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c 
 
 

 / 
 
 REMARKS 
 
 ON 
 
 CANADIAN STRATIGRAPHY. 
 
 BY 
 
 THO.AIAS .AIACFxVRLANE. 
 
 
.13 
 
 1^0^ 
 
 
 liiiiy^^'^' 
 
 iiiiiiiiiiiiiiMiil^^ 
 
 iMii 
 
 tkmm 
 
REMARKS ON 
 
 CANADIAN STRATIGRAPHY. 
 
 BY THOMAS MACFARLANE. 
 
 Mr. Selwjn's recent paper " On the Stratigraphy of the 
 '' Quebec Group and the older crystalline rocks of Canada" marks 
 an important event in the history of the Geological Survey. To 
 those who, like myself, have not heretofore accepted unhesitatingly 
 the theories of the Survey authorities, the publication of this paper 
 is of great interest. At the same time, many will, I think, regret 
 that it is unaccompanied by any geological map or rsections of the 
 territory whose stratigraphy is discussed. Without this it is quite 
 impossible for the general public, and quite difficult for the stu- 
 dent of Canadian geology, to follow Mr. Selwyn, to obtain a clear 
 idea of the reasons which have cuused him to differ so profoundly 
 from his predecessor Sir W. E. Logan, or to form a judgment as 
 to the relative merits of their respective conclusions. Mr. Selwyn 
 indeed informs us that " a considerable amount of careful inves- 
 " tigation and laborious work in the field is yet required before 
 " the indicated divisions can be correctly delineated on the map," 
 but, although this may be an excellent reason for not as yet 
 ^ablishing any map illustrative of Mr. Selwyn's views, still it 
 cannot be regarded as affecting the map of south-eastern Quebec 
 by Sir W. E. Logan, so long promised by him, and upon which 
 he laboured so earnestly. Indeed, I trust that the members of 
 the Natural History Society and the public generally will join 
 with me in urging upon Mr. Selwyn the advisability of publishing 
 this map, for I think that we have all been under the impression 
 that the views of the former Director of the Survey derived their 
 strongest support from stratigraphical considerations. 
 
 I 
 
My object in making these remarks on Canadian Stratigraphy 
 is to eliminate, as far as posniblo, from Mr. Selwyn's paper, the 
 facts upon which he bases his conclusions, and to examine how 
 far the latter are new, or acceptable. Mr. Selwyn in referring to 
 the opinions of those who have gone before him in the study of 
 Quebec rocks, asserts that " most of these opinions have been ad- 
 " vanced on palseontologioal, minerulogical or theoreticul grounds, 
 " without any study of the actual stratigraphy of the field." 
 Indeed, be has expressed himself to the effect that his views are 
 the result of a careful examination and mapping of the strati- 
 graphy, whilft those of myself and others are the results of either 
 mineralogical or palaeontological comparisons, the former of which 
 especially he supposes to be very misleading. From theses utter- 
 ances, and from the very excellent opportunities which we know 
 Mr. Selwyn possesses for making observations in the field, we are 
 entitled to expect to find in his memoir a careful dci^cription of 
 the new facts and data which have influenced his opinions, and 
 these I shall endeavour to point out. We must, however, dis- 
 tinguish betwixt these and Mr. Selwyn's general geological descrip- 
 tions, and also try to ascertain whether they involve negligence or 
 inaccuracy on the part of previous observers. 
 
 I. Among these newly observed phenomena is that having 
 reference to the Champlain and St. Lawrence fault. "The line of 
 "this dislocation," says Mr. Selwyn, "or unconformity — which- 
 " ever it may be — has oecn supposed to pass in rear of the Quebec 
 " citadel. This I hold to be a mistake, and I think it can be dif- 
 " tinctly shewn that it passes from the southwest end of the Island 
 " of Orleans, under the river, and between Point Ldvis and Que- 
 bec." To an ordinary observer the rocks underneath the city 
 and citadel of Quebec bear a much greater resemblance to the 
 contorted strata of Point L^vis than to the even-bedded shales 
 and limestones which generally occur on the northwest side of 
 the fault. But, after all, even if the fact be as Mr. Selwyn 
 states, he will probably admit that this is not of the slightest 
 importance so far as regards the correctness of his theoretical 
 views. 
 
 II. Mr. Selwyn places on record the results of an actual exami- 
 nation of certain supposed Potsdam rocks, described in the Sur- 
 vey Report for 1866-9, and has not observed anything in their 
 architecture or fossils to justify their separation from the L^via 
 formation. This is quite an important fact, of which I shall 
 
8 
 
 take notice when discussing the theory which Mr. Solwyn builds 
 upon it. 
 
