6o /. B. TYRRELL 



and to the west, toward the middle Hne of the intermediate plateau 

 or valley. For the most part they ended before they reached the 

 present river channel, but in other cases they discharged into great 

 lakes, in which the white silts which form such conspicuous cliffs 

 near Prince George were deposited. 



The glaciers always moved inward from the mountains which 

 form the sides of the valley toward its median line, and the ice 

 was thicker on the mountains than in the valley. At no time was 

 this portion of the interior plateau covered by a glacier of the 

 extent and thickness indicated by Dr. Dawson, namely 6,000 feet 

 deep over the lower land, from which the ice moved outward in 

 all directions. 



This conclusion is in accord with the observations of the late 

 G. S. Malloch, of the Geological Survey of Canada, who, in 1909, 

 made a geological examination of the upper part of the Fraser River 

 from Tete Jaune Cache down to Prince George. He states that 



bowlder clay occurs at different points along the river. These deposits 

 were formed by two sets of glaciers, the first of which descended into the 

 Interior Plateau from the mountains to the east, and the second from those 

 to the west. The drift of the latter is characterized by the presence of granite 

 fragments from the Coast Range, and volcanic rocks from the western part 

 of the plateau. On the other hand, that from the east contains fragments 

 of older rocks, and it alone is seen on the river from Tete Jaune Cache 

 to Giscome Rapids, where it is overcapped by the drift from the west.' 



These observations therefore exclude the possibility of the exist- 

 ence of a great longitudinally moving Cordilleran Glacier on this 

 portion of the interior plateau in latitude 54°, and my own observa- 

 tions show that it was absent as far south as Quesnel in latitude 53°. 

 From there to the southern end of the glacier as defined by Dr. 

 Dawson is only a little more than 300 miles, and even if the whole 

 of the country throughout this distance were covered by ice it would 

 not fulfil the idea of a great continental glacier. As to what were 

 the ice conditions north of Prince George, between latitude 54° 

 and 63°, we have not yet sufficient information available to enable 



us to decide. 



/ 



^Geol. Surv. Can. Sum. Rep. for igog, Ottawa Govt,, 1910, p. 128. 



