G36 . REPORT— 1897. 



To what extent the above subdivisions of the Archaean may be legitimately 

 employed in other parts of the continent, more or less remote from the Protaxis, 

 remains largely a question for future investigation. In the southern part of New 

 lirunswick, however, the resemblance of the Archsean to that of the typical region 

 is so close that there can be little risk of error in applying the same classificatory 

 li-ames to it. The Fundamental Gneiss is there in contact with a series comprising 

 crystalline limestones, quartzites, and gneissic rocks, precisely resembling those of 

 the Grenville Series. Later than this is a great mass of more or less highly altered 

 locks, chiefly of volcanic origin, comprising felsites, diorites, agglomerates, and 

 schists of various kinds, like those of the typical Huronian. The e.xistence of this 

 iipper group correlatively with that representing the Grenville Series, constitutes 

 au argument, so far as it goes, for the separateness of these two formations in the 

 general time-scale. All these Archaean rocks of New Brunswick are distinctly 

 unconformable beneath fossiliferous beds regarded by Matthew as older than 

 <'ambrian. 



In the Cordilleran region of Canada, again, a terrane is found lying uncon- 

 formably beneath the lowest rocks possibly referable to the Cambrian, evidently 

 Archfean, and with a very close general resemblance to the Grenville Series. To 

 this the local name Shuswap Series has been applied, and a thickness of at least 

 .'ijOOO feet has been determined for it in one locality. It consists of coarsely 

 crystalline marbles, sometimes spangled with graphite and mica, quartzites, 

 gneisses, often highlv calcareous or quartzose, mica schists, and hornblendic 

 j^neisses. With these is a much greater mass of gneissic and granitoid rocks, like 

 those of the Fundamental Gneiss of the Protaxis, and the resemblance extends to 

 the manner of association of the two . terranes, of which, however, the petro- 

 graphical details remain to be worked out.' 



While it is true that a resemblance in lithological character, like that existing 

 between the Grenville and Shuswap Series, far remote from each other geographi- 

 cally, may mean only that rocks of like composition have been subjected to a 

 similar metamorphism, both the series referred to are separated above by an un- 

 conformity from the lowest beds of the Palaeozoic, and there is thus sufficient 

 ■evidence to indicate at lea.st a probability of their proximate identity in the time- 

 «cale. In Scotland, an analogous series, and one apparently similarly circumstanced, 

 seems to occur in the rocks of Gairloch and Loch Carron.^ 



Particular attention has been directed throughout to the southern part of the 

 continental Protaxis in Canada. In this region it happened that the Archrean 

 rocks and those resting upon them were originally studied under exceptionally 

 favourable conditions, for ever since the great revolution which succeeded 

 Huronian time, the region is one which has remained almost stable. Selwyn and 

 N. II. Winchell Lave particularly insisted on the importance of the stratigraphical 

 break which here defines the Archa?an above. It is not everywhere so well marked, 

 Cor in the Appalachian province and in the country to the south of the great lakes, 

 in Wisconsin and Michigan, repeated subsequent earth-movements have flexed and 

 ^jroken the older strata against the base of the table-land of the Protaxis. It is not 

 from these districts, subjected to more recent and frequent disturbance, that the 

 ruling facts of an earlier time may be most easily ascertained. Much careful and 

 conscientious work has been devoted to them, but it is largely, I believe, because 

 of the attempt to apply, for purposes of general classification, the still unsettled 

 and ever-changing hypotheses derived from such more complicated tracts that so 

 much confusion has been introduced in regard to the Archaean and early Palaeozoic 

 rocks. 



If the unconformity closing Archaean time in the vicinity of the Great Lakes 

 bad been observed only in that region, it might be regarded as a relatively local 

 phenomenon ; but subsequent observations, and more particularly those of the last 

 few years, due to Bell, McConnell, Tyrrell, and Low, show that rocks evidently 

 representing the Animikie and Keweenawan, and practically identical with those 



' Cf. Annval Report Geol. Sur. Can., 1888-89, p. 29 B. 



^ Cf. Geikie, Ancient Volcanoes of Great Britain., vol. i. p. 115. 



