and a new cycle of erosion was begun. Where the upland 

 possessed weak rock structures, as in the Carboniferous 

 areas of eastern New Brunswick and the Triassic areas 

 of Nova Scotia and southern New England, the new 

 denudation progressed rapidly, and by mid-Tertiary time 

 broad lowlands had been developed. Meanwhile, wherever 

 weather-resisting rocks predominated, gorges and narrow 

 valleys were cut, dissecting the upland into a rolling hilly 

 country. By the time this second cycle of denudation 

 had been nearly completed in the lowlands, another 

 elevation of the region occurred, attended like the first, 

 by local warping. The lowlands were again carved by 

 streams until a fairly mature topography had been evolved 

 beneath the Tertiary surface. 



All this occurred before the Glacial period. With the 

 development of an ice sheet over all northern North 

 America, at the beginning of the Pleistocene, a series 

 of events took place, whose exact nature and sequence, 

 so far as the Maritime Provinces are concerned, are still 

 largely problematical. Most of the region in question 

 was sooner or later covered by the continental ice, and 

 given a new coat of mantle rock or "drift." Portions 

 of the Gaspe peninsula and Nova Scotia may have remained 

 outside the limits of glaciation. No one can say positively, 

 as yet, whether the ice which spread over this region 

 came from the centre east of Hudson bay, or whether 

 there were two or more separate centres of dispersal of 

 the continental glacier within the limits of the Maritime 

 Provinces. From evidence gathered during twenty years 

 of field work, the late Dr. Robert Chalmers came to 

 believe that the more easterly portions of the region, at 

 least, were glaciated solely by ice from the interior of 

 New Brunswick and the Gaspe peninsula, while southern 

 Quebec, only, was reached by ice from the Hudson bay 

 region. 



There is much uncertainty, also, about changes of level 

 in land and sea during the Pleistocene. Whatever eleva- 

 tions or subsidences may have gone on in the earlier 

 epochs, it is plain that when the ice sheet finally withdrew 

 from the south coast of the lower St. Lawrence and the 

 Champlain valley, the land stood several hundred feet 

 lower than now. The coast of New England and New 

 Brunswick, likewise, was deeply submerged. The elevation 

 of these coasts to their present position appears to have 

 35063—2 



