CHAPTER II. 



SURFACE GEOLOGY. 



g^ e coiogy.— Mr. Arnold Hague has described the general geology of 

 this mining district," as well as that of the whole region lying within a radius 

 of ten miles from Prospect Peak, and little more is therefore necessary here 

 than a reference to his results. The Cambrian, Silurian, Devonian, and 

 Carboniferous are all represented in the formations of this district, though 

 it is only in the rocks of the first two that metalliferous deposits of any 

 kind have been found, and excepting the Hoosac mine, in the Eureka 

 quartzite of the Silurian, it is only in the rocks of the Cambrian period that 

 deposits of anv great value have been discovered. 



Formations.— Mr. Hague distinguishes the following beds in the Cambrian, 

 beginning with the oldest: Prospect Mountain quartzite, Prospect Mountain 

 limestone, Secret Canon shale, Hamburg limestone, Hamburg shale. These 

 five formations have all been laid down conformably. The rocks of the 

 Silurian in the order of succession are Pogonip limestone, Eureka quartzite, 

 and Lone Mountain limestone. According to Mr. Hague, the first two ot 

 these beds have been laid down conformably with the formations which 

 represent the Cambrian, but there appears to be a non-conformity between 

 the Lone Mountain limestone and the overlying quartzite. The rocks ot 

 the Devonian in this neighborhood are the White Pine shale and Nevada 

 limestone, in the latter of which the mines of Alhambra Hill, in Silverado 

 District, are situated. 



nations of the mines to the formations.— With the exception of the HoOSaC mine 1U 



the Eureka quartzite, and the Bullwhacker and other mines imthePogonip 



_ "Abstract of Report on the Geology of the Eureka District, Nevada, by Arnold Hague; Third 

 Annual ReportoftlK- Director of the U.S. Geological Survey, 1882. M, Hague's full report » not yet 

 in print. 5 



