LEAD. 



583 



Fig. 64. 



Section and plan along line E-F on map (Plate XXI), crossing the most southern of the 

 Burnetian Folds exposed in the Central Mineral Region. 



The area in which there may be some little chance of the discovery of cop- 

 per ores in this belt may be roughly defined as extending from west of Round 

 Mountain, in Blanco County, to aline east of Loyal Valley and Cherry Spring; 

 but there is very little of the tract in which the copper bearing strata are 

 near enough to the surface to make mining profitable in any event. In fact, 

 the existence of the belt as such is chiefly predicated upon the discovery of 

 traces of malachite in the deeper workings of the Nonly mines, near Enchanted 

 Rock. At that point the structure is very complicated, and the inducements 

 offered by the returns have not been such as to justify extensive exploration. 

 It may be confidently predicted that if any copper deposits of economic value 

 be hereafter found in this region they will be such as conform in all essential 

 particulars to the conditions here announced. 



2. LEAD. 



The distribution of lead ores in the Central Mineral Region has received 

 much attention at our hands the past season, the conclusions reached in 1889 

 and published in the Report of that year being well substantiated by the ad- 

 ditional facts ascertained. 



The percentage of lead in the districts referred to under the title "Silver" 

 (this Report) is comparatively small. The galena which may eventually be 

 mined from these areas will be of more importance as a smelting* factor for 

 the associated ore than for any figure it may cut in the lead mining industry. 

 But there are other deposits of this mineral which carry but little silver ordi- 



