628 REPORT— 1897. 



Section C— GEOLOGY. 

 Pkesideitt of the Section— Dk. G. M. Dawson, C.M.G., F.R.S. 



THURSDAY, AUGUST 19. 

 The President delivered the following Addi-ess : — 



The nature and relations of the more ancient rocks of North America are problems 

 particularly Canadian, for these rocks in their typical and most easily read develop- 

 ment either constitute or border upon the continental Protaxis of the North. The 

 questions involved are, however, at the same time, perhaps more intimately con- 

 nected with a certain class of world-wide geological phenomena than any of those 

 relating to later formations, in which a greater degree of differentiation occurrecJ 

 as time advanced. A reasonably satisfactory classification of the crystalline rocks 

 beneath those designated as Palaeozoic was first worked out in the Canadian region 

 by Logan and bis colleagues, a classification of which the validity was soon after 

 generally recognised. The greatest known connected area of such rocks is em- 

 braced within the borders of Canada, and, if I mistake not, the further understand- 

 ing of the origin and character of these rocks is likely to depend very largely upon 

 work now in progress, or remaining to be accomplished here. 



This being the case, it seems very appropriate to direct such remarks as I may 

 be privileged to make on the present occasion chiefly to these more ancient rocks, 

 and the subject is one which cannot fail to present itself in concrete form to the 

 visiting members of this Section. Personally I cannot claim to have engaged ia 

 extended or close investigations of these rocks, and there is little absolutely new 

 in what I can say in respect to them ; but work of the kind is still actively in 

 progress by members of the staff of the Geological Survey, and the classification 

 and discrimination of these older terranes present themselves to us daily as im- 

 portant subjects of consideration in connection with the mapping of vast areas ; 

 so that, if still admittedly imperfect in many respects, our knowledge of them 

 must be appraised, and, at least provisionally, employed in a practical way in order 

 to admit of the progress of the surveys in hand. 



Although it is intended to speak chiefly of the distinctively pre-Cambrian rocks 

 of Canada, and more particularly of the crystalline schists, it will be necessary 

 also to allude to others, in regard to the systematic position of which dift'erences 

 of opinion exist. Of the Cambrian itself, as distinguished by organic remains, 

 little need be said, but it is essential to keep in touch with the palaeontologically 

 established landmarks on this side, if for no other reason than to enable us to 

 realise in some measure the vast lapse of time, constituting probably one of the 

 most important breaks in geological history, by which the Cambrian and its allied 

 rocks are separated from those of the Huronian and Laurentian systems. 



In attempting to review so wide a subject and one upon which so much has already 

 been written, the chief difficulty is to determine how much may be legitimately 



