Lawson.] 



The Upper Kern Basin. 



34.") 



lake. A sudden large addition to these debris cones, in the 

 spring of 1868, seems to have caused the damming which brought 

 the lake into existence. Whether such an excessive dejection 

 of debris in this year is to be ascribed to disturbances caused by 

 the earthquake, which shook the southern Sierra in that year, or 

 whether it was due to an exceptionally heavy winter, remains an 

 unsettled question.* 



The extent to which Upper Lake has been silted up by delta 

 extension affords us a check upon the age of Lower Lake. As 

 has been stated, this delta has extended down the lake about half 

 a mile and is, therefore, comparable in extent with the levee 

 which shuts off Lower Lake from the Kern. Probably but little 

 addition has been made to the levee since the formation of Upper 

 Lake, for the sediment has for the most part been trapped by 

 the latter. The levee may, therefore, be assumed to have been 

 completed at the time that Upper Lake was formed, that is, 36 

 years ago; and if it took as long for the formation of the levee 

 as for the delta accumulation on Upper Lake, the Lower Lake is 

 at least 72 years old; which agrees with the former estimate 

 based on the age of the trees growing upon the rock- slide which 

 dammed Lower Lake. 



GLACIATION. 



Frequent references have been made in the earlier parts of 

 this paper to the glaciation of the Upper Kern Basin. It is now 

 proposed to devote a more extended, but still summary, note to 

 this part of the subject, as an important factor in the morphogeny 

 of the region. We may conveniently begin at the lower limit of 

 glaciation in the canon of the Kern. 



Terminal Moraines of the Trunk Glacier. — The lowest point 

 reached by the great trunk glacier, which once flowed down Kern 

 Canon, is just south of the mouth of Coyote Creek. Here the 

 snout of the glacier crowded in toward the west wall of the canon 

 and pushed up into the north end of a kerucol, for a few hundred 



* Professor A. G. McAdie, of the U.S. Weather Bureau, has, since the above 

 was written, informed the writer that the winter of 1867-68 was decidedly one of 

 heavy precipitation. He says: "At Sacramento, the rainfall was nearly 13 inches 

 in December '67, and January, February and March '68 all had good rainfalls. In 

 all likelihood the snowfall was exceptionally heavy in the mountains." 