 III. Mr, Selwyn states that, on the River Etohcmin, the rocks 
 of his second division crop out apparently unoonformably from 
 beneath the fossiliferous belt or L^vis formation. But he is 
 uncertain whether this " apparent unconformity " may not be a 
 fault, and therefore it would seem hazardous to base much 
 theorizing upon it. I cannot detect, elsewhere in Mr. Selwyn's 
 paper, any unequivocal example of discordance such as would 
 prove that the L^vis formation is quite distinct from the under< 
 lying " Volcanic Group." 
 
 IV. Mr. Selwyn notes the occurrence in his second division 
 of " altered volcanic products," both intrusive and inter-stratified, 
 and speaks of a great development of those Volcanic rocks. The 
 term " volcanic " Is very seldom used by modern lithologists as 
 iodictaing a particular texture or composition in a rock. Among 
 older authors, Sartorius von Waltershausen writes of the volcanic 
 rOcks of Sicily and Iceland, all of which occur in the neighbour- 
 hood of active volcanoes. Von Richthofen, in his Natural System 
 of volcanic rocks, written in 1868, refers exclusively to tertiary 
 and post-tertiary eruptive rocks ranging from rhyolite to basalt. 
 Mr. Selwyn in applying the term to intrusive rocks of Cambrian 
 or Silurian age probably uses it in the sense of eruptive, for it 
 would be very diflBcult to shew any connection between them and 
 volcanic vents. In this case he does not put on record a new 
 fact, but merely an old opinion expressed by previous observers. 
 But Mr. Selwyn claims further in reference to these rocks " that 
 *' neither their true stratigraphical position nor their geological 
 *• characters have been correctly defined, and they have, regardless 
 *' of these, been confounded and incorporated with the true Sillery 
 ** sandstones, which are only a local development of thick sand- 
 " stones at several horizons in the Quebec group or fossiliferous 
 '* Ldvis fornitition." The geological characters mentioned have 
 probably reference to their lithological features, and we are left to 
 infer that certain eruptive crystalline or sub-orystaliine rocks have 
 been described as sandstones by Mr. Selwyn's predecessors, and 
 that he has been the first to determine them correctly. But when 
 Sir William and his assistants classed a certain diorite, for 
 instance, in the Sillery formation they did not therefore deter- 
 mine it as a sandstone. When I speak of the Primitive Gneiss 
 formation I do not necessarily mean that every rock in it a is 
 
true gnciBs. And, similarly, if previous observers have placed 
 certain "volcanic" rocks in the same formation with the Sillcry 
 stmdstoncs, we may be certain that they did so iDtclligcntly, and 
 that Sir William Logan and his staff (ircrc fully aware of the 
 differences between a crystalline aud a fragu; otary rock. 
 
 V. Mr. S ilwyn calls attention to two characters not pointed 
 out by Sir W. E. Logan which distinguisii the "Volcanic " from 
 the Ldvii area on the Riviere du Sud. One of these is the 
 occurrence of fossils in the district north of the river ; but this 
 does not seem to be a new discovery. The other distinction is a 
 peculiar schistose structure in the sandstones of the "Volcanic" 
 group, which is not to be observed among those of the L^vis 
 formation. It is worthy of note that here we have Mr. Selwyn 
 himself making use of a lithological peculiarity for separating 
 two different groups of rocks. The absence of fossils from his 
 sesond or " Volcanic " division is emphusised by Mr. Selwyn ; and 
 DO doubt this difference, as compared with the Ldvis formation, 
 is a most important one. Still we know that Sir W. E. Logan 
 was aware of this distinction ; so that here again we have, not the 
 announcement of a new fact by Mr. Selwyn, but simply a new 
 explanation of a certain peculiarity. Sir William accounted for 
 the absence of fossils by metaniorphic action ; Mr. Selwyn would 
 probably attribute it to volcanic interference : the difference is, 
 after all, only in theory. 
 
