THE MIDDLE AND UPPER EOCENE OF TEXAS. 
E. T. DumbleA 
In the Tertiary section as determined by the work of the Geological 
Survey of Texas, we recognized no Eocene deposits of later age than 
the Claiborne, which stage was divided into four substages based 
primarily on lithological differences, but afterward found to be also 
valid divisions paleontologically. These substages were called the 
Marine, Yegua, Fayette and Frio. 
The principal observations on which the three upper divisions 
were based were made west of the Brazos river. More recent work 
through the coast country has shown the correctness of the proposed 
divisions not only in this territory and in Northeastern Mexico, but 
also east of the Brazos, where for several years some confusion has 
existed by reason of incorrect correlation made of certain beds found 
there with those of our western section. 
In the Third Annual Report of the Geological Survey of Texas, 
Mr. W. Kennedy, in his paper on this Section from Terrell to Sabine 
Pass gives the details of the section as he made it from the Ange- 
lina river to Corrigan along the line of the H. E. & W. T. Ry. He 
describes the Lufkin or Angelina county deposits as extending from 
the Angelina river southward across the Neches river and the Fay- 
ette sand as extending from the south side of the Neches, where it 
overlay the Angelina beds, southward to and beyond Corrigan, where 
it was overlain by the Flemming clays. Later, when the Yegua beds 
were differentiated along the Brazos drainage, the Angelina beds 
were correlated with them, owing to their position above the recog- 
nized Marine beds and below the supposed Fayette, and the Flem- 
ming beds were called Frio. 
Fuller collections made by Mr. A. C. Yeatch from near the base 
of the supposed Fayette south of the Neches river resulted in the 
finding of a Jackson fauna and Prof. G. D. Harris, who determined 
these fossils, in his report on the Geology of Louisiana, classed our 
supposed Fayette as Jackson and assigned the Flemming-Frio to the 
base of the grand Gulf of Oligocene. This apparently conflicted with 
our former grouping of the Fayette and Frio with the Claiborne. 
As there was no question but that the beds in Western Texas, 
to which these names were originally given, contained Claiborne 
fossils in abundance and did not contain forms connecting them with 
the Jackson, I had an examination made of the region between Nac- 
*Former State Geologist. 
