160 SOUTHWESTERN NEVADA AND EASTERN CALIFORNIA. 
bedded with it. These beds at Ash Meadows form white limestone- 
capped mesas and buttes, which are landmarks for miles. A section 
of the bluff north of Ash Meadows is as follows: 
Section of bluff north of Ash Meadows. 
Feet. 
1. White, carious, dense limestone, with many lenticular openings parallel to 
the bedding. The limestone is finely handed parallel to these openings 
and has the characteristics of chemically precipitated limestone 10 
2. White, fine-grained clay, massive, inclosing small crystal aggregates of" 
selenite 40 
.">. Limestone like No. 1 1 
I. Clay like No. 2 20 
."». Limestone like No. 1 i 
6. Clay like No. 2 30 
These beds lie horizontal, although Campbell states that farther 
south they dip to the west. The playa deposits and gravels are 
without doubt members of the older alluvium, which is considered 
in part of late Pliocene and in part of Pleistocene age. 
AMARGOSA MOUNTAIN SYSTEM. 
The Amargosa Mountain system, including the Amargosa Range, 
Gold Mountain, Slate Ridge, and the Bullfrog Hills, is the most 
important uplift in the area under discussion. The mountain mass, 
which has a northwesterly trend, lies between Death Valley on the 
wesl and Sarcobatus Flat and the Amargosa Desert on the oast. 
Geologically this mountain system is characterized by the widespread 
distribution of early Paleozoic locks and in its northern portion by 
the presence of granite. 
AMARGOSA RANGE. 
TOPOGRAPHY AND GEOGRAPHY. ' 
The mountain range between Sarcobatus Flat and the Amargosa 
Desert on the east and Death Valley on the west is designated the 
Amargosa Range by the United States Geographic Board, which 
also calls that portion of the range north of Boundary Canyon the 
Grapevine Mountains and that south of the canyon the Funeral 
Mountains. The mountain range as a whole is a unit, the most 
natural division on physiographic and geologic grounds being at 
Furnace (/reek, south of the area surveyed, as suggested by Spum 5 
The range here changes its trend; moreover, to the south of Furnace 
Creek it is composed principally of Tertiary sedimentary rocks and 
to the north of much older rocks. 
The sinuous crest line of the Amargosa Range trends N. 40° YV. 
and roughly coincides with the California-Nevada boundary line. 
a Campbell, M. R., Bull. T T . S. Geol. Survey No. 200, 1902, p. 14. 
6 Spurr, J. E., Bull. U. S. Geol. Survey No. 208, 1903, p. 187. 
