186 Adventures in Scenery 



debris. Boulders of the later moraines are fresh and compara- 

 tively little weathered. Granite boulders of the older moraines 

 have become so decomposed, so disintegrated by weathering, 

 that they crumble and fall to pieces with a blow of the ham- 

 mer. Boulders of the same original character in the later 

 rnoraines are still fresh and hard, and when broken show the 

 crystal minerals of which they are composed just as they occur 

 in the ledges of undisturbed granite in the mountain sides. 



Cinder Cones and Basaltic Lava Flows 

 Mark Valley floor 



On the flat level plain of Owens Valley a few isolated groups 

 of hills rise above the general level, but they are dwarfed by 

 the great bordering mountain ranges. These are, from south 

 to north, the Alabama Hills, northwest of Lone Pine; Poverty 

 Hills, between Independence and Big Pine; and the Tungsten 

 Hills, west of Bishop. A volcanic field lies southwest of Big 

 Pine, and its finely preserved cinder cones and lava flows are 

 notable features of Owens Valley, and a marked feature of the 

 east flank of the Sierra Nevada between Independence and Big 

 Pine. The highest of the extinct volcanoes is Crater Mountain, 

 which rises 2,000 feet above the valley floor. (El. 6,123 feet.) 

 It is composed largely of black basalt lava flows capped by a 

 cinder cone with a crater in its top about 100 feet deep. The 

 cinder cones of this field are fine examples of their type. Some 

 are symmetrical conical heaps of scoria and lapilli. In others 

 the craters have been broken by the escape of molten lava. It 

 is interesting to note that some of the cinder cones are situated 

 upon fault lines, and that motion has recurred along some of 

 these fault lines as recently as 1872. The most perfect and 

 symmetrical of the cinder cones is Red Mountain. It rises 600 

 feet above the alluvial slope upon which it stands. An exten- 

 sive flow of basalt issued from its vent, but the crater rim ex- 

 tends unbroken over the head of the lava flow. The cone is 

 built mainly of fragments, commonly 6 inches in diameter, 



