67 Geological Bibliography of Virginia it 



Coal-field near Richmond, Virginia. 



Quart. Jour. Geol, Soc, vol. iii, pp. 281-288, pis. lo-ii, 

 1847. 



Campbell, H. D., Tin Ore (Cassiterite) in the Blue Ridge 

 in Virginia. 



Amer. Jour. Sci., vol. xxvii, 3d ser., p. 411, 1884. 



The Potsdam Group East of the Blue Ridge at Balcony 



Falls, Virginia. 



Amer. Jour. Sci., vol. xxix, 3d ser., pp. 470-474, map 

 and figure, 1885. 



For further references, see under Campbell, J. L. & H. D., 



Campbell, H. D., & Brown, W. G., Composition of Cer- 

 tain Mesozoic Igneous Rocks of Virginia. 



Bull. Geol. Soc. Amer., vol. ii, pp. 339-348, 1891. 

 {Abst.) Amer. Geol., vol. viii, p. 54, 1891. 



" Amer. Nat., vol. xxv, pp. 1002-1003, 1891. 



Campbell, J. I/., Geology of Virginia: Balcony Falls. The 

 Blue Ridge and its Geological Connecftions. Some Theo- 

 retical Considerations. 



Amer. Jour. Sci., 3d ser., vol. xviii, pp. 435-445, map 

 and se(5tion, 1879. 



{Abst.) Geol. Record, 1879, London, 1887, p. 135. 



Details of Archaean, Primoidal and Lower Silurian Rocks; the 

 mode of contortion and denudation is suggested. 



Geology of Virginia: Continuation of Se(5tion across the 



Appalachian Chain. 



Amer. Jour. Sci., 3d ser., vol. xviii, pp. 119-128, 239, 

 se(5tions, 1879. 



Ibid. p. 239, an omission in the above article inserted in this 

 place; omission was on p. 121 of article. 



{Abst.) Geol. Record, 1879, London, 1887, p. 135. 



Describes Upper and Lower Silurian and Devonian Rocks. 



Silurian Formation in Central Virginia. 



Amer. Jour. Sci., vol, xviii 3d ser., pp. 16-29, 1879. 



{Abst.) Geol. Record, 1879, London, 1887, p. 135. 



Stratigraphical description of the Upper Silurian (8 divisions), 

 Lower Silurian (13 divisions, including 2 Cambrian) and Archaean 

 (4 divisions). 



