RIVER TERRACES AND GLACIAL SERIES 441 



walls of the old canyon, so that the steep rocky walls of a modern 

 appearance rise to 200 and 300 feet above the river. This canyon 

 is so narrow, crooked, and rough-walled, and there are so many 

 projecting narrow rock points, that it is unreasonable to suppose 

 that it has ever been glaciated. If the serpentine-bearing horizon 

 which occurs above this canyon is truly referable to glacial action, 

 the valley has been cut down into very resistant hornblende schist 

 to a depth of at least 200 feet and probably nearly 300 feet 

 since the glaciation. Channel C is far below and very much 

 newer than these supposed old glacial deposits. 



The School-house Flat, opposite the mouth of the Little 

 South Fork Creek, probably 500 or 600 feet above the river, has 

 dimensions about 40OX 500 feet, seems to be composed of broken 

 hornblende schist, shows slight landslide topography, no gravel 

 and is very steep on the side toward the river, so that it resem- 

 bles an old river terrace remnant. A considerable area for some 

 distance west of this flat shows typical landslide topography. 

 Farther up the valley there is another terrace-like landslide 

 deposit, occurring probably 600 feet above the river and occupied 

 by Lakeview, a small ranch. 



At the lower end of the Deep Bank deposit the bottom of 

 Channel C is 45 feet above the river. Just across the river on a 

 small point there is a fragment of the same channel and below 

 it a newer channel (Channel D) with its rock floor 15 feet above 

 the river. The outer edge of the Deep Bank is about 200 feet 

 above the river and the inner edge about 250 feet. Just west of the 

 Deep Bank, resting on a steep slope at about the level of the inner 

 edge of the Deep Bank, there is a large granite bowlder (Channel 

 A). The face of the Deep Bank displays stratified, coarse, sub- 

 angular dark brown (reddish in layers) Crosby Creek alluvium 

 about 100 feet thick. In the channel deposit there are many 

 granite bowlders, rotten but with a hard core. The rock cutting 

 of the new canyon is from lOO to i 50 feet in depth, the latter on 

 the south side. 



The first south point above the Deep Bank has a marked rock 

 bench at 15 feet above the river (Channel D, occurring in the 

 new canyon) and back of it a remnant of Channel C. Immediately 



