vaughan.] EOCENE FORMATIONS. 51 
Section of well on S. Gobbett survey. 
Feet. 
Soil 1 
Yellow and red clay 5 
Red sandstone, with occasional layers of hard rock 39 
Clay (the local "soapstone") 20 
Hard rock 28 
Soft clay and thin layers of sandstone 16 
Sandstone 20 
Clay and sand mixed 20 
Water-bearing sand 10 or 11 
Total 147 or 148 
The water rises to within 17 feet of the surface of the ground. 
The sandstone around Carrizo Springs is reddish in color, rather 
coarse-grained, crystalline, and slightly micaceous. 
Alternations of sandstone and clay outcrop along the road from Car- 
rizo Springs to Encinal for about 11^ miles from the former village. 
Here they pass below clays containing calcareous and hematitic concre- 
tions. From this locality to Santo Tomas the exposures consist of 
alternations of sandstones and clays, which often contain calcareous 
concretions. The sandstones are usually soft and micaceous. 
FRIO RIVER SECTION. 
(PI. Ill, A and B; PL IV, A.) 
Section across Eocene- Cretaceous contact, 2 miles below the Engelmann ranch and about 
5 miles due north of the southern boundary of Uvalde County. 
Ft. in. 
7. Rather soft yellow sandstone 22 6 
An interesting lithologic feature of this sandstone is the occurrence in 
it of large, oval, sandy nodules, which stand with their long axes verti- 
cal. They are from 1 foot to 1 foot 6 inches in length, and vary in dia- 
meter from 3 to 7 inches. Sometimes these nodules, when broken across, 
form sandstone disks. Some of them are more nearly globular. 
6. Soft, yellow, sandy clay, with bluish streaks; some small pebbles in the 
lower part 2 6 
5. Nodules of glauconitic sandstone, usually 6 inches thick; contain a considera- 
ble number of small pebbles. In the lower few inches of this layer con- 
siderable numbers of Ostrea cortex are found. It is in this layer thatiVaw- 
tilus n. sp. is found in so great abundance < i 
4. Soft, yellow, very argillaceous sands, quite glauconitic. There is a ledge of 
Ostrea cortex just about the top of this layer. A Turritella, probably T. trilira 
Conrad, was also found in it. This bed is the uppermost Cretaceous. 
3. Harder, sandy claystone, whitish blue and yellow in color 1 4 
2. Soft, yellow, sandy clay 8 8 
1. Sandstone, originally bluish, oxidizes brown and contains fucoidal impres- 
sions. In its upper part this stratum becomes softer and more yellowish 
and is in rather thin ledges 11 9 
There are about 25 feet of Eocene strata exposed in the bluff. 
Above the oyster (Ostrea cortex) ledge are 25 feet of soft sandstone 
ledges. Farther along downstream, at a still higher horizon, are 30 
feet of rather soft sandstone, very massive, and somewhat though not 
