcoiiH (|uart/it('.s, mica and liornhlcndo scliists, massivfi 
 pyroxene, and l)Otli massiv(! and fi)liale(! ialiradoritu rooks. Con.sideralile areas of jjranito 
 and syenite occur in the tbrnrition. These, as >v(!!l as the pyroxene rocks, and perliaf.,s 
 also tlie hornlilendic hands, are evidence of iniier)us action. The dykes ot <,'reen-itono and 
 porjihyry wliuh cut the upper Laurentian ma;/ helong to a Ir.ter jt^eological jieriud. 
 
 rpvvards of sixty dilh-rent mineral spociea havo W-^n found among tlio upper Laur- 
 entian rocks in Canada. Diey also contain a variety of economic minerMJH, amou'< which 
 may he mentioned gi'aphite, apatite, mica, serpentine and limestone marhles, limestones 
 suitahlo for calcining, felspar for jmrcelain, ])orphyriesand other ornamental stomas, pyrite, 
 sulphates of harium and strontium, asbestos, crysotile, building stones, and ores of iron 
 and othi-r metals. 
 
 It is not impo.s8il)le that gneiss may havi^ h(!en formed in more than one way. Wliile 
 some varieties, from their mioioscopical characters and other circumstances, appear to he 
 of clastic origin, it seems to he eijually certain that others owe their foliation to pressure 
 and internal changes which may havo taken i)lace in rocks of igneous origin. Dr. Steiry 
 Hunt is of the opinion that we have not yet discovered any rocks which can he regarded 
 as having formed part of the oiiginal crust of the earth, that is, if we suppose the crust 
 to have heen first formed hy th(! m(;re ruperhcial cooling of a molten lUass, since the 
 earliest rocks of which we have any knowledge all contain water and free silica. 
 
 The lower Laurentian gneisses are the oldest rocks witli which we are acquainted. 
 Their thickness is entirely unknown, and it may ever l)e found impossible to arrive at 
 even an approximatinn to their volume. It must however be enormou.s. The upper 
 Laurentian, of which some kind of measurement is possible, n.ay be roughly estimated 
 in the Ottawa valley, wliere it has been more studied than elsewhere, at from 50,000 to 
 IQO.OOO feet, or nearly 20 miles in tliickness, and even much more. 
 
 Although tlie older Laurentian rocks may afford no mechanical proof of the per- 
 manent existence of a sea ujion the earth, unless their foliated or stratiform character be 
 taken as such evidence, water appears to have been present, perhaps as only temporary 
 precipitations upon the surface, at every stage of their formation. But in the upper 
 Laurentian the great de])osit8 of nearly [)ure carborate of lime and of tolerably pure 
 silica in distinct bands afford strong support to the tqueous theory of their deposition, 
 while it negatives that of their igneous origin. Ai. important feature in the general 
 character of the Laurentian system is that its rocks, as a whole, are of an acid nature, 
 or contain a preponderance of silica in their ultimate chemical composition. We shall 
 see further on that in this respect they contrast with a considerable proportion of those 
 of the Iluronian system, which are largely of a basic character. 
 
 Whether we reganl tlie bulk of the Laurentian rocks as having had a clastic or an 
 igneous origin, the general condition of the surface of the earth does not appear to have 
 undergone any great change while they were being formed, or while the cooling process 
 was going on to the extent of their thickness. Even in the upper Laurentian we have 
 found no proof of the pre existence of solid rock or dry land such as might be afforded 
 by conglomerates. 
 
 A P K li 1 O 1 1 OF C H A N G E . 
 
 But with the beginning of the Huronian period came a new order of things. Great 
 volcanic activity took place, and at the same time we have distinct evidence of the per- 
 manent abode of water on the surface of the earth and of the wear and tear of the sea 
 on the solid rocks. Immense^ quantities of volcanic ashes, cinders or tufa, broken rock 
 and other ejectamenta were thrown out, in some cases with explosive violence. Molten 
 matter was poured forth in great quantities from vents and rents in the crust, forming 
 thick sheets and large masses that became incorporated among the marine sediments 
 which were probably accumulating rapidly. The surface of the earth would be almost 
 *2 (M) 
 
■■ 
 
 i 
 
 4 
 
 entirely covered hy tlu; sow, wliioh would likely lie slmllow, hot and (u!I of disHolved 
 mineral matters, the greater part of which have Hince heen eliminated. It would l)n untit 
 to Hupport animal or plant lil'c, and it is therefore improltalile that we shall »iver lind any 
 organic remains in this >ystem. Soun? of the (Tupted rocks remain massive and un- 
 chan^'ed to the pre.ient day. except hy the internal or molecular action among the con- 
 gtituenth themselves, hut the hulk ot" them had heconu! hroken up under the strong 
 weathering iidhiencea of the period, or hy contact with water, and spread out on the 
 V)ottoni of the sea to foini tlu; various stratified rocks of the system. The general cliar- 
 acter of thf! Huronian rocks may therefore he said to he pyroclastic, this term signii'ying 
 that although fiagniental they have nevertheless had an igneous origin. The lluronian 
 rocks of lake Superior, and the coi:ntry norlli ^md west of it, c(;nsist largely of greenish 
 Bchists wh" .. . .e, chemically speaking, hasic as distinguished from the gneiss ot the 
 Laurentia!!, whicli, as already stated, is of an acid or silicious character. A considerahle 
 proportion of the great Huronian lielt is made up of greenstones and allied rocks that 
 are also hasic. 
 
 Rocks soitii ok t ii k Hi iuinian Hki.t. 
 
 In the country represented upon the map, tlu^ rocks lying hotwoon the great Huron- 
 ian Iwlt and the shore of Georgian hay appear to helong to the upper Laurontian for- 
 matio I. In the French river region the gneisses are generally oliaracterized hy much 
 regul irity in their dips and strikes, which often maintain the same course and ahout the 
 same angle of inclination for long distances. The dips vary from a horizontal to a 
 vertical attitude, but in the majority of cases they are ahout intermediate between these. 
 
 This region is noted for its peculiarly straight and almost parallel rocky channels, 
 many miles in length, having a general course neaily east and west, which are intersected 
 at large angles by othjr channels almost equally straight, the whole forming a sort of nst- 
 work quite unique in its character. Some of these channels belonging to both sets run 
 with the strike of the f,neiss, which v/hen mapped has a sort of zig-aag arrangement on 
 a large scale, while Ma others follow the lines of the principal set of joints. It some- 
 times happens that between two leading joint-planes other and parallel joints occur, un- 
 usually close together, breaking the rock up into blocks which have been removed by 
 glacial denudation, thus producing these channels. The angles of dip being only moder- 
 ately steep, those channels which follow the strike occupy ditch-like notches formed along 
 the outcrops of paiticular sets of beds which have been more easily excavated by eroding 
 agencies than those on either side of them. 
 
 It will be observed that the French river flows in two principal east-and-west channels 
 between lake Nipissing and its rocky delta, and that about half way down they both jog to 
 the southward at right angles. This interruption in their course is perhaps originally 
 due as much to somo northand-south break or disturbance in the rocks as to changes in 
 the strike. The long east-and-west channels, whether parallel with or transverse to the 
 stratification, are also probably situated upon lines of crushing, and possibly of some dislo- 
 cation, along which the strata have been broken up so as to permit of the deeper pene- 
 tration of the surface waters and the conse([nent decay of the lock prior to the glacial 
 period, during which these channels have been excavated below the general level ot the 
 country. They are really only long and very narrow lakes, with slight falls or lapids 
 between them, and they persist in their courses uninfluenced by the changes in the strike 
 of the rocks they pass through. Besides the channels shown upon the older maps, there 
 are many others in the French river country, all of which belong to the reticulating system 
 of waters which forms so remarkable a feature in .is whole district. 
 
 The curious rocky delta of the French river has a breadth across its mouths of fifteen 
 miles. The channels, which are very numerous as we leave the coast, form three groups, 
 the east, middle and west, each of which unites by cross channels into one at a short 
 distance up. They are all nearly parallel and have a general northeast and north-north- 
 east course as we enter from Oeorgian bay. The gneiss in the whole interval covered by 
 these channels runs parallel with them and has a uniform dip to the south-east and east- 
 Boutheast, with an average inclination of from 40° to 60''. This general strike extends 
 
j 
 
 for twenty niileH inland from (icorjjiftii l>fty, whf-n it hcconics disturbed, and a little fur 
 ther on is cut off by a northwesterly strike in siinilar gneisNes which prevail on the 
 upper part of the Frcp.uh river and the country to the norlliwarJ of it. 
 
 In the ccmtral part of the course of the river tlie strike in dill'eient intervals runs 
 about north and south, east and west, northwcsst and northeast, while between these 
 groups of toliMably strai<,'ht liands it in often more oi h^ss bent or distorted. In some 
 parts of th(f French river rej^ion. oven when- the striki's are regular, Mr. Murray consid- 
 ered the structure to indicate a series of unticlitiul and syne' folds, in which some of 
 the strata are repeated, and that the thickness of the gne' in con.seijuence made to 
 appear much greater than it really is. But after making i ' unce for this partial repe- 
 tition, the actual thii.kness must be very great. 
 
 Southeastward of the mouths of French river, along the shore of (ieorgian bay, the 
 rockw are (verywhen; well exposed, and the structure of the gneiss and associated strata 
 or their local contiguration is well brought out by the erosion to which they have been 
 Subjected. This fact is graphically illustrated by Iht! recent charts of Captain Boulton. 
 
 Locally the run of the stratification is often imlicated by the form or direction of the 
 points and bays, the larger islands and the chains of smaller ones. The curving; outlines 
 of the islands, channels and inlets opi)osite to l*enetanf;uishene, the twisted appearance of 
 Parry island and of the channel on its southeast side, as well as the sinj^iilar straiirhtness 
 of Partridge bay. the Lonj; inlet, the points on the west side of Parry island and al)0ut 
 Shibaishkong islaijd, all correspond with the local strike of the rocks nud are due to the 
 effects of denudation, which lias formed cliannels along the courses of tfie more yielding 
 strata, and left ridges or higher j^round wliere the I'ocks i-esisted decaj- and erosion. 
 Along this shore there is however a class of channels and inlets due to another cause, 
 namely, the existence of dykes of trap and breccia and of granite veins, and also of parallel 
 'oints or cracks alon^;- which the rocks l.iavo been rendered more decomposable ; or these 
 .alter mav have acted merely as starting points or guiding lines for the action of glaciers 
 or other denuding agencies which constantly enlai-ged and deepened the depressions, once 
 they had been commenced. The channels and inlets of this class usually run nearly east and 
 west and have steep sides, while those which follow the stratification have usually some 
 other course and are not so abrui)t.* 
 
 Thestj lines of rock-crushing and subsequent erosion have doubtless had a great 
 effect in producing the river and lake features in most of the regions occupied by our 
 upper Laurentian rocks, as well as in some other metamorphic districts of Canada. Dykes 
 of greenstone and breccia have also played an important part in this connection, generally 
 giving rise to river-channels and long lake-basins, but occasionally, where hard or resisting, 
 having the opposite effect, producing ridges, or causing falls and rupids where they happen 
 to cross streams. 
 
 Near the head of Byng inlet, a short distance southeast of the mouths of French 
 river, a brecciated rock is exposed near the edge of the water which apparently forms 
 part of an east-and-west dyke, alo g the course of which the channel of the inlet and of 
 Maganetawan river have been excavated. Parallel to this dyke are joints stained red 
 by oxide of iron, giving a dry and crumbling character to the gneiss along their course, 
 which is east and west, while the gneiss they cut runs in various direetions tra, iverse 
 to the joints. 
 
 On the lower or western north channel of French river Mr. Murray noticed a triable 
 brick-red quartz-syenite at the Grand Recollet falls and for some miles below it. This 
 probably belongs to aner .ive dyke-like mass, following a line of weakness in tlie course 
 of the channel. 
 
 In the French river country the gneisses are most commonly of dark reddish-grey 
 shades, and they comprise both the mica and the hornblende varieties. Their texture is 
 usually from medium to coarse grained. As a rule the latter are gray and darkly colored, 
 while the finer grained varieties are generally reddish. Silicious belts, in some cases 
 amounting to vitreous quartzites, bands of mfca schist with garnets and of hornblende 
 schist c^cur among the gneisses, and in, some localities they are largely developed. 
 
 * Dr. Robert Bell in the Report of the Geological Survey for 1876, page 195. 
 
A^cins of coarse rt'ddi.sh atid nearly wliite ijranite running' in different directions cut 
 the l)ornl)lende and mica sciiists and sulu..tose i^neisseH about tiie nioutiis of b'rencli river, 
 and similar veins are also met with occasionally in the interior. A few giennatone dykes 
 were noticed along the river, but they do not appear to he verj common in this region. 
 
 Quartz veins running in various directions are of frequent occurrence in the French 
 river region, hut they are all of a " hungry " character, and none of them have been 
 observed to carry economic minerals in promising ijuantities. 
 
 The di\idin,g line between the Huronian and Ls 'rentian systems runs northeastward 
 from the head of Shibaonaning or Killarney l)ay. "Between this locality and thi! middle of 
 Philip Edward island, including the township of Rutherford and most ot Oarlyle, the rock is 
 a massive red ([uartz-syenite ov liornblende-granite, which occasionally shows patches of an 
 indistinctly foliated cliaracter ■ but this rock does not appear to extend far inland, although 
 it occupies about twelve miles along the coast. Mr. Murray mentions the occurrence of 
 a similar rock, which seems to have a breadth of about two miles and a length of about four 
 miles, in a northeasterly direction between the western and middle groups of mouths of 
 the French river. 
 
 In the region covered by tlie map certain differences may easily be observed in the 
 general characters of the Laurentian rocks on the southeast side of the great Huronian 
 Vielt as compared with the rocks on its northwest side, whicli we have for the present 
 classified for convenience with the same series, because we have not yet found it practi- 
 caV)le to separate them by a definite line from the undoubted Ijaurentian still further 
 northwest, with which they are continuous. Between the shore of Georgian bay and the 
 Huronian l>elt, and about as far north as the line of the Canadian Pacific Railway, the 
 gnei~ses are of the typical Laurentian varieties, all evenly stratified and regularly arrang- 
 ed in anticlinal and synclinal forms, according to the structural laws governing strati ed 
 rocks. The angles of dip are on an average not far from 4.")'-', although in some cases 
 they are nearly horizontal and in others almost vertical. Except in a few localities the 
 bedding is not contorted, but runs straight and evenly for considerable distances, and 
 these gneisses have every appearance of lieing altered sedimentary rocks. Red and grey 
 varieties are represented in about e(iual proportions, and they alternate with each other in 
 both thick and thin sheets. They are mostly mica gneisses, although the mica is present 
 in rather small proportions, but in some cases hornblende replaces the mica in whole or 
 in part. 
 
 No beds of crystalline limestone have been found among these rocks west of the 
 longtitude of Iron island in lake Nijiissing, where this rock has been noted by Mr. Alex- 
 ander Murray. These limestones are also associated with them jn some of the islands in 
 the eastern part of this lake and at lake Talon on the Mattawa. Further east, in the 
 Parry Sound district, the writer in 187G traced five distinct brands of Laurentian lime- 
 stones running for considerable distances in a northerly direction from the shore of Geor- 
 gian bay. 
 
 The Laurentian rocks between Georgian bay and the great Huronian belt, from the 
 characters which have. just been described, would therefore ho classified along witli those 
 of the counties of Ottawa and Argenteuil, which belong to the upper portion of the 
 system. 
 
 R O C K S N O It T H W K S T O K I' M K H U R O N I A N B K L T . 
 
 On the northwest side of the great belt the conditions are different. At some dis- 
 tance to the northward of this belt the heavy contorted gneisses of the lower Lanrentian- 
 cover an immense area, but there is an intermediate region in which red hornblende 
 granites prevail, but they are mingled in some parts with gneiiii'.. The granites are 
 largely developed along the northwest border of the Huronian belt all the way from the 
 west side of lake Wahnapitfie soutliwestwaud to the Sable river, and probalily still further. 
 From this geological boundary they extend northwestward out into the midst of the 
 lower Laurentian gneisses to a variable distance, their greatest extension being un- 
 known. Along the main line of the Canadian Pacific Railway they are fimnd all the 
 way from the junction of the Huronian at Onaping station to Spanish Forks and west- 
 
 it 
 
 gai 
 of 
 
Wiird frani the railway to the Spaniwli river, liut beyond tjiese limits tlie country has not 
 been carefully exidored. 
 
