campbell.] GEOLOGY ALONG ROUTE TRAVERSED. 13 
and it occurs as a bedded deposit from 5 to 30 feet in thickness, 
interstratified in lake sediments. These lake beds are composed of 
semi-indurated clays, sandstones, and coarse conglomerates, with inter- 
calated sheets of volcanic tuff and lava. The rocks are severely folded. 
the axes of the folds lying in an east-west direction. The lake beds 
extend in the same direction across the mountains for a distance of 
about 8 miles. It has been supposed that these deposits probably con- 
tinue westward under the Pleistocene drift of the desert, but there i- 
no evidence at hand to prove such an assertion. In fact, the lake beds 
at Borate do not come down to the foothills of the mountain; they are 
cut off and infolded with the crystalline rocks of the Calico district. 
Lake beds are present west of Calico Valley, and a bed of colemanite 
has been struck in a shaft in this locality at a depth of 200 feet. rt 
Although the colemanite is interbedded with sand and clay, it is not 
coextensive with these strata. As a traceable bed it probably extends 
for a distance of a mile and a half; beyond this limit it is very thin, 
and in many places it is wanting in the section. At the Borate mine 
there are two outcrops of colemanite, either on parallel beds or on one 
bed that has been so closely folded as to give two parallel layers 
about 50 feet apart. The beds strike approximately east and west, 
and dip to the south from 10° to 45°. A railroad connects the mine 
with the mill, which is located on the west side of the mountain, and 
also with the Sante Fe Railway at Daggett. 
South end of Death Valley. — From Daggett the route lay to the 
northeast, along the old Amargosa borax road and through a part of 
the country not heretofore described in any geologic report. The 
rocks are generally granitic, with here and there small areas of highly 
metamorphosed sedimentary beds. In the descent from Cave Wells 
into Death Valley, lake sediments were seen on the left of the road. 
These are identical in composition with the beds near Daggett. Many 
of them are strongly alkaline, but no beds of colemanite were seen. 
Later it was learned at Resting Spring that these sediments contain a 
bed of pure rock salt about 60 feet in thickness. 
The beds composing this series strike northwest and southeast, and 
dip about 20° toward the northeast, or toward Death Valley. The 
northwestward extent of the deposit is not well known. As seen from 
Saratoga Spring, the rocks in the Owls Head peak resemble lake sedi- 
ments with intercalated sheets of dark lava. The distance is too great 
to determine this with certainty; but it is, in a measure, corroborated 
by the occurrence, reported by Mr. Spurr,* of similar beds on the 
flanks of the Panamint Range at Windy Gap. 
At many points in the Panamint Range south of Emigrant Canyon 
there are traces of recent and profound movement, and it seems alto- 
gether possible that the lake in which these sediments were deposited 
occupied a valley trending in a northwest-southeast direction across 
a California Mining Bureau Report, Vol. XII, p. 35. <> Unpublished manuscript. 
