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University of California Publications. 



[Geology 



Ely limestone dipping beneath it at somewhat steeper angles. 

 As we pass along the southern border of the district as mapped 

 eastward and westward upon the Ely limestone terrane, we pass 

 into the complementary anticlines of the Ruth syncline. That 

 to the east is of so low an arch that it is difficult to determine 

 with precision the direction of its axis. It is probably, however, 

 north-northeast. It may be referred to as the Saxton anticline 

 from the Saxton mine which is situated upon it. That to the 

 west is much more sharply flexed, and the trend of its axis is 

 northwest and southeast, the pitch being to the southeast. It 

 may be called the Eib Hill anticline from the most prominent 

 feature upon it. 



In the heart of the Saxton anticline there appears a broad 

 belt of the White Pine shale dipping beneath the Ely limestone 

 on the foothills to the south of the Lane city. On this belt are 

 situated the Saxton and Chainman Mines. Flanking the White 

 Pine shale on the south side of Lane Valley are some areas of 

 limestone the relation of which to the shale is not clear. On 

 petrographical grounds they are mapped as Ruth limestone. 



In the Rib Hill anticline, the White Pine shale again appears 

 beneath the Ely limestone, although the direct relationship is 

 largely interrupted by the porphyry of Jogalong Ridge and the 

 monzonite of Weary Flat. The dip of the shale with its included 

 bed of hard limestone beneath the Ely limestone may, however, 

 be clearly observed to the west and northwest of Pilot Knob. In 

 the same anticline, as it broadens out to the north on the north 

 side of Weary Flat, appears the Nevada limestone from beneath 

 the White Pine shale, extending as an important terrane in the 

 hills to the north of the western part of the district. 



THE IRRUPTIVE ROCKS. 



MONZONITE BATHOLITH. 



One of the most interesting features of the geology of the 

 district is the occurrence of an intrusive mass of monzonite. 

 The chief interest attaches to the fact that it appears to be an 

 example of a rather frequent occurrence of plutonic intrusives 

 of granitic habit which have been reported from various parts 