 Similar red hornblende i,'ranit(!, occasionally showinj,' j^neissoid texture;, forms an 
 elongated area in the middh; of the Huronian bolt in the Sudbury district, extend- 
 ing from near the South bay of lake Wahnapitae south westward to the towiishi|) of 
 Drury. The southei'ii boundary of the main granitic area crosses the Spanish river mid- 
 way ljet\ve< n tht; nortliern and southern lines of township 111, whence passing westwaid 
 it sweeps round to the south and forms a promontory in the townshi))8of (Jough and May. 
 From the nortliern part oi' the latter township the boundary botwe<!n the granite on the 
 ncrih and the Huronimi (|uartzites, gr^ywackes and schists on the soutii runs westward 
 parallel to the shore ot lake Huron, as far as the- townshij) of Proctor, were it turns 
 noithwestward and the Huronian rocks occu))y a large area lying to the northward of 
 Algoina Mills. 
 
 Allliough the granites which have just been described are provisionally classed with the 
 Laurentian, it is uncertain that they are all really pf this age. In some localities they are 
 so intimately associated with gneis.ses of the ordinary Tjaurentian types that it would be 
 ini|iO>sible to draw a line betwe<'n them. In such cases they may have been foinied 
 out of jiortions of the gneiss softcnid by heat and re-crystallized alter having lost 
 their stratiform cliaraclcr. In other places it is quite possible th<>y uiay be due to 
 the alteration of arkose or gi-ey wacke similar to that wliich is so counnon in the adjacent 
 Huronian series. Or it iiiav be that thest; granites are mainlv eruriti\(> ir their origin. 
 The writer has pointed out in various reports on the Arcluean rocks of northern Canada 
 that the conunonest situation of the granitic areas among these Tocks is at and neai' the 
 junction of the Laurentian and Huronian series, and tlicre is perhaps no good reason yet 
 known why they should be assigned to the one more than the other. 
 
 In the legion at present under consideration, along the line of contact between these 
 granites and the Huronian (|uarizites, schists, etc., the rocks are often much broken up 
 and intermingled with oiH^ another, both in great iiiasses and smailt^r fragments. This 
 effect has probably been produced when thegrc.nite was in a soft coiulition and subject to 
 inti use pressure, coupled with more or less movement. Referring to th(i last mentioned 
 consideration, it is not imjirobable that faiilis of considerable extent have taken place along 
 tlie lines of junction between these two classes of rock,,, not only in this region but in 
 otlier localities nhi re the Laurentian and Huronian rocks come into contact. This is 
 only what we might expect to occur along the lines dividing rocks having unecpial jiowers 
 of resisting the great strains to which the crust of the earth must have bei'ii su'oject in all 
 ager.. These faulls may be looked f(ir more especially at those parts of tln' junction of the 
 two sets of rocks wliich have been most e'xpused to lateral pressure, antl along rhose por- 
 tions of the lines of contact which are tolerably straight for considerable distances. The 
 bed-planes of the Huronian and Laurentian rocks on the opposite sides of a contact thus 
 faulttd might show some want of parallelism, and from this accident a general un- 
 confoiiiiity of the two series might be erroneously inferred. The few instances of 
 apparent local want of conformity which have been observed seem to be capable of ex- 
 planation in this way. Out of these instances may l)e seen at the Wahnapitae river where 
 it is crossed by the Canadian I'acidc Railway. 
 
 Within the area represented on the map, besides the gneissic and granitic rocks 
 flanking the great liuronian belt, there remain to be noticed a few inliers of these rocks. 
 One of them, consisting of gneiss, lies between the north and northeast arms of Tema- 
 ganii lake. Another, also of gneiss, which has been described by the writer in the report 
 of the Geological S'urvey for 1875, surround.- Paul's lake on the upper part of Sturgeon 
 river, and appears to extend for .some distance to the soutli of it. A short distance 
 east )f the angle formed by the junction of Prondfoot's east-and-west and north-aud- 
 south lines an area of red hornblende granite was discovered, which ma^' extend to the 
 northward, but its limits have not been traced out. Two belts of gneiss projecting from 
 the north ward cross Montreal river, one at Elk lake and the otlier at the sharp turn in 
 the r'ver about midway between this lake and the junction of the east branclt. Both 
 of these belts appear to terminate at no great distance to the south of Montreal river. 
 
T II K GREAT II I' I! N I A N B K I- T . 
 
 Sir Williiim Lofjan and his assistant, Mr. Alexander Murray, after exaininiiij? the 
 crystalline rocks of lakes .Superior and Huron, gave the name Huronian (at the siig<,'es- 
 tion of Dr. Sterry Hunt) to Jl those of both regions which lie above tiie granitic series 
 which they called Laurentian. These terms, were not restricted to any particular area, 
 but were meant to designate the two great divisions of the Archaean rocks and to be 
 of general application in Canadian geology. IJoth sets of rocks extend into the United 
 States and the Canadian names, having priority, were adopted there. But of late years 
 efforts have been made to abolish the convenient and well establi.shed de.signa'ion Ifur- 
 onian, except for one small area of these rocks lying on the north sidn of lake Huron and 
 forming only a part of the great belt which is contii.uous from lake Superior to lake Mis- 
 taasini, a distance of 700 miles following its axis, on the asserted grouml that the selected 
 part alone forms what some geologists call the '' typics' Huronian." 1 cannot however 
 understand why one particular portion of one belt (jf nicks of tlio Huronian system 
 should now be selected for this distiuction to the exclusion of tiie remainder of the 
 belt which is continuous widi it, and also of other areas of rocks which are mo.st naturally 
 placed with them and which were expressly included by Logan when he classitied tliem 
 and gave them this name. 
 
 The rocks of the Huronian .'lystem as defined by Logan consist of crystalline scliisis 
 in great variety, (juartzites, conglomerates and agglomerates, clay slates, greenstones, 
 dolomites, etc. At the time referred to, more than forty years ago, th(! science of 
 petrology was in a crude state compared with its present position, and the microscope 
 was l)ut little used in determining the nature of rocks. Hence Logan did not recognize 
 the volcanic or rather pyroclastic character of a large proportion of the Huronian loeks. 
 Some of the rocks of the system, such as tlie quartzites and clay-slates, although tley do 
 not themselves show a direct igneous origin, may have been derived from the products of 
 volcanic activity through tlie intervention of water. 
 
 Owing to tlie pyroclastic origin of the majority of these rocks the various memberi* 
 in any region are not usually persistent for any great distance, but diminish in volume 
 and are replaced by other beds which increase in thickness as the first diminish. As these 
 rocks are usually tilted to high angles, the sections afforded by the surface of the earth are 
 generally nearly at right angles to the bedding, and when mapped often show the inter- 
 locking character of the different bands as they terminate in both directions. This want 
 of persistence is exhibited on both a small and large scale, so that the general character.-* 
 of wide belts of Huronian rocks differ much in different regions. 
 
 In other [larts cf the world, such as Scandinavia and Scotland, where Archiean rocks 
 are largely developed, series corresponding with our Laurentian and Huronian are met 
 with. Nowhere have rocks of a different character been f )und to intervene between them. 
 Ve might therefore infer that in a gem ral way the two systems are conformable to one 
 aiiother. This inference i;^ borne out by our observations over the enormous area of 
 Arclnean rocks which we have in the Dominion. It might be expected that in some 
 parts of this great area a local want of conformity might be detected at the same time 
 that the two systems were conformable on the grand scale. But in the few instances 
 where there appeals to be a want of parallelism in the stratificat'.on on the opposite sides 
 of the contact, this is more probably due to faulting. 
 
 On the other liaml, we have observed numerous instances where there is a gradual 
 and conformable transition from the lower into the upper series. The ))eds of passage as 
 a general rule consist of hornblende and mica schists alternating with fine-grained gneisses, 
 and these are followed by other crystalline schists. In the Huronian areas of lake 
 Superior crystalline schists predominate, although representatives of all the otiier 
 varieties of the rocks of the system are not wanting, while in the lake Huron region 
 and to the northeastward cf it greywackes and (juartzites with clay slates are the most 
 coi- picuous rocks, bui the various crystalline schists similar to those of the lake 
 Superior region are likt wise to be found. 
 
 An impression has got abroail in some quarters that one of the distinguishing 
 
 thf 
 
11 
 
 featurtsof thn Huronian rocks on the nortli side of lake Huron is that they usually 
 clip at vory moderate angles. Kven if this were true, it would be a matter of no con- 
 sequence in chronological geology. It is however only an incorrect assumption, and on 
 the contrary as a rule the rocks of that region are highly inclined, as shown in a sec- 
 tion by Mr. Murrny in the report of the Geological Survey for ISfiG, and in my own 
 section across the Sudbury district juiblished in 1891. They do however dip at low 
 angles in certain limited areas, such as the tract lying northward from St. Joseph's island 
 and in that situated to the east of lake Wahnapitae, and again between lake Temagarai 
 and the Montreal river. l!ut instances of equally low dips are to be seen among the 
 np])er Laurentian gneisses, as for exam|)Ie in a large region to the northward of Mon- 
 treal. 
 
 Although in the lake Superior region and thence westward to Lake of the Woods 
 the Huronian rocks consist so largely of crystalline schists, still there are silioious rocks 
 among them, which may be the eciuivalents in diminished volume of the (juartzites of 
 lake Huron , also conglomera*"s, clay-slates, serpentines, dolomites, et(;., and on the 
 other hand tliere is an abundance of crystalliiu! schists among the Huronian rocks of 
 the lake Huron region. Conglomerates occur at various horizons among these rocks 
 in both regions, but any single conglomerate bed is probably only of local occurrence 
 and cannot be held to be the eijuivalent of any particular conglomerate in another re- 
 gion. As these conglomerates cannot be connected with one another in dirt'ercnt 
 Huronian areas it can scarcely be said that they represent a general break in the 
 chronological continuity of one piirt of the system with another, much less a time 
 break between this .system an<l any other. 
 
 F'rom what has been said of the nature of tlu' Huronian system we should not exp'ct 
 even contemporaneous ])arts of it to be everywhere I'epresented by the same kind of rocks. 
 On the contrary, great local dillerences might be looked for at the same horizon. In a 
 given re-^ion one variety may be largely developed, and yet in another this may bi^ en- 
 tirely replaced l)y a different rock without there being any difference in the age of the 
 two. Rocks like those of the Lake of the Woods may be the equivalents in time of 
 those of the north .oide of lake Huron, or of some other part of the system wliere the 
 lithological ditl'erence is e(iually great. Still we have always admitted that perhaps the 
 prevailing schistose series of the lake Superior region may belong to an older part of the 
 system than the quartzite, clay slate and greywacke series of lake Huron, which appar- 
 ently forms the newest p(jrtion of the great belt. Thus the area characterized by the 
 great development of quartzites in the region extending from lake Huron to lake 
 Abittibi may be somewhat newer as a whole than those portions of the series whf re the 
 quartzites are in small amount or entirely absent. iVt the same time it is not to be 
 forgotten that the qiuvrtzites of the region n)entione<l are associated with a variety of 
 crystalline schists, such as may be seen on Spanish river, around Temagami lake, 
 on Montreal river and in the region to the northward of it. The stratigraphical sequence 
 of the various kinds of rocks found in the Huronian belt within our region has not yet 
 been ascertained with sufficient certainty. The following descriptions of these rocks are 
 therefore not given in the supposed order of their superposition. 
 
 guishing 
 
 Q r A K T Z I T K s . 
 
 It is an interesting fact in connection with the origin of these rocks that the 
 quartzites and clay slates are so often found together. The decomposition of the arkose 
 or greywacke and the separation of the siiit^ious grains and the clayey portion would give 
 rise to these two kinds of rock. Or they might result from the decomposition of the 
 binary granite, from which the greywacke itself is probably derived, by the sepnration of 
 the quartz grains from the argillaceous matter that would be produced from the felspar. 
 Nearly all the quartzites contai'i more or less felspar, ami sometimes it is present in largo 
 propoitions. giving the rock the general outward appearance of granite. In some 
 instances observed by the writer this mixture had become so far metamorphosed back 
 into granite that it required to be examined in thin slices under the microscope before ifc 
 could be decided that it had ever been a clastic rock at all. 
 
12 
 
 Thesi) liij»hly tolspalliic ([uartzites are ahuiulaiil aloiij^ tlus North riven- cauoo-route 
 from lake Mattagaiiiashini; (just east of lake Wahnapitae) to the upper partof iSturyeon river, 
 and again wi st of Laily Kvelyn lake, which lies noith of Teiiiiij^riiui lake. In other roifioiis 
 howevei' the proportion of fekspar in these roeks is generally small, ami the texture of the 
 nearl_y pure (juart/,it(>.s varies from compact with conchoidal fra(;tiire and composed of 
 microscopic grains up to coarsely granular, made up of small p(d)bles closely crowded 
 together. Some i^eds in almost every large; outcrop of these rocko are of a distinct con- 
 glomerate charactc^r, tilt! pchhles luang well rounded and almost all of white (juartz. 
 
 In the country just north of Bruce Mines, and again on the norrh side of (.4oulais bay, 
 lake Superior, some beds and groups ot' Ixid.s of these conglomeiates contain pebhhis of red 
 and dark jasper and lightcolort \ chalcedony, thickly scattered among oth< rs of white 
 quartz, ail in a matrix of white (juartzite. Tliis beautiful lock has long been known as 
 jasper conglomerate, and forms a line ornamental stone, but owing to its hardness it is 
 expeiLsive to cut and polish. / few scattered pebbles of jasp(>r are found here and there 
 in the (juaitzites all the way from the above localities to .Slontreal river. 
 
 Light grey and nearly white quartzites form the north shore of lake Huron from the 
 mouth of Spanish river eastward to ivillarney bay. They constitute the LaOloche moun- 
 tains, which run as two and sometimes three parallel ridges close to the shore, and nearly 
 due east iind west with the strike. The height of the front ridsre varies from -ICO to 755 
 feet above lake Huron, but tlie altitude increases in tlie continuation of these hills to the 
 eastward, and it rises at one point to an elevation of 1,180 feet. The dip is everywhere 
 nearly vertical. Similar quartzites, also standing nearly on edge, form the long and high 
 points jutting out into lake Huron in a southwesterly direction between McUregor and 
 Killarney bays. The strata terming these points are probably repetitions of those of the La- 
 Cloche mountains, on the opposite side of a synclinal n\ nearly verti(!al strata, one extremity 
 of which would be in the vicinity of the east et d oi lake Panache. The quurtzite of the 
 points and islands south of Frazer bay continue^ .outhweslward, and appears on Hey wood 
 island, and further on upon (.Ji-and Manitoulin isi <\, at the head of Sheguiandah bay, and 
 thence past the northern sides of Bass and Pike la ^. Quartzites, mostly of light colors, 
 constitute the prevailing rock around lake Panache und the great bend of Spanish river, 
 and northeastward to the township of iiroder, but beyond this, for some distance on the 
 general strike, they diminish in volunu;, and a conHiderable proportion of what remain 
 merge into greywackes in passing through the contracted part of the belt in the Sudbury 
 district. Still lurther on in tlie northeastward strike, or in the country to the eastward 
 of lake Wahnapitae, the greywackes have passed into or have been replaced by clay-slates 
 and argillites, dipping at much lower angles. 
 
 Northward of lake Wahnapitae the quartzites are again met with in great abundance. 
 Along the upper Wahnapitae river they strike north-northwestward parallel to the 
 Laurentian boundary in that direction, and dip at high angles. On the North river chain 
 of lakes the general strike is east of north, turning more easterly in approaching Sturgeon 
 river, beyond which the quartzites run northeasterly towar/ls Lady Evelyn lake and 
 Maple mountain to the west of it. These rocks are exposed in numerous places along 
 the main Montreal river, and both its branches south of the great bend. Still further 
 north they are largely developed in the counti'y along the height of land westward from 
 its intersection with the north and south inter-provincial boundary line. 
 
 In the region northeast of the St. Mary river the quartzites show considerable 
 differences of color, and on this ground Mr. Ale.<and< r Murray separated them into diff<ir- 
 ent bands. In thu southern part of the district shown on our mip they are nearly all of 
 light shades, but near its northern border ihere are red, pink and purple varieties. These 
 are however of local occurrence. Greenish and yellowish tinges are common in all parts 
 of the distribution of the lighter varieties. 
 
 C r, A V-S I. AT KS ANU A U U I L L 1 1' E S . 
 
 The term slate should be given only to rocks formed principally from clay, in which 
 arallel cleavage planes have been developed independent of the bedding. It is not properly 
 pplied to those crystalline schists in which the cleavage ia mora or less imperfect and thv3 
 
pill 
 
 Clr; 
 
 kill 
 
 liv 
 nor 
 til. 
 kk 
 
 coll 
 .slia 
 
 Will 
 
 al)f 
 a hi; 
 occ 
 
 OIK 
 
 for 
 
 th<' 
 
 or 
 
 roc 
 
 of 1 
 
 the 
 
 As 
 
 old 
 
 the 
 
 scr 
 
 itit 
 
 of 
 
 oce 
 
 are 
 
 am 
 
 in 
 
 Sin 
 Gn 
 of 
 
 nar 
 
 not 
 div 
 nia 
 of i 
 son 
 gra 
 siz( 
 di-si 
 Frs 
 por 
 this 
 of! 
 
 wit 
 
13 
 
 plrtnos aro not parallel to otio anotlier. Argillites are clayHtones in wliicli the slaty 
 cleavage has not been devolopoil. 
 
