182 Adventures in Scenery 



broken into segments by faults by which the range has been 

 much rent, and the lava segments cap blocks that have been 

 thrown downward along the fault slips, so that the lava beds 

 appear as terraces high on the mountain range. 



Batholith Intruded under Sedimentary 

 Rocks 



It has been stated that the sedimentary rocks that occur in 

 the Inyo range include most of the formations from pre-Cam- 

 brian to Triassic. The formations are separated by uncon- 

 formities, showing that the region was not continuously sea 

 bottom, but was at intervals elevated and became dry land. 

 During the next great era, the Mesozoic, probably in late 

 Jurassic time (the next period following Triassic) a tremendous 

 revolution occurred during which disturbance the Inyo range 

 acquired much of its complex internal structure. The rocks 

 were faulted and folded, and this was followed by an up-well- 

 ing from the interior of the earth of a vast mass of molten rock 

 forming a batholith. During this revolution the Inyo range 

 acquired the major portion of its complex internal structure. 

 It acquired its present topographic form, however, by profound 

 faulting that occurred probably about the end of Tertiary 

 time. The intruded mass of molten rock forced upward the 

 originally horizontal sedimentary rocks. The great batholith 

 did not reach the surface but lifted the superjacent rocks as a 

 great roof. The revolution was of mighty power. The sedi- 

 mentary rocks were not only uplifted but were crumpled, 

 folded and contorted. Rocks that had been originally hori- 

 zontal came to rest in vertical position, folded, bent, and vari- 

 ously deformed. Lavas were poured out. It has been stated 

 before that a series of basaltic lava sheets rest horizontally on 

 vertically upturned strata and form the plateau summit of the 

 southern portion of the range. The molten rocks that were 

 welled up from the interior of the earth, and which formed the 

 great batholith, cooled slowly under the great mass of roof 



