Xliv REPORT OF THE STATE GEOLOGIST. 



Beds, or Eagle Ford Shales, of the Cretaceous, as may be seen in the 

 vicinity of Fiskville and other localities in Travis County, and still 

 others southwest of the Colorado. Similar springs are found in Burnet 

 and other counties in the older rocks. 



The deposits which have been examined most fully are those of An- 

 derson County east of Palestine, where there is an asphalt bearing sand. 

 This appears to be due to the oxidation of the residuum of oil left in 

 the sand. Here they are of unknown and somewhat uncertain extent, 

 as they are apt to run into an oil bearing sand. This is possibly the 

 case with many of the deposits of East Texas. 



In Uvalde County there are several outcrops of bitumen impregnat- 

 ing both sandstone and limestone. Of the former, Mr. Owen says 

 (First Keport of Progress, page 72) : " This oyster bed is underlaid 

 by eight feet of black asphaltum sandstone, from which in warm weather 

 the asphaltum exudes and forms small pools." This is on the Nueces 

 Kiver fourteen miles southwest of Uvalde. The stratum here de- 

 scribed is continuous. The stratigraphical position is some thirty feet 

 below the San Tomas coal vein (that which is worked above Laredo), 

 and Mr. Owen states that the sandstone occurs at nearly every locality 

 where its stratigraphical position was exposed. The connection of this 

 asphaltic material and the coal seam mentioned over an area exceeding 

 one 'thousand square miles opens one of the most profitable fields of 

 fuel industry in Texas. 



Analyses of these asphaltum sands give an average of fourteen per 

 cent asphaltum. Beds of similar sands are known in Jack, Montague, 

 Martin, and other counties. Analyses gave the following percentages 

 of bitumen: 



Montague County, 8.90 to 10.20. 



Martin County, 10.72. 



The asphaltic limestone found in Uvalde County, specimens of which 

 are in the Museum, is richer in asphaltum than any of the sandstones, 

 the average of three analyses giving 20.35 per cent of bitumen. This 

 gives it the same composition as the best grade of asphaltic limestone 

 gotten in the Val-de-Travers, Switzerland, of which the famous asphalt 

 streets of Paris are made. It is a natural mixture of asphaltum and 

 limestone in the best proportion for good road making. 



OIL. 



Oil is often an accompanying material when the tar springs and de» 



