246 W. N. THAYER 
mountainous character of the initial (or at least an early) uplift, but 
the southern parts were eroded to the condition of a peneplain, then 
elevated again and dissected.t Standing above the general surface 
of the uplifted peneplain are numerous residual mountain masses 
or peaks, typical of which are Monadnock and Katahdin.? 
The Connecticut Valley, though a structural as well as a topo- 
graphic depression throughout its entire length, also has northern 
and southern divisions of unlike characteristics. In this case, 
however, the contrast is not due so much to differential uplift 
or depression as to inequalities of hardness and resistance to 
erosion. 
The general conditions just cited for New England are con- 
tinued across the International Boundary into Canada. The Green 
Mountains of Vermont, the northern expression of the western 
axis, extend into Quebec under the name of the Notre Dame | 
Mountains. They border the estuary of the St. Lawrence and 
continue into and through the Gaspé Peninsula, where they are 
known as the Shickshocks. ‘The White Mountains of New Hamp- 
shire, the northern expression of the eastern axis, extend northeast- 
wardly through Maine, close to the border of Quebec, and gradually 
blend with the elevated tracts of New Brunswick and the Maritime 
Provinces. ‘‘ Though the general course of the hills of the Maritime 
Provinces parallels that of the Appalachians, the propriety of 
including the territory in the Appalachian region is better shown 
by the geologic features, such as the Appalachian folding, and by the 
pronounced northeastwardly trend of the whole Province of Nova 
Scotia, the parallel long indentation of the Bay of Fundy in the 
southeast and that of Chaleur Bay with the valley at its head in 
the northwest.’ 
The Appalachian part of Canada is generally regarded as having 
participated in the Jurassic-Cretaceous base-leveling, and locally 
at least in the Tertiary base-leveling. The accordance of summit 
elevations, particularly in the eastern portion, and the presence of 
isolated residuals rising here and there above the upland level. 
indicate a former peneplain which probably correlates with the 
1W.M. Davis, Bull. Geol., Soc. Am., Il, 557. 
A alek leona Mois (Gaal 2 UL state 3C. A. Young, op. cit., pp. 30-32. 
