42 
TRANSACTIONS OF THE TEXAS ACADEMY OF SCIENCE. 
Eagle Ford Shale.— The soils of this belt differ but little from those 
of the two already described. The subsoil is a blue friable clay marl in 
a finely divided state, and on thorough weathering forms a deep soil. 
The surface is level or gently rolling where not cut by streams, and there 
is no waste land. It comprises the rich black lands about Hillsboro and 
between Hillsboro and Alvarado. Also eastern Denton, western Collin 
and western Grayson counties. 
The Eagle Ford soils are very close to the Ponderosa in chemical com¬ 
position, as shown by analysis No. 29 of a residual soil from Williamson 
county. 
Insoluble matter.... 
Soluble silica. 
Potash. 
Soda. 
Lime. 
Magnesia. 
Iron. 
Alumina . 
Phosphoric acid_ 
Sulphuric acid. 
Carbonic acid. 
Water. 
Organic and volatile 
29* 
57.03 
.20 
.65 
1.06 
3.78 
.32 
5.21 
10.52 
.03 
.13 
2.73 
5.64 
12.99 
* Third Annual Report Geol. Sur. Tex., p. 379. 
106.29 
Lower Cross Timbers.— The soils of the Lower Cross Timbers are of 
two kinds. The eastern third and more level portion gives sandy loams, 
which are well adapted to fruits and are more fertile than those of the 
western portion. The western soils have their origin in a fine grained 
friable sandstone, containing very little clay, and yielding in the hilly 
portions light sandy soils and in the lower and more level lands a deep 
loamy sand. 
These lands are much better suited for orchards and vineyards than 
for cotton and corn. 
A Dakota sandy soil is represented by analysis 30, from Tarrant 
county. 
30* 
Insoluble matter. S5.086 
Soluble silica . 5.313 
Potash.213 
Soda. 079 
Lime.342 
Magnesia.174 
Manganese .015 
Iron. 2.469 
Alumina. 2.672 
