84 GUIDEBOOK OF THE WESTERN UNITED STATES 
and Thurston sidings the chalky-white massive lower member of the 
Buda limestone is conspicuous in places overlain by Eagle Ford beds, 
On the low plateau to the north is a mantle of gravel and sand which 
was deposited by an earlier Lozier Creek at a higher level, a stream 
which had its source in the highlands far to the west. Remnants of 
this deposit occur south of Dryden, about Mofeta, and in the region 
south of Maxon Creek, 20 miles southwest of Sanderson. It con- 
tains chert, sandstone with Pennsylvanian fossils, and novaculite, 
from the Marathon uplift, and lavas from the Davis Mounteins. 
About 5 miles west of Thurston siding an increase in dip brings up 
the basal member of the Buda limestone and reveals the underlying 
Del Rio rusty buff clay, which has come in again underground and 
extends to and beyond Dryden. 
At Dryden State Highway 3, which crosses the highlands to the 
south, comes to the railroad and continues westward for some distance 
along its south side. Dryden is in a broad, shallow 
Dryden. valley bordered by low ridges of Buda limestone 
Elevation 2,108 feet. underlain by Del Rio clay of rusty buff color. The 
tion 60.* A ° . 
New Orleans 854 miles. Buda consists of two massive limestone members sep- 
arated by softer yellowish marly beds which contain 
distinctive fossils. A mile or so west of Dryden these strata are 
covered by the old river deposit above referred to, which constitutes 
a wide, level plain. On the west side of this plain, about 2 miles 
west of Mofeta siding, the Georgetown limestone comes to the surface. 
To the south are high mountains in Mexico, which appear to be not 
very distant. A short distance beyond Mofeta the railroad descends 
into the canyon of Sanderson Creek, which it then ascends to its 
head, 40 miles to the west. The picturesque canyon walls are about 
200 feet high and consist of Edwards and Comanche Peak limestones 
at the base and Georgetown beds above, the latter mostly massive lime- 
stone but in places including some thin members of a more marly 
nature in which Washita fossils are found. In this area the beds rise 
to the west on the beginning of a large dome-shaped uplift which cul- 
minates in the Marathon Basin and Glass Mountains. Some years ago 
a deep boring for oil was made on the east slope of this dome at a point 
about 12 miles southeast of Sanderson. It penetrated all the Lower 
Cretaceous strata, 840 feet thick, and more than 1,000 feet of the un- 
derlying black shales of Pennsylvanian age, but obtained no petroleum. 
Another deep hole near Emerson, 10 miles west, had a similar result. 
is the first town of any size west of Del Rio and is a 
local center of trade and a shipping point for stock. It lies on the 
: massi 
Population 1,24. Edwards limestone lying on slabby beds of Comanche 
Serene Peak limestone and overlain by a succession of massive 
_ and softer beds representing the Georgetown limestone, about 200 
