88 
RIO GRANDE COAL FIELDS OF TEXAS. 
[bull. 164. 
The following data were furnished by Mr. R. E. Russell, former 
general manager of the San Carlos Coal Company: x 
Analysis of coal from Presidio County, Texas. 
No. 1. 
No. 2. 
Moisture 
Per cent. 
1. 
39. 05 
49. 05 
10. 
Trace. 
Per cent. 
0. 94 
34. 48 
58. 96 
5.62 
.64 
Volatile matter 
Fixed carbon 
Ash 
Sulphur 
This analysis was undoubtedly made from picked samples. 
A test of the coal for steaming purposes was made on the Southern Pacific Rail- 
road. The coal tested had been subjected to exposure for five or six months on the 
various dumps, and was practically crop coal, yet the average mileage for a ton of 
coal was 52.21 on passenger trains of five or six coaches. 
Tests of the coking qualities of the coal were made at Connellsville, Pennsylvania, 
with good results. Forty-eight hour coke, burned in the oven at the mine, quite 
recently gave the following results: 
Analysis of coke from Presidio County, Texas, coal. 
Per cent. 
Combustible matter 
93.7 
6.2 
Ash 
REPORT ON IGNEOUS ROCKS FROM THE VICINITY OF 
SAN CARLOS AND CHISPA, TEXAS. 
By E. C. E. Lord. 
The material submitted to me by Mr. T. Wayland Vaughan for 
petrographic examination was taken from a series of late Cretaceous or 
early Tertiary lava flows, constituting a large part of the Vieja 
Mountains, Texas. 
The geologic relationship and distribution of these igneous rocks 
is explained by Mr. Vaughan in the foregoing text. 
The only literature bearing directly upon the petrography of the 
region is a short report by A. Osann 2 on a specimen of nepheline- 
tephrite and a series of s}^enite-porphyries or quartzless porphyries 
from the Vieja Mountains. The description of the latter rock corre- 
sponds somewhat with that of the quartz-pantellerite given below, 
but no reference is made by the author to triclinic feldspar, eegirine- 
augite, or porphyritic quartz. 
1 Mineral resources U. S. 1893, p. 385. 
2 A. Osann, Report on the rocks of Trans-Pecos Texas : Fourth Ann. Rept. Geol. Survey of Texas, 
1892, p. 34. 
