PRELIMINARY REPORT 



COAL FIELDS OF THE COLORADO RIVER. 



RALPH S. TARR. 



The section covered in this report includes the northwestern portion of 

 Lampasas County, along the Colorado River; about two-thirds of San Saba 

 County, principally north of the San Saba River; McCulloch County north 

 of Brady Creek; the eastern part of Coleman County, from the Colorado as 

 far north as Jim Ned Creek; Brown County, east of Pecan Bayou; and the 

 southeastern corner of Mills County. The greater part of this area is under- 

 laid by rocks of the Carboniferous system, and the chief object of the work 

 was to determine the amount of coal, its position in the series, and the rela- 

 tion which it and the surrounding rocks bear to each other. The object of 

 this report is to state, in general terms, and as briefly as possible, the most 

 important results of the work, as a preliminary report, to be followed later 

 by a more comprehensive and detailed statement. 



This portion of the Carboniferous area is bordered on the east and west by 

 outcrops of Cretaceous rock, which overlie the Carboniferous unconformably, 

 the dip of the former being southeast and the latter northwest. To the 

 north the Carboniferous rocks extend away toward the Indian Territory; but 

 just north of Coleman County a band of Cretaceous covers the Carboniferous, 

 nearly connecting the east and west Cretaceous areas. Pecan Bayou has cut 

 through this capping rock and revealed the Carboniferous below, thus con- 

 necting the Palo Pinto field with the southern field by a narrow neck. In 

 the center of the Carboniferous area buttes of Cretaceous are found resting 

 upon the Carboniferous, either as isolated peaks, as in the case of Santa 

 Anna Mountains and Harkey Knobs; or in a broad area, as, for instance, 

 that south of Brown wood, in the angle formed by the Colorado River and 

 Pecan Bayou; or as in the case of Brady Mountains, in the form of a long 

 spur connected with the main body of Cretaceous rocks. 



It is plain from this and other evidence that the Carboniferous has been 

 uncovered by the erosion and removal of the Cretaceous rocks which once 

 buried them, and that this removal is very recent and still in progress. At 

 its southern border the Carboniferous rests on older formations. The older 

 Paleozoic rocks of Llano and Mason counties were the chief land areas from 