 Confining our remarks always to the iir';a i('{)r(^s(»nted on the map, rocks of these two 
 kiiuls are met witli most larj^ely in the country hotwecii liike Wahmipitae and Stuff^eon 
 river, aloni» that stream between the Maskinoii^e and Hound lake Ijranches, about the 
 north "lid of Tcmai^ami lake*, and thenci^ liy [jiidy iCvelyn lake co .Montreal river, and on 
 the latter ; likewise along the Matahechnwan river, which disclrMj^es into the foot of 
 laki- 'i'emiscaming. Tlies(! slates arc^ mostly of olive or l)luisli j^rucii, purplish, drab and ,L,'t'ay 
 colors, and are often barred across the cl(!ava<^ " with narrow parallel bands of '.litl'ereiit 
 shades. At the northern outlet of Temagami lake a jjreenish cotupact variety is marked 
 by thin interrupted black bars. This rock, when cut, takes a smooth surface, and 
 was much prized by t.'io ancient Indians for ornaments and ceremonial stones. 
 
 These principal acounuilations of slates and argillites appear to be in a general way 
 about contemporaneous with thi' (luartziies, that is to say, they were l)eing depositcnl in the 
 altove localities at th(^ same time that tlie (juartziies were forming in others. Wlnirt^ they 
 occur in smaller vohunes they are sometimes found in proximity or ii\terstratitied with 
 one anotlier. As already stated, they m:iy both be derived from the greywackes, which 
 form so laig(; a proportion of the rocks of the great Huronian lielt in this region ; and 
 till' gicywiickes in tiieir turn arts evidently iiiaih! iii> of the (M>riti of a (piartz-felspar rock 
 or binary granite. Ur th(;y may have been formed directly from tlie decomposition of this 
 rock and its rearrangiinent Viy water, the silica and the undecoinposed felspar, when any 
 of the latter remained, going to make the, (juartzit(>s, wliile the tine mud resulting from 
 the di'cay of th<; felspar was carried elsewhere, and now constitutes the slates and argillites. 
 As far as our present knowledge goes, tlie (juartzites therefore cannot bo said to be either 
 older or newer than the slates of this part of the Huronian series. 
 
 Tlio rooting slati's found among the metainorphic rocks of the Eastern Townships in 
 the province of Quebec are probably of somewhat newer geological age than those just de- 
 scribed, which in some places may be found suitable for roofing purpoH(>s. Among tlie local- 
 ities where; the argillitcis or non-clcavable varieties occur may lie mentioned the southern part 
 of ^Mattagamashing lake, Koo-kagamiiig and Lady Evelyn lakes. Good cleavable slates 
 occur on the Canadian Pacific Railway a short distance east of Algoma Mills. Felsitea 
 are soinetiiins found associati-d with the slates and ([uartzites, but they are more abundant 
 among the greywackes. 
 
 Dark gray or drab and almost black clay slates are found along the .Spanish river, 
 in the northern part of IJaldwin, and at tlie tails on lot I, fifth concession of Nairn. 
 Similar slates are met with on the Oanadian Pacific Railway in the southwestern part of 
 Graham, antl again just south of Geneva lake. Tiiey are alto said to occur in the township 
 of Drury and a short distance east of Bannerman lake. 
 
 G R E V \V A C K K OK A It K O S K . 
 
 In some parts of our region a rock which may be described under either of the above 
 names is met with in great abundance. It has some resemblance to sandstone, but does 
 not usually occur in distinct beds with parallel faces, and is generally either massive or 
 divided by joints or a rough sort of cleavage. Under the hammer it breaks readily, and 
 may be easily bruised or scratched, thus showing the presence of a considerable proportion 
 of ingredients softer than quartz. It has an ashy appearance, and its color is usually 
 some shade of ash-gray. On closer examinatior, it is found to consist of comminuted 
 granitic debris, and generally holds *juantities of pebbles and angular fragments of all 
 sizes of the granite itself. The latter are mostly of the same character in all parts of the 
 district, and consist of a binary granite or cpiartz-felspar rock of either a red or gray color. 
 Fragments of gneiss and other crystalline rocks are occasionally mingled in small pro- 
 portions with those just described. Under the inicrosco|)e the matrix or finer portion of 
 this rock is seen to consist of somewhat rounded grains of (juartz, and more angulai ones 
 of felspar, with a tilling of fine serecite or of some dark amorphous mineral. 
 
 Rocks of this kind occur here and there in almost all parts of the Huronian belt 
 within our region, but they are particularly abundant in the narrowed portion in the 
 
14 
 
 Sudbury district and around Teinagami lalte and Rabhit luko to thu east of it. They 
 are also common in tho Onapin^ anil Stniij^ht lake outlitM'.s and all alou',' the Spani.ih 
 river, below the granite area, and thence westward as far nt MisHiHsajja river. 
 
 Sometimes, us on the Montreal rlvei, ti.c; iiu-luil:'d fragint^uts of <{ranite attain tlio 
 size of boulders, and these, as well us the smallet inciithion , nviy occasii nally be found so 
 closely packed together that only the interiti(^es are tilled by the finer material. Th^ 
 fragments are most common in the greywackes where the latter occur in large volume, and 
 in these cades there is little evidence of stratification. The more uniforndy-i^rained 
 varieties, without angular fragments, are often fo'ind interstratifying quartzites, as in 
 the Sudbury and Whitetish lake regions, and they nay i)e seen containing every firoportion 
 of (luartz grains II they themselves become quartzites. 
 
 There wiis no doubt great volcanic activity on the earth at the time these greywackes 
 and their associati'd rocks were being formed. The thick unstratified and brecciatfd 
 maisses of greywackes may represent volcanic ashes or mud with stones thrown out upon the 
 land or in shallow water, while the stratified varieties may have been similar ejectamenta 
 thrown into deeper water and modified by the currents or waves of the yea. Some of these 
 rocks, whether stratified or otherwise, may represent volcanic products which wei'e origi- 
 nally poured into the sea in a molten condition and became broken up and disintegrateil. 
 The glass breccia already referred to as forming such a thick belt in the Sudl)iiry district 
 is direct proof of volcanic activity with explosive violence on a scale probably grander 
 than any such action in modern times. Even without this and many other proofs v/hich 
 might be cited from the earliest records of the rocks themselves, it would only be in ac- 
 cordance with the general geological history of the globe to f)elieve that volcanic or igne- 
 ous action was going on upon the surface more generally and on a greater scale in the 
 earlier than in the later geological times. 
 
 From a study of the greywackes and the rocks associated with them there would 
 appear to be little doubt that the former constituted the crude material from which the 
 quartzites and clay-slates were derived by the modifying action of watfr. Again by the 
 action of time, pressure, heat, electricity, and perhaps othei metamorphosing agents upon 
 different varieties of grey wacke, some of our granites, syenites, gneisse.s, felaites and pos- 
 sibly other rocks were formed. Many instances were noted in the Sudbury district where 
 the more massive greywackes exhibited a proneness to revert to granite again, while some 
 of the stratified varieties showed different stages of their passage into gneiss, and again 
 certain of the finer-grained and more homogeneous kinds had been altered into felsites. 
 
 Slat i-C o n <; l o m k r a t e. 
 
 Some of the argillaceous varieties of the grey-/acke containing pebbles of granite, and 
 occasionally some ^ ! quartz, jasper, etc.and h.wing more or less slaty cleavage, were call- 
 ed sla'"! conglomerates by Mr. Alexander Murray, and he even extended this term so as 
 to include massive brecciated forms of grey wacke, which show no cleavage at all. This 
 name was also given to certain Huronian schists containing rounded pebbles and boulders, 
 and likewise to dioritic schists full of lens-shaped inclusions parallel to the cleavage or 
 bedding, and which in cross-section look like elongated pebbles but which may be of a 
 concretionary character in the majority of cases. They are often inconspicuous or diffi- 
 cult to distinguish on dry surfaces of the rock, but when wet are quite distinct, having a 
 lighter color than the matrix. But they do not appear to differ much in "ompositi>n 
 from the rest of the rock. The.se rocks, which have sometimes been called dioritic schist- 
 conglomerates, are very common in the lake Superior region, hut they appear to be 
 scarce in our present district. 
 
 Imperfect Gneisses. 
 
 Imperfect gneisses are met with in most of the Huronian areas in both the lake 
 Superior and lake Huron regions, but they always occur in limited quantities. They 
 difler from the Laurentian gneisses in being usually finer grained and less perfectly crys- 
 talline. Under the microscope they sometimes show traces of clastic origin. In all of the 
 numerous cases tried by tho writer it was founa that they invariably contained carbonate 
 
 All 
 
l.i 
 
 lu! lake 
 . They 
 tly crvs- 
 lII of the 
 r*)omite 
 
 of lime, 'horeas the Lanrentian gneisHeH are Hpldoni calcareous. Where their crystalliza- 
 tion has lieen coarse enoiif»h to observe their felspars easily these have sometimes proved 
 to be of triclinic species, while the felspurs of the Laureiitiaii j,'neiH8e8 are ehielly ortho- 
 clase. 
 
 G It K K N H T O N K S . 
 
 Within that portion of the great Huronian belt which imvcrses our district are 
 numerous areas of greenstone, varying in dimensions from masses too small ro di'Hnc on 
 the map up to others many miles in length. The word greenstone is used in this [lap-r 
 to include ii variety of (rappeaii rocks which cannot always be distinguished fr()m imo 
 another in ilie field. These crystalline masses have often undergone metamorphism as well 
 as the sedimentary rocks, and it sometimes happens that even a microscopic and chemical 
 study of them in the laboratory fails to prove what their original condition has been. 
 The term greenstone, which includes them all, is therefore a very convenient tield-iia:iie 
 In the Sudbury district they consist of diabises, dioriles and gal)b os. The hst niiiiH'd 
 constitute some of the dykes, while the others shadt into each other, and as a cl iss may 
 be divided geologically into three groups. 
 
 The first of these consists of masses of highly crystalline dark green d'orite (some- 
 times passing into diabase) of medium texture and hoUling disseminated specks and sp.)t8 
 of pyrite, pyrrhotite and clialcopyrite. These masses occur principally among the grey- 
 waokes, quartzites and clay-slates, and with few exceptions their gi'eatest lengths are in 
 the direction of the general strike ot the surrounding rocks. They may have been origi- 
 nally laid down as molten sheets in nearly horizontal positions with the enclosing strata, 
 and hiibst quently tilted to the present high angles of iiiciinatiun. fn a i't'W cases the lower 
 suiface of a ^reenstoni* moss may be seen tilling inequalities which seemed to have been 
 worn in the underlying rock prior ti the advent of t\w greenstone. As these masses 
 appear to have become incorporated with the strata before the la'ter had assumed thijir 
 present positions it becomes uncertain that they are all intrusive, although some of them 
 probably are so, but their original positions with regaidto the horizon have be.^ii chang- 
 ed owing to the subsequent folding which has taken place in Lhe c. ust of the earth. 
 Greenstone masses of tiiis kind are lound in the Huronian belt all the way from the shore 
 of lake Huron northward to the border of our sheet, and thence for a great distance towards 
 James bay. They are nunierous atid often large in the Sudbury district, where upwards 
 of fifty occur, and also around lake Tamagami and in the v.'Ury of the Montreal river, 
 but towards lake Huron they become smaller and do not form so prominent a feature in 
 the geology of the region as they do further north. 
 
 Our second variety of these rocks has a grayer color and more coarsely crystalline 
 texture, while the disseminated specks of metallic sulphides are not by any means so 
 abundant as in the first. Its composition appears to be always that of a diabase. This 
 rock forms three distinct belts among the granites and gneisses of the Sudbury district, 
 and they appear to cut through them as intrusive masses. They all run northeast and 
 southwest. 
 
 Windy lake on the main line of the Canadian Pacific Railway lies upon the central 
 portion of the most northwesterly belt, which has there a breadth of about one luili-, but 
 narrows to a point in the northeastern part of LH\ack on the one hand and in Trill on 
 the other, the total length being about eighteen miles. The second belt runs northeast- 
 ward through Morgan towards Sagi-tchi-wai-aga-mog lake, while the third runs from lhe 
 township of Creighton to the vicinity of Whitson lake. 
 
 The third variety differs from the first mainly in being schistose in some parts, ami in 
 frequently containing rounded and angular pebbles and masses of all sizes and of various 
 kinds of rocks, but especially of quartzites, other varieties of greenstone.s, gran- 
 ites and greywackes, Lhus constituting agglomerates and breccias. These portions 
 appear to run in ill-dtfined bands about parallel with the longest diameters of the 
 i.iasses. The greenstone belt which extends from Garsou to Graham belongs to 
 this class, as do also the areas of this rock in the fourth and fifth concessions of Denison. 
 All these lie against the southeast side of a long granitic are-i, and it miy be that they 
 
IG 
 
 have 811 fTcn'tJ more from Intcral |)rPH8urc cniiiinij frnin tho Houtlu'iiHtwanl tlmn tlic dioiitic 
 JiiassrsdcBi rilicd under tlic first div ision, wliicli iimy Imvc hccii pri)t<'ctcd liy the iimrt' yicld- 
 i!i<; roiks w itli which they are Hurroundcd. Examiilcs of th(! f^rceiistoiic aL'iiloiiicin'cH 
 mid lirccfiiis rcfcrrcil to may li<^ hcimi in'ar the lUt-ziird, .Stuhic, Copipcr dill', < 'n an and 
 Vcrmihon miiif's, and also where tho main lino of tho Canadian Paiilic Railway croHsea 
 lot S ill the fourth rani;(! of Mclvim, and aijuin wlieii- it oiohscs lot .') in the liftli ooiiccHsion 
 ol .Mqncricn. 
 
 D I A II A S K I) ^ K KS. 
 
 Dykes form an int(>rPHtiiig feature ainonj^ the rocks of our district, and th"y may also 
 piovo to have some, hearins^ upon Us cconoiiiic f,'eoloyy. 'I'hey consist of fjaliltro and oliv- 
 ine iiahaso, and are of rather freijuent occunenw! in Home sections. As far as direction 
 is coneerneil they may lie saiil to licloni,' to t\vf)sets, the course ot one varyimj; from went- 
 northwest to northwest, and of tiie oilier I'rom north to norih-noriheast. MosLofthem 
 dei (impose more rajiiiUy than tlie containiiiE; rocks, and their posilions may li(> reco^'nized 
 li\ the depressions they form on the land and tin? ciianm^ls in the lak'-s. On tln^ shore 
 of lake Huron some of those lielnii^iiii,' to the northwesterly set may he seen in the 
 viiinitv ot Shiliaoiianiiii); or Killarney, and around Krazer hay. Many dykes of liotii sets 
 are shown un the yeolojiical map ol' Sudbury district by the writ(;r. Around Ministi..' lake 
 in Krmatinjier and Cascaden, where a number of them cut the gneiss, their {general coarse 
 is norihwest. Almost in continuation of these, a larye dyke at tin- j'unciion of Ai^nes 
 river with the Spanish in townsliip lOS cuts ilie granite there in the same direction. 
 
 Dykes belonging to the northwesterly set may be setm here and there along tlie 
 main line of the ('anadian Pacitic Railway between Sudbury .function and Straight lake, 
 lietween Sudbury a:id tlic Murray mine and again beiwtjen Windy lak(^ and Cartier station 
 they have facilitate^ the building of the line by tlie depressions whicli now niark their 
 courses through, the rocky hills wlios', general course lies across that of the railway. In 
 the granitic region l)etweeii the Onaping and upper Vermilion river dykes lielonging 
 to both sets are met with. A large dyke running north-northeast crosses the Vermilion 
 river near the middle of the east line of township GO. 
 
 The basin of Onaping lake appears to be excavated along the course of parallel dyke.s 
 cutting the granite and gneiss in a northerly direction. The lake is about twenty-six 
 miles long, and except towards the south end is very narrow. In some parts the shores 
 are formed by tin; dyke walls, to wliich patches of greenstone are still adhering. A large 
 dyke running a little west of south is traceabh; along the east side of the .'southern part 
 of the lake. A dyke which may be a continuation of this occurs also on lot t in the third 
 concession of JMoncrietl". 
 
 A short di.stance north of the head of Onaping lake we pass over the height-of-land 
 and come to the head-waters of the Mattagami river, which flows northward in nearly the 
 same longitude and falls into the western side of the lake of the same name. Mattagami 
 lake has about the same length as Onaping, and is a';;o narrow. Its outlet flows north- 
 ■ward in the continuation of the valley, and at aliout seven miles falls into the head of 
 Kinogamissc' lake, another long narrow sheet of water, also running north and south and 
 ha\ ing a length of twenlytwr- .ailes. 
 
