132 



University of California Publications. 



[Geology 



made by a granite block somewhat similar in form to the peculiar 

 granite outcrops in north Little Valley, a long narrow block 

 with a flat top twenty-five or thirty feet wide. On the west of 

 this narrow top the slope leads steeply down to the flat below, 

 forming part of Little Valley. To the east there is a shallow 

 col and then a steep rise up to the plateau remnant which forms 

 the ridge crest. On the west side of Little Valley there are two 

 steps, the higher one of large size and the lower just above the 

 creek and smaller. The actual valley bottom is narrow but flat, 

 being but a few hundred feet across. 



The upper portion of this division of Little Valley is of a 

 wide, flaring form, in marked contrast to the gorge-like form 

 below. The general effect is that of maturity (see plates 24b and 

 25a). The valley floor slopes gradually upward to the south and 

 joins by moderately steep slopes with the highest summits. The 

 steep scarp on the east is persistent southerly to the limits of the 

 valley, while oh the west the range crest is reached by a fairly 

 gentle grade, broken, however, as noted before, by a number of 

 subcrests which mark fault-lines. Between these two portions of 

 south Little Valley there is a pronounced structural and physio- 

 graphic change. This change is along another east-west fault- 

 line between Incline and Lakeview, and is characterized by a 

 variety of effects. From the shore of Lake Tahoe southeast of 

 Incline up to the crest of the high west ridge there is a complex 

 of fault-scarps that face in all directions. These are due to the 

 junction of a number of faults, as shown in the map, one of 

 which is the east-west fault line dividing the two parts of south 

 Little Valley. Where this line crosses the west ridge there is a 

 low pass or col, over which the road to Incline is laid. Eastward 

 from the west crest the line lies between the two dissimilar por- 

 tions of the west wall of Little Valley. The northern one of 

 these is characterized by fault-scarp topography and absence of 

 well-defined streams ; the southern shows a long, gentle slope 

 broken by a few rock buttress forms, and has a well-developed 

 drainage, that is in part at least governed by east-west fault 

 planes. On the east of Little Valley the long ridge, presented 

 for nearly three miles, shows little evidence of cross-faults on 

 cursory examination in the field, and none from the topographic 



