374 



STEPHEN R. CAPPS, JR. 



7, In the fine example on the west side of McCarthy Creek (Fig. i, 

 No. i), the creek, a swift stream of large volume, is now actively 

 cutting into the lower end of the rock glacier, which has been in exist- 

 ence long enough for large spruce trees to grow upon its surface. 

 Nevertheless, the creek has so far been unable to do more than keep 

 a narrow channel open along the foot of the rock glacier (Fig. 6). 



Fig. 10. — Rock glacier at head of White Creek. The detritus from the two sides 

 of the rocky island flows together to form a single stream below it. 



Yet there is no evidence that the rock glacier ever extended the 75 

 feet farther east which would have carried it to the rock bluff on the 

 east side of the valley. It seems unusual that this mass of material, 

 if it came down with a rush, should have failed by just the width of 

 the creek to cross the valley, and also that the stream, which is now 

 actively cutting into the face of this rock glacier, has been unable to 

 do more than keep its channel open. It appears as much more prob- 

 able that the slowly advancing edge of the rock glacier has been 

 removed by the stream as rapidly as it has moved forward. 



8. There is no evidence that important landslides have taken place 



