340 CENTRAL MINERAL REGION OF^TEXAS. 



trict, there are several areas which have been reported as possible producers 

 of the metal. Of these tracts, only one has yet shown good warrant for the 

 hopes of its advocates, although it would seem that this can not monopolize 

 the essential conditions, for there are other very similar exposures. 



The Beaver Creek District, in Burnet County, has been explored by shafts 

 which do not extend to a great depth. The situation, geologically, is pecu- 

 liar, and I have not yet had time to give it the attention it deserves. But 

 nothing is given herein at second-hand, and enough personal observations were 

 made in 1889 to get a clue to the main features. To bring the information 

 as near to date as possible, my efficient aid, Mr. Charles Huppertz, was sent 

 to the district in February, 1890, and such later data as he obtained are em- 

 bodied herewith. 



At the head of Silver Mine Hollow, a branch entering Beaver Creek from 

 the left bank not far above its mouth, there is a granite exposure in contact 

 with the Potsdam strata. The adjoining region is much faulted, and alterna- 

 tions of Cambrian and Silurian beds make up much of the section exposed 

 in the canyon walls of the Beaver Creek drainage basin. Apparently in the 

 fault courses, or part of them, there are veins or dykes, the courses of which 

 are north 25 degrees east, and perhaps east- west and northeast, although the 

 effect of the first named, or Post- Silurian, irruption seems to be most marked. 

 The granites, however, are of both this and the Post-Carboniferous type. 



The veins are not quartzose or granitic, but rather sandy and ferruginous, 

 the lead-bearing mineral (galena) being scattered through the mass in small 

 crystals. The galena is not confined to the veins; in fact, it is more abun- 

 dant in dark gray to green magnesian limestones, perhaps near the Cambro- 

 Silurian contact. The ore is scattered through the mass of the rock, as if 

 segregated, but it does not occur usually at any great distance from the veins 

 in the limestones. The excavations have chiefly been made in the search for 

 silver, and this has probably prevented the prospecting of the neighboring 

 cavern limestones, which may perhaps really be the sources of supply if 'they 

 are the equivalents of the galena limestones of Missouri and Wisconsin. The 

 whole subject needs careful examination, which it will receive at the writer's 

 hands as soon as practicable. The hopes for a silver industry based upon 

 these deposits is not promising, for there is nothing but the galena to yield 

 that metal, and the assays do not indicate its presence in paying amounts. 

 Assay No. 4, Table I, gives an idea of the present product, such as may be 

 easily obtained in moderate quantity by very simple methods of excavation 

 in the veins and the adjoining limestone. It is very probable that system- 

 atic exploration in this region may result in the discovery of large and valu- 

 able deposits of galena, for the rocks, the mode of occurrence, and the geologic 

 age of the ore beds correspond generally with the conditions existing in Mis- 



