358 



T. L. WATSON — VIRGILINA COFFER DISTRICT 



greater part of the belt to depths of 40 to 500 feet afford excellent oppor- 

 tunity for exceptional collections of the rocks and ores. 



The covering of loose, decayed surface rock and soil is very thin, and 

 the moderately fresh and firm rock is encountered at slight depths be- 

 neath the surface. 



At the mine openings some alteration in the vein constituents is indi- 

 cated to the entire depth of the workings, 400 to 500 feet. This is shown 



Figure 1. — Virgilina Copper District, Virginia and North Carolina 

 Copper district indicated by shaded area 



in the case of the sulphide ores, which in several places are slightly 

 changed by the percolating carbonated waters to the green copper car- 

 bonate (malachite) found slightty staining the vein material and the 

 unaltered ores. The rocks taken at these depths are of the same char- 

 acteristic green color, and the thin-sections indicate the same amounts 