 Although I have searched very carefully, I have filled to find 
 in Mr. Selwyn's paper any other traces of original observation 
 than those I have enumerated. The first of these items has no 
 bearing upon the mutual relations of Mr. Selwyn's second divi- 
 sion and the Ldvis formation ; the fourth cannot be said to be a 
 new observation at all, and thus we have, as the actual basis of 
 fact for Mr. Selwyn's new conclusions, the absence of Potsdam 
 strata from the neighbourhood of the Ldvis formation, the sup- 
 posed unconformity on the River Etchemin and a trifling litho- 
 logical peculiarity among the sandstones of the Riviere du Sud. 
 The supposed unconformity is by far the most important part of 
 this basis ; but we must recollect that Mr. Selwyn is far from 
 being positive about it, and, further, that the same difficulty 
 occurred to him as regards the contact of the rocks on the 
 northwest edge of the fossiliferous belt. There too, he does not 
 distinguish between an unconformity and a fault, and I believe 
 were this latter point decided it would go far to settling this 
 vexed question of the age of the Quebec group. 
 
 ai 
 
 tt 
 
 & 
 
pluocd 
 
 Sillcry 
 
 tly, and 
 
 5 of the 
 
 pointed 
 B " from 
 B is the 
 but this 
 tioD is a 
 oloanio " 
 le L^vis 
 Selwyn 
 ■para ting 
 from his 
 
 ryn 
 
 and 
 
 irmation, 
 S. Logan 
 e, not the 
 »ly a new 
 anted for 
 yn would 
 ference is, 
 
 ed to find 
 bservation 
 ns has no 
 cond divi- 
 id to bo a 
 il basis of 
 
 Potsdam 
 ), the sup- 
 fling litho- 
 ■e du Sud. 
 int part of 
 s far from 
 
 difficulty 
 sks on the 
 16 does not 
 i I believe 
 ittling this 
 
 i 
 
 After this examination I think it can reasonably be submitted 
 that these new data are altogether insufficient to destroy the 
 confidence which many have heretofore placed in the conclusions 
 of Sir W. £. Logan and in the labours of those who worked 
 under him during the last thirty years of his life. If laborious 
 and painstaking *' study of the actual stratigraphy in the field " 
 is to count for anything, it is no discredit to Mr. Selwyn to say 
 that his work in this respect is fur outweighed by that nerformcd 
 by Sir William. FurtKar, we all know that the closing years of 
 his life, even after his official connection with the Survey ceased, 
 were devoted to a re-examination of the Eastern Townships rocks 
 and to the completion of his map. Surely all this ought not to 
 be thrown aside as useless work. Surely Sir William, had he 
 lived, would have hnd something to say in these days in defence 
 of his opinions. Although he is gone from us, it is surely our 
 duty to take care that justice is done him, and I contend that it 
 would be only an act of simple justice to his memory to give to 
 the world the results of his labours, just in the shape which they 
 attained at his death. Apart altogether from his theoretical 
 conclusions, the correctness of which Mr. Selwyn disputes, the 
 observations of Sir William and his assistants, as to the actual 
 phenomena exhibited by the rocks of south-eastern Quebec, have 
 a practical value to the country, and to all future observers, 
 which I conceive it to be the duty of the Survey to put on record. 
 
 When we consider the very slender foundation of new material 
 upon which Mr. Selwyn's views regarding the Quebec group are 
 built, it would seem that the conclusions he has arrived at are, 
 to a very large extent, theoretical, nd therefore just as little 
 entitled to immediate acceptance as those of others who have 
 written upon the subject. In reviewing Mr. Selwyn's conclusions, 
 I shall attempt to state them as briefly and honestly as possible, 
 and I shall fir&t refer to those which from my own point of view 
 appear to be well founded. 
 
 1. The principal feature of Mr. Selwyn's essay is of course 
 the new view he takes as to the stratigraphy of the Quebec 
 group. The order, in age, of its different members he main- 
 tains is just the reverse of that indicated by Sir W. E. Logan ; 
 the fossiliferous belt or Ldvis formation is newer than the more 
 crystalline rocks to the south-east, and the latter are probably of 
 Cambrian age. Now although I cannot see that Mr. Selwyn 
 has brought forward any new and adequate proof of the correct- 
 
