Vol. 6] Rcid: The Geomorphogemj of the Sierra Nevada. 



127 



flood. It has already cut about five feet, and has exposed stream- 

 deposited sands and fine gravels, always characterized by cross 

 bedding. At the north end of the middle portion of the valley 

 the creek turns abruptly to the east, and leaves the valley through 

 a sharply notched canon. The rate of its downward cutting in 

 the granite at the entrance to this canon governs its work in the 

 valley alluvium. The north branch joins the main stream just 

 before it enters its canon. This branch has cut deeply into the 

 valley alluvium, disclosing the fact that this material abuts 

 sharply against the south face of the small granite fault-block 

 that bounds on the north the middle portion of Little Valley. A 

 few tributaries flow into the main creek off the steep west scarp ; 

 none flow off the east ridge, nor have any ever done so. The ab- 

 solutely flat floor of this portion of the valley is broken only by 

 the emergence above the alluvium of a few low granite knobs, 

 one of which, shown on the geologic map, is covered with ande- 

 site. The position and profile of these small areas of granite are 

 significant, as are the features of the slopes bounding Little Val- 

 ley on the east. South of the point where Franktown Creek 

 turns to enter the canon, the few small granite areas in the valley 

 floor are low and level topped. The first slope up to the east 

 from the valley shows traces of a terrace-like fringe of low-lying 

 granite of the same flat aspect. Just south of the east course of 

 the creek above the canon a long finger of granite extends into 

 the valley alluvium. This finger is also level topped. On all 

 these small areas the surface is deeply soiled with boulders of dis- 

 integration lying quite thickly about. The similarity of the ap- 

 pearance of all these small bits of weathered crystalline surface 

 to the unmistakable plateau remnants is remarkable. The low 

 granite slope rising to the east from the valley ends more or less 

 abruptly against a steep rise to the ridge crest capped with its 

 plateau remnant. The eastward slope to Washoe Valley from 

 this crest is peculiar in that in several well preserved sections 

 two distinct slopes are present, joining at a distinct angle whose 

 location frequently shows strong granite outcrops. (See pi. 24a). 

 The higher slope is gentle ; the lower steep. 



The northern portion of Little Valley presents some striking 

 differences in topography from the middle. Of these the most 