 On the course of the riv r connecting Mattagami with Kinogamisse lake a great 
 north-and-south dyke makes its appeaiance, and below the latter lake large dykes, cut- 
 ting the Hnronian and Laurentian J ^cks and all having a northerly course, are met with 
 at intervals along the Mattagami river until it enters upon the Silurian and Devonian 
 ba.^in extending to James bay. Several of these occurrences may brt only diflPerent 
 sections of one great dyke. Some of them are 300 to 400 feet wide. They are more com- 
 pact near the walls than along the centre, which has been more easily eroded and in some 
 parts forms the channel of the riv.er. 
 
 The head waters of Moose river, from tJie Missinaibi to the Abittibi, covering 
 a hre.adth of 120 miles in the lattitude of Abittibi lake, comprise upwards of a dozen 
 nearly parallel north-flowing branches which afterwards converge to form the main jiver. 
 The Montreal river is remarkable for drawing its waters from several nearly parallel 
 
 augi 
 
 striK 
 
 pale 
 
 refr,'( 
 
 dish 
 
 zone 
 
 fillin 
 
 dorit 
 
 one ol 
 
17 
 
 |t-of-land 
 
 larly the 
 
 .ttiitjami 
 
 north- 
 
 heiid of 
 
 lUth and 
 
 a j^reat 
 [rkes, cut- 
 met with 
 )evonian 
 J (lifferont 
 liore coni- 
 \{ in some 
 
 covering 
 a dozen 
 lain -iver. 
 parallel 
 
 strcivniH, also tlowin'^ north, hut tlicy full into n viiUcy in which they arc immcdiati'lj 
 turned round to th(! eastward throu^li nion' than a riyht ans^'le and pursue almost a 
 straight line southeast to the Ottawa. The north and south valleys of those streums 
 lieloiio, as far as their orif^in is ooncerned, to th(i samo set as the extraordiniiry parallel 
 valleys of the; l)iisi!» of Moose* river. Dykes and elont^ated masses of greenstone with a 
 general north aiid-south course were found ak)ng hoth tlii; east and west hranchos of the 
 Alontieal river, and it may he assuux'd that they also exist along the other parallel 
 tributary streairs and lakes of tliis system. 
 
 As far &a our present knowledge goes, this parallelism of the water-courses in hoth 
 th<i hydrogiuphic basins which have just been named is due to the guiding inlluence on 
 eroding agents of the large ;,'reenston(* dykes with wliicli the whole region is seamed. 
 There is no doubt that dykes like these have played an imp )rtant p^irt in determining 
 th(! present topographical features of this part of th<! country, Previous to the glacial 
 period tlie dykes probably decomposed to a greater depth than the enclosing rocks, 
 and when the ice passed over the land the trenches which would soon be excavated along 
 tliem under this powerful denuding agent would act as guiding lines for further erosion, 
 and the depressions along them would become deepiMied and enlarged until they had 
 formed tlie various lake basins and river valleys that lie ui)on th^'ir courses. In the 
 uppijr parts of th(! .Moose and the .Montreal river basiins the general direction of the 
 glaciation was siiliicicsntly near that of the great dykes which have been mentioned for 
 it to adjust itself locally to tiiem.* 
 
 These dykes, whether of diabase or gabbro, when undergoing decomposition at 
 the surface weather into rounded boulder-like ma.sses, the result of the disintegration 
 and crumbling away of their angles and *;dges along the joints which had originally 
 divided thtmi into blocks. After they have been reduced to the rounded form they 
 scale otf in conc(mtric layers, and this giv(!S them a concretionary appearance. This is a 
 common characteristic of sucli dyk(*s everywliere, and often causes their outcrops to 
 resfMnble rows or ridges of boulders. When fresh, both of the above-named dyke-rocks 
 are very tough or difHcult to break. The gabliros are as a rule of a lighter color, and 
 resemble granites more than tlie diabases do ; but they are generally deeply penetrated 
 by the eU'ecta of the weather, which gives them a brownish discoloration, and it is only 
 when deep-seated or completely unexposed portions are broken that the true color is 
 seen. One of the principal ditforences between the two rocks is that in the gabbros 
 the augite or pyroxene takes the form of diallage. 
 
 Micuoscoric Ch.vracteristics. 
 
 Samples from both tlieae varieties of the dykes of the region liave lately been 
 examined microscopically for the writer by Professor George H. Williams, lithologist of 
 Johns Hopkins University, and in order to convey a correct idea of their structure, 
 composition, etc., we cannot do better than (juote a description of each by this distinguished 
 authority. 
 
 On the Spanish river, opposite the foot of the 5th portage, or just below the junction 
 of the Agnes river, in township 108, there is to be seen a dyke of medium-grained gray 
 olivine diabase 240 feet in width, running north -tO*^ west, from which a specimen was 
 submitted to Prof. Williams. He says : 
 
 The niiorosco|ic shows this specimen to be a fresh ae;grey;ate of olivine, reddish 
 augite, pla'.jioclase and iluienitc. with accessory apatite and biotite- Its diabase or ophitic 
 structure is very typical. The olivine in tills rock is remarkably fr«rsh. It is in small 
 pale yellow jjrains. which rarely show e.xteinal c.ry^tal bo\indari«-s. It has a very Ir'gh 
 I'efraotive index, no pI(!ochroism and contains {i;lass inclusions. The au>i;itc is of the red- 
 dish and slightly pleochroic variety common in diabase. It not uncommonly sliows 
 zones of growth, liavinu; different shades of color. In form the anjjite is allotriinorphic, 
 filling the interstices between the laths of plaR'Oclase. The felspar (probably labro- 
 dorite) is idiomorphic, and forms an interlacing net-work of lath-shaped crystals. It is 
 
 * Th J a;<ency of dyke< in foriniiii; a river v illi'\- is sulticieiitly clear in the case of the Mattap;aini river, 
 one of the parallel branches of the Moose, ani which han been alrea'iy described. 
 
IM 
 
 the only constitiu'iit that shows iiiiy alteriitioii, anil this i: comparatively slight. 'I'hti 
 opa(|ii(i irou oxido is [nolnihly ilmenite. It is without distinctivo foini or alteration, and is 
 Kometimes siirroundud hy a narrow rim of hiotito. Apatitu is abundant. 
 
 At the Dominion Mineral (Company's miiiH on lot 4, sfcond rantje of Mle/uid, there is a 
 dyke from .50 to ."jO ftiet wide, running north ;$.")" cast, a wp ■oiinen from wh ' Ih deserihod 
 hy IVof. Williams as a (juartz liyperstheno >j;ahl»ro with aocesHory l>iotit«). He says : 
 
 The microscope shows this to he an eruptive rock of (|uite except ioriiil character and 
 interest. Ii helon^s to the nenoral type of ^'ahhros. hut has tiici's of a diahiiscdike struc- 
 ture in its lonn idiomorphic- felspars : is related to theiH)rit»s hy the ahuiKJaiice of its 
 hyperstheue, and contains what is excejitioiuil for nil of these' n ck-types an ahundance of 
 oriKimvl M"'"''''" The rock is miite fresh, hut shows the elTcict if (lynamic action in the 
 bendin;; of felspar crystals and the uralitization of the pyroxene, 'f'he felspar is in stout 
 lath-shujied crystals of cood size which pr'^duce a coarse ophitic or diahaso structures as 
 in many of the well known Scandinavian K'll'hros. They i)resent a brownish color in the 
 thin si;C,tion from an iihundance of ultra- microscopic dust-like inidusioiis They exhibit, 
 in a beautiful nuiiiner the effect of striiin, in the bending of the crystals and the (iroduc- 
 tion of secondary- twinning lamelhe. The i yroxene is both monoclinic (dialla^jo) and 
 orthorhcmbic (hypersthene) in about equal amounts, iioth are underKoinj^ alteration into 
 compact ),crcen hornblende. The mica is an intensely pleochroic biotlte. It is abundantly 
 j)re.sent in lar>;o tlakes of irre^jular size and has all the projierties of an ori^imil constituent- 
 t^Uiartz is also quite abundant in larj^c clear Ki'fiins of irregular shape, and was apparently 
 the last mineral to crystallize. ,\patite. zircon and majjnetite are also present in consid- 
 erable amount. This rook, althoiif^h a typical fi'il'lJi'O. is unusually acid and approaciies 
 in its quartz and zircon to the auj. ite granites. 
 
 L INKS OK Cms K I N(i. 
 
 In '.he region we are considering the etFecta of cleavage and beddin<,', tissures and 
 joints, rock-crushing, intrusive dykes, etc., on the topography are so well marked that it 
 is worth directing attention to some points in connection with the subject. The joints, 
 fissurer and dislocations of the rocks in any given district generally run in two sets, those 
 of each one being nearly parallel to one another. One set is usually more strongly marked 
 than the other and exercises an important influence in the decay and disintegration of the 
 rocks, and this in its turn affects the contours and other topographical features of the 
 district. 
 
 Greenstone dykes, even wh.en thin, are often remarkable for persistence in length. 
 They are also oft*"! parallel, or nearly so, and transverse to the strike or cleavage, and in 
 these respects au allied to both joints and dislocations. This is only what might have 
 been expected, for the igneous matter could not have come up from below to form tiiem 
 unless the rocks had first been rent. The forcing asunder of the walls of the original 
 fissure or joint may have been due to the hydrostatic pressure of the molten matter itself, 
 V hich must have been very great on such extended surfaces. In the various processes 
 of decay, denudation and erosion of dykes, joints — fissures and dislocations have co-operated 
 to produce j)aralleli8m in the natural features of many parts of our district, as well as in 
 other regions underlaid by crystalline rocks. 
 
 Among Archiean rooks evidence of intense pressure is ilmost universal, which is 
 not the case with regard to the newer and undisturbed strata. When thin slices of these 
 rocks are made, so that their elementary structure ruay be examined under the micro- 
 Fcope, it is found that in some parts they are crushed, while in others there is evidence 
 that they have been slowly stretched, proving that they have been subjected to great and 
 long continued strain. In this process the patches and grains of rock had time to con- 
 stantly adjust themselves, ana tliey lave been kept firmly cemented together by the con- 
 tiguous mineral matter, so that tlie strength and outward firmness of the rock have not 
 been affected by this internal rearrangement of its component particles, and therefore 
 when lithologists speak of a rock as "crushed" they do not mean that its present strength 
 is weakened. But this latter state has been produced along certain lines of more recent 
 movements affecting only the present outward condition. This phenomenon will be more 
 fully described further on. 
 
 Although the textural crushing just described may be detected so generally among 
 the ancient orystallire rocks, it is particularly manifest at points unusually exposed to 
 
 has 
 
 proac| 
 horizq 
 remov 
 case ol 
 and df 
 
19 
 
 Ulil \^ 
 
 re iuii 
 :rilje<l 
 
 \r iind 
 struc- 
 
 of its 
 ini't^ of 
 in tho 
 1 stout 
 ire, as 
 
 in tho 
 xhiliit, 
 iioiUic- 
 ;o) and 
 on into 
 idantly 
 tituent. 
 larontly 
 consitl- 
 iroaches 
 
 urea and 
 1 that it 
 le joints, 
 its, those 
 marked 
 )n of the 
 !8 of the 
 
 length, 
 and in 
 it have 
 m them 
 original 
 ter itself, 
 processes 
 operated 
 well as in 
 
 \vhich is 
 8 of these 
 le micro- 
 evidence 
 great and 
 me to con- 
 the con- 
 have not 
 therefore 
 strength 
 ore recent 
 1 be more 
 
 lly among 
 xposed to 
 
 tho action of thf forces which produced it. One of tliese occurs o the west side of lake 
 Wahiiapitat', whereii [>rouiont()iy of tht! granitic rockn projoLts into ulie Iluronian belt at its 
 narrowest point. 
 
 Tiie HpaccH wliich have been h'ft by tlie inecpinliticH tiloni; lines of fracture after dis- 
 location in certain Archii-an rocks havt! sometiineM lieeii lillcd by the debris ground oil the 
 walls, and which ntiw forms dykes of breccia. An example of tliese may be seen at tho 
 first rapid in tiie .Maganetawan river, eastward of tlm head of Hyng inltjt. The breccia 
 dykt' runs eastwiiKl witli the couise of th<» stieani. Its matrix is aiiiorphotis and very 
 brittle. .Some of the fragments coi'sist of a dark riMl<liHh lirown (ipa([ue clierty rock, and 
 others of a d'.rk variety of syenite. The muM holds a little calcspar and specks of iron 
 pyrites. 
 
 IJut thcs.! Ion/ -iieH of fracture are not often marked by any consolidated tilling. 
 The conditioMb i ear t.ie surfacn may not have been favoralile to the formation of such 
 a tilling, and many of tliese fractures are perhaps too recent to have allowed of sntlicient 
 time for this process to liave taken place. Close to thfse lines the rock all along is broken 
 intosuiall |)ieces, which however have been only sliglitly moved Irom tlfir ptiginal sit(\s ; 
 but p • we recedt from tlm lines of crushing tho angular pieces l)ecorae larg(«. and larger 
 till tne whole rock has resumed its normal solidity. 
 
 This broken condition has p(!ruiitted the percolation of the surface waters to great 
 depths, which has been followed by the decay of the fractured rocks more or less rapidly 
 in proportion to the fineness of the pieces into which they have been crushed. The joints 
 for some distance on either side of those lines are stained with the oxide of iron, resulting 
 from the general decomposition. 
 
 The disintegration of the rock on such lines, as well as that of the greenstone dykes» 
 has caused valleys to be formed along them as the result of glacial and other eroding 
 agencies. In the district under consideration the writer in referring to this subject in 
 1870 said : 
 
 " Between the mouth of the MaTranetavvan river and the first fall, especially along 
 the north side, the pneiss, whicli runs in various directions, is of a dry, cruraolinK char- 
 acter along a set of joints which run parallel to the stream and are lined with oxide of 
 iron. The course of Bynj? inlet and of the .Maganetawan river (in continuation of it) is 
 remarkable for being comparatively straight and crossing tho general course of the 
 gneiss and mica and hornblende schists, as well as that of the lakes and the numerous 
 smaller streams of the district. This would appear to indicate tliat the formation of this 
 channel has had something to do with the existence of the brecciated dykes or the joints 
 above de.scr;bed."* 
 
 Lines of crushing in the Laurentian rocks were seen by the writer in some of the 
 precipices in Hudson strait, where they were observed traversing walls of gneiss, and 
 were well marked by the crumbled gneiss, still quite fresh. 
 
 Transverse depressions or gaps in crystalline rocks have also been formed in the fol- 
 lowing manner : The parallel joints which so frequently traverse granite, gneiss, quartzite, 
 etc., are apt at intervals to occur in groups closer together than usual, or two or three 
 may run side by side, which are stronger and more persistent than the single ones and 
 comparatively distant from the nearest of them. The narrow walls of rock between such 
 joints have suffered decay or injury from the surface influences in pre-glacial times, and, 
 yielding to erosion more easily than the rest, have formed the starting lines of depressions 
 and valleys. This phenomenon was referred to in connection with the erosion of water- 
 channels in the French river region, and it may also be observed in various rocks in other 
 parts of our district. 
 
 Two sets of nearly vertical joints often traverse crystalline rocku at angles ap- 
 proaching 80'' or 90" to each other. When such rocks are cut by a third set almost 
 horizontally they are then divided into rhombohedral blocks, and are much more easily 
 removed by aljrading and disintegrating forces. It not unfreqnently happens, as in the 
 case of some granites, that there may be four sets of joints, t. Ickly penetrating the rock 
 and dividing it into comparatively small triangular pieces. This imparts a shattered 
 
 *Report of the Geological Survey for 1876-7, p. 202. 
 
•JO 
 
 chiiracter to tho whole niasw, ivnd rendois it useless iov l)uildiiig or nioiiunientai ^ ^joses. 
 Some masses of granite have heen saved from the foiees >^hich produ(;ed tliese numerous 
 joints or cracks, apparently by the protection afforded by yielding; belts of schist. At all 
 events tiie n>ore solid and serviceable "ranites are often thus sheltered. 
 
 C li Y s T A I, r. I N E Schist s. 
 
