140 SOUTHWESTERN NEVADA AND EASTERN CALIFORNIA. 
May, 1904. In the fall of 1904 several hundred people rushed to 
the camp, but few remained long. At the time of the writer's visit 
(July 7, 1905) a number of lessees were at work. The country rock, 
silicified and kaolinized biotite andesite, has been fractured and in 
many places faulted and brecciated. The intensely silicified ande- 
site is a white or gray rock with conchoidal fracture. In some 
instances it is porous through the removal of the phenocrysts and in 
others the casts have been filled by milky quartz. The iron-stained 
outcrops are very rugged, since silicification and consequently the 
resistance of the rock to erosion are very irregular throughout the 
mass. Under the microscope (his silicified facies is seen to be a 
medium to very fine mosaic of quartz and some chalcedony, with here 
and there a blotch of limonite. No phenocrysts remain, although a 
few sagenitic web- of rutile suggesl the former presence of biotite. 
By kaolinization the rock is reduced to a chalky mass, in which biotite 
phenocrysts. altered to a silvery mica, alone are visible. It is in- 
tensely stained by limonite and hematite, especially along fractures, 
and from such places rich gold pannings are obtained. A little 
chrysocolla was observed along some joints, while a thin coating of 
hyalite has been deposited since the oxidation of the sulphides. The 
ore is said to run from $40 to ^2W in gold per ton. 
Waters carrying silica and metallic salts in solution appear to have 
ascended along faults, brecciated zones, and joints in the country rock 
and to have deposited silica, pyrite, and some copper sulphide. Later 
surface waters oxidized the sulphides and set the gold free. The 
original deposition was without much doubt an impregnation of the 
country rock, as is the case with the secondary minerals. There is a 
notable resemblance between these deposits and those of Kawich and 
certain of those of Goldfield. 
Gold Crater derives its water supply from tanks on the basalt mesa 
and from two wells, 3 and 9 miles distant. Fuel for mining purposes 
is obtainable from Stonewall Mountain. Goldfield is 27 miles distant. 
OTHER AREAS. 
Some of the pegmatitic quartz in the granite 5 miles north of west 
of Whiterock Spring i- stained by limonite, but no other indication of 
mineralization was noted. It is probable that some of the masses of 
the older Tertiary volcanic rocks protruding through the later lava 
flow are worthy of prospecting, but such were not observed in the 
course of the present work. Prospecting in Pahute Mesa can be most 
advantageously pursued in the winter or early spring, when water 
can be obtained from snow or the tanks. 
