74 GUIDEBOOK OF THE WESTERN UNITED STATES 
Eagle Ford and Buda limestones and Del Rio clay, the Eagle Ford 
beds being exposed for some distance along the railroad near Ange 
siding. Big Mountain, a mile northwest of Ange, is made up of 
Georgetown limestone. The Cretaceous strata in this vicinity are 
penetrated by igneous masses, some of which, on account of their 
hardness, crop out prominently. (Turn to sheet 11.) 
The train passes about 2 miles north of Uvalde, with which the 
station is connected by a paved boulevard. Uvalde is the name of a 
Spanish officer who with 20 soldiers defeated many 
Uvalde. times that number of Comanches. The region is 
petinrgectcatoaag mostly a smooth alluvial plain in which rise many 
rieans 664 miles. Small ridges and knobs of Cretaceous strata or the 
igneous masses that penetrate them. There are also 
higher terraces of considerable extent capped by gravel, which mark 
an earlier stage of the topographic development of the region. Not 
far north is the edge of the Edwards Plateau,” a highland consisting 
of a wide area of the hard Georgetown and Edwards limestones lying 
nearly horizontal and deeply trenched by many rivers and creeks. 
Not far north of Uvalde and at intervals to the east and south- 
east are exposures of Eagle Ford limestone, Buda limestone, and the 
yellow Del Rio clay. Along or not far from the railroad to the south 
are small outcrops of Austin chalk, and from 10 to 20 miles southwest 
and south are exposures of sandstone and clay of the Indio forma- 
tion (Tertiary), in places underlain by Midway formation. Some 
of the general relations are shown in the cross section on sheet 11. 
The stratigraphic succession is given in the following table: 
The Edwards Plateau constitutes | areas from which the younger lime- 
a large part of central Texas and near | stone has been removed. 
Big Spring is overlapped by the High e sharp rise at the eastern and 
Plains without much topographic break. | southern edge of the Edwards Plateau, 
The late Tertiary deposits of the High usually referred to as the Balcones 
ins were on a plain of the | escarpment, owes its prominence to th 
limestones of the Edwards Plateau but presence of the hard limestone, in 
did not cover the portion south of places uplifted by faults but generally 
latitude 31°. The Edwards Plateau rising rapidly on the dip. Parts of 
extends west to the Marathon uplift | the plateau are so deeply trenched as 
and east to the vicinity of San Antonio | to present many isolated mesas and 
and Austin. In larger part it is capped | buttes. (Mesa (may’sah), a Spanish 
by 100 feet or more of Georgetown | word meaning table, is applied to a flat- 
limestone (Washita group), the Ed- topped butte or hill; one that has a 
wards limestone appearing in the sloping tabular surface is called a 
slopes of the valleys and on some of the cuesta (kways’tah),) 
