REPORT OF THE STATE GEOLOGIST. xlix 



interference in the water-bearing beds, are few in number. With the 

 advantages of climate, rainfall, soil, health, and the boon of unfailing 

 artesian water, this region is indeed a favored one. 



Eagle Pass Coal. — While the Cretaceous was for the greater part 

 a period of marine conditions, there were periods which favored the 

 formation of coal in larger or smaller quantities. Beginning even in 

 the Trinity sands (to be described beyond), we find numerous traces of 

 lignite, sometimes in considerable quantities. Higher in the series 

 small seams of coal, sometimes approaching a bituminous character, are 

 found, but are never more than a few inches in thickness and of very 

 limited extent. The only exception now known occurs on the Rio 

 Grande in the vicinity of Eagle Pass. Here there is a local deposit of 

 considerable value. The fact of its existence and value is most inter- 

 esting. It is the heaviest bed of coal that has yet been discovered in 

 the State, averaging, according to our measurement, about five feet in 

 thickness. It is a good fuel for household and steam purposes, but we 

 have not yet been able to obtain any definite information in regard to 

 its coking qualities under proper treatment. It is reported as forming 

 a coke in a gas retort, but this is not a good criterion from which to 

 judge of its merits or demerits, and the matter can not be regarded as 

 finally settled until it has been given a fair test in properly constructed 

 coke ovens. The great demand for coke for metallurgical purposes in 

 Western Texas should be incentive enough to the owners of the mines 

 to have these tests made. 



Concerning the age of this bed many opinions have been expressed. 

 It has been variously referred to the Carboniferous, Permian, Triassic, 

 and Cretaceous, by different writers. Paleontologic evidence seems 

 to prove that this bed is geologically lower than those known as 

 "Laramie," to which Dr. White* decided the Sabinas, Mexico, coal be- 

 longed, and that it is clearly Upper Cretaceous ; but it will require 

 closer stratigraphic and paleontologic work than has yet been devoted 

 to it to determine its exact horizon. 



This coal bed dips to the southeast, as do the enclosing strata of this 

 formation, and it will probably be found by boring at other places 

 around Eagle Pass. 



*American Journal of Science, January, 1881, No. XXXIII, pp. 19, 20. 



C* 



