158 N. S. SHALER — EVIDENCES AS TO CHANGE OF SEALEVEL. 



island havesteep cliffs, with very little talus materials beneath their sub- 

 marine bases. Some of these cliffs, as, for instance, those on the northern 

 side of Anticosti, indicate a very great amount of shore erosion. Those 

 last named could not well have been brought into their present shape 

 without the wearing back of the shore for the distance of some miles. 

 Therefore, if we supposed that the formation of these steeps was due to 

 the work of the sea since it stood at its present level, we would have to 

 reckon on a great lapse of time since the last downgoing, and would be 

 unable to class the movement with those which have taken place in the 

 geologic yesterday along the more southern shore. Owing, however, to 

 the prevailing absence of talus material at the base of these cliffs, I am 

 disposed to regard them as due to erosion, accomplished during some 

 preglacial age. They may, indeed, be escarpments formed subaerially, 

 which have been but slightly modified in form by marine action. It is 

 manifestly difficult to explain the origin of these steep faced islands on 

 the supposition that they are due to marine work and at the same time 

 regard the basin of the Saint Lawrence gulf as a flooded valley; yet I do 

 not think that the reconciliation of the views is impossible. It does not 

 seem to me well, however, to discuss the matter further in this paper. 



Labrador. — The fiords of the Labrador coast, though they constitute 

 deep reentrants, so far as we yet know, may be due to glacial excavation. 

 As I have not seen the shores of the peninsula beyond the straits of Belle 

 Isle, and as the topographic evidence is not clear, I shall not undertake 

 to discuss the question of flooding along this part of the shore. 



Arctic Shores. — In what may be termed the Arctic section of the At- 

 lantic coastline of this continent the general topographic evidence is 

 clearly in favor of the hypothesis that the land has been subjected to a 

 great lowering, and that the land basin and valley topography is pro- 

 longed beneath the sea for a great distance beyond the present shoreline. 



Hudsons bay and the strait which connects it with the Atlantic has a 

 form winch is not readily to be explained by the hypothesis of local 

 downwarping, but is better accounted for on the supposition that it is a 

 flooded basin. The marine trough which separates Greenland from the 

 American continent appears rather as an invaded valley than an original 

 strait, and the divisions between the numerous islands lying between 

 Greenland and the mainland appear to be best explained on the suppo- 

 sition that they too, though perhaps somewhat affected by ice-action, owe 

 their existence to river-work. 



Although it would be perhaps reasonable to adduce the hypothesis of 

 differential warping to account for some part of the entanglement of sea 

 and land along this part of the coast, it seems to me unreasonable to 

 auppose that the assemblage of facts can fairly be thus exjDlained. Taken 