 The Huronian system comprises a j/reat variety of crystalline schists In botli the 
 lake Huron and lake Sujierior regions. In the latter the older portions of the series are to a 
 great extent formed of mica, hornVdende, diovite and chlorite schists, while these and other 
 varieties of schists are interstratified with different rocks higher up in the scale. In the 
 Sudbury district the northwestern border of the Huronian belt in the townships of 
 Waters, McKini and Hlezard is largely made up of crystalline schists, of which dioritic, 
 hornblendic, silicious and felsitic are the most abundant. Further to the northeast 
 similar schists are abundant on lake Temagami. Silicious and felsit'c schists are largely 
 developed between lake Wahnapitae and the line of the Canadian Pacific Railway. Coarsely 
 crystalline hornblende rock, such as is found among the ITuronian strata of lake Superior, 
 has been met with just east of the Stobie mine in Blezard, in the fifth conjession of McKim, 
 and near the McConnell mine in the fourth concession of Snider ; also at the southwest 
 bend of Spanish river and at Lamorandiere bay in the northwest corner of Rutherford. 
 Green schists, schistose grey wacke and gueissoid schist, the latter enclosing boulders, occur 
 among the rocks of the Straight lake Huronian outlier. 
 
 In illustration of the mode of occurrence of crystalline schists among the Huronian 
 rocks of the lake Huron region, the following examples on the Spanish river are selected 
 from the descriptions in the report of the writer for 1888-90. 
 
 Half a mile up the west brunch of this river a rock was met with which consisted of 
 a mixture of gi een schist and fragments of granite. At the bend of this branch, four 
 niiles from the main stream, there was found what Professor Williams describes as a 
 " pinkish to brownish crypto-crystalline banded rock, which might be macroscopically 
 described as a banded jasper or felsite. The microscope shows that it is a clastic rock, 
 consisting mostly of quartz which has been whoU re-oi-ystallized under the influence of 
 intense pressure, and that it has thus had the parallel structure developed in it by an 
 elongation of its grains in one direction that is commonly known as stretched." 
 
 Oil lot 1, sixth concession of Baldwin, just bf low a large island in Spanish river, the 
 rocks in the bed of the stream consist of fine-grained pink quartzite in thin layers, inter- 
 stratified with rough surfaced black slute, dipping southward at a high angle, while at a 
 greater elevation there is exposed a heavy band of dark green mica-schist formimg the 
 top of a long ridge. 
 
 At the narrows of the river, on the east side of lot 12, first concession of Hyman, 
 there is a coarse gray glistening schist and a sm-ill quantity of a dark greenstone. Below 
 the narrows, on the next lot (11 in the same concession) a glossy dark bluish grey schist 
 and a slaty grey wacke strike northeast along the flank of i mass of diabase which has a 
 length of more than a mile in a northeasterly direction. .V fine-grained hornblende rock 
 also occurs at this lo.ality. In the same vicinity, where the line between lots 10 and 11 
 intersects the north bank of the river, quartzite occurs dipping south at an ai.gle of 55°. 
 
 In the northwest corner of lot 8, first concession of Hyman, there is a chute in the 
 Spanish river with a fall of 15 feet. At this locality there is an extensive exposure of 
 rather tine-grained silver-gray mica-schist with crystals of staurolite, thickly scattered over 
 the cleavage surfaces. 
 
 In the middle of lot 5, second concession of Hyman, the river passes through a canon or 
 narrows, with gray schist en the northern side, and the northern flank of a ridge of fine- 
 grained splintery greenstone running north 70" east on the southern. At a rapid in the 
 north half of lot 3 in the same concession, a bluish gray satiny schist striken due north 
 and south, the dip being east at an angle of 45". This sudden change in the strika is 
 accomi)anied by an equally sudden turn in the course of the river. 
 
tai 
 
 ,j()ses. 
 
 (se numerous 
 hist. At all 
 
 i in both the 
 series are to a 
 ese and other 
 cale. In the 
 townships of 
 hich dioritic, 
 le northeast 
 ts are largely 
 ^ay. Coarsely 
 [ike Superior, 
 )n of McKim, 
 ;he southwest 
 Rutherford. 
 )ulders, occur 
 
 he Haronian 
 r are selected 
 
 1 consisted of 
 branch, four 
 escribes as a 
 croscopically 
 L clastic rock, 
 ! influence of 
 d in it by an 
 id." 
 
 lish river, the 
 layers, inter- 
 
 e, while at a 
 forinimg the 
 
 n of Hyman, 
 ione. Below 
 h grey schist 
 i which has a 
 rnblende rock 
 3ta 10 and 11 
 u.gleof 55°. 
 
 , chute in the 
 3 exposure of 
 scattered over 
 
 
 igh a canon or 
 ridge of firie- 
 1 rapid in the 
 iei due north 
 the strika is 
 
8 
 f- 
 
 81 
 
 R 
 e 
 
 8 
 
 1< 
 b 
 
 V 
 
 P 
 o 
 
 a 
 
 1 
 
 tl 
 c< 
 ti 
 T 
 
 S( 
 
 oi 
 
 tl 
 tj 
 
 ]V 
 f( 
 
 tl 
 
 S] 
 
 'fi 
 
 8l 
 
 ai 
 h 
 
 ii 
 
 ai 
 
 q' 
 
 M 
 re 
 tc 
 cr 
 n( 
 th 
 
 oi 
 Hi 
 oi 
 
21 
 
 The rocks at Kettle falls, on lot 2, second concesHion of Flyman, are gniy and satiny 
 schists with a tiiree feet band of nearly black hornblende schist, all striking north 7G^ 
 east, with a southerly dip of 75". On the line between lots 2 and 1, first concession of the 
 same township, and opposite the west end of an island in the river, the rock is a glossy 
 gray, tinely-arenaccous schist nearly on ed^'e and striking north 85'^ west. A gray gli.st- 
 ening schist, standing vertically and striking north To*^ east, occurs at the falls on the 
 south side of the island. 
 
 A soft bluish-grHy schist striking eastward with the course of the river is found on 
 lot 11, first concr-ssion ; and on the northeast corner of lot 1) there is a glossy green schist, 
 but without strong cleavage. 
 
 A gray hydro-mica schist running southwest occurs where the Canadian Pacific 
 Railway crosses the Spanish river, in the centre ol lot 11, second concession of jVairn. 
 
 •S ER 1' KN r IN K, Steatite and Dolomite. 
 
 These three kinds of rocks may be mentioned among thoee which occur in minor 
 volume in the Huronian system. Serpentine has not yet been found at all within onr 
 present region, but some ex])osure8 of it were met with at Pigeon lake on the west l)ranch 
 of Montreal river, a short ilistance to the northward. The serpentine occurs by itself, or 
 associated with calcspar, or pa.ssing into limestone, on some small islands in this lake. 
 
 On the shores ii' the vicinity are fine-grained and massive reddish-gray quartzite, 
 gre^ -.ish-gray clay-slate, fine-grained "ddish-gray syenite, light greenish-gray finely crys- 
 ,' e diorite, with disseminated grains of iron pyrites and gray porphyry very thickly 
 ■>, .vied with opa(|ue-white crystals of felspar and a few of shining black hornblende. 
 1.... serpentine on fresh fracture shows different shades of green, and is somewhat mot 
 tied. Under the weather the natural surface becomes rough and of a rusty color. It 
 contains oxide of chromium, both in the form of small grains and in chemical combina- 
 tion with the rest of the rock, and thus resembles the serjjentines of the Eastern 
 Townships in the province of Quebec. The writer has been shown speciinons of 
 serpentine said to have been collected among the Huronian rocks some miles north 
 of Pigeon lake. On the point about the middle of the west shore of Abittibi lake 
 the late Mr. Walter McOuat of the Geological Survey met with dark green serpen- 
 tine, weathering dull white, strongly magnetic and containing grains of chromic iron. 
 M r. E. B. Borron informed the writer that he had heard of serpentine having been 
 found in the country lying north of the west end of Abittibi lake. 
 
 On the Mattagami river, tHrty chains below the junction of the Muskoota branch, 
 there is an exposure of massive gray semi-crystalline steatitic rock, holding grains of 
 specular iron and cut by small veins of whitish bitter spar. Although this locality, as 
 veil as those for sorpentine which have been mentioned, are outside of the limits of our 
 sheet, both of the rocks referred to above may be looked for wherever similar rock 
 associations exist within this area. The greenstone of the Evans mine, near Sudbury, 
 has changed in some parts into a vaiiety of steatite or soapstone. 
 
 Dolomites or magnesian limestones, having ceitain characters in common, occur spar- 
 ingly in th(i Huronian system in the most widi'ly separated areas of these rocks. They 
 are usually fine grained to compact, silitaous and marked by strings and fine threads of 
 quartz and sometimes of calcspar, which have commonly a reticulating arrangement. 
 Most of them are ferruginous, jind the weathered surface is generally yellow, brown or 
 red, but sometimes gray or black. The iron is often present in large enough proportion 
 to form a spongy crust of the oxide. Oi-casicnally these dolomites become rather finely 
 crystalline, like saccharoidal marble, and nearly white. In our present region they have 
 never been traced far on the strike, although they attain from 100 to 300 feet in 
 thickness. 
 
 Midway up the northeast side of Pigeon lake, already mentioned, on the west branch 
 of Montreal river, there is a blufi' thirty feet high of semi-crystalline, yellowish gray 
 limestone, mottliHl with green and reddish-brown patches and full of reticulating strings 
 of white calcspar. The weathered surface has a ferruginous crust, from one-half to one 
 
 *3 (M.) 
 
22 
 
 incli tliick, showiiit; th» rock to contain a lar'o proportion of iron. A thickness of 
 upwards of one luindred feet of the litnestono is exposed at this place, and it continues north- 
 ward along the sliore for a qn irter of a mile oi mo-e. The other rocks in th(! vicinity of 
 tliis diilouiite cons'st of syenite, diorite, serpentine, porphyry and different varielieH of 
 quartzite. 
 
 On the eastern side of South l)ay, lake Wahnapitae, and thence round the promontoiy 
 towards Outlet hay, .Mr. Ale.xunder Muu'ay desc ibed a calcareous breccia associated with 
 quartzites and greenstones.* 
 
 In (ieneva lake, about a niil<! and a-half northeast of the on let, there is an islet 
 entirely composed of tliinly l)edded light gray, dove-colored r xd nearly whit(! dolomite, 
 fc.riking north 35" easi., and dipping to the westward side at an angh^ of 80^'. It is com- 
 jiact and has a conchoidal fnictun^, but is traversed l>y fine threads of quartz, which pre- 
 v( nt it from tak'Tg a good p)lish, otherwise it might be suitable for maibl.). The same 
 rock is exposed on the east side of the lake on the point Just southward of the above islet, 
 but the l)and could not be found on thi' northern side of I'le lake, towards which it strikes 
 in the opposite direction. On thi- railway track threequa _'rs of a mile south of the 
 outlet of Geneva lake there is a liftet'ii-fi ^t b^d ot' gray to dove colored tine-grained dolo- 
 mite, weathering d irk brown. It strikes north 4.)" easu, and the bedding is about 
 vertical. This dolomite br.nd is separated from hornblende granite to the southeast by 
 about three hundred feet of ash-gray greywacke. The g/ani d towards its contact with the 
 If ter becomes mixed with coa^.se breccia and conglomerate. Ou the other side, or to the 
 r >rthwe:-ttward, the doloniile is followed by coar.se felspathic sandstone and silicious grey- 
 wacke-conglomeiate or brec(5ia. At the outlet of Oisn-iva lake the rock is a greywacke 
 passing into granite, and it includes some black slate and a patch thirty feet thick of 
 impure dolomite. 
 
 A band of magnesian limestone occurs at Island Portage on Wahnapitae river, 
 about four miles below the outlet of tlie lake of the same name. Ic has a width of 
 at least 300 feet across its general strike, but owing to the undulation of the strata 
 the true thickness of the band could not be determined. On fresh fracture it is 
 mostly light greenish-gray in color, tine grained, soft, somewhat impure, and weatii^rs 
 to a brown color. The weathered i irface in Kome parts is marked by small co. 
 rugated ridges, like that of the Huroiiian limestone of Echo lake, which result from 
 the weathering ou.- of minute silicious streaks following the bedding. An exposure 
 of tlie limestone at the head of Island Portage shows a more massive variety with a 
 brownish gray color on fresh fracture, t 
 
 Referring to the magnesian limestones of lake Panache Mr. Alexander Murray 
 says : 
 
 On the north shore of lake Panacho, about midway between the inlet from lake Lavase 
 and its western extremity, a hand of limestone occurs which when first observed ap|.ear.s 
 to be l;otli underlaid iiiid overlaid by syenitic slate con^iilomerate. The mass of this 
 limestone, wliicli measures aliout sixty yards across and may be about 150 feet thick, is of 
 a pale gray color on fracture, weathi'rint; to a bhii.ih ij;ray. with thin layers which have 
 ttie appearance of chert, but are in i-eality only harder portions of the limestone, weather- 
 int; quite black. About the base of the calcareous strata some of the beds are blue, holding 
 more silicious matter than tlie Ki'^^y beds, while ott'.ers are of a brecciatcnl I'haracter. The 
 beds are all more or less intersected by small veins of fine greenish jaspery-looking trap 
 whi"h wcath'>rs brown or yellowish. 
 
 To the eastwaril of this exposure the onl.v indications oljservedof the presence of lime- 
 stone were on the east side of the large island at the entrance of the south bay. and in the 
 peninsula on the north side at the entrance of the eastern arm ; in both of these localities 
 small exposures of a black-weatherintc brecciated r(jck, which proved co be calcareous, 
 came uji in one or two jiarts just over the surface of the water. On the island the cal- 
 careous rock is overlaid by a bbuk-weatherinu; slate whicli, though without pebbles, 
 resembles the matrix of portions of the slate-conglomerate. On the peninsula at the 
 eastern arm the brecciated rook comes directly in contact with greenstone. 
 
 At the head of the lower south expansion of 'ake Panache the limestones are again 
 seen on both sides, and also on the two islands near the middle, striking about east by 
 
 * Rf'tiort of (he <J<'"]'){;ical Survey for 186<), p. 177. 
 tHeixirt of tlif' (ieologiciil Survey for 1876, p. 29(J. 
 
•?:{ 
 
 licktK'ss of 
 
 nuH9 noi'th- 
 
 vicinity of 
 
 variotieH of 
 
 promontory 
 ciated with 
 
 is an islot 
 ; dolomite, 
 
 It is com- 
 which pre- 
 
 Tlic same 
 above islet, 
 li it strikes 
 (utli of the 
 ained dolo- 
 t is about 
 utheast, by 
 ct with the 
 !, or to the 
 cious grey- 
 grey wacke 
 et thick of 
 
 itae river, 
 I width of 
 the strfv^a 
 dure it is 
 [ weathers 
 small CO. 
 esult from 
 exposure 
 3ty with a 
 
 Murray 
 
 ke Lavase 
 d apiiears 
 ss of tills 
 liick, is of 
 hich have 
 weather- 
 e. holding 
 cter. The 
 >kinp; trap 
 
 c,c of lime- 
 uul in tlie 
 localities 
 iilcareous, 
 1 the cal- 
 t pebbles, 
 ila at the 
 
 are a(<;ain 
 It east by 
 
 norfli and west by soiiMi. and sliowinu; a southerly 'lip on the north siilo of the exposures • 
 but the slate (^on^jlonicrato with which it seemed to he associated at other parts onl ■ 
 ajipears on the soutli side of the Ur^e island lyint< iit the entrance to the nortli(u-n army' 
 and between this island and the exposure of liiuesroiie on the west side of the bay there jj* 
 a fioint to the northeast of the limestonedisplayini;- liue-irrained ^,n'een slate which, tliouj^h 
 very much disturbed and intersected by ipiartz veins, appears to show r. K^'ieral dip to the 
 northwest.* 
 
 Mr. Muri-ay thinks that some of the above strata niii^ht yiehl good stone for burnin<' 
 into lime. A specimen from the section on the north side of lake "anache was analysed 
 by Dr. T. Sterry Hunt, and yavc in 100 pirts .oj. 10 carbonate of lime, (i.oO carbonate of 
 magnesia, .'58.40 insoluble sand and a trace of iron. A specimen of the limestone at the 
 lower end of lake Panache, analysed by the same chejnist, gave 41.97 per cent, carbonate 
 of lime, 2.40 carbonate of magnesia and T^v)^V.^ insoluble nssidue ; and a specimen from 
 tlie lower lake near the outlet, lying between the two ridges of the mountain range gave 
 36.50 per cent, carbonate of lime witli a little niagnesia.t 
 
 Along tlie northern arm of the larger La Cloche lake calcareous rocks or impure lime- 
 stones occur at several places passing below a considerable thickness of slate onglomer- 
 ate, and tliey are again met with on the smaller lake to the northwest. High ridges of 
 quartzite, standing nearly on edge and forming part of the La Cloche mountains, rise on 
 either side of the southern arm of the larger lake, while greenstone and quartzite are found 
 on the northern side of the smaller one. It would tlierefore appear that in this part of 
 the great Iluronian btdt tlie inagnesian limestones occur among the quartzites, and are 
 sometimes more inimcidiately associated with slate-conglomerate. 
 
