2i6 THOMAS L. WATSON 



leopardite is reported to be found is referred to by Genth, namely, 

 near the Steele mine in Montgomery county. 



More recently the leopardite occurring near Charlotte has been 

 noted by Merrill' and Lewis^ After briefly describing the general 

 appearance of the rock, Professor Merrill makes further statement 

 of its economic value. In connection with his work on the building- 

 stones of North Carolina, Lewis visited the locality to the east of 

 Charlotte, where the leopardite is exposed, and, so far as contained 

 in published accounts of the rock known to me, he was the first to 

 note its true geological occurrence. 



Quartz porphyries in association with other closely similar acid 

 volcanic rocks are developed, in places, over the central and the 

 northwestern parts of the state. So far as known at present, the 

 areas of acid volcanic rocks are confined to the volcanic belt which 

 skirts the western margin of the Triassic sandstone in the eastern 

 Piedmont region,^ and to several of the extreme northwest counties"^ 

 of the state. These rocks show no essential differences, so far as 

 they have been studied, from certain areas of similar ones which 

 occur and are traced at irregular intervals northward along the Atlan- 

 tic border region of North America as far as Newfoundland. 



Of those occurrences in North Carolina, the quartz porphyry 

 found near Charlotte is the only one visited by me that shows the 

 characteristic spotted appearance so suggestive of the name "leop- 

 ardite." Except for the mottled or spotted appearance produced 

 by rounded black areas of metallic oxides, the Charlotte rock differs 

 but slightly, if at all, in essential characters from quartz porphyries 

 described from other localities. (See table of analyses on p. 223). 



' George P. Merrill, Stones for Building and Decoration (New York, 1897), 

 2d ed., pp. 272, 273. 



= T- V. Lewis, Notes on Building and Ornamental Stone, First Biennial Report of 

 the State Geologist, N. C. Geological Survey, 1893, p. 102. 



3 George H. Williams, "The Distribution of Ancient Volcanic Rocks Along the 

 Eastern Border of North America," Journal of Geology, Vol. II (1894), pp. 1-32; 

 J. S. Diller, "Origin of Paleotrochis," American Journal of Science, Vol. VII (1899, 

 4th sen), pp. 337-42- 



■•A. Keith, Bulletin No. /68, U. S. Geological Survey, p. 52; Geologic Atlas of 

 the United States, " North Carohna-Tennessee, Cranberry Folio," 1903. . 



