HISTORICAL REVIEW. 19 
because they form an important part of a belt of similar rocks extend- 
ing northward and southward along the Atlantic Coast. 
Following is a list of publications on the rocks of South Mountain, 
Pennsylvania : 
BIBLIOGRAPHY. 
1755. Lewis Evans. Analysis of a map of the British colonies. 
1787. Schopf. Beytriige zur mineralogischeii Kentniss des ostlichen Theils von Nord- 
amerika unci seiner Gehiirge, chap. 30, pp. 66-101. 
1858. Rogers. Geology of Pennsylvania, Vol. I, pp. 203-209. 
1860. Tyson. Report on the Geology of Maryland, pp. 31-35. 
1875-1877. Frazer. Second Geological Survey of Pennsylvania; Report of progress 
in the counties of York, Adams, and Franklin, Vol. CC, p. 285. 
1876. Hunt. Proc. Am. Ass. Adv. Sci., pp. 211-212. 
1877. Frazer. Copper ores of Pennsylvania; Polytechnic Review, Vol. Ill, p. 170. 
1878. Hunt. Second Geological Survey of Pennsylvania, Vol. E, p. 193. 
1879. Frazer and Hunt. Trans. Am. Inst. Min. Eng., Vol. VII, pp, 331, 332, 338. 
1879. Blandy. The Lake Superior copper rocks in Pennsylvania; Trans. Am. Inst. 
Min. Eng., Vol. VII, p. 331. 
1880. Frazer. Second Geological Survey of Pennsylvania, Vol. CCC. Appendix. 
1883. Frazer. Iron ores of the middle James River; Trans. Am. Jour. Min. Eng., 
Vol. II, p. 203. 
1883-1884. Frazer. An hypothesis of the structure of the copper helt of South 
Mountain ; Trans. Am. Inst. Min. Eng., Vol. XII, p. 82. 
1883-1881. Henderson. The copper deposits of South Mountain; Trans. Am. Inst. 
Min. Eng., Vol. XII, p. 90. 
1891. H. R. Geiger and A. Keith. The structure of the Blue Ridge near Harpers 
Ferry ; Bull. Geol. Soc. Am., Vol. II, pp. 155-161. 
1892. Lesley. A Summary Description of the Geology of Pennsylvania, Vol. I, p. 116. 
1892. G. H. Williams. The volcanic rocks of South Mountain, in Pennsylvania 
and Maryland; Am. Jour. Sci., Vol. XLIV, pp. 182-496, PI. X. Reprinted 
in the Scientific American, Jan. 14, 1893. 
1892. C. D. Walcott. Notes on the Camhrian rocks of Pennsylvania and Maryland, 
from the Susquehanna to the Potomac; Am. Jour. Sci., Vol. XLIV, pp. 
169-181. 
1892. A. Keith. The geologic structure of the Blue Ridge in Maryland and Vir- 
ginia; The American Geologist, Vol. X, No. 6, pp. 362-369. 
1893. G. H. Williams. Piedmontite and scheelite from the ancient rhyolite of 
South Mountain, Pennsylvania; Am. Jour. Sci., Vol. XLVI, pp. 50-57. 
1896. C. 1). Walcott. The Cambrian rocks of Pennsylvania; Bull. U. S. Geol. Sur- 
vey No. 134. 
