Lawson.] 



The Upper Kern Basin . 



351 



Plate 32 b. The former of these had its source in the region 

 between Mt. LeConte and Mt. Whitney; the latter headed at the 

 western base of Mt. LeConte, but may also, perhaps, have been 

 fed in part by a neve lying upon the Siberian Outpost. Where 

 these two glaciers become confluent in the broader canon of 

 Rock Creek, south and southwest of Guyot, there are extensive 

 lateral moraines, the crests of which are from 500 to 700 feet 

 above the floor of the canon. These afford an excellent idea of 

 the thickness of the glacier. The lateral moraines on the south 

 side of the glacier are crossed by the trail in descending from the 

 Siberian Outpost to Rock Creek, and are well seen from the 

 summit of Mt. Guyot. Those on the north side are crossed in the 

 climb from Rock Creek to Guyot Pass. Where the summit of 

 these lateral moraines spreads out the surface is marked by 

 numerous ridges, indicating minor fluctuations of the edge of 

 the ice, but where the moraines flank the steeper sides of the 

 canon two distinct crests are seen, perhaps 100 feet apart verti- 

 cally. The highest indicates the maximum thickness of the ice 

 and the lower a well defined stage in its shrinkage. The fact 

 that, below the second moraine, there are no other morainal 

 crests indicates that the shrinkage of the ice from that point was 

 at a steady or uniform rate. The behavior of the tributary gla- 

 ciers, after they had attained their maximum, thus appears to 

 have been similar to that of the trunk glacier in Kern Canon as 

 inferred from its terminal moraines. 



Above these lateral moraines on the south side of Rock Creek 

 is a hanging valley which is evidently the path of a local glacier. 

 The valley is a broad, glaciated trough, cut down into the north- 

 western margin of the Sub-summit Plateau. It is shown in 

 Plate 32 b. A similar but less extensive hanging valley lies 

 about a mile to the east of it. 



The next tributary glacier to the north of Rock Creek, on the 

 same side of the Kern, was that which flowed down Whitney 

 Creek. This stream, above Crabtree Meadows, has also two 

 branches, and from each there came a glacier, the two becoming 

 confluent and forming a common stream from Crabtree Meadows 

 to the Kern. The larger of these two branches of the Whitney 

 Creek glacier was the more northerly. This had its source in 



