88 TRANSACTIONS OF THE TEXAS ACADEMY OF SCIENCE. 
writer, from the fossils common to both localities, as being the horizon 
of the great asphaltnm deposits north of Ardmore, and this determina- 
tion was afterwards confirmed by the investigations of Dr. Stevenson. 
So far, however, the oil in these beds in Texas seems to be entirely 
confined to the western slope of the Carboniferous geanticlinal, since the 
well at Fort Worth, on its eastern slope, penetrated the beds for more 
than a thousand feet without finding a trace of either oil or gas. 
The beds of the Cretaceous, which cover so large an area in Texas, 
show several distinct oil horizons. The lowest of these is in the Trinity 
Sands in Jack and Montague counties. Here is found a very heavy oil, 
locally called asphaltnm, which impregnates the sand beds, and has been 
used to a limited extent for paving purposes. 
In the vicinity of Burnet, the Pieuroceras ( Vicarya branneri, Hill) 
limestone carries a heavy oil or asphaltnm in such quantities as to give 
promise of becoming commercially valuable as a paving material. 
The Washita division also yields some asphaltnm in Western Texas 
and in Northern Mexico, but I can not say at present whether the de- 
posits in the vicinity of Cline, IJvalde .county, are of this age or later, 
as such fossils as I have seen are not sufficient to determine the age of 
the horizon positively. 
The Eagle Ford (Benton) shale also furnishes a small supply of oil. 
In the cut on the International and Great Northern Railway south of 
Austin these beds are quite oily — so much so that they will bum. A 
number of years ago a well was sunk at Fiskville, northeast of Austin, 
and a small amount of oil was found, which is supposed to come from 
this horizon. 
The horizon succeeding these — that of the Ponderosa marls — bids fair 
to be one of the most productive of the State. This great clay deposit, 
which is the substructure of our famous black waxy prairies, and whose 
economic value has always been considered as confined to these soils, 
now proves to contain great mineral deposits as well. In Presidio county 
it contains beds of bituminous coal; in Bexar, Navarro, and Hardin(?) 
counties it furnishes flows of oil and gas; in Van Zandt, Smith, and 
Anderson counties large beds of rock salt occur in it; and in it, in Cal- 
casieu parish, Louisiana, are the great sulphur and gypsum deposits. 
While the production of the oil wells south of San Antonio is limited, 
the wells have been flowing for several years, and are still productive. 
At Corsicana oil was first found by Major Alex. Beaton in boring for 
water on his place “Gem Hill/’ southeast of the city. In 1894 the city 
drilled an artesian well near the “Cotton Belt” track, and at 1040 feet 
struck a vein of oil. This was shut off and the boring continued to the 
water sands (Dakota) at 2470 feet. The oil, however, forced itself to 
the surface of the ground outside the pipe put down to case it off from 