 A band of finely crystalline limestone occurs among the Huronian rocks in the 
 northern part of the township of Rutherford. The locality is near the boundary line 
 between red granite to the southward and a great thickness of quartzites to the north 
 ward. The junction of the granite to tlie soutlieast with the Huronian quartzite and 
 hornblende schists to the northwest occurs at the .south side of a rather elevated 
 rocky island in a cove almut one mile north of the western entrance to " the passage " or 
 channel, on the north side of which Killarney village is built. The geology of this 
 locality and tlie relatioi"' of the limestone referred to can best be given ijy (juoting the 
 description in the Geological Survey report by the writer for 1876, page 209 : 
 
 On the west side of the township of Rutherford, from the nortliern limit of the granite 
 (at the elevated rocky island above mentioned) quartzites and hornbleiiQo scdiists hold the 
 shore as far US Lamorandiere bay. in the northwest cornei' of the township. A blackish 
 groi n massive and rather coarsely crystalline hornblende-iock. having an exceedingly 
 rough or irreurularly i)itted surface, is exposed on either side of the narrow entrance to tliig 
 bay. Upon the sloi)e of the hill, about 100 yards in from the north shore of the bay, at a 
 point about half-a-inile from the above-named narrows, a band of finely-crystalline lime- 
 stone occurs among the Huronian rocks. It has a vertical attitude and runs about north 
 70' west at the part examined. Its total thickness is about 7.o feet, of which the 2.5 feet 
 along the northern side consist of a single solid hand of nearly white finely-crystalline 
 limestone, clouiled with light greenish and grayish patches. The remaining .")() feet are 
 mixed with shaly patches of hornblende, together with a lirtle shining granular magnetic 
 iron ore. Adjoining the limestone on the north side is a ])and, only a few f»et in thickne«s, 
 of dark smoke-colored chert-rock. ril)bonod with streaks of a dull red color. It breaks 
 easily with a fine conchoidal fracture, and ajipears to be identical with a rock which was 
 used by the mound-builders for making some o.' their arrow-heads. This is followed to 
 th". northward by a dark-colored dioritic conglomerate, in whicli the pebbles are mostly 
 small and generally widely scattered, and farther on by a very dark gray, soft massive- 
 looking micaceous schist, most of which is full of small i)ebbles. Measured fro.ii the 
 limestone band, a thickness of between loo and 200 fi'ot of these rocks is exposed. 
 
 On the north shore of Lamorandiere bay. a few hundred yards eastward from the 
 outcrop of limestone above described, are two exposures of very tough massive hornblende 
 rock, and bHtween the two arms of the bay is a more fissile variety, interstratiiied with a 
 reddish gray quartzite. which also overlies the mixed rocks. The dip is here northwest- 
 ward at an angle of 00" to 70 . and the series is underlain by granitoid gneiss. 
 
 •Report Geological Survey for 1856, pp. 181-183. 
 
 ill. p. 190. 
 
24 
 
 I N r K r S I V K (J R A N 1 T K S . 
 
 The red grHiiito of George island and the township of Rutherford may he of 
 intruaive ori<rin, notwithstanding that it shows an approach to lamination towards 
 tlie odges of the mass. " Its position is along the junction of th(' Laurcntian with 
 the lluronian series, and it appears to belong to the latter rather than the former, 
 ft has a medium texture, and is composed of reddish felspar and bluish-white quartz 
 with a little hornblendes, which however is often wanting. Excepting at the sides it 
 has a massive homogeneous structure, but in a few instances a single reddi.sh or yel- 
 lowish green shaly streak, an incli or two in thickness, was observed running in a 
 northeasterly direction with a dip to the southeastward of about 50". Towards each 
 side the grain of the rock begins to assume a sort of parallelism or a gnessoid structure. "* 
 
 Reference has already been made to an area of red granite measuring about four 
 miles in length by two in breadth between the western and middle outlets of French river, 
 and also to a brick-red granite or syenito along the upper ])art of the lower north channel 
 of that river just l)elow (irand Recol let falls. 
 
 Red granitic rocks border the newer ones which lio to tlie south of them all the way from 
 the township of Cascaden to lake Wahnapitae. Althou'.^h the macroscopic appearance of 
 thete rocks is that of a red granite, yet in some parts, as on the east side of Windy lake, 
 the textural arrangement of the component minerals is more like that of a quartzdiorite, 
 and they are certainly of eruptive origin. Professor (ieorge H. Williams examined under 
 the microscojie a thin slice of a fine grained variety of these locks from Ivin-ni-wabik lake 
 in the township of fjovack. He pronounced it raicropegmatite, and stated that it was an 
 undoubted eruptive. Towards lake Wahnapitae similar rocks continue to be fine grained, 
 but in that direction they become dark grayish-red in color. Around Washai-gamog or 
 Fairbank lake the rocks have a similar color and te.vture to the last, and their appear- 
 ance is the same except that they are distinctly stratified aiid occur in vary even Ijeds. 
 The granitoid rocks above described merge into gneiss at varying but not great distances 
 to the northward. 
 
 Al)Out a mile east of the angle formed by the intersectiv^n of Proudfoot's east-and-west 
 with his north-and-south line red hornblende granite was found. Its extent has not been 
 ascertained, but it may continue a considerable distance northward. 
 
 A Laurentian inlier has been mentioned as occurring around Paul's lake on the upper 
 part of Sturgeon river. Where first entered upon in ascending the river at four miles 
 below the lake the rock of this inlier con.sists of a rather coarse dull red quartz-syenite, 
 or hornblende granite, but this passes into gneiss before the lake is reached. An area of 
 coarse red granite crosses lake Temi.^caming about the middle. 
 
 (Jenkuai, Xai'vkk ok tmk Hiudnian Rockh. 
 
 While the greater portion of the Huronian rocks show the agency of water in their 
 formation, there is also abundant evidence of widespread contemporaneous volcanic 
 action. These detrital oi- clastic sediments were largely derived from igneous matter 
 which had been more or less recently erupted, and hence they may be called pyroclastic, aa 
 indicating both phases of their nature, liesides rocks of this character, we have seen that 
 tlie Huronian system contains large igneous or crystalline masses. The whole series having 
 been considerably metamorphosed, the true origin of some portions may not be at first 
 apparent. JJut our study of them on a large scale in the field as w ;ll as the microscopic 
 examination of hand specimens go to show that the above is the general nature of the 
 lluronian rocks in all the areas which have been explored. The pebbles and i)ouldi ("s of 
 the conglomerates rf the Huronian system consist of l)inary-granite, scliist;s,quartzitt; white 
 quartz and red jaspar, grei nstoue, gneiss and other rocks derived from older parts of tlie 
 same series or from the underlying Laurentian. 
 
 The pre.ojnce of these conglomerates and the ripple-marks which are sometinu>s ])lainly 
 seen <m ^he surfaces of beds of quartzite prove the existence in tl;ose days of either dry 
 land or of seas which were very shalbw in some places. The limestones or dolomites are 
 
 *l)r. Bell in Report of Geological Survpy for 1S76, p. 
 
fc,{s» ';r;!?jj 
 
 25 
 
 rimy he of 
 n towards 
 itian with 
 be former, 
 lite quartz 
 he sides it 
 iah or yel- 
 ning in a 
 varda eacli 
 Tuoturo."* 
 
 about four 
 3nch river, 
 th channel 
 
 i way from 
 ^arance of 
 'indy lake, 
 tz-diorite, 
 ned under 
 vahik lake 
 it was an 
 e grained, 
 i-gainog or 
 ir appear- 
 ^ven I)eil8. 
 ; distances 
 
 t-and-west 
 s not been 
 
 the upper 
 Four niilos 
 z-s3'enite, 
 In area of 
 
 in their 
 volcanic 
 IS matter 
 clastic, as 
 seen that 
 PS having 
 )e at tiist 
 croscopic 
 re of the 
 )uldt '•s of 
 tc. white 
 •ts of the 
 
 3 plainly 
 ither dry 
 uites are 
 
 only of local extent. They are sonietinies nearly pure, or, as we hav(! seen, th(!y may be 
 largely mixed with insoluble matter, or they may i)e brecciated with silit-ioiis fragments. 
 The lime and magnesia may have been derived from the decomposition of the pyroxene 
 and hornblende of the grtumstones. Some of the masses may be of a segn.'gated or a 
 concretionary character, while others were precipitated from wattT. 
 
 Nkwkst Rocks oi' t ii k !■. f n ii r k y DisruK t. 
 
 The newest rocks of the Sudbury district form a distinct basin extending from near 
 the west side of lakt* Wahnapitae southw('st to about the centre of the township of Trill, 
 a distance of thirty six miles, with a l)readth of eight miles in the centre. This l)asin con- 
 stitutes a prominent feature in the g(!ology of the district, and it. iiiiy prove to be of 
 lower (,'ambrian age. Along its iiortluirn side it is iiounded by the ^'raiiitoid rocks already 
 described, and on its southern by a belt of Huroniim schists and greywacke. The rocks 
 of the basin con.sist of two principal divisions, — (1) the lowest being ii Irind, probably 
 tliree or four thousand feet thick, of dark colored or almo.st black siiicious volcanic breccia 
 or vitrophyre tuif, most strongly developed along the northern side and passing into black 
 slate and black slate-conglomerate along the soutliern ; and (2) drab and ilark gray 
 argillaceous and nearly black gi'itly sandstones with ahaly bands which vary in color tr.im 
 greenish dral) to black. At the itasc; of the volcanic breccia a conglomerate consisting of 
 a grey silicious matrix with rounded white <iuartz pebbles is seen in .some places, l>ut 
 this may belong to the underlying series. 
 
 The area of this geological basin corresponds in a striking manner with certain well 
 markeil physical and geographical features. The volcanic breccia f rms a range of hills 
 more conspicuous and rugged than any others in the district, whi..; the Hand.stones and 
 shales constitute a low and nearly level tract from which likes, elsewhere so common, are 
 absent. The Vermilion river Hows southwestward with the strike all along the northern 
 side of this division, and Whitson creek flows in the same direction along the southern 
 side. 
 
 The silicitied glass-breccia or vitrophyre tuff maintains the same character and 
 apparently^about the same thickness all the way from the vicinity of lake Wahnapitae to the 
 township of Trill. It occurs in massive form and falls from cliffs or ridges in large blocks. 
 It breaks with a conchoidal fracture, and when fresh is seen to be made up of angul.ir 
 fragments, mostly small and closely crowded together and flei-ked with irregular white 
 spots. Tlie fragments are not .so dark as the matrix, and present various shades. When 
 examined with a lens many of the fragments show a distinct vesicular structure. Prof. 
 George H. Williams has examined this breccia carefully both in hand specimens and 
 under the microscope, and says that it is " composed of sharply angular fragments of vol- 
 canic glass and pumice, which, in spite of almost complete silicification, still preserve every 
 detail of their original form and microlithic flow-structure with a distinctn(!ss not to be 
 e.xceeded by the most recent productions of this kind . . The fragments even down to those 
 of the smallest dimensions have the angular form characteristic of glass shreds produced by 
 explosive eruptions. The ilow-structure is as perfectly marked by sinuous lines of globu- 
 lites and niicrolites, which terminate abruptly against th'^ broken edges of the glass 
 particles as in the most recent vitrophyre. Minut<i spots of opaque pyrrhotite are scattered 
 through the section. The groundmass is of a dark color, owing to the massing in it of 
 minute black globulites, to whose nature the highest magnifying power gives no clue . . . 
 After a careful study of this rock I find it possible only to interpret it as a remarkable 
 instance of a very ancient volcanic glass breccia, preserved through the lucky accident of 
 silicification. Nor did this process go on as is usual through devitrification and loss of 
 structure, but rather lik' the gradual replacement of many silicilied woods, whose every 
 minute detail oi structure is preserved. The rarity of such rocks in the earth's oldest 
 formations is readily intelligible ; but, for this very reason, the exceptional preservation 
 of a rock like this is all the more welcome proof that explosive volcanic activity took 
 place at tlie surface then as now, and on a scale if possible even greater than that with 
 which we are familiar."* 
 
 "BuUetinH of the Geological Society of America, 1890, \>\i. 1^^-40, 
 
A fri'tih s(!otion of this rock Ih t'.\[)OH(itl in a ciitliiii{ on tlic! Ctinadian Pivcitic Railway 
 at the liij;li falls of Onafiinf; river, twenty niileH nortliwfstof Su ll>ury Junction. An 
 anaiysin of an aveiaj,'e s|teuinif ii from this jiiae(^ was made liy .Mr. Ilollinann of tiio (i(^olo- 
 fjieal Survey, and it was t'oinid to uontaiu liU.L'ii per cfiit. of .silica. A siiieothed surfnoe 
 of this iliirl ': has a handsome ap|i(>aranc(.', hut it is incapahh; of a hi^li pulish. 
 
 The da. K ar^^illaccoua sandstones and drah and tiark sliales of the lii;,dier division of 
 the rocks of this newer hasin may In- s-en at all tlii southward hends of the Vermilion 
 river from Unwatin lake ntariy t<» Vermilion lake. Tho .strike corresponds with the 
 fjeneral course of the river, and tht) dip is soutiieastward at rather hii,'h angles. Tho 
 sand.stont s are characterized iiy dissendnated "grains of transparent ([Uart/, and they often 
 holil rounded or ovate spots from an inch or two up to three feet in di.imeler, of a li^^hter 
 color than the re t of the rock. On exposed surfacoa these spots W(;ather into depression.s. 
 8e\('ral parallel ridijes of tins smulstone with a northi'asteriy course cross the Canadian 
 Pacilij Railway line diagonally hetween Liuchwood and Clielmsford. It appears to lit* 
 well suited for l)uilding purjioues. This sandstoiii', Imtii as rej^ards the spots Just 
 described and its dark color and massive character, hears a .stron;^ resemliltiice to the, 
 silicious rocks whicli, in the form of houlders and smaller pieces, are .siiattered so ahundantly 
 around the sliores of James hay and over the country lb r a threat distanee to the south- 
 west of it. A similar rock is found in place on Lout,' island on the east coast, and at 
 Clniichill on the west coast of Hudson Ixy, and there are reasons for believing that 
 it is very e.\te':siveiy developed on the lloor of that sea. 
 
 1. O »V K 11 .S 1 L I' li I A .\ o It O K I) 1 V I C I A .N S Y .S T K .M. 
 
 The islamls of ilu; lia Cloche j^roup and the peninsula of the same name in the south- 
 westein corner of our sh(;et condst of lltt-lying fossiliferous rocks of the? Lower Silurian or 
 Ordivician system, witii some ridges and knobs of Huroaian quart/ite protruding through 
 them. The middh; portion, which constitutes the bulk of this group, is made up princi- 
 pally of ratlier thinly-bedded, lumpy and uneven surfaced gray limestones, with many thin, 
 shaly l)(;ds and partings int(;rstratifying them. I5nt underlying these measures are from 
 50 to 100 feet, or perliaps more, of reddish and chocolate colored calcareous marls \dth 
 greenish hiyers and mottlings, together witli some beds of fine grained white and redilish 
 sandstones, while overlying them and interstralifying the upper portit)n are beds of 
 hard, coiiipa(;t, dark gray magnesian limestone, which weathers to various yellowish and 
 redtlish shades. 
 
 The lower or marly and arenaceous portion of the series has yielded no fossils by 
 which its age can be identified, but it is believed to represent some formation older than 
 tlie Trenton group, and it was thought by Logan that it might be the equivalent of the 
 jSault Ste. Marie sandstones, which he considered to be Chazy, but which are referred to 
 the I'otsdam formation by the United .States geologists. 
 
 The, upper beds of the Trenton group are seen at the north end of >Strawl)erry 
 island, and in the nortii-facing bank at Little Current at the northern extremity of 
 llanitoulin island. At these localities they are overlaid by the black bituminous shales 
 of the U tica formation. The breadth across tho strike from the north side of La Cloche 
 island to the commencement of the Utica shales on Strawberry island is eight miles. 
 The aver.tge dip to the south is assuuied to be 40 feet in the mile, so that the total thick- 
 ness of the Trenton group would he about 320 feet. Che fossils which have been 
 collected among these rocks from the summit of the marly and arenaceous portion up to 
 the highest beds on La Cloche island, and also from the islands just west of the latter, 
 belong to the Birdseye and Black River divisions of this group, so that the Trenton 
 foiiiiation proper in this region is confined to a strip bordering the shore for six miles in 
 the neighborhood of Little Out rent and thence round into West V)ay, tlie northern part 
 of Strawberry island and the peninsula between Manitowaning and Snntli bays. On 
 Heywood or Rat island, along with a little Utica shale there is some limestone which 
 Appears to belong to the Trenton formation. Patches and margin.s of tossiliferous gray 
 
ill of 
 
 liiiiHHtuneH resting on the quiut/.iio aiicl ili|i|iiiig into tlie lake are found here and tliere 
 uloiif^ tht) lii;,'li j.dint which luns IVoni Killiirncy Ixiv InwardH Mi-ywood isliiiid iin<l on tin* 
 ihUmdH juat nouth of it. Tlics*- roclis appear to In- idcnticiil with those forininj; thr i.ciitral 
 part of La Clo<;h») island, and they woulil thorefon; l)(!lon;^ to the Birdseye or Black Kiver 
 formation. 
 
