158 SOUTHWESTERN NEVADA AND EASTERN CALIFORNIA. 
lime-carbonate concretions of rude cylindrical form are embedded in 
the pi ay a clay. Similar concretions occur in the play a clay of the 
Alkali Spring flat. 
Adobe bricks have been made from the playa clay at several places, 
and it is probable that the clay of all the playas is well adapted to 
their manufacture. Borax is said to have been leached from the 
clay of this flat 3 miles south of east of Montana Station. The in- 
dustry was never extensive, and until the rich bedded deposits of 
borax minerals are exhausted these playa deposits will be commer- 
cially unimportant. A number of wells, sunk in or near the large 
playa, have uniformly obtained water. In the center of the playa the 
surface and the water table are practically at the same level (see fig. 
2, p. 21). The coyotes scratch holes from 2 to 3 feet deep in the clay 
and get water. The water is adequate for domestic and stock pur- 
poses and for the most part pure, although some is brackish and that 
in one well is unfit for use. Water was obtained at the following 
depths in the various wells: Forks of Goldfield-Bullfrog and Gold- 
field-Beatty roads. 180-1DO feet; Farmer Station, 8-10 feet; Thorp's 
mill, 30 feet; Montana Station. L8 feet: Summerville, 1 mile south 
of Montana Station. 8 9 feel : Tonopah Well, 10-12 feet, and Seattle 
Well, 40-50 feet. Mr. F. L. Rickard reports that the water at Mon- 
tana station occurs in a layer of quicksand. 
AMARGOSA DESERT. 
The Amargosa Desert is one of the most extensive depressions in 
the Great Basin. The main valley heads against the Amargosa 
Range and Bullfrog Hill-, south of Sarcobatus Flat, with which it is 
connected by a thin ribbon of Recent gravels, and trends southeast to 
Ash Meadows, and thence south GO miles to a point where it swings 
around the Funeral Mountains to join Death Valley. Within the area 
mapped the valley i- about 10 miles wide at the north end, contracts 
in the middle, and expands to a width of 21 miles at the southern 
holder of the area. The valley sends branches well into the surround- 
ing mountains. From the summit south of Currie Well the valley 
descends 1,600 feet in 10 miles and but 500 feet in the next 20 miles. 
The cross section of the valley is comparatively flat except in the 
northern part. The lowesl portion within the area shown on the map 
lies at an elevation of 2.500 feet. The channels of the so-called Amar- 
gosa River and of Fortymile Canyon, each characterized by bowlders 
and coarse gravel, arc -lightly depressed beneath the surface. of the 
valley. The valley i^ without grass, but is covered with a sparse 
growth of creosote bush and other shrubbery, while mesquite trees 
grow north and east of Ash Meadows. 
The Recent detrita] deposits in the southern portion of the valley 
are fine grained, and the wind has heaped these into dunes. The most 
