SOUTHERN PACIFIC LINES 109 
these sections that the caverns are in the Carlsbad limestone member, 
which is a northern extension of the upper part of the Capitan lime- 
stone. The strata dip to the east. The opening is on the east slope 
of the mountains, some distance above the plain underlain by Castile 
gypsum which here skirts the east foot of the mountains. The 
opening is a wide natural arch from which a broad stairway and an 
elevator descend into the cavern, which has a total depth of more than 
700 feet. Some of the upper chambers of the cavern are the homes of 
myriads of bats, which fly out for a nightly foray at sunset every 
evening in a veritable cloud of wings that darkens the sky; they 
return atdawn. Many visitors linger in the evening to see the exodus. 
Last Chance 
>» Canyon 
° 
0 
i 
Sere : ok Caverns ne 
SSS Shoo ==. 3 
= 5 ler limestone 
SSS era 2 ere ee 
risbad = 
limestone Cerisbad = 84 E. 
ember 
_ <= 
=. 
ee 
-<—. 
~ 
nL 
“<2 
~ ee 
=~ 
Delaware 
sa SWOre Mc 
3,000" 
= Limestone 
de probably — 
*% Pennsylvanian 
° 5 10 1s Miles 
1 L L — j 
FIGURE 20.—Sections across the Guadalupe Mountains at E] Capitan, Tex., and Carlsbad Caverns, 
N. Mex. 
LOBO TO EL PASO, TEX. 
Three miles beyond Lobo State Highway 3 crosses the Southern 
Pacific tracks and goes to Van Horn, a small town on the Texas & 
Pacific Railway, dimly visible down the valley, about 8 miles to the 
north. The old military trail from the east followed the Lobo Flats 
to Van Horn Wells, thence north and west to Eagle Spring, Fort 
Quitman, and San Elizario on its way to El Paso, whence a trail 
continued on into Chihuahua. 
East of Fay are the Wylie Mountains,” a deeply dissected elevated 
plateau of limestone of Permian age cut off on its west side by a fault, 
as shown in Figure 21. 
Many chapters of geologic history are indicated by the rocks of 
western Texas. Although some of the conditions and events are 
clearly shown, some intervals of geologic time are not represented by 
7 The limestone of this range is the | pink quartz-muscovite schist, quartz- 
same as that which caps the Sierra | biotite ite schist, chlorite schist, 
Diablo north of Van Horn. The | and amphibolite schist, with quartz 
schist exposed on the west face of the | veins and lenses. The ike is nearly 
Wylie Mountains is composed of light- | east and the dip 20°-30° S. (Baker) 
