vaughan.] EOCENE FORMATIONS. 45 
Dr. C. A. White has collected some fossils near Santo Tomas, but 
they have not been determined. These specimens, also those from the 
coal shaft, are poorly preserved. 
The dip at Santo Tomas, according to information furnished by Mr. 
Davis and based upon mine workings, is 2° N. 40° E. 
From the sandstone which immediately overlies the coal Mr. Davis 
had collected several fossil leaves, which he presented to us. Professor 
Knowlton has examined them, and finds a new species of Juglans, and 
another species which could not be determined. 
From the clays just above the coal (locality No. 280) Mr. Stanton 
collected some leaves and a Unio. The leaves were too poor for identi- 
fication. Professor Knowlton states that one looks like a Ficus; he is 
also of the opinion that the plants from Santo Tomas have a Laramie 
facies, but does not feel justified in expressing an opinion as to whether 
they are from the upper or the lower Laramie. 
The following is a resume of the section of the Eocene based on 
observations and the data accumulated: 
Resume of section of Eocene. 
Feet. 
5. The coal beds and the clays and sandstone immediately overlying them were 
the highest beds seen. Between the two coal seams is a bed of fossils not 
yet determined 190 
4. Below the coal beds is a series of alternations of clay, shales, and sandstones 
of a thickness of at least 400 
3. A series of fine-grained micaceous sandstone 300 
2. The coarsely crystalline Carrizo sandstone, with a thickness of at least 150 
1. Bluish clays — ascertained by a well boring, below which are more sandstones 
and clays. 
The fossils reported by Penrose * from Webb bluff probably occur 
below the Carrizo sandstone. 
It is evident that the coarse sandstone seen at and near Chupadero 
ranch has not been reached in the prospect drill at Carbon, near 
Santo Tomas. It is difficult to correlate the records of the drill at 
Pilot ranch with the Santo Tomas section. Lithologically the section 
resembles very much the coal-bearing portion of the Santo Tomas 
section. In the Pilot ranch drill hole the lower sandstone has not 
been reached. 
The disturbance in the dip at Santo Tomas, together with the 
extreme similarity in lithologic character of the beds, introduces such 
complications that reliable estimates of the thickness of the beds and 
the determination of the number and relative position of the coal 
seams can not be made until the area has been studied in detail. 
The following is taken from Penrose's description of the section 
along the Rio Grande from Webb bluff to Laredo. 2 The section of 
Webb bluff has already been given. 
1 First Ann. Rept. Geol. Survey of Texas, 1890, p. 41. 
2 First Ann. Rept. Geol. Survey of Texas, pp. 42 and 43; see also Dumble's Report on the brown 
coal and lignite of Texas: Geol. Surv. of Texas, 1892, pp. 137-139. 
