204 SOUTHWESTERN NEVADA AND EASTERN CALIFORNIA. 
From one locality the following Pennsylvanian fossils, determined 
by Dr. George II. Girty, wore collected : 
Fusulina sp. Small indeterminable gasteropod. 
Crinoidal fragments. indeterminable fragments. 
Fenestella sp. 
Fragmentary fossils were collected from two other Localities, and 
concerning these Doctor Girty states that while they are undoubtedly 
Carboniferous, they indicate nothing further. 
Older alluvium. — On either side of Emigrant Wash and at the 
north end of the Panamint Range are a number of areas of the older 
alluvium. The deposit east of Emigrant Wash forms intensely dis- 
sected hills which are continuations of the ridges of Tucki Mountain. 
The two large areas across the valley to the northwest are eastward- 
sloping plains cut by erosion into low hills, and each is separated from 
Death Valley by a low ridge of Paleozoic limestone. A few small 
outliers occur higher up in the mountains at a maximum altitude of 
».ooo feet. 
These deposits are composed of beds of angular bowlders and well- 
stratified -and. These are locally so well cemented by calcium carbon- 
ate that caves 25 feet high exist in them. Around Emigrant Spring^ 
in the southern extension of the area west of Tucki Mountain and in 
the area at the north v\\(\ of the Panamint Range, white and pink clay 
similar to that of the present playa deposits is interbedded with the 
bowlder beds. At i lie north end of the range the series has an exposed 
thickness of 2,500 feet. 
Recent desert gravels unconformably overlie the older alluvium, 
which in turn lies upon the eroded surface of the quartz-monzonite 
and Paleozoic rock-. The upper portion of the series and the basalt 
are contemporaneous, and in consequence the older alluvium is prob-i 
ably of Pliocene and early Pleistocene age. In Pliocene-Pleistocene 
time, when Death Valley was occupied by an extensive playa. the 
Panamint Range was. comparatively low and insignificant. The oldeij 
alluvium areas are the remnants of alluvial slopes which once fringed 
its border-. These alluvial slopes near Goldbelt Spring reached an 
elevation of 5.000 feet, while to the north of Tin Mountain no rem- 
nants remain above 4.000 feet. Considerable portions of the Tin and 
Tucki mountain deposits are forme:! of playa clays, showing that 
during period- of exceptional rainfall the playa of Death Valley ex- 
tended well tip on the Panamint Range. 
Recent alluvium. — The valley above tin 1 head of Cottonwood Creek 
is covered with coarse soil and loam. A more resistant portion of the 
quartz monzonite has narrowed and partially dammed the valley, mid 
behind this barrier the material washed from the surrounding hills 
has accumulated. Four miles north of Goldbelt Spring is a basin 
whose bottom in depressed 275 feet below the inclosing rim of hills. 
