Vol. 6] Eeid: The Geomorphogeny of the Sierra Nevada. 117 



at hand no other hypothesis seems able to account for this form. 



Throughout the whole region north of Clear Creek these but- 

 tress-like forms or fault-blocks are found, some of large size, 

 and many small. Some typical ones are worthy of note. Two are 

 shown in plate 23b, one on each side of the creek. They are several 

 hundred yards long and relatively narrow. The top of each is 

 level and covered with loose boulders of disintegration and coarse 

 sand. Each is separated from the higher blocks adjacent by a 

 long, narrow col. These cols are filled with deep sand composed 

 of the angular fragments of disintegrated granite ; no trace of 

 stream-worn material is present. The side slopes are sharp-cut 

 and unbroken. The ends of the blocks descend steeply under the 

 deep sand. The creek is far below and distant from the two 

 blocks shown, and no streams have ever been on or near them. 

 We are thus justified in regarding these blocks and buttress-like 

 forms as the products of rock dislocation. Further discussion will 

 be had under the treatment of Little Valley. 



From the cross-section of the range through the old river 

 channel we thus obtain conclusive evidence of the faulting move- 

 ments in north-south planes. To the south the faulting becomes 

 even more complex until the Genoa topographic area is reached. 

 The key to the whole, however, is given by the section described, 

 as the major fault lines are continuous. The greatest complexity 

 of the rock movements is in the schist area east of Snow Valley 

 Peak. As already noted, the long east slope consists of a series 

 of step-like flats connected by steep rises. This schist area is 

 deeply notched by a number of east-west stream gullies. If the 

 north-south plane through one of the steep rises be traced into 

 the gullies on either side, the existence of a north-south fault is 

 stratigraphieally slrown. This cannot be done in all eases, but 

 wherever the test is possible, a fault-line is shown. Further, the 

 stream courses themselves offer a different and as conclusive a 

 proof. The bottoms of the several stream courses are all step- 

 like in profile. Opposite the flats, the streams are cutting slowly ; 

 opposite the steep rises, the waters descend in cascades and rapids 

 and are cutting comparatively very rapidly. The first steep rise 

 west of Kings Canon is the most pronounced of all and is prob- 

 ably the most recent. This rise is an unequivocal scarp stand- 



