366 G. F. Monckton — Human Skeleton, B. Columbia. 



less than 1,000 feet, but it is possible that some of the lower-level 

 deposits have been secondarily formed from the denudation of the 

 higher. 



" In the valley of the South Thompson the Silt formation is most 

 characteristically represented, forming, as before stated, broad terraces 

 or benches along the sides of the valley, with the surfaces gently 

 sloping towards its axis, where the river has formed for itself a deep 

 subsidiary channel. In some places, as above Kamloops on the south 

 side of the valley, the edge of the White Silt bench has been cut up 

 by little streams descending at times from its summit into complicated 

 and ragged ridges. The eroded faces are always very steep and 

 occasionally vertical, and in the sunlight have a peculiar glossy 

 shimmer due to the great abundance of particles of mica, which when 

 the bank is wet become arranged parallel to its surfaces, and on 

 drying adhere in that position. The bedding is generally almost 

 or quite horizontal, and layers of a few inches in thickness succeed 

 one another with great regularity. The deposit is remarkably fine 

 throughout, and no boulders or stones so large as to imply the action 

 of ice were seen. 



"These White Silts very often rest directly upon the boulder-clay. 

 They are generally fine and uniform in texture and are usually well 

 bedded in perfectly horizontal layers of 1 to 2 or 3 inches in tliick- 

 ness. Where occasional sandy or gravelly layers are intercalated 

 these are attributable to local causes, being most frequently found 

 opposite the mouths of valleys down which streams have flowed. 

 The silts have evidently been laid down as a rule in tranquil water 

 of considerable depth, and their material has as obviously been 

 supplied by streams or rivers discharging from glaciers not far 

 removed." 



From the general correspondence in elevation between this and 

 other deposits in the Cordilleran region and the Red River Valley he 

 draws the conclusion that the inland lake in which these silts were 

 formed was connected Avith the sea, and " governed in its level by 

 that which the sea held at the time ". It does not appear to me that 

 this was so. If it had been, one would expect to find beaches with 

 marine deposits on the coast at much higher levels than that at 

 which they have been found, which does not exceed 200 feet. 

 I think we may find sufficient reason for the formation of a large 

 inland lake which would include the valley of the North Thompson 

 for 100 miles north of Kamloops, and the South Thompson Valley 

 from a short distance below the Little Shuswap Lake to below 

 Spences Bridge, about 125 miles more, with some tributary valleys. 

 This reason is the narrowing of the outlets through high mountain 

 ranges which would result in the blocking of the channel by the 

 meeting of glaciers from the two sides. As to the outlet leading 

 to the Eraser, at Gladwin the 4,000 ft. contour-lines on opposite 

 sides of the Thompson are only 2^ miles apart, and at the 3,000 ft. 

 1-^ miles. Sixteen miles further up the river, near Spences Bridge, 

 the difierence is barely 2 miles at the 3,000 fc. level, and less than 

 3 miles at Pukaist, Avhich is 8 miles higher up. At the 2,500 ft. level 

 they are a mile and a half apart at the first two points and scarcely 



