Lawson.] 



The Upper Kern Basin . 



321 



vent. Its crater is irregular and ragged and lacks the symmetry 

 of the cinder cone. 



Looking eastward along Toowa Valley from the summit of 

 tins same cinder cone, one sees at a distance of about six miles 

 two other conical or dome-like hills of dark rock, which arc in 

 marked contrast to the white weathering granites of the region. 

 These hills, although not visited, are in all probability volcanic 

 cones. The smaller one lies in the axis of the valley and the 

 larger one lies to the south of it. Both appear as if they were 

 sessile upon the valley floor. The slopes of the two cones are 

 continent at a level not much below the summit of the smaller cone. 



• The sixth volcano is situated in the valley which is tributary 

 to Volcano Creek from the north at Groundhog Meadow, about 

 four miles up stream from Kern Canon. 



From what has been said of these volcanoes it is evident that 

 the period of their eruption and the upbuilding of their cones is 

 later than that of the formation of the valley, and that they are 

 features imposed upon, and independent of, the erosional geo- 

 morphy of the valley. The valley had attained its present 

 character, as far as erosion is concerned, before the volcanic 

 eruption began, and has been but little modified since eruptive 

 activity ceased, except by aggradation. 



Disregarding, then, these volcanic cones as foreign to the 

 discussion of the essential character and geomorphic evolution of 

 the valley in which they occur, we may proceed to describe the 

 general featui'es of the valley as seen from the summits of the 

 two more commanding cones. The floor of the valley is in two 

 stages. The lower of these may be characterized as a broad, 

 flat-bottomed succession of meadows and alluvial plains. This 

 flatness and breadth of the bottom lands is evidently due to a 

 process of aggradation; and this is doubtless, in some consider- 

 able measure, a consequence of the interference of the normal 

 drainage by the volcanic accumulations which have grown up 

 upon the floor of the valley, although other causes may have 

 also, perhaps, been concerned in the process. But the breadth of 

 the valley is not measured by its bottom lands. The meadows 

 do not fully occupy the floor, but are simply the lower part of a 

 very wide valley. Looking toward the summit crest from the 



