Lawson] 



The Upper Kent Basin . 



315 



Keru Basin is correct, then the application of the hypothesis of 

 differential degradation to that surface is negatived, and we must 

 regard the Sub-summit Plateau as having been evolved as a 

 broad valley bottom nearly at base level. 



THE HIGH VALLEY ZONE. 



Chagoopa Plateau. — The Chagoopa Plateau is, perhaps, the 

 most remarkable feature of the basin of the Upper Kern. It is 

 the ancient floor of the basin before it was trenched by the canon 

 of the Kern. That trenching, and all the long history that it 

 involves, has left the ancient valley floor singularly intact. Its 

 ancient characters, when it was still functional as a valley floor, 

 are wonderfully preserved and fresh. It is not merely a geo- 

 morphie feature to be detected by the trained eye of the 

 geomorphologist ; it is a broad and impressive element in the 

 landscape which causes even the amateur mountaineer to pause 

 and wonder. It is best seen from the top of Mt. Guyot, which 

 commands a fine view of the entire central portion of the basin. 

 Looking to the southwest from this vantage point, it spreads out 

 as a broad plain on the far side of Kern Canon, extending from 

 the brink of the canon to the base of the pi*ecipitous eastern 

 slope of the high mountains of the Great Western Divide. (See 

 Plate 34 a.) Its abutment upon these mountains is a fairly sharp 

 line; but there are transitional slopes, and the plain extends 

 within the salient spurs of the high range. This edge of the 

 plateau, skirting the base of the high mountains of the Western 

 Divide, converges southward upon Kern Canon in the vicinity 

 of the mouth of Coyote Creek, and beyond that point the plateau 

 is not traceable except, possibly, in certain doubtful terracedike 

 shoulders on the western side of Kern Canon. On the north 

 this portion of the plateau is bounded by the high ridge of the 

 Kaweah Peaks and Red Spur, which extends out into the basin 

 from the Great Western Divide as far as Kern Canon. Its 

 abutment upon the southern flank of this ridge is by well defined 

 transitional slopes. (Plate 33b). Along the western brink of 

 Kern Canon the altitude of the plateau is from 8,500 to 9,000 

 feet above sea level between Coyote Creek and Red Spur. From 

 this line it rises steadily to the northwest towards the head- 



