SOUTHERN PACIFIC LINES 75 
Formations of central Texas 
[Vaughan and others] 
‘ * a Thick- 
Formation Character and notable fossils ness (fect) 
Pliocene and | Alluvium.__-____- Sand and gravel; terraces along streams 0-70 
Pleistocene. ‘High tern eke Gravel with much chert; caps hills and old terraces________ 0-80 
—_— Unconformity |_——_-——~ 
ndio. edded and cross-bedded sands and sandstones and dark- |800-850 
genet clays, for the mos 908 mab nonmarine and in places 
ma ; Ostrea Of Wilcox age. 
Eocene (early | Midway Concretionary gray fastens and sandy clay with no observed | 10-120 
Tertiary). fossils, in ag wae 10 to 20 feet, followed below by glauco- 
nitie sands, in places loosely indurated, with a calcareous 
eat ste tis yellow calcareous pack sand containing 
Cucullaea, Venericardia, Turritella, and Enclimatoceras. 
————|-Unconformity. 
Escondido--__--_-__. Shale and calcareous sandstones, coarse and fine; Ostrea 700 
cortex, Sphenodiscus pleurisepta, 
Guifaertes Anacacho_.--.-.__ Impure limestone and marl; Echinocorys terana, Exogyra | 0-350 
(Upper Cre- pon etaebntey Eyed-eoncpi shalt Baculites asper, Scaphites hip- 5 
pocrepis, ces, 
taceous). | austin ._____. Chalk, white and yellow; Gryphaea aucella, Inoceramus |350-400 
undulato-plicatus, lietentaes teranum 
Eagle Ford_..:.... ares and flaggy limestone, mostly impure, Inoceramus 150(?) 
atus. 
Mv aua oreng IU 
INES 2 CSS ee Pimpstonet 25 ii tec -| 60-75 
Del Rio ie eee ane Yellow ra ; Exogyra arietina 30 
Comanche se-| Georgetown_-_-____ Lim imastotion Ki Wgene ACOs oe ae a 50-150 
ries (Lower | Edwards__-_....__ Limestone, mostly hard, massive, cavernous; much flint in 500+- 
Cretaceous). copy: 
Comanche Peak...| L estone, yellow, impure; many Erogyra terana..__._.... 60 
There is considerable agriculture about Uvalde, but the climate 
approaches the semiarid, with an annual rainfall of approximately 
inches. Although Sogn i is usually a short rainy season in the spring 
or ants summer and another in the autumn, most of the streams are 
dry for the greater part of the year. Watacve pastures sustain many 
cattle, sheep, and goats. In places there is an extensive growth of 
‘‘prickly pear,” or me (no-pahl’), which is used rather extensively 
for forage after the thorns are singed off. A large amount of honey 
is produced in this region, aided greatly by the presence of various 
plants such as mesquite and huajillo (wah-hee’yo), which yield much 
nectar for the bees. There is a notable spring on the Leona River 
a mile below Uvalde, which is locally estimated to furnish about 
7,000,000 gallons a day, but the volume varies somewhat with the 
seasons. The water is used for irrigation. 
In the region between Uvalde and Del Rio portions of the Rio 
Grande Plain, which is a western extension of the Gulf Coastal Plain, 
reach the Southern Pacific line in places notably about Spofford 
and westward. The lower lands are mostly level and the valleys are 
shallow. Smooth surfaces prevail about Spofford and westward to 
Del Rio. The Edwards Plateau lies some distance north, beyond 
limestones, and many buttes or knobs of hard, igneous rocks peeves 
prominently above the general surface. 
