36 
TRANSACTIONS OP THE TEXAS ACADEMY OF SCIENCE. 
proportions of sand and clay that they contain They may be classed as 
prevailingly sandy. The southern portion of Live Oak county furnishes 
typical bodies of these soils. 
Frio Clays. —In eastern Texas these clays are very limited in extent, 
occurring in a comparatively narrow belt in the northern parts of New¬ 
ton, Jasper, and Tyler counties. They are covered in many places by 
deposits of later date, but may be recognized in limited areas west of the 
counties named, as at Riverside and southwest of Huntsville. They are 
more important west of the Colorado, and are found at the mouth of the 
Frio and in the valley of the Nueces in McMullen county. They yield 
black sticky to black waxy soils, and contain considerable lime and 
gypsum. 
Fayette Sands. —This belt, from five to twelve miles in width, gives 
rise to a veiy broken country. Its northern border usually presents a 
precipitous face and its forest-covered surface is quite rugged. Its soils 
as seen at Groveton and Trinity are gray sands, which are, however, often 
obscured or replaced by gray sands of still later date. The soils around 
Ledbetter, where not covered with the later gravel and sand, are also of 
this age. 
To the west the Fayette belt yields sandy soils or sandy loams, usually 
timbered, and clay loams forming prairies or with only a meager growth 
of mesquite. 
Yegua Clays. —This belt is also largely covered with later deposits, and 
in the eastern part of the State the soils are less important than they are 
in the west. They underlie a wide area, however, from San Augustine 
county west, and where exposed form dark clay loams to light gray sands, 
while the subsoil is, of course, the sandy clays and lignitic clays of the 
formation. 
In Brazos county they produce fine grained sandy loams of dark grayish 
color with considerable excess of sand. They readily leach to a pale yel¬ 
lowish gray or white. These gray sands frequently form extensive prai¬ 
ries. 
Westward this belt furnishes brown and chocolate clay loams, with only 
a few comparatively narrow bands of light gray or brown sandy soils. 
In places the beds carry considerable lime and the soils become more marly, 
in certain localities forming black sticky if not quite black waxy soils. 
The light brown sands sometimes form level prairies entirely devoid of 
timber growth. 
The gray upland soils of the Tertiary plain, as shown in analyses Nos. 
8 and 9 of samples from Grimes county, are deficient both in potash and 
phosphoric acid; hence they are soon exhausted. When the subsoil is a 
clay like that at College Station, deep plowing would in some manner rec¬ 
tify this as shown by the amounts of potash and phosphoric acid found in 
the clay. (Analysis No. 10.) 
