208 The American Geologist. May, 1902. 
marls containing the remains of fish, fresh water Mollusca, 
and leaves of deciduous trees like the oak and fig. as well 
as tree trunks, six feet in diameter, and also abundant ferns 
and marsh grasses. 
The evidence as to the flowing streams is rather a logical 
deduction from the lakes, than direct evidence obtained from 
old river deposits; although such deposits exist in minor 
amount. In all regions of sufficient precipitation to support 
lakes there are of course always flowing streams. The 
evidence of the former existence of large volcanoes, is the vast 
amount of volcanic material in many of the ranges. The 
craters of these ‘Tertiary 1olcanoes, however, have long since 
been worn away. ‘There arc, to be sure, finely preserved cra- 
ters within the county, but these are clearly of Pleistocene age. 
Tertiary Lake Reds. 1 other publications* there has been 
described a series of lake beds well exposed in Clayton valley, 
in the south end of Big Sincky valley, at the north base of the 
Silver Peak range and clsewhere. The beds consist chiefly ot 
sandstone, buff colored shuie and slate, often somewhat flinty, 
and soft lake beds or lacustral marls. There are local devel- 
opiments of conglomcrates and -reccias on a large scale. Near 
the north base of the Silver Peak range there are workable coal 
seanis. These contain fresii water shells, and fish and plant 
remains. According to Dr. j. C. Merriam of the University 
of California, and Prof. F. H. Knowlton of the U. S. Geologi- 
cal Survey these fossils undicate a middle Tertiary age; but 
since the fossils came chiefly from near the base of the beds, 
and since the series 1s a thick one, nearly all Miocené and 
Pliocene time may be represented. There are thin buff col- 
Ored shales similar to the shales of the lake beds referred to 
(Esreralda formation) im a basin north-west of the Pilot 
mountains between Summit Springs and Crow Springs. 
There are lake beds contasing abundant fossils, four miles 
west of Dlack Springs near the line between Esmeralda and 
Nye counties by the road from Sodaville to Cloverdale. A 
block of this material was obtained from Robert Stewart of 
Sodaville. It was made up chiefly of fresh water shells, ce- 
niented by minute shells ‘cstracods). The fresh water shells 
*AmM. GEOLOGIST. Vol. XX V. 1800, p. 168, and the paper on the Esmer- 
alda Formation in the 21st Ann. rep. of the U. S. Geol. Survey. 
