56 OIL FIELDS OF TEXAS-LOUISIANA COASTAL PLAIN, [bull. 212. 
sands are in close connection with and in many places form a portion 
of the upper margin of these deposits, so that in all probability they 
will ultimately be found to be of the same age as these red and white 
sands, the difference in color being largely due to bleaching. 
Along their southern edge the sands of this division merge so imper- 
ceptibly into the overlying Columbia sands that it is often difficult 
to say where the line should be drawn. To add to this difficulty, the 
upper sands of both Lafayette and Columbia have a tendency to 
weather to a dirt} 7 brown white, and few sections showing the con- 
tact are visible anywhere. Both series are water bearing to a high 
degree. The Columbia sands also contain a series of mottled brown 
and blue and brown and white sands, although no clays of this char- 
acter have been observed. 
In their general composition these beds resemble those toward the 
middle and western portion of the field, and it is hardly necessary to 
describe them here. Few sections of over 10 to 25 feet are obtainable 
anywhere throughout the area, and even wells scarcely ever exceed the 
latter depth. In the overlapping at Colmesneii the section shows a 
heavy deposit of brown sand containing nodules or inclusions of a 
pinkish-purple clay. These inclusions generally have a rounded or 
nodular form and appear to have been transported to their present 
location. 
On the Missouri, Kansas and Texas Railroad, near Colmesneii, in 
Tyler County, these mottled sands appear to have a thickness of 10 
feet and to overlie the fossiliferous cross-bedded sands. A section is 
as follows: 
Section near Colmesneii, Tyler County, Tex. 
Feet. 
1. Gray sand 6 to 8 
2. Mottled blue clay in small irregular elliptical pockets i to 2 
3. Mottled brown sand or soft sandstone broken into irregular blocks and 
containing lenticular patches of pale grayish-blue clay stratified at each 
end of cut •_ _ . 10 
4. Gray cross-bedded sand, containing siliceous pebbles and fossil wood .__ 15 
Three and a half miles south of Colmesneii the contact between 
these brown sands and the underlying Frio clays may be seen in the 
following section : 
Section 3\ miles south of Colmesneii, Tyler County, Tex. 
Feet. 
1. Gray sandy soil 1 
2. Brown clayey sand 4 
3. Brown laminated sand 3 to 10 
4. Brown sand with pale-blue streaks 4 
5. Brown sand with a pinkish shade . _ 1 to 10 
6. Thinly stratified blue clay and red sand 6 
7. Blue clay with lime nodules (Frio) 6 
The purplish-pink clays of the Lafayette extend eastward through 
Jasper and Newton counties. In these locations, however, the} 7 
