82 KEMP'S ORE DEPOSITS. 



2.01.20. The Siluro-Cambrian limonitesrun across Maryland in 

 Carroll and Frederick counties, and are mined to small extent. 

 (E. R. Benton, Tenth Census, Vol. XV., p. 254.) 



These limonites are again strongly developed in the Shenandoah 

 Valley along the western base of the Blue Ridge, and in south- 

 western Virginia in the Cripple Creek and New River belt. The 

 ores occur in connection with calcareous shales, calcareous sand- 

 stones, and impure limestones, but have not justified the expecta- 

 tions formed of them. In Carroll County, Virginia, the gossan of 

 the great deposit of pyrite is dug for iron ore. The walls, however* 

 are older than the Cambrian. 1 



2.01.21. The limonites of eastern Tennessee are the southern 

 prolongation of the area of southwest Virginia. They lie between 

 the Archaean of the Unaka range on the east, and the Upper Silurian 

 strata in the foot of the Cumberland tableland on the west. The 

 ores outcrop in the longitudinal valleys or " coves." The bottoms 

 of these valleys, according to Safford (p. 449), are formed by the 

 shales, slates, and magnesian limestones of the Knox group, and in 



of York and Adams Counties," Proc. Amer. Phil. Soc., March, 1875. J. W. 

 Harden, " The Brown Hematite Ore Deposits of South Mountain between 

 Carlisle, Waynesborough, and the Southeast Edge of the Cumberland Val- 

 ley," M. E., I. 136. J. P. Lesley, Summary, Final Report, Vol. I., 1892, 

 pp. 205, 341. Rec. A. S. McCreath, Second Geol. Survey Penn., Vol. 

 MM, 199. F. Prime, Second Geol. Survey Perm., Reps. D and DD ; "On 

 the Occurrence of the Brown Hematite Deposits of the Great Valley, " 

 M. F.., III. 410 ; Amer. Jour. Sci., ii., IX. 433 ; also, XL 62, and XV. 261. 

 Rec. B. T. Putnam, Tenth Census, Vol. XV., p. 181. 



1 E. R. Benton, Tenth Census, Vol. XV., p. 261. J. L. Campbell, 

 "Report on the Mineral Prospects of the St. Mary Iron Property," etc., 

 The Virginias, February, 1883, p. 19. See also The Virginias, January, 

 1880, p. 4 ; March, p. 43. F. P. Dewey, " The Rich Hill Iron Ores," M. E., 

 X. 77. W. M. Fontaine, "Notes on the Mineral Deposits of Certain Lo- 

 calities in the Western Part of the Blue Ridge," Tlie Virginias, March, 

 1883, p. 44 ; April, p. 55 ; May, p. 73 ; June, p. 92. B. S. Lyman, "On the 

 Lower Silurian Brown Hematite Beds of America," A. A. A. S., XVII. 

 114. A. S. McCreath, " The Iron Ores of the Valley of Virginia," M. E., 

 XII. 103; Engineering and Mining Journal, June, 1883, p. 334. E. C. Mox- 

 ham, " The Great Gossan Lead of Virginia," M. E., February, 1892. E. C. 

 Pechin, "The Iron Ores at Buena Vista, Rockbridge County, Virginia," 

 Engineering and Mining Journal, Aug. 3, 1889, p. 92; "Mining of Potsdam 

 Brown Ores in Virginia," Engineering and Mining Journal, Sept. 19, 1891, 

 p. 337; " Iron Ores of Virginia and Their Developments," M. E., XIX. 101 ; 

 "Ore Supply for Virginia Furnaces," Engineering and Mining Journal, 

 Vol. LI., 1891, pp. 322, 349. Rec. 



