Bulletin of the Scientific Laboratories of Denison University. 



Vol. XIl. Article VII. July. 1903. 



COPPER-BEARING ROCKS OF VIRGILINA COPPER 



DISTRICT, VIRGINIA AND NORTH 



CAROLINA^ 



BY THOMAS LEONARD WATSON. 



CONTENTS. 



Page 



Introduction, ........ 97 



Previous work, ...... 98 



General field characters and occurrence, - - - 102 



Petrography, ...... 105 



Macroscopic descriptions, - . . , 105 



Microscopy of the rocks, .... 106 



Chemical analyses, - - - - - no 



Evidences of eruptive character, - - - - 114 



Field evidence, - - - - - 114 



Microscopical evidence, - - - - 115 



Chemical evidence, - - - - - 117 



Comparison with other areas, - - - ■ 117 



Ore deposits of the district, ... - - 121 



Weathering, ...... 123 



Age relations, - - - - - - 124 



Conclusions, ...... 126 



Introduction. 



Some time was spent during the month of August, 1901, 

 in a field examination of the Virgilina copper district, and the 

 specimens of the rocks and ores collected were subsequently 

 studied in the laboratory. Study was principally confined, 

 both in th i field and laboratory, to the rocks of the area, to 

 determine their nature and origin. The ores were given only 

 secondary consideration. 



' The author is under special obligations to Professor J. Morgan ClementSi 

 of the University of Wisconsin, for kindly reading and criticising this paper in 

 manuscript, and he is indebted to Mr. W. H. Pannebaker, of Virgilina, for the 

 photographs illustrating it. 



Reprinted from Bulletin Geological Society of America, Vol. XIII, pp. 

 353-376, 1902. 



