lx REPORT OF THE STATE GEOLOGIST. 



The quality of the ores vary from those adapted to the manufacture 

 of steel, or "Bessemer ores," to those of low grade. 



CRETACEOUS IRON ORES. 



The ochres of the Cretaceous are found in Uvalde and Yal Verde 

 counties, and probably elsewhere. From analyses they appear to be of 

 very high grade, but no examination has yet been made of them by the 

 Survey. 



CARBONIFEROUS IRON ORES. 



A great quantity of hematite ironstone is reported to occur in the beds 

 adjacent to the Waldrip-Cisco Division, which, if it equal the sample 

 analyzed, is a very valuable ore. It will be found described on page 

 215, First Annual Report. 



IRON ORES OF THE CENTRAL MINERAL REGION. 



These ores are of three classes, Magnetites, Hematites, and Hydrous 

 ores, each of which has its own place and mode of occurrence. The 

 Magnetites lie in the northwest trend in the Archaean rocks, which for 

 practical purposes may be confined between " northwest-southeast lines 

 drawn through Lone Grove town upon the east and through Enchanted 

 Rock upon the west. This blocks out a district twenty miles wide, 

 and extending perhaps thirty miles in the direction of the strike. 

 Within this field, however, various structural features have prevented, 

 in many places, the outcropping of the iron bearing system, so that 

 probably two-thirds of the area is not in condition to yield ore without 

 removing thick deposits of later origin. Assuming that one-third of the 

 territory, in scattered patches, will show the Fernandan beds at surface 

 or at depths that may be considered workable from.an economical stand- 

 point, it must be understood that only a small fraction of the thickness 

 of these strata is iron ore. Keeping in mind also the folded condition 

 of the rocks, it is evident that the chances for mining will be dependent 

 largely upon the character of the erosion, it being premised that the 

 iron bed, if such it be, is not very near the top of the system to which 

 it belongs."* 



The general section of this system of rocks shows that the magnetite, 

 sometimes associated with hematite, occurs in a bed usually about fifty 

 feet thick at a definite horizon in it. The investigations of the Survey 



*First Annual Report, p. 348. 