 Ah ain-ady stated, tin; Idack shales of the Utica formation re.st upon the to)> of the 
 Trenton liiiic'^torK's in the viilaj^'c of Little Current and covir the yreater i)ait <>f Straw- 
 l)erry island. Tiiey arc? found near the (luart-ite ritii.'f at She^uiundidi vilhi;,'c, al.so at the 
 base of the Hudson Kiver formalinn lictwccn Manitowaninj^ antl Suiith hiiys, and in a 
 similar position at cape Smith. 
 
 ssils by 
 ■ than 
 of the 
 red to 
 
 wl)erry 
 inity of 
 
 shales 
 Clocha 
 
 miles. 
 
 thick- 
 been 
 1 up to 
 
 latter, 
 renton 
 ales in 
 n part 
 
 . On 
 
 which 
 IS gray 
 
 K U O N O M I CJ .Ml .\ ;■; II A L .s . 
 
 Only 11 small part of the district represented on the accorapanyin;,' map has yet bnen 
 explored lor useful luineral.s, but the discoveries already nuide are sullicicntly nuuierous 
 and import.iiit to lead to the belief that a promisin,^ fiiturti is in sturo for thi^ part of 
 Canada as a miniut,' rej^don. The metallic ores appear to i)e confined to the Murouian 
 rocks, which are here so e.xtensiveiy deveiopeil. The, Sudbury district has becoiin> well 
 known for its txtensive nickeliferousdi posits, and prospejtiufj has been as yet conhiied 
 chiefly to that region. Ores of several other meta'^ have also been found in the district, 
 and the iruiications are in favor of imieling witii souk^ of them in payiiiij i|uantities. 
 NN'liat has lieen a(coiiiplish(d in the Sudbui'i district may be repeatetl in \aiious parts of 
 the great unexplored Ihironian belt to the northeastward. 
 
 But the us(iul luinerals of our present rei,'ion do not consist entirely of metallic ores. 
 The non-metallic mineral products, such as building and oraanuMital stontjs, rock for lime 
 and glass-making, etc., are also important. Some of these occur amontf the Lmirentian 
 and others among thelluronian rocks. As the district is only beginning to tie inhal)ited, 
 and the need of such materials has scarcely been felt, little or no effort to lind tiiem has 
 jet been made; but as soon as there is any demand they will no doubt be found in many 
 iiew localitit s. The possibility of discovering workable deposits of phosphate of lime 
 among the Laurentian rocks ot the district, and of asbestos along with the lluronian 
 sfrpentines, is well as of other substances usually found among these rocks, should be 
 Lome in mind. 
 
 Iron. 
 
 Among the (juartzites of Llie La Cloche region small isolated deposits of ma.ijnetite 
 and one or two of hematite have been found, but none of those yet discovered appear 
 to bo sutliciently extensive to justify mining operations. From analyses reported to 
 have been made of the ores from two or three o*' the.se deposits they would appear to 
 be sutiiciently free from titanium, phosphorus anu sulphur to constitute lirst.-class ores. 
 It is to be hoped that further explorations among these rocks may bring to light larger 
 masses of iron ore. 
 
 Tliin veins of good magnetite, accom])anied by (juartz, occur in the red hornblende- 
 granite two miles north-northwest of Oaitier station, and again in the same rock on the 
 Soanish river a short distance below The Elbow. 
 api)ear to be promising for the ores of iron. 
 
 The existence of iron ore on Iron island in lake Nipissing is oidy known to most of 
 those interested in the minerals of the district by vague report. It may therefore be 
 wntli while to quote the description of it given l)y the late Alexander Murray of the 
 Oeological Survey. 
 
 Small masses of specular iron ore are common to nxost of the rook in'the island, and in 
 the crystalline limestone there is a very ijreat di.-jjlay of it. For a breadth of about forty 
 yards ixlon^ the clijT on the east sid(! tlie rock holds masses of the ore of various sizes, 
 somet imes running in strings of an inch thick or upwards and at otlier times accumulating? 
 in huj^e lumps, some of which probal)l\' wei^h over half a ton. Tlie beach near the out- 
 crop is strewn with masses of all siz-'s, from great boulders weighing several humlred 
 pounds to small rounded pebbles not bigger than marbles. The limestone with which the 
 
 But the granitic districts do not 
 
28 
 
 ore is as.sociatetl is frequently cavernous, and tiie crevices and small fissures are thickly 
 lined with crystals of blue fluor-spar and rod sulphate of baryta or cocksconih-sr ir- 
 
 Crystalline limestone crops out on the opposite or west side of the island and. judf^inp 
 by the strike on tlie north siiU-, it must correspond with that holding the iron ore on the 
 east. The same minerals were found disseminated through thfj ro(^k and sti-ewn upon the 
 beach. At the extreme southwest point of the island the rock is attain crj'stalline lime- 
 stone, and a lonjf beach running out from it to the westward is perfectly covered with 
 boulders of specular iron ore. Iron ore occurs also at the southeast point of the is'and, 
 although not in such Kfeat abundance and only in detached masses strewn upon the 
 beach.* 
 
 In the Fluronian iron-bearing region of lake Superior the ores have two diflerent 
 sets of asBociations or modes of occurrence. In the one case they are associated with 
 hornblendic or cliloritic schists which appear to belong near the base of tlie system, and in 
 tlie other they occur with fine grained silicioim and Jaspery rocks. The magnetite of the 
 Atik-okan region is an example of the first, and that of Hunter's island and Kamini8ti(iuia 
 river of the second. 
 
 N I C K K L , 
 
 The comjiaratively recent discovery of workable deposits of mixed copper pyrites and 
 nickeliferous jjyrrbotite over a large area in the Sudi)ury district is one of the most im- 
 portant events in the history of mining in Canada. Although masses of pyrrhotite are 
 known to cxi.st in other parts of the Dominion, there is no ;)ther region where they are so 
 numeious and in such proximity to one another, and with the exception of one near .St. 
 Stephen in New Brunswick they do not appear to be nickeliferous to an economic degree, 
 whereas in Sudbury district all the deposits so far tested are com])at'atively rich in nickel. 
 The pyrrhotite of this region is found in the midst of rocks of diflerent characters and belong- 
 ing to diflferent horizons, but it is always more immediately accompanied by greenstone. 
 Indeed this rock may be regarded as the parent of the ore. These facts would seeni to 
 indicate that in the Sudbury region the greenstone had a common and deep seated origin. 
 The area over which the ore has been discovered is of an eliptical form, and measures 
 about 70 miles from southwest to northeast and r)0 miles from southeast to northwest. 
 
 The first discovery of nickel in this region was made about 1846, at the Wallace 
 mine in Bay of Islands on the north shore of lake Huror., about a mile west of the 
 mouth of Whitetish river. This mine was opened in 1847 and was visited in 1848 by the 
 late Alexander Murray of the Geological Survey, but at that time mining operations had 
 been temporarily suspended. The ore consists of chalcopyrite with magnetic and arseni- 
 cal pyrites rich in nickel, occurring in chloritic and quartzose schists close to a mass of 
 greenstone. The extent of the deposit cannot at present be seen on account of the debris 
 on the surface and the shaft being full of water. Mr. Murray in his report says : 
 
 The temporary condition of the mine at the period of our visit rendered it impossible 
 to obtain such specimens as might be considered an average sample of the material exca- 
 vated from the shaft ; but with a view of ascertaining the quality of the nickeiiferoui por- 
 tion ot the ore a specimen of it, as free as possible from the copper pyrites, was submitted 
 to analysis by Mr. Hunt, who found it to contain 8.26 per cent, of nickel with a trace of 
 cobalt; hut as nearly two-fifths of the specimen consisted of earthy materials which 
 might readily be separated by dressing, the quantity of nickel in the pure ore which this 
 would represent would equal nearly 14 per cent.f 
 
 The existence of nickel and copper in the greenstones of what is now the Sudbury 
 district was Hr.st made known by Dr.T. S. Hunt and Mr. Alexander Murray of the Geological 
 Survey in 18.')6. In that year Mr. Murray explored Salter's base line, running north- 
 ward from Whitetish lake, and in what is now the township of Waters he found a mass 
 of magnetic trap which proved to contain disseminated nickel and copper. He says : 
 
 Sptcimens of this trap have been given to Mr. Hunt for analysis and the result of his 
 investigation shows that it contains magnetic iron ore and magnetic iron pyrites generally 
 disseminated through the rock, the former in very small grains; titanif-^rous iron was 
 found associated with the magnetic ore and a small quantity of nickel and copper with 
 the pyrites. J 
 
 *Ue]iort of Progrpss for 18.')4, page 12.3. 
 +(je(>l(>Kical Survey Report for 1848, i>. 44. 
 ^Report of the Geological Survey for 1860, p. 180. 
 
nis 
 
if 
 
•JO 
 
 Again referring to this Hubjnct Mr. Murray says : 
 
 The maj^netic trai) liisrovored on Mr. Salter's tnorMian lino north of Whitefisli laki' was 
 obsorvod to hold yellow siilphuret of copper oci'asionally ; and .Nlr. Hunt's atialysis of a 
 hand-spociniiMi of tho rock. \veip;luni.' ten ounces, gave twenty grains of motallifcrous 
 material, of which eleven wore m'VKn(Uic and consisted of iua|.;netii' iron oro, with a little 
 titaniferous iron ore and miKnotic iron pyrites containing; traces of nickel. 'Phi nine 
 ,?rains of non-magnetic mineral consisted of iron pyrites, oontalnintc from two to throe 
 per cent, of copper and about one per (^ent. of nickel. Many larije i|uartz veins oci'-ur on 
 the lower lakes of the Wl.itolish river, hut iron pyrites was the only nK'talliferous sub- 
 stance which they were observed to contain.* 
 
 fn constructing the ('anadian Pacillc Railway line in 1882 the mass of oro which is 
 now beinj; developed as tlu .Murray mine, three miles and a lialf northwt^st of Sudbury 
 Junction, was out through at the surface. This discovery was followed in 1881) by the 
 fitu'ing of or(! at wliat are now the Stoltie, Clipper clitr, .McCJonnell and otli(>r mines in 
 the neighborhood. These occurrences were at first regarded as of velue only for the cop- 
 per which they might contain, and, notwithstanding that tho existence of nickel among 
 the associated rocks of the region had been pointed out by Murray and Hunt so long be- 
 fore, it was not till three or four years after the above discoveries had been mvde ami a 
 thousand tons of dressed ore had been sent to England from the Ooppr>r-olifl' mine tiiat 
 the value of *;he ores for nickel was recognized. 
 
 The ore is very much the same at all the occurrencos in the Sudbury districc. It consists 
 of a mixture of nickelif rous pyrrhotite or magnetic pyrites, witii more or less chalcopyrite or 
 copper pyrites. The larger itre-masses generally approach lenticular forms, with their 
 longer diameters parallel to the strike or to the line of junction of the enclosing rocks. 
 Their attitude is usually nearly perpendicular, the dip or undtudie being sometimes ap- 
 parently at higiier angles than those of the adjacent rocks. 
 
 Each of the larger ore bodies is made up of a hrecciated or a conglomerate-like nii.\ture 
 of the above-mentioned sulphides and the country rocks next to it, the fraguients of the 
 latter varying in dimensions from n)ere grains and very small pieces up to immense boul- 
 ders, but the average size is a few inches in diameter. In some cases the stony fragments 
 constitute .so large a proportion of the upiss that they come aln ost into contact with each 
 other, the interspaces being filled with the sulphides, while in others there are consider- 
 able bodies of nearly pure ore with only occasiojial rocky fragments scattered through 
 them. In a few instances a granitoid filling between the fragments takes the place of the 
 sulphides. A good e.vample of this may l)e sren at an opening in one of these ore-masses 
 on lot 3, fifth concession in the township of Levack. 
 
 The usual site of the.se ore bodies is at the junction of greenstone with some other 
 rock, especially granite, gneiss or felsite. Another circumstance which appears to have 
 influenced the localization of the ore is the intersection of the ore-bearing planes by one 
 of the dykes which have been described, or by a throw, or a number of minor dislocations. 
 The existence of one or other of these conditions has been noticed at or near most of the 
 larger ore-bodies of the district. 
 
 These deposits ha e not yet been worked to a surii ;ient extent to prove much in 
 regard to their persistence or otherwise, in depth. The Copper-cliff mine however has 
 been already wrought to a depth considerably greater than the horizontal length of the ore- 
 ma.ss, either on the surface or in any of the levels. Oro deposits of a similar character in 
 other parts of the world have sometimes proved on working to possess a much greater 
 depth than horizontal measurement. In the r.osence of any indications to the contrary, 
 it may therefore be e.xpected that the nickeliferous deposits of the Sudbury region will 
 prove equal in depth to their horizontal extensions. 
 
 As to the genesis of the ore bodies, the evidence points to their origin from a state of 
 fusion. The fact that the ores always accompany the greenstone (itself of igneous origin) 
 is a strong proof of this supposition. The.se sulphides fuse at ab)utthe same temp'^rature 
 as the greenstone, and in the cooling of the latter they would naturally tend to oalesco 
 in small and large masses. The dissemination of both the chalcopyrite and the 
 
 Report of the Geological Survey for 1880, p. 189. 
 
pyrrliotite sn generally tliroughout the wliole mass of tlie coiniiiotier varieties of the green- 
 stones, and the lich iiiipregniition of these rouks witli the sitnie sulpliides in the vicinity of 
 the ore bodies, arc luldi'.ional evidence in the same direction In the isolated liernels of 
 ore, often scattered so tliickly througli tiie greenstone in the vicinity cf the workable 
 deposits, we tind groups consisting of either of the sulphides, separately or intermingled, 
 and often the indi\idiial kernels will be made U]) of the two kinds mixed to'j^ether. These 
 kernels, together wiih larger patcli(!S of the ores, constitute t!very pi oportion of the rock, 
 from a su)ail percentage up to halt'lhc! total weight or more, when the mass has become 
 SM(Hci( utiy rich to put upon the roast heaps, In tl e mixed Hulphides of th e ore bodies 
 the pyi ihotite generally cuntains a certain proportion of disseminated grains of quartz and 
 other stony matter, while tli(^ chalcopyrite is usually tolerably pure. This may be owing 
 to the manner in wln'cli th<! latter separated itself from the former, whether in a state of 
 fusion or by some subt'equent process. Although most of these ores appear to have 
 .seoaratod themselves from a cooling magina, we lind occasionally evidence of subse<iuent 
 modifying processes. Still there can ))e little doubt that the larj.'er ore bodies of this dis- 
 trict were no', originally deposited from aqueous solution like the gangue and ore of ordi- 
 nary metalliferous veins. 
 
 The above ores do not contain a veiy hi /.i ))ercentage of nickel or copper, their value 
 depending more on their abundance and the facility with whicli they can be mined than 
 on their richness. The Canadian (.'opper Company, after having smelted thousands of tons 
 of the ores irom the Coj)perclili', Evans iind Stobie mines, found the average yield of 
 nickel for tlie year 1890, to have been 3..")l' per cent, ard of copper ■i.32 per cent. The 
 ore smel'.ed at the Blezard mine up to March, 1891, averaged 4 per cent, of nickel and 2 
 per cent, of copper ; that smelted at the Murray mine up to the same period averaged 1.5 
 per cent, of nickel and 7a per cent, of copper. Mr. F. L. Speriy, late chemist to the 
 tJanadian Copper Company, found the average of nine assays of ores from the mines of his 
 company to be 2.38 per cent, of nickel and G.44 of copp>-r. Assays of eleven samples of 
 the ores of the district made under the supervision of ^Ir. Hoffmann, chemist to the Geolog- 
 ical Survey, gave an average of 1.6'J per cent, of nickel. The average of all the above 
 smeltings and assays givis us 2.G2 percent, jf nickel, which may be taken as the general 
 average of the ores of the Sudbury district. Exceptionally rich ores however have been 
 found in smaller quan^'ties, especially at the Worthington mine in Drury and the Ver- 
 milion mine in Denison. 
 
 C O li .\ L 1 . 
 
 Cobalt amounting to little more than a trace has been detected in many of the Sud- 
 bury ores. In connection with the Wallace mine it has been mentioned that in 1848 Dr. 
 Hunt ascertained the presence of cobalt in the ore which Mr. Murray had brought f»'om 
 this locality. 
 
 C o P P K K . 
 
