SOUTHERN PACIFIC LINES 111 
down, some of them porous limestones and locally ciays, red beds, and 
gypsum. (P.B.King.) A great interval of sand deposition is indicated 
by the sandstone of the Delaware Mountain formation. In part of 
the region extensive mud flats of red clay were built on lowlands sub- 
ject to overflow, and in some of the shallow intervening basins there 
was a thick accumulation of salt and gypsum. On the adjoining 
lands lived many animals, largely strange reptiles, of which many 
remains have been found in the Permian red beds. One of the most 
peculiar of these animals, the finback lizard, is shown in Plate 16, A. 
After Permian time there was widespread uplift with considerable 
flexing of the strata and extensive erosion. In certain local basins 
limy sediments were laid down, as shown by the thick mass of Juras- 
sic limestone of the Malone Mountains, the product of a sea or marine 
estuary. Through the Cretaceous period there were several marine 
occupations of wide extent and long duration, in which the Comanche 
strata (Lower Cretaceous) and the clays and chalks of the Upper 
Cretaceous were accumulated. Late in Cretaceous time, however, 
western Texas was elevated above the sea, and it has been an upland 
ever since. Volcanic action began at this time, with the ejection 
of tuffs and ash and thin flows of acid lava, the earliest of which were 
buried by sand. Later there were tremendous eruptions of lavas 
of many kinds, with the building of high volcanic cones, some of cinder 
and scoria, which continued into Tertiary and later time. There 
was in late Tertiary time a widespread uplift in which the lavas 
were tilted, flexed, and faulted. Since then they have been widely 
removed and sculptured by erosion to their present forms, and thick 
mantles of alluvium have been deposited in some of the valleys. 
The Lobo Flats support much tobosa grass, a plant that carries its 
moisture a long time and is therefore in high favor for pasture. This 
wide valley was a favorite rendezvous for Apache Indians and out- 
laws, who committed many depredations. At Fay siding a 2,012- 
foot boring found but little water. Beyond Fay siding the railroad 
passes around the north end of the Van Horn Mountains, an outlying 
knob of the Permian limestone reaching the railroad at milepost 702, 
2 miles beyond the siding. At Collado siding, 2 miles farther on, the 
railroad deflects around a knob of the same limestone at the south end 
of the Carrizo Mountains.” 
% These mountains consist mainly | basal conglomerate of schist and 
of Carrizo Mountain schist (pre- | quartz. The Carrizo Mountain schist 
Cambrian), with small overlapping | extends north to the gap in which the 
areas of Van Horn sandstone (Upper | Texas & Pacific Railway crosses the 
stone varies in thickness but in places | Bass Canyon, north of Dalberg siding, 
is more than 200 feet thick, consist- | where it strikes northwest and includes 
ing of red micaceous sandstone with a nen heh Ne 