ncss of this view, still I feci bound to advooato it, bccauso of 
 my cxpcricnco among similar rocks in Soundinavia and Qor- 
 many, and stratigraphical and lithological comparisons which 
 I have mudo between these and Cunadiiin rocks. Indeed in 
 the first paper which I had the honour of presenting to the 
 Natural History Society of Montreal, dated 8th April, 1802, in 
 speaking of the so-called mctamorphio rocks of the Eastern Town- 
 ships, I maintained that " so soon as the true limits and effects 
 *' of mctamorphism are recognized, it will probably be acknow- 
 " lodged that, whatever view may be cnterl.iined us to their 
 " origin, the schistose rocks above referred to underlie the Silu- 
 ** rian and all unaltered or metamorphosed strata." Further, 
 in a pamphlet publiHhed by me in 1871, entitled " Observations 
 on Canadian Geology," I made the following remarks : ** Indeed 
 " in the attempts which have been made ut determining the age 
 " of the Eastern Townships rocks it has always been the rule to 
 " begin with the Potsdam sandstone as the oldest rock, and to 
 " assume that those to the eastward (regardless of their litholo- 
 " gical characters) follow each other in ascending order. Any 
 " one who has studied the structure of similar regions in Europe, 
 " such as those above mentioned, can scarcely fail to come to the 
 " conclusion that the opposite of this assumption is the truth ; 
 " that the oldest rocks are tliose of New England, and that as wo 
 '* come north-westward, we pass over more and more recent 
 " strata." (p. 13.) In mentioning the Silurian rocks in the 
 same pamphlet, I made a still more distinct statement of my 
 view of the matter, which I give here in full. "We have seen 
 *' that in comparing the great mass of the New England and 
 " Eastern Townships rocks with strata of similar lithological 
 " characters in Europe, such as those of Saxony above alluded 
 " to, there is no difficulty in recognising them as Azoic and pre- 
 " Silurian. This applies to tho gneiss, mica schist, chlorite 
 ** schist, and to much of the clay slate of the region referred to. 
 " As in Saxony, there exists a passage (perhaps only apparent) 
 « from these crystalline and semi-crystalline rocks into others of 
 <' a distinctly detritul and fossiliferous character, so in the Eastern 
 " Townships we have a similar passage from roofing slate into 
 " softer grey slates, grauwacke (Sillery sandstone), graptolitic 
 " shales and fossiliferous limestones. This peculiar structure 
 " was indeed the reason why these oldest fossiliferous strata were 
 " formerly called the Transition (Jlehergangs) formation. The 
 
because of 
 and Gcr- 
 ons which 
 Indeed in 
 Ing to the 
 , 1862, in 
 mn Town- 
 itnd effects 
 10 acknow- 
 8 to their 
 a the Silu- 
 
 Further, 
 bservations 
 ; «' Indeed 
 ing the age 
 the rule to 
 )ck, and to 
 leir litholo- 
 rder. Any 
 ) in Europe, 
 ;ou)e to the 
 1 the truth ; 
 
 that as wo 
 iore recent 
 9cks in the 
 iicnt of my 
 I have seen 
 ngl.ind and 
 lithological 
 ove alluded 
 lie and pre- 
 st, chlorite 
 referred to. 
 f apparent) 
 ,0 others of 
 the Eastern 
 Z slate into 
 
 graptolitio 
 r structure 
 
 strata were 
 ition. The 
 
 i( 
 
 " Bamo Borios of rocks in the Province of Quebec ocoupicH a belt 
 " along the west side of the Quebec group, having a breadth of 
 " about twenty miles, and including all undoubted sedimentary 
 " and foiisiliferous strata. It is the same band of rocks which 
 " continuing Kouthward into Vermont has there been called the 
 " Taconic, and which Dr. Hunt wishes to classify as Upper Cam- 
 " brlan. We have already seen that the term Cambrian is much 
 ** more applicable to the Green Mountain series, and there would 
 ** appear to be no good reason for ceasing to regard these rocka 
 " as belonging to the Silurian system. As lias already been ex- 
 plained, however, it would be proper to exclude from that 
 " series any non-fossiliferous rocks whoso aspect is semi-crystal- 
 " lino, and which have been so frequently classed as mctamorphic 
 " Lower Silurian. These, as we have seen, it is much more 
 •* reasonable to class with the Cambrian rocks." (pp. 15 and KJ.) 
 From these quotations it will be perfectly evident that Mr. 
 Selwyn's views as to the age and structure of the Quebec group 
 are the same as those I have held for the last seventeen years 
 and repeatedly brought before the public. It may seem a mutter 
 of little consequence as to where the merit of priority lies, but I 
 confess I think differently, and maintain that Mr. Selwyn's recent 
 paper ought ro have contained some allusion to the passages 
 above quoted. 
 