 Reference has already been made to the copper always contained in the ores of the 
 Sudbury district. The result of smelting several thousand tons of the ores from the three 
 mines worked by the Canadian Cop[)er Company was a yield of 4.32 per cent, of copper 
 from these ores as placed on the roast heaps. It has been mentioned that the roasting 
 ores smelted at the Blezard mine yielded 2 per cent., and at the Murray mine 0.75 per 
 cent, of copper. In the ores of all the mines the chalco|)yrite or copper pyrites is gener- 
 ally so intimately mixed with the pyrihotite as to make it almost impossible to separate 
 it by any mechanical process. But at the Stobie mine masses of several tons of almost 
 pure copper pyritt s are occasionally encountered, and the Copper-clifi mine when tirst 
 opened showed a large body of the .same ore near the surface. 
 
 At the Vermilion mine on lot 6 in the fourth concession of Denison copper has been, 
 found in paying quan'itics. The ore consists of clialeopyrite, which however is remark- 
 able for having a dei p purplisii-blue tarnish, causing it to rt emble bornite or purple 
 copper ore. It occurs as a streak about four feet wide in greenstone, but it has no distinct 
 walls like a vein, nor any gangue except a mixture of the country rock. A shaft had been 
 sunk on this deposit to a depth of twenty feet when it was visited by the writer in 1888. 
 
;u 
 
 of the 
 three 
 
 copper 
 •oasting 
 ).7r) per 
 
 gener- 
 ieparate 
 
 iihuost 
 eu tirst 
 
 las beeu 
 remark- 
 purple 
 distinct 
 lad been 
 11 1888. 
 
 The upper ten feet was decomposed to a loose gossan, mixed with fragments of rock, 
 whirh had probably been held in the ore streak before its dccomjio.sitinn. The r<;c'ently 
 discovered mineral sperrylite, whicii is an arsenides of platinum with a little tin, and 
 whidi occui.-) in tine crystalline grains, was found by washing this gossan. (Jopper pyrites 
 has l)een found on almost every lot in the iifth concession nf Ucnison, along the southern 
 border of a belt of gr^'jnstone that runs nearly east and west tlirough tliis concession. 
 
 A short distance north of the region under description tht; writer in 1S75 met witlia 
 group ot eojjper-bearing quartz seins running north 70 west, and south 70 ea.-,t, crossing the 
 east branch of tlie .Montn al river ten miles and a half before it falls into the main stream. 
 Tliis gioup of veins is about a quarter of a mile wide. Tli<!y vary in thickness from nu're 
 strings to thirty or forty feet, and contain a good deal ot specular iron, ;'.nd in some places 
 promising indications of copper in the form of pyrites. IMr. Hoffmann found a samph; of 
 tJie specular iron to contain 39.41 per cent, of the metal. The country rock liere consists 
 of i.ia.ssive beds of (juartzite and greenstone, both holding large bunches or " clouds " of 
 fragments of syenite, (juartzite and Huronian schists, and all interstratitied with sandstone 
 and clay-slate 
 
 On the north shor(^ of Xarrow bay or liaie Fine, and two miles east of its entrance, 
 a small vein cutting the {juartzite contains gray copper ore. This V)ay lies between Frazcr 
 and McUrei^or bays, and the above-mentioned occurrence of copper on'. has been described 
 by Mr. James T. B, Ives in the Tranaactions of the American Institute of Mining 
 Engineers for 1889- 'JO. 
 
 The most productive co))per mines ever worked in Canada were those of the West 
 Canada Mining Company, wliich included the Bruce on the east, the Wellington in the 
 centie and the Huron Copper liay mines on the west. These mines are situated at the 
 western extremity of the north sliore of lake Huron, and although they are outside of our 
 piesent sheet they deserve a brief notice as affording the best examples of the occurrence 
 of copper in the Huronian greenstones. These mines were opened in 184 (J and worked 
 till 1875, a peiiod of thirty years. The actual workings extended for a distance of over 
 two miles east and west. The ore occurs principally as the yellow sulphide in veins of 
 white quartz, cutting a dark grayisli-green diabase. But when the veins on the Bruce 
 location were first opened a good deal of the purple sulphide was found near the surface. 
 On this location several nearly parallel veins running about east and west were worked, 
 the thicker ones being about four feet wide. But on the other two locations work was 
 carried on chiefly on two master veins called the Main lod( , which varied from three to 
 fifteen feet in thickness, and tlie New or Fire-lode, a branch of the latter, and about equal 
 to it in breadth. On the Bruce location the veins were worked to a depth of only about 
 thirty fathoms, but on the other two locations the average deptli was from forty to sixty 
 fathoms. Between the latter levels an almost barren floor was generally encountered, 
 although in some place profitable mining extended to seventy fathoms in depth. 
 
 The vein-matter as mined contained an average of five per cent, of copper, but it was 
 concentrated by crushing and jigging to a\)out twenty per cent, before shipping to 
 England, which was the chief market. At different times in the history of these mines 
 both smelting and cementation had been tried upon the ground, and abandoned. From 
 information supplied by Captain Benjamin Plimimer and other reliable authorities the 
 writer ascertained that copper ore, preci]ii;ates, ingots and slags amounting to 40,515 tons, 
 and realizing about .$3,300,000, had been shipped from these mines in the thirty years 
 •luring which they had been worked. 
 
 Lead a x i > Zinc. 
 
 Small quantities ot galena and zincblende have been found in veins in the belt of 
 black volcanic breccia and slate, which lias been described as occurring in the Sudbury 
 district, and they are worth mentioning as possible indications that these ores may be 
 dikcm ered in greater abundance in these rocks. One of the localities is on Pawatik river, 
 about a mile and a quarter northward of the Vermilion, in township (15 ; a second is just 
 below Oiiaping falls, and a third on the south side of Vermilion lake, near the outlet. 
 Vein-iik(> ma ssts of blende mixed with pyrite occur at Stobie falls on lot 10, sixth con 
 
32 
 
 cession of Creif»hton. Cialena has been detected with the pyrrhotite in the Copper-cliflT mine, 
 and on lot 6, third concession of Graham. It is also associated with this mineral on 
 Moore's location on lots 2 and 3 in the tilth concession of Craig. It occurs in small 
 quartz veins in dioritic schist on lot fi, fovirth concession of Denison. 
 
 (lOLT). 
 
 In 1 887 a rich auriferous V)unch was found in a vein of light gray Hnely granular quartz 
 about two feet thick on lot G, fourth concession of Denison. Theopening made on this vein 
 came known as shaft No. 2 of the Vermilion mine. The gold was mostly in the form of 
 small nuggets scattered rather plentifully through the quartz. It is said tliat several 
 thousand dollars worth were mined, but the gold did not appear to hold out in depth. 
 The country rock on this part of the lot reseml)les a Hne grained greenish gray greywacke, 
 bu*^ on critical examination it is found to be an altered greenstone full of very small grains 
 of iron pyrites. Prof. George H. Williams, who examined thin slices from two specimens 
 of this rock under the microscope, describes it as an extremely changed basic eruptive, 
 probably originally a gal)bro or a diabase — most likely the former. Its present composi- 
 tion is H confused aggregate of chlorite, biotite, epidote, sericite, quartz, yrite, opaque 
 iron oxide, leucoxene, calcite and apatite needles. 
 
 Among the quartzites and greenstones on the south side of lake Wahnapitae a dis- 
 covery of gold in visil)le specks Wiis made in 1888. It occurs associated with mispickel 
 in some thin veins of qisartz following a belt of quartzite, boulder conglomerates and 
 reddish felspathic quartzite having i-omewhat the appearance of granite. A sam|)le of 
 the quartz from one of these small veins, which also contained mispickel and pyritc, was 
 assayed by Mr. HotTmann of the (Jf^ological Survey and found to contain •"> 1 '_'•") ounces of 
 gold and 0.233 of an ounce of silver to the ton of 2,000 pounds, but the quartz trom an- 
 other of these small veins contained neither gold nor silver. A band of tine grained dark 
 colored greenstone runs . irallel to and at no great distance from either side of this gold- 
 bearing l)elt of quartzite. It is not unlikely that gold may be found among the rocks of 
 the western part of lake Wahnapitae, which, as already mentioned, have been subject to 
 much crushing in past ages. Gold is reported to have been found liy Prof, hfeys and 
 others in quartz from veins in the northwestern part of Creighton and the eastern i)art 
 of Fairbank. Out of a considerable number of samples of ([Uartz from the Sudbury dis- 
 trict assayed for the precious metals by Mr. Hoffmann of the (Geological Survey, the 
 following results were obtained : From vein No. 1 on mining location W. R. 3, township 
 40 (southeast of lake Wahnapitae), the property of Mr. Donald McLaren, 0. 117 oz. of 
 gold per 2,000 pounds ; from location M. 3, at the south extremity of lake Mattagamash- 
 ing, a short distance ea.st oi lake Wahnapitae, owned by Donald McLaren, 1.167 oz. of 
 gold and 0.233 oz. of silver per 2,000 pounds; from Simpson's mine, lot 11, second 
 concession of Graham, near Whitetish station on the Canadian Pacific Railway, 0.350 oz. 
 of gold per 2,000 pounds 
 
 Some distance to the west of our district, or in the western part of the township of 
 Galbraith and about fifteen miles north of Bruce Mines, a large vein of auriferous quartz 
 occurs in a country rock of greenstone. The vein runs about west-northwest, is of a mottled 
 gray color, contains a considerable sprinkling of various sulphides, and is tolerably rich 
 in gold. Of three assays made by Mr. Hoffmann, the highest result was .583 oz of gold 
 per 2,000 pounds. 
 
 I'LATINI M. 
 
 Sperrylite, already referred to as occurring at shaft No. 1 of the Vermilion mine in 
 l)enison, was first determined to be a distinct mineral species, containing 52 57 per cent, 
 of platinum, by Prof. H. L. Wells of Yale College early in 188i). Some months pre- 
 viously however Mr. Robert Hedley had ascertained the presence of plitinum in the ore 
 of this shaft, the proportion in one assay amounting to about five ounces to the ton It 
 is unlikely that the occurrence of platinum at the Vermilion mine will prove to he the 
 only one in the district ; it is more probable that intelligent research will show the ex- 
 istence of this valuable metal in other places among the lluronian rocks. It is reported 
 to have been detected in small quantities at one of the mines on Lake of the Wo ids. 
 
33 
 
 mine m 
 per cent, 
 tnths pre- 
 in the ore 
 ton lb 
 to lie the 
 w the ex- 
 reported 
 Old'*. 
 
 BuiLDINfi AND OkNAMKNTAI. S T O V K S. 
 
 The red granite of George island and vicinity would make an excellent stone for 
 massive strncturcs and monnnients, as well as for ordinary buildings, Nfany of the 
 evenly and somewhat thinly beddf d gneisse,-. of the French river region and of the shore 
 of Georgian bay from I"'rench river to Parry Sound would serve a& very substantial and 
 tolerably easily wrought biiilding rtones. 
 
 The nearly horizontal beds of limestone of the Trenton group on the isliinds in the 
 North channel, at Little Current and on Strawberry island are well adapted for ordinary 
 building purposes and are very conveniently situated for transportation by water. 
 They are mostly tine grained or compact, ajid of dark bluish and grayisli colors. 
 
 The dolomites of the Niagara formation further south on the Grand Manitouliu 
 ifland are more heavily bedded, soft(;r or more porous and iiiuch lighter in color. 
 
 The light gray and cream-colored dolomites of the Guelph formation are found on 
 the southeastern extremity of Grand Manitoulin island and the south end of Fitzwilliam 
 island, but in tliese localities tliey aie coarsely spongy or full of small cavities. 
 
 On the shores of the high jioiiits and islands to the no.-th and west of Killarney the 
 light gray and whitish ([uartzites in many places would make very serviceable building 
 stones. The bed-planes are generally very even and parallel, and layers can lie found of 
 almost any thickness desired. 
 
 Some varieties of the greywackes, so common among the Iluronian rocks, split 
 readily in any direction, and as they are tolerably easily dressed they may be found suit- 
 able for purposes of heavy construction. The argillaceous sandstones of the supposed 
 Cambrian basin of the Sudbury district also afford ^'ood building stones and tiiey have 
 been quarried to a small extent on the line of the Canadian Pacitic Railway between 
 LarchwGod and Chelmsford. 
 
 In regard to ornan\entai stones, the dolomites of the Huronian system when cut 
 often show good colors for marbles, but as already stated they generally contain silica in 
 scattered grains and as strings and threads running in all directions through the mass, 
 which prevent.s them from taking a good even polisli. Exceptions to this general rule 
 may however be found in such cases, for example, a.s the finely crystallint; and nearly 
 white variety found on the north side of Lamorandiere bay in the township of Kutherfonl, 
 which has not yet been tested as marble. 
 
 The olive and greenish argillites barred with black, such as occur at tlie northern 
 outlet of Temagami lake, and which were so highly prizeil for ornamental stones by the 
 ancient Indians, may be found serviceable for the manufacture of a variety of artistic 
 objects. 
 
 The brecciated green chalcedony, which occurs in abundance at the outlet of White 
 Beavt-r lake, at the head of the east branch of Montreal river, would form a hamlsome 
 stone for fine ornamental purposes. 
 
 ROO K 1 N li S I, A T K . 
 
 It sometimes happens that clay-slates show a good cleavage in natural exposures 
 resulting from the long continued action of surface influence.s, while t'le same rock, when 
 freshly quarried deeper down, will not split readily under artificial treatment. It is there- 
 fore ditiicult to pronounce upon the value of such slates without practical experiment. 
 
 In our district slates showing fair natural 
 
 have been observ(Mi in various 
 
 localities, among which may be mentioned the banks of the Matabechawan river which 
 dischargis Ral)bit lake into lake T<Mniscauiing, Maskinongewaganiing lake and the lower 
 part of Matlagamashing lake and Spanish river both above? and below the (Jreat Bend. 
 It has be( n already mentioned that a good chavable slate occurs on the line of the 
 Canadian Pacific Railway within a mile or two east of Algoina Mills. While these slati-s 
 may not lie as good as those of Mflbourne and Shipton in the province ( f Quebec, they 
 are bettei- than the slates used for roofing purposes in many paits of Great Hritaiii, and 
 it IS considered worth while to call attention to ihem among the mineral products of 
 economic value occuring in this region. 
 
:h 
 
 L I M K , 
 
 The limoHtones and dolomites which make up the hulk of the rocks of the vnrious 
 Silurian formations of the islands of the La Cloche group and of (Irand Minitoulm 
 island are well adapted tor lJurnin^' into lime, the calcin.Kl dolomite passin;,' under this 
 name. Stone suitable for burning into lime and also for metallurgical purposes inay be 
 found among Mie Huronian magnosian liiiiestonea already described at Limorandiere bay, 
 lake Panache, on Wahnapitae river, near Oartier station and on Geneva lake. 
 
 StONK vnn frI,ASS-M AKINn. 
 
 Suitable material for glass-making may be found almost anywhere among the Huroa- 
 ian quartzites near lake Huron, where thev are nearly all of light colors. In addition to 
 their occurrence in the La Cloche mountains and on the high points and islands towards 
 Killarney, these quartzites are met with on the north lide of La Cloche island, at the 
 Bouthern extremity of La Cloche peninsula and in a ridge which runs into Manitoulin 
 island from the head of Sheguiandab bay. 
 
 Al'ATITK OK PHOSPIIATK OK L I M K. 
 
 This mineral has not yet been found in economic (luantities within our district. Tt 
 exists however as a constituent of all the greenstones of the region which have been 
 examined under th« microscope, and large crystals of it have been met with among the 
 ores of the Copper-cittand some of the other mines in the district. Numerous crystals 
 of apatite were found in a vein near Nasl)onsing station on the Canadian Pacitic Rail- 
 way, east of lake Nipissing, As this mineral may be looked for among the Ujjper 
 Laurentian rocks generally, it would not be surprising if it should be discovered in com- 
 mercial quantities in the Nii)issing or Parry Sound districts. It occurs in various 
 localities in other parts of the province among the Upper Laurentian crystalline lime- 
 stones, but elsewhere it is found in larger masses in association with pyroxene rock an\oiig 
 gneisses and quartzites, as in the countj of Ottawa. Five bands of crystalline limestones 
 among the Upper Laurentian rocks were traced through the Parry Sound district by the 
 writer in 187G, but th. region northward of Georgian bay has not yet been sutticiently 
 examined to determine whether pyroxene rocks exist there or not. Should they be met 
 with in sulKcient abundance the finding of apatite in economic ouantities would be pretty 
 sure to follow. 
 
 M I 
 
vurious 
 litoulin 
 icT this 
 nay be 
 re hay, 
 
 Huroa- 
 
 ition to 
 
 ;owar(ls 
 
 at the 
 
 litouliii 
 
 let. Tt 
 ,'e been 
 )nsf the 
 crystals 
 c Rail- 
 Upper 
 in cora- 
 various 
 LH litne- 
 c an\oiig 
 lestones 
 by the 
 [iciently 
 be met 
 e pretty