78 
Tran^s ACTIONS Texas Academy of Science. 
drake^ isr. F. 
tion's of Aceumulation. 'Iron Ore. Clays. Bulldinig Stone: Weather- 
ing and 'Durahility of Building Stones j Building iSltones of the Oarhoni- 
ferous Beds; Strawn Division; Canyon Division; Cisco Divison; Albany 
Division; Cretaceous Building Stones. /Road-making fMaterial. Paving 
Material. Grind Stones; Lime Manufacture. 
“The region embraced in the following report lies between 31° 10' and 
32° north latitude and 98° 30' and 100° west longitude. This area, about 
4000 square miles, includes nearly all of Brown and Coleman counties, 
Runnels county east of Norwood, the northeast part of Concho county or 
the part lying east of- Paint Rock and north of Eden, McCulloch and San 
Saba counties north of Brady creek and the town of San Saba, the north- 
west corner of Lampasas county. Mills county west of the Gulf, Colorado 
and S'anta Ee Railway, and a small area in Comanche county north and 
northwest of Oomanche. 
“Preliminary examinations of the Carboniferous beds of this area have 
been made by Messrs. W. F. Cummins and R. S. Tarr, and like investiga- 
tions of the Cretaceous areas have been made by Messrs. R. T. Hill and 
J. A. Taff. 
“These geologists have determined the stratigraphic relations of the 
divisions and terranes of these formations, and their classifications have, 
for the most part, been followed in this report. The work of the present 
season has been of a more detailed character than that hitherto undertaken. 
Each bed has been studied with reference to its extent, stratigraphic rela- 
tions, lithologie characters, fossil forms, and economic features. 
“The whole of this region, except that portion embraced in Comanche 
county, is drained by the Colorado river and some of its tributaries. While 
it is practically all in the same hydrographic basin, it has branching basins, 
which are of considerable extent, and are more or less distinct within them- 
selves. iSo we may consider this area under its main and two other prin- 
cipal branching basins., These three basins are as follows : In the south 
we have the lower part of the San Saba river basin drained by the lower 
course of that river, with Brady creek and other smaller streams emptying 
into it from the north; the central portion comprises a part of the Col- 
orado river basin, drained by the Colorado river and its numerous small 
tributaries from either side, together with a little of the lower course 
of the Concho river; and the noirtheastern part is -drained by Pecan bayou, 
with its tributary creeks. Wild Horse, Willis, and Jim Ned from the 'west, 
and Eliott, Brown, Bull, Elm, Hog, Paint, and other creeks from the east 
and north. 
“The general slope of the country is to the southeast, but this slope is 
modified to form the above named basins. The San Saba river and Brady 
creek basin slopes to the east, the main Colorado river basin to the south- 
east, and the Pecan bayou basin to the south. These three basins converge 
towards a common point near the northeast corner of 'San Saba county. 
“There are two principal or general phases of the topography, one char- 
acteristic of the Cretaceous, and the other of the Carboniferous. The Cre- 
taceous formation, lying nearly horizontal and composed of beds of increas- 
ing hardness from the base upwards, with some horizons that slightly 
alternate in hardness, presents bluff, bench, or terraced undulations along 
