264 H. W. TURNER GEOLOGY OF THE SILVER PEAK QUADRANGLE 



and broken and at some points stand vertical. A basalt dike has been 

 intruded along the fault, and this is shown as a dark ridge in the mid- 

 dle of figure 2, plate 9. I am informed that a thirty-foot gouge was 

 passed through in prospecting a coal seam close to the fault. This doubt- 

 less represents the exact line of faulting. To the north of the fault zone 

 the sandstones dip evenly to the north at angles of from 25 to 35 degrees. 

 This line of faulting was first recognized by M. A. Knapp, a mining 

 engineer, when examining the coal beds. 



The steep north slope of the Palmetto mountains is also regarded as 

 due to uplift along a normal east-west fault, the existence of which is 

 further indicated by a rhyolite dike intruded along a part of it and by 

 a line of vigorous springs, two of which are shown on the topographic 

 map, one being at Indian Garden. Some of these springs are warm. 

 What is presumably a continuation of this line of faulting is a fault 

 wall (shown in figure 1, plate 9) in the northern foothills of the south- 

 east end of the Silver Peak range. This wall shows slickensides. It is 

 composed of a friction breccia of rhyolite hardened by infiltrating waters, 

 and was traced by exposures similar to that shown in figure 1, plate 9, 

 for a considerable distance. Other croppings of this fault breccia may be 

 noted in the distance in the figure. 



The slates and limestones of the Lower Cambrian of the west side of 

 the Silver Peak range south of Emigrant pass have been uplifted along 

 a north-south normal fault for a distance of several miles, and the coarse 

 conglomerate beds of the Esmeralda formation here dip to the west or 

 away from the fault line, and at the fault line itself there is distinct 

 evidence of faulting. 



What is probably a strong north-south fault zone forms the steep 

 escarpment facing west of the rhyolite hills 10 miles southeast of Silver 

 Peak. The north continuation of this fault line is east of the Silver Peak 

 quadrangle. It is expressed in a steep scarp of Paleozoic rocks (probably 

 Cambrian) that lies 8 miles due east of Silver Peak, exposing a very fine 

 section that has not yet been examined by a geologist, so far as known. 

 Still farther north the northeast end of the Clayton marsh abuts against 

 this fault wall, the continuance of which still farther northward is indi- 

 cated by a narrow north-south valley. 



Smaller faults of the normal type are abundant, erosion along them 

 often forming vertical walls which show smoothing and grooving due to 

 movements along the faults. One of these walls has been used as a wall 

 to a storehouse near the spring that furnishes drinking water to the 

 town of Silver Peak. 



