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University of California. 



[Vol. 3. 



blocks of comparatively fresh granite. The summits of the high 

 peaks, whether flat topped as in the case of Mt. Whitney, or 

 acutely pointed as in the case of Sawtooth, are characteristically 

 encumbered with large angular blocks of granite almost or quite 

 free from finer fragments or sand. These larger blocks present 

 the appearance of having been detached from the underlying 

 surface of granite by a process of decrepitation without the 

 intervention of any appreciable rock decay. It is a process of 

 denudation which has been operative very generally on the high 

 summits of the Sierra Nevada and, indeed, on similar peaks in 

 various parts of the world, as, for instance, Pike's Peak in Col- 

 orado, and Ben Nevis in Scotland. But while the encumbrance of 

 angular blocks of fresh granite is characteristic of the high sum- 

 mits and is without doubt due to certain peculiar conditions 

 which obtain there, the tendency to secular decay, which yields 

 the granite sand, is by no means uniform. Large areas of the 

 unglaciated surfaces, even when these are of gentle slope favor- 

 able for the accumulation of such sand, show but little of it; 

 while other areas of the same rock, even where the surface is so 

 steep that the sand lies at the angle of repose of loose material, 

 are deeply buried by such waste products. We have in this fact 

 an indication of differential resistance to atmospheric erosion 

 which does not appear to be suggested by the usual petrographic 

 characterization of the terrane, although doubtless the causes for 

 the difference of behavior under the weather could be revealed by 

 sufficiently thorough petrographic investigation. 



Kaiceah Peaks and the Mineral King Belt. — It must be noted, 

 also, that certain limited portions of the Upper Kern Basin are 

 not composed of granite, and that at least one notable feature of 

 the relief is due in no small measure to this exceptional character 

 of the rocks. The bold group of the Kaweahs (Plate 33b), 

 which extends southeasterly into the basin from its western rim, 

 has a certain individuality and character which distinguishes it 

 from all the other mountain peaks, either in the basin or on 

 its rim. The rocks of this group appear to be metamorphic 

 sediments judging from the similarity of their appearance to such 

 rocks in the Mineral King metamorphic belt, in which occur vari- 

 ous crystalline schists, clay slates, quartzites, and limestones. 



