DALY: PHYSIOGRAPHY OF ACADIA. 19 
from the Admiralty charts of the coast-line (republished by the 
Hydrographic Office at Washington), from the maps of the Canadian 
Geological Survey so far as published, from the wall-map of Mackinlay, 
and from the small-scale geological map accompanying the text of Daw- 
son’s “Acadian Geology.” The physiographic literature treating of 
Acadia is mainly concerned with glacial and post-glacial problems and 
with recent crustal movements. The following pages will be restricted 
almost entirely to the problems of bed-rock forms. The aim will be to 
express certain conclusions regarding the pre-glacial denudation of this 
region. Those conclusions do not demand an accurate knowledge of 
pre-glacial drainage ; it is certain that the body of fact already deter- 
mined will not permit of our constructing even a tolerable map of the 
pre-glacial river-systems. 
The Uplands, 
THe SouTHeRN PuiaTEau.— Rather more than three-fourths of the 
province of Nova Scotia (excluding Cape Breton Island) is occupied by 
the largest topographic unit of which I shall have to speak in detail. 
It may be called the “Southern Plateau.” It is sharply defined in its 
western half by the steep front overlooking the Cornwallis-Annapolis 
valley, and by the ragged Atlantic shore-line; in the eastern half, the 
Atlantic bounds it on the south, the Truro-Pictou lowland, Northum- 
berland Straits, and St. George’s Bay on the north and northeast. 
Structure. — The plateau is underlain by a complex of ancient rocks. 
Most of the area exhibits the outcropping edges of a very thick series 
of slates associated with a likewise extensive older group of quartzites ; 
both of these series are presumed by the officers (Bailey, ’98, p. 27 ff.) 
of the Canadian Geological Survey to be of Cambrian age. Van Hise 
('92, p. 247) regards them as possibly Algonkian. Much less important 
from the point of view of superticial extent but significant for the 
unravelling of the history of the plateau, are the isolated patches of 
fossiliferous Upper Silurian and Devonian sediments occurring in the 
northern half of the long upland belt. Each of these three ancient 
members has been involved in the late Devonian mountain-building, 
which, more than any other single event, has rendered the structures of 
the plateau rocks complicated and difficult of interpretation. During 
that revolution which must have erected over the region an alpine 
chain of high mountains, the base of the resulting range was punctured 
and displaced by enormous masses of exotic granites deeply buried at 
