NOTES ON THE GEOLOGY OF GEