342 



J. D. IVtS 



Demarest and Washburn (1942) in the Shickshock Mountains is faced with 

 the same problem of relative age of the erratics and Flint has commented 

 that such fresh-looking erratics are no proof that the glacial inundation did 

 not pre-date the Wisconsin stage (Flint, pers. comm. 1958). Similarly, it is not 

 implied that all summits were necessarily inundated at the same time, so that 



Fig. 3. A large block of granite gneiss resting upon Mugford Volcanics. The figure 



gives an indication of the scale. Altitude 650 m. {Photo by R. F. Toiiilinsoiu July 



1958, Kaiimajet Mountains.) 



the possibility of plant refugia remains. Furthermore, from the evidence 

 presented below, it is argued, for northern Labrador at least, that the glacia- 

 tion responsible for emplacement of the high-level erratics was certainly 

 earlier than the Classical V\ isconsin equivalent, and possibly much earher. 



Next it will be profitable to examine the evidence supporting the existence 

 of ice-free areas during the Pleistocene; in particular the importance of the 

 mountain-top detritus must be evaluated in the light of the available data. 

 Both the author and Loken conclude that a distinctive lower limit to the 

 mountain-top detritus can be recognized in the Torngat Mountains. This is 

 described as a glacial trim line and can be seen to slope from west to east, and 

 from south to north from a high point west of the head of Saglek Fjord. The 

 slope is equated with that of the upper surface of the inland-ice and outlet 

 glaciers during a recent glaciation, termed the Koroksoak Glaciation (Ives, 

 1958a). The northerly slope of the trim line traced roughly along the axis of 

 the Torngat peninsula is from 830 m in the Saglek Fjord vicinity to 430 m 

 south of Telliaosilk Fjord, 160 km farther north (roughly 2,5 m/km). Leken 

 has calculated a minimum isostatic tilt of 1:1000 up towards the south- 

 southwest (Token, 1962b) so that the slope of the trim line should be reduced 



