PALEOZOIC SEDIMENTARY SERIES 241 



Number 690 is the basal dolomite from the section north of Clayton valley. 



Number 468 is a doloniitic marble taken at the contact with the white gran- 

 ite of Mineral ridge, 6.3 kilometers west of north from Red mountain. 



Number 545 is a dolomitic marble from near the white granite of Mineral 

 ridge, G.6 kilometers northeast of Red mountain. 



Number 563 is Lower Cambrian limestone from the Silver Peak range, con- 

 taining an abundance of little orbicules. 



The isolated areas in the extreme northeast part of the quadrangle, to 

 the south of Lone mountain, are probably Lower Cambrian, but no fossils 

 were found in them. The rocks of these areas are for the most part 

 highly metamorphosed by the granite of the Lone Mountain mass, the 

 limestone being converted into marble and the argillaceous rocks into 

 schists. 



The larger portion of the higher parts of the Silver Peak range, from 

 a point about 2 miles south of Emigrant pass to Red mountain, is made 

 up of Lower Cambrian slates and limestones. The slates and some 

 associated quartzites are green in color, and the microscope shows that 

 this color is due to abundantly disseminated chlorite. 



The Lower Cambrian area to the north of the Emigrant road, at the 

 west base of the range, consists at the base of, green schists containing 

 little conical shells. Overlying the schists are limestone layers full of 

 little orbicules. The Lower Cambrian limestone is crushed and faulted 

 to a remarkable degree, while the overlying thin bedded limestone of 

 Upper Cambrian age lies quite regularly at some points on this Lower 

 Cambrian foundation, some reddish and green slate intervening at othei 

 points. The dip of the Lower Cambrian series varies. At some points 

 it is northeast 45 degrees and at other points southeast 10 to 40 degrees. 

 The overlying Upper Cambrian rocks in this vicinity dip rather regularly 

 to the southeast at angles from 5 to 10 degrees. 



The Lower Cambrian rocks of Mineral ridge have largely been eroded, 

 but two higher ridges with a north-south trend remain as a capping to 

 the pre-Cambrian complex. The small areas of Lower Cambrian rocks, 

 represented as capping the pre-Cambrian at various points on Mineral 

 ridge, and especially along the east base, are composed mostly of buif 

 dolomitic marble, which is possibly of Algonkian age, as are also some 

 quartzite masses just west of the village of Silver Peak. 



The areas of supposed Cambrian rocks at the west base of the Silver 

 Peak range, south of the Silver Peak-Fish Lake road, are mostly schistose 

 rocks in which no fossils were found. Their age is therefore a matter of 

 doubt. At one or two points in these areas are small masses of old 

 igneous rocks, one of which is, perhaps, a metamorphic basalt. The areas 

 to the north of Piper peak are also largely schist, somewhat resembling 



