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University of California. 



[Vol 3. 



and various greenstone phases. The fresh bank shows frag- 

 ments of wood at various levels down nearly to the base. The 

 end of one log was worn round by glacial abrasion. I sawed 

 off a twenty-inch and a ten-inch log and forwarded fragments 

 to Professor Knowlton, who has not yet reported on them. 

 There is not a trace of stratification visible in the mass, and 

 this wood occurs without orientation, as do the boulders. The 

 deposit rests on a bed of coarse, angular rocks, which resists 

 removal, and the creek in consequence is here very high grade. 

 It seems to have eroded about as much of the glacial deposit as 

 it has left. The till is partly covered by an extensive landslide 

 from the steep mountain on the south, and has by it been pre- 

 served from entire removal. 



Although this deposit is as typical of glacial action as any 

 in America, from its low altitude, and the absence from the 

 valley above of common glacial characteristics, I was at first 

 seriously inclined to consider the possibility of its being a land- 

 slide. When I first came into this region I discovered that I 

 was not always able to discriminate readily between a landslide 

 and a glacial deposit. Many of the larger landslides have a 

 topography similar to that of the great Kettle Moraine in Wis- 

 consin, even to the presence of small enclosed basins containing 

 lakelets. Curiously, the moraines of these mountains are 

 smoother in outline, and the landslides have nearly a monopoly 

 of the exceedingly undulating topography. Where a landslide 

 is several hundred feet in thickness the lower side of it is com- 

 monly lined by a sheet of stony clay, from one to twenty feet 

 thick. This is the result of the great weight and the kneading 

 of the mass where it slides over the solid rock. The softer 

 particles of the rock are crushed into stiff clay, while the harder 

 particles are rounded, smoothed, and in not a few instances 

 distinctly scratched. The process is very similar to that by 

 which a glacier forms its ground moraine, and in consequence 

 the product often bears a strong resemblance to a glacial deposit. 

 In the Pioneer Mine, with which I am connected, we have tun- 

 neled through several extensive landslides, and after passing a 

 loose mass of angular fragments we invariably find a sheet 

 of stiff clay containing round rocks. Streaks of clay containing 



