lxiv REPORT OF THE STATE GEOLOGIST. 



still further westward in Mason County, and some in Llano, but all are 

 apparently connected with the same series of rocks. 



The ores at the surface are largely carbonates, both Azurite and Mala- 

 chite occurring, but the latter predominating. Tetrahedrite is more or 

 less common, and sometimes carries considerable silver.^ Chalcopyrite 

 is also present in small quantities, and in some places Bornite occurs. 



The various prospecting works which are scattered through this area, 

 beginning at the Houston and Texas Central Kailway diggings on the 

 east, includes many trial shafts and pits sunk by Capt. Thomas Gr. Mc- 

 Gehee on Little Llano, Yoakum, and Wolf Creeks, Hubbard Mining 

 Company on Pecan Creek, others by the Houston Mining Company on 

 Wolf Creek, and the Miller Mine also on Pecan. Further west in Ma- 

 son County similar prospecting works are found. In addition to these 

 some prospecting has been done in the vicinity of Llano, and also south- 

 east of that city. Specimens taken from the different localities by dif- 

 ferent members of the Survey assayed all the way from one per cent 

 to forty five and six-tenths per cent copper, in silver from nothing to 

 107.8 ounces per ton, and of gold from nothing to one-fifth ounce. 



There have been several attempts at development, but there are no 

 mines in successful operation at present. The work that has been done 

 on the different outcrops has not been carried sufficiently far, nor has it 

 been of such a character, as to make it possible to speak with certainty 

 regarding the existence of extensive bodies of copper ore in the district. 

 What has been done, however, taken in connection with the outcrops 

 and assays, and our knowledge of tne geological formation of the coun- 

 try, suggests the accumulation of ores of considerable importance below, 

 and will justify a much larger expenditure for the purpose of develop- 

 ing them than has yet been made. 



COPPER ORES OF TRANS-PECOS TEXAS. 



The ores of this district have been known for many years, and con- 

 siderable prospecting has been done on them. There is, however, only 

 one mine in operation at present — the Hazel Mine in the Diabolo Moun- 

 tains, near Allamore, El Paso County. This mine is situated at the 

 foot of the Sierra Diabolo on a lime-spar lead cutting through a red 

 sandstone. The principal ore is copper glance or sulphide of copper, at 

 times carrying a good deal of wire silver, and occasionally rich pockets 

 of grey copper. This pay streak runs in a vein from a few inches up 

 to ten feet in width, in a gangue of strongly siliceous limestone, which 



