No. 2.] DAWSON — POST-PLIOCENE. 169 



between the deposit of the Leda clay and the close of the Post- 

 pliocene. This question we shall have occasion to consider in the 

 sequel, in connection with the second depression of the European 

 land above referred to. 



Since the publication of the first of these papers, Dr. Newberry 

 has kindly sent me a paper of his published as early as 1862, in 

 which he states the remarkable fact, quoted above from his more 

 recent Report on Ohio, that the drainage of the great lake basins, 

 open in the early Post-pliocene period, was obstructed by the gla- 

 cial deposits, and has been only partially restored. He also 

 desires me to state that he refers the old drainage not exclusively 

 to the action of glaciers, but to the " ice period, or an earlier 

 epoch." I am happy to make .these corrections; the latter more 

 especially, as it brings our theoretical views more into harmony. 

 Dr. Newberry, however, for whose conclusions on such subjects 

 I have the highest respect, still, in his latest expressions of opinion, 

 adheres to the action of land ice in producing the glacial striation, 

 which from his descriptions is, I should suppose, quite as definite 

 and strongly marked as that in the St. Lawrence valley. 



The grand series of Post-pliocene changes was thus uniform in 

 Europe and America, pointing to great general causes of subsi- 

 dence and re-elevation ; but locally there is the most extreme 

 irregularity in these deposits, giving great uncertainty to their 

 arrangement. Some of these difi'erences we shall have occasion 

 to notice under the following geographical subdivisions. 



1. Newfoundland and Labrador. 



In the Journal of the Geological Society of London, for Feb- 

 ruary, 1871, is a communication from Staff-commander Kerr, R. 

 N., of the Coast Survey, in which he gives the directions of twenty- 

 eight examples of grooved and scratched surfaces observed in the 

 southern part of Newfoundland. The course of the majority of 

 these is N.E. and S.W., ranging from N.8" E. to N. 64° E. 

 The remainder are N.W. and S.E.,most of them with a predomi- 

 nating Easterly direction. Boulders are mentioned, but no marine 

 beds. The author refers the glaciation to land ice, supposing 

 certain submerged banks across the mouths of the bays to be 

 terminal moraines. 



The latest information on the Post-pliocene of Labrador is that 

 given in a paper by Dr. Packard in the memoirs of the Boston Society 