 But, in spite of all this, I feel bound to say that the matter is 
 not ended here ; that the independent student of our geology 
 will neither accept Mr. Selwyn's views nor any others, unless they 
 satisfactorily dispose of the difficulties which have all along beset 
 this subject. Mr. Selwyn banishes Potsdam strata from the 
 proximity of the L«5vis rocks, and claims that his new divisions 
 have '* at least the advantage of simplicity." This may readily 
 be admitted for what it is worth, but they do not in the slightest 
 degree meet the question with which Sir W. E. Logan found 
 himself face to face during the latter part of his lifetime, and 
 which may thus be stated ; How can this Ldvis formation be 
 really Lower Silurian in age when it underlies, unconformably, 
 the lowest of Lower Silurian rocks, namely, the typical Potsdam 
 sandstone of the St. Lawrence valley ? Mr. Selwyn says, that 
 the L6vis formation is Lower Silurian, and the horizontal Pots- 
 dam sandstone is Lower Silurian too, and thinks that he has 
 effectually disposed of the question " without invoking any of 
 " the numerous almost impossibilities in physical and dynamical 
 
'' (^colof^y whioli uro n^rjuinid to oxpluiii tho prcvinm tlioory of 
 " tlio Htructuro." Mill, wo must not iina^'iiio thnt hiicIi i\ Mimplo 
 <'xplatiati(»ii could not poMhihly liavo oo«!urrtnl to Hir W. K. liO^^an, 
 iind thai Iijh in<roilu<'ti<in of tlioNo " aInioHt inipoMNihiliticH" was 
 unn('(;i>Hf<ttry. I am inulintMl to tliink that iho phttnouMtna whi<!h 
 Kir Wilhain worktMl ho indftati^'ahly utid ho loyally to explain, 
 riimain to thin day aH taii^ihlo an t^vttr, and that Mr. Kt'lwyii'H nuw 
 tlu!ori(!H afford no hojution of the pmhlom. 
 
 12. Mr. tSiilwyn maintains iIm; i^MiitouH origin of many of tho 
 cryHtallino rocks of his m'cond diviHioti, and cHpcoially of tho 
 "diorilcH, dolirilcH and iimy;_'daloidH " wliich occur in connection 
 with certain coppt-r oh-h. This Ih another view I have oft«!ii 
 liuiiiitaiiicd, and I nii;^hl nadily (piotc pusHa^;eH from my papurN 
 ^ivin^ lilt! authority of Naumann and others in support of it. 
 
 .'J. Mr. Selwyn particularly iiisist-^ upon this point, "that tho 
 •' fact of cryHtallin<^ rocrks (^r«!<'nhtoiies, dioritcH, dolerit<!s, fclsitcH, 
 " noritcH, <Vc.) iippearinj^ tin Htnitiijed masHCH and puf-Hin^ into 
 *' HchiHt<»h<! rociks, is no pnxtf of their not lieinii' of ttruptive or 
 •' volcanic ori;_'in." This is a principle of very wide application, 
 und cannot in my opinion he controverted. In my paptir on 
 the Acton mine, dated liHlh Octoher, 1H(!2, I descrilx'd a Htrikin^ 
 itiHtarMH) in support of thih very point. I said, " Mtrtweou tho 
 •' cupriferous limestone a'.d the underlying shale, thcro is often 
 " in'rudcd u fm*; graintMJ ^^reenstone, which HomelinM^s formn 
 " very considerable and irregular masses; Hometim<!s interscctH 
 " the limehtone strata, an<i often presenlH a peculiar banditd 
 " Htru(!tur(!, r«'send)lin)4 mor<! that produced by ij;;neous flow than 
 " that due to deposition imm wal<!r." l*'urtlicr, when discussiritj; 
 the orifi;in of eruptive und p.imary rocks in January, IHtM, I 
 itisihted upon the view now brought forward by Mr. St-lwyn, and 
 gave an explanation of it in tho followinj/ words : " The iuHtancoH 
 " of u Himihir moditi(;ation of slru(;ture amon;^ thogre<>nNtonosnro 
 " very numerous, and thtty are oven more important an shewing 
 " more cKiarly th<! cause of this Htru(!ture nmon^ ij^neouH rooks. 
 " The diorites usually occur in the form of vitinH, irr<!f^ular massea 
 '• and layt-rs. The veins Hoiij(!linu!s exhibit the followinj^ ro- 
 " markable phtmoniena : Iii the middle they oonsist of Kranular 
 " diorite, und at the sides of slaty diorite or hornblende seliist, u 
 '*graduul transition bein)< generally observable from tho granular 
 " to tho Hchistose rock. Tho oauso of thoHO phonoiuonu may 
 " inuHt roaHonably be Hou^ht for in tho cirouiuHtunooM uttcnding 
 
