ANALYSES OF ALLANITE 475 



SOUTH ATLANTIC STATES 



General observations. — In the South Atlantic States, allanite occurs as 

 parallel intergrowths with epidote in the granites of Maryland, and as a 

 constituent of pegmatites associated with a variety of other less common 

 minerals in Virginia and the Carolinas. At many localities in these 

 States, especially in Virginia, and to a less extent in the Carolinas, the 

 mineral is found in quantity in crystalline lumps and masses, coated by 

 a reddish brown crust when found above local ground water level, that 

 affords excellent material for the study of allanite weathering. 



Maryland. — The occurrence of allanite in Maryland is as a microscopic 

 accessory rock-forming mineral in the granites of Ilchester, Dorsey Run 

 Station, Woodstock, on Gunpowder River, and to the northeast of Balti- 

 more.*^ In each of these localities allanite is intimately associated with 

 epidote as parallel intergrowths,*^ and has been generally regarded as an 

 original magmatic mineral. Allanite has not been reported as a con- 

 stituent in any of the pegmatites of Maryland, although they have been 

 worked in a number of localities. 



Virginia. — Pegmatites occur in many of the Virginia Piedmont coun- 

 ties, some of which are allanite bearing. The mineral is known to occur 

 in at least seven counties in the crystalline province of the State (map, 

 figure 1). These are Amelia County, in the middle eastern part of the 

 Piedmont Plateau, and Amherst, Bedford, Fauquier, Nelson, Page, and 

 Roanoke counties, each of which lies partly in the Blue Ridge Mountains. 

 In addition to these, the writer has examined specimens of allanite re- 

 ported to have come from Franklin and Patrick counties. It is found in 

 considerable quantity in several of the Blue Ridge Mountains localities, 

 probably the most notable one of which is on Little Friar Mountain, in 

 Amherst County, where the allanite is associated with magnetite and the 

 very rare mineral sipylite.*^. With only one exception (Amelia County), 

 the Virginia localities have yielded crystalline masses of the mineral in- 

 crusted by its alteration product nowhere excelled, so far as the writer is 

 aware, for chemical and microscopic investigation of allanite weathering. 



In the pegmatites*'' of the Amelia County area the associates of allanite, 



"C. R. Keyes: 15th Ann. Kept, U. S. Geol. Survey, 1893-1894, pp. 704-710. 

 *^ W. H. Hobbs : Johns Hopkins Univ. Circulars, 1888, No. 65, p. 69 ; Am. Jour. Sci., 

 vol. 38, 1889, pp. 223-228 ; Tschermak's Min. u. Pet. Mitth., vol. xi, 1889, p. 1 ; Ameri- 

 can Geologist, vol. 12, 1893, pp. 218-219. 



C. R. Keyes : Bull. Geol, Soc. Am., vol. 4, 1892-1893, pp. 305-312. 

 **J. W. Mallet: Am. Jour. Sci., vol. 14, 1877, p. 397. 

 *»W. M. Fontaine: Am. Jour. Sci., vol. 25, 1883, pp. 330-339. 

 Thomes L. Watson : Mineral resources of Virginia, 1907, pp. 280-283 ; Bull. Am. 

 Inst. Mng. Engrs., 1916, pp. 1237-1243. 



