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



would be practically uninhabited. Some of the springs, however, supply 

 an abundance of good drinking water, while others contain so much 

 alkali as not to be of value for domestic use. Xear Silver Peak there 

 is a hot spring with a temperature of 132° Fahrenheit (November, 

 1900), containing a large amount of chloride of sodium, while a few feet 

 away is a cool spring. The best available water in the district comes 

 from springs along the summit of the Silver Peak range to the west and 

 south of Eed mountain and along the north base of the Palmetto moun- 

 tains. At Silver Peak there is a pond in which there is water standing 

 the year round, and another, known as Fish lake, may be seen in Fish 

 Lake valley. 



PRECIPITATION 



No systematic records for any great length of time have been kept 

 within the limits of the quadrangle, but the records at Hawthorne, Soda- 

 ville, and Palmetto, all points in Esmeralda county, indicate that the 

 average annual precipitation varies from 3 and 5-10 inches in the valleys 

 to 15 inches on the highest ridges. It frequently rains or snows on the 

 mountain tops when the neighboring valleys receive no precipitation 

 whatever. 



SCENERY 



Except on the higher ridges and about some of the marshes, the vege- 

 tation of the region ordinarily presents a gray effect; but the general 

 somber tints are relieved at some points by the varied and sometimes 

 even brilliant colors shown by the rocks. The ridges being usually 

 devoid of soil, the colors of the rocks are conspicuous. The Cam- 

 brian rocks are dark limestones, buff marbles, green quartzites, schists, 

 and slates. The Ordovician rocks are usually black siliceous argillites and 

 gray and red slates. The Tertiary lake beds are chiefly light buff shales, 

 tawny sandstones, and tern gray marls. By far the most brilliant colors 

 are those of the volcanic rocks. The basalts and basic andesites are 

 usually dark brown or black, but the rhyolites exhibit great diversity. In 

 a little group of rhyolite hills may be noted buttes of dark brown rhyo- 

 lite — the color in this case being mostly the effect of surface weathering — 

 slopes of cream and pink tuffs, and little hillocks of a bright brick red. 

 This is particularly true of the north portion of the Silver Peak range, 

 the north face of which exhibits a series of horizontally bedded rhyolite 

 tuffs and breccias of diverse colors (figure 2, plate 9). At other points 

 the rhyolite is of a green color. A chemical examination of this rock by 

 Doctor Hillebrand showed that the green coloring material is probably 

 an iron silicate. It does not contain chromium. 