 ^ 
 
 
 
 
 
 
 
 
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 Ol 
 
 a 
 
 w; 
 
 n, 
 
 I 
 
 h(!ll 
 
 lin 
 
thoory f»f 
 a Hitiiplu 
 
 LIoh" was 
 I'lia wliioli 
 I) uxpliiin, 
 Yyii'H now 
 
 ,ny of Uio 
 lly of Iho 
 ::()tiii(!Ctioii 
 IIIVO ol'UiU 
 my piipDrN 
 ■t of it. 
 " tliut tlio 
 ,(;H, fclHiliiH, 
 if-Hin^ into 
 iruptivt! or 
 ipplic.'ition, 
 r papor on 
 1 a Hlrikit)j{ 
 I'lwiusn tlio 
 sro IH oJ'U'H 
 iiut!H \\>ru\A 
 s iiitorrtootH 
 iar baii<l<)(l 
 m ilow tiian 
 » (liHCUHsinj^ 
 ry, 18()4, I 
 Stilwyii, and 
 
 lilt illHtaiKM!H 
 
 i'uhUhids nri) 
 nH Hhcwiti^ 
 iii'oiiH roukH. 
 ^ular niaKHiifl 
 idlowitij^ r«- 
 oi* (j;ratiular 
 lido Hohist, a 
 tlio granular 
 iioinuiia may 
 !UH attending 
 
 
 " the oonjirif? of tlio rook, and tlioy aro most llkoly tho namn an 
 '• tliowi wliioli oooaHJoiicMl a Miiiiijtir Htriioturo iimoii^^ tho porpliy- 
 '• rioH. Tlio fluid rook of the diorito voiri wiih pndiahly in motion 
 "in tho ocritro, whilo tho paitM a<ljoiniiij; tho nido wallH vvro 
 " Hoiidilictl. 'J'lio oiirroiit in thoociitro would liavo a diHt(>iidiii^ 
 "tind nrraii;:itiv: action at iIk; junotion of tho fluid with tho noli- 
 " diflt'd partH, iiikI an olnii^atioii and parallid frroupin^ of tho 
 " miriofiilH tin r(! hcin;^ form<'d would bo Iho c<tiiM(!(jut*n«!o. Not 
 " only has thiH uliity toxtiiro l»r«Mi ohsorvod in ooniKfctioii with 
 " vttiiiH, hut it has aim* hcon remark*"! that tho mriro irregular 
 " iiMiHWH of diorito aHMiimo a nhUy Htnu'turo towards their juiic- 
 " lion with tho older roekN, the Hlr!iti(i(!.'it!.iii heiii^ aH in tlio oiho 
 " of tho veitiH parallel with tho liuo of huoIi junction." 
 
 1 havo thuH hrouf^ht into proiiiitionco thnui of Mr. Selwyn'H 
 condu^ioiiH with whi(di I feel hound to a;;ri!o, hut [ havo yot to 
 iiolic<; tho^o («f whoHo cornuttintMM I Imvo very jrravo douhls, 
 
 1. In dlM'UHMiiijj; the di.strihuiion of eop|M!r oiom in the Qm'lx^o 
 ^roiip, Mr, Si'lwyii hhhitIs tli;il the copper oreH of his thiril divi- 
 r«ion occur I'olh in liedH and lenticular layeiH parallel with tho 
 Htratiflcutioii, " hut in no caw; accompanied hy inlruHivc! crys- 
 " lallino roi'ks." ThiH poHilion cannot ho mainluineil with ri';:;ai'd 
 to tho miticrt of (lapelton. In tlntCJapel initio intruHiv(! dykes aro 
 nuft with, and in the Hartford thent is ono about twenty feet 
 thick, aliiiiist vertical, with scpiralimi joints exactly reHeinblin^, 
 on ils sides, titc inortir seims in a stoint wall. 'IMiis dyku 
 appeared to inllueiicc the copper deposit <|uiti* favorably. It 
 was <d' a basallio nature, but inlrusidiis of diabase are also to bo 
 found at this mitn; both under;j;i'ound and on the surface. Mr, 
 Selwyn's reference to the Acton mine in eijually unfurtunato. 
 TIh' " diiiriie " lli(!re occurriiijj; is not itself (!uprilerous, and an 
 for the limestone which carrien the (U"e, althou;^!! I had oppiU'tu- 
 nilies for observin;: it daily, it never o(M:urred to me (m regard 
 ;lie whole mass as " vein lik<*," iwir did it seem to behave other- 
 wise than as a beti " beloii;ji;in;;; to the stratillealion." 
 
