586 



CENTRAL MINERAL REGION OF TEXAS. 



considerable portion of Gillespie County. Moreover the geology of the Bea- 

 ver Creek district is very similar to that of the country westward as far as 

 Little Llano Creek, where the effect of this same Silurian geanticline is well 

 marked, and where a prominent fault has left the Burnetian axis upon the 

 eastern side far beneath the present surface. Again, the granite here, as in 

 other places where the undoubted Post-Silurian uplift is manifest, contains in 

 places the characteristic schist inclusions. Another confirmation of the same 

 reference is the very similar geologic situation in the Pedernales River galena 

 district, which lies very nearly in the course of the Silurian axis prolonged 

 southward from Beaver Creek. 



Workings. — Since 188V) Mr. G. C. Gage has been more or less constantly 

 engaged in testing the outcrops in Silver Mine Hollow and in Beaver Creek 

 Canyon above the mouth of Lacy Branch. Former excavations made in the 

 path of the dyke and along the granite-Silurian contact have afforded con- 

 siderable information regarding the positions most favorable for develop- 

 ment, but with all the explorations heretofore made no profitable accumula- 

 tions have been discovered. We may better discuss the causes for this after 

 the situation in other cognate districts has been described. 



THE PEDERNALES TRACT, BLANCO COUNTY. 



North of Hye Postomce, in Blanco County, in the neighborhood of the 

 now abandoned Westbrook Postomce, there is a small area in which the 

 segregations of lead ore are of sufficient moment to attract special attention. 

 The geologic situation so far as the galena deposits are concerned is very sim- 

 ilar to what has been described under the preceding head in Burnet County. 

 Figure 66 shows this more clearly than it can be stated in words. 



Pig. 66. 



Plan and section along line I-J of map (Plate XXI), illustrating the geology of the Lead 



District north of Hye Postoffice, in Blanco County. 



