Science, Geology and Physics 



the St. Lawrence and Ottawa valleys, and in the basin of Lake 1903 

 Champlain, fossiliferous marine beds overlie the glacial drift, p am 

 whence the name Champlain epoch has been given to this final 

 part of the glacial period. Closely attending and following the 

 retreat of the melting ice border, a general re-elevation, varied in 

 some regions by oscillations of uplift, ensuing depression, and 

 renewed uplift, has brought the glaciated areas to their present 

 altitude, which is probably now nearly steady and permanent 

 for the greater portions of these areas. 



The basin of Hudson Bay, in the central part of the glaciated 

 area of North America, is ascertained by Dr. Robert Bell's 

 observations to be now slowly rising, mainly at the rate of a few 

 feet in a century ; but perhaps this uplift has ceased, as Mr. J. B. 

 Tyrrell thinks, in the vicinity of the mouths of the Nelson and 

 Hayes rivers, on the southwest coast of the bay. On our Atlantic 

 coast, from Boston to Cape Breton Island, where the re-eleva- 

 tion from the Champlain depression ranged upward to a maximum 

 of about 300 feet in Maine, an ensuing subsidence of the land, 

 that is, a movement of opposite direction, has lately taken place 

 and is probably still very slowly in progress, its maximum amount 

 near the head of the Bay of Fundy being apparently at least 

 80 feet. In Southern Sweden the Champlain depression was 

 succeeded during the retreat of the ice-sheet by re-elevation of 

 the land somewhat above its present height; next it was again 

 depressed, but less than before; and from this second depression 

 it is now slowly rising at a maximum of two or three feet in a 

 hundred years. 



These notes of the continuance of the great Quaternary move- 

 ments of the continental areas which suffered glaciation are pre- 

 sented for the purpose of directing attention to their inconstancy, 

 oscillations, and reversals. From the consideration of these well 

 ascertained continental changes, it seems to me that the evidence 

 of very slight tilting of the Laurentian lakes region now taking 

 place, as made known by surveys of precise leveling which give 

 comparisons between dates less than forty years apart, should 



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