 2. .Mr. Selwyn is unwillin;,^ to asMi;j;u "either an a;;o or an 
 " ori;^in to the oupriferous dioriles, doleriles and amy;j;diloiils of 
 " tho Maslern townships dill'erent from that of the almost ideiw 
 " tie.'il rooks of Like Superior." Leaving; a^e and orif.;iri asid'% 
 I sliall mention a few partiiodai-s in which the two groups aro 
 Njarcely " idiiilical." In Quebec the eruptive rocks are mostly 
 fin'! j^r liuttd, frecjui-ntly scliist<)se, never sufUoieutly cupriferous to 
 
10 
 
 I i 
 
 
 furnish a paying mine ; their small percentage of copper is com- 
 bined with sulphur ; amygdaloids are comparatively rare, and 
 seldom contain anything else than calcspar; these bt^ds are in- 
 truded amongst or interstratified with slates, shales and limestones; 
 contorted strata are often observable, and a belt of tbssiliferous 
 rocks adjoins them to the north west. On Lake Superior the 
 supposed identical rocks are distinctly granular, seldom schistose, 
 frequently support remunerative mines on their native copper; 
 amygdaloids are abundant, and filled with native copper, calcspar, 
 quartz, zeolitic and other minerals in profusion ; they have the 
 form mostly of overflows, not intrusions, and they are associated 
 with sandstones and the coarsest of conglomerates, shewing por- 
 phyritic, Laurentian and Huronian boulders ; the strata are not 
 contorted, have a regular dip in one direction, are innocent of 
 fossils themselves, and are far distant from any formatious con- 
 taining them. 
 
 3. Mr. Selwyn disputes Dr. Hunt's contention that the Kewee- 
 nian series overlies the Huronian unconformably, and cites U. S. 
 authorities against this view. Preferable to these would have 
 have been Mr. Selwyn's own testimony as regards this question, 
 and it is to be regretted that he has not yet devoted much time 
 to the Lake Superior region. When any one wanders along a sea- 
 beach, with overhanging clifl's on one hand, and observes on the 
 other thj water-worn boulders, pebbles and sand derived from it, 
 be feels pretty certain that the shingle is unconformable to the 
 cliffs. So, on Lake Superior, along its eastern shore, between 
 Sault Ste. Marie and Michipicoten, there are frequently found, 
 betwixt the water and the Huronian or Laurentian hills, narrow 
 strips or patches of the rocks of the Upper group, which often jut 
 out as small islands into the lake, and doubtless extend out great 
 distances beneath its waters. Such limited strips of these rocks 
 are found, for instance, skirting the base of Gros Cap, along the 
 south shore of Bachewahnung Bay and at Cape Gargantua. 
 Among these rocks the conglomerates are full of Huronian debris, 
 and in those of Bachewahnung Bay boulders may be observed 
 of red jasper conglomerate, the characteristic rock of the typical 
 Huronian. If this, and the position of the Maimansc series, uncon- 
 nected with any Huronian background, be not sufficient, I would 
 mention the attitude of the rocks of Michipicoten Island. Here 
 the strata, igneous as well as sedimentary, have an average strike 
 of N. 68° E. and a dip of 25'' southeastward. The nearest Huro 
 
 
 
r is corn- 
 rare, and 
 Is are in. 
 mestones; 
 issiliferous 
 perior the 
 schistose, 
 e copper ; 
 ', calcspar, 
 y have the 
 associated 
 ewing por- 
 ita are not 
 [inocent of 
 atioas con- 
 
 the Kewee- 
 cites U. S. 
 rould have 
 s question, 
 much time 
 along a sea- 
 rves on the 
 ed from it, 
 I able to the 
 re, between 
 ntly found, 
 ills, narrow 
 h often jut 
 id out great 
 these rocks 
 p, along the 
 Gargantua. 
 aian debris, 
 )e observed 
 the typical 
 ries, uncon- 
 3nt, I would 
 and. Here 
 erage strike 
 rarest Huro 
 
 11 
 
 nian rocks on the north shore run nearly cast and west, dipping 
 34° to 55° northward. To these, the island rocks are conse- 
 quently as unconformable as are the walls of a house to its roof. 
 
 It is further to be remembered that the discordant relation of 
 the Nipigon group to the Huronian system is admitted by Mr. 
 Selwyn to be an " apparent great unconformity," and as the Ni- 
 pigon group is held by Mr. Selwyn to be part of the " Upper 
 Copper bearing rocks," this is almost conceding Dr. Hunt's posi- 
 tion. This Amission is not at all weakened by Mr. Selwyn's 
 supposition that they are the products of an ancient volcanic cra- 
 teriforra vent, and that Lake Nipigon is an extinct volcano, a 
 gigantic Maare, or water-filled ancient crater, like the Lake of 
 Laach. This invention almost justifies the opinion that Mr. 
 Selwyn is himself sometimes ready to invoke " almost impossi- 
 bilities in physical and dynamical geology " when any of his own 
 ^'^H theories require support. 
 
 4. Writing of Dr. Hunt's Norian system, Mr. Selwyn pens 
 the following remarkable passage : '* If it is admitted — which, 
 " in view of the usual associations of Labrador feldspar, is the 
 " most probable supposition — that these anorthosite rocks repre- 
 " sent the volcanic and intrusive rocks of the Laurentian period, 
 " then also their often massive and irregular and sometimes 
 " bedded character and their occasionally interrupting and cut- 
 " ting oiF some of the limestone bands, as described by Sir W. E. 
 " Logan, is readily understood by any one who has studied the 
 " stratigraphical relations of contemporaneous and sedimentary 
 •* strata, of volcanic, palaeozoic, mesozoic, tertiary and recent 
 *' periods. Chemical and microscopical investigation both seem 
 " to point very closely to this as the true explanation of their 
 " origin. That they are eruptive rocks is held by nearly all geo- 
 " legists who have carefully examined their stratigraphical relu- 
 " tions. But I am not aware of any one having suggested that 
 " they are the products of volcanic action in the Laurentian or 
 *' perhaps lower Huronian epoch." It is unnecessary here to 
 combat the doctrine that norites are not merely eruptive, but 
 volcanic rocks. I must content myself with remarking that on 
 Mr. Selwyn rests the burden of proving any new theories he may 
 choose to bring forward, and consequently of shewing that vol- 
 canoes were active in the Azoic age. 
 
 5. Mr. Selwyn underrates the very praiseworthy eflForts which 
 Dr. Hunt has made towards bringing order out of the chaos of 
 
12 
 
 I •■ 
 
 our primary geology, and can see no utility in the names he 
 employs for distinguishing certain non-fossiliferous formations. 
 He not only condemns such " mineralogical stratigraphy," but 
 adverts, in a manner which must grate very harshly on the feel- 
 ings of many, to the " palaeontological stratigraphy" of his 
 revered predecessor. Yet on the next page Mr. Selwyn proceeds 
 to class together groups of rocks of almost every conceivable 
 origin, and very questionable age, as belonging to the Huronian 
 system. I need not detail the extraordinary diflPerences which 
 distinguish the various members of this heterogeneous com- 
 bination, both in mineralogical, lithological and stratigraphical 
 respects. Mr. Selwyn himself points out one of these diflFerences 
 when he maintains that the copper ores of the Huronian and 
 " Upper Copper bearing " rocks occur under conditions quite as 
 distinct as those of his first and second divisions in the Quebec 
 group. Mr. Selwyn's own recapitulation of what is to be classed 
 as Huronian is a proof that his plan of applying stratigraphy 
 pure and simple is not likely to be a great improvement on the 
 methods of those who have preceded him. It may, like his 
 views on the Quebec group, have the merit of simplicity, but we 
 must not allow ourselves to be influenced overmuch by the ad- 
 vantages of this peculiarity. Instead of disparagement, such 
 efforts as those of Dr. Hunt merit our warmest thanks, and we 
 must wish him every success in his efforts to determine the value 
 of mineral fossils in crystalline rocks. As he himself very fitly 
 remarks, " In no other way did William Smith prove, in Great 
 " Britain, the value of organic fossils, and thus lay the foundations 
 " of palaeontological geology." 
 
 (Read before the Natural History Society of Montreal, 28th April, 1879.) 
 
aes he 
 ations. 
 ," but 
 le feel- 
 of his 
 roceeds 
 seivable 
 jroniao 
 3 which 
 IS com- 
 *aphical 
 Ferences 
 ian and 
 quite as 
 Quebec 
 i classed 
 tigraphy 
 it on the 
 like his 
 , but we 
 f the ad- 
 jnt, such 
 I, and we 
 the value 
 very fitly 
 in Great 
 iindations 
 
 1, 1879.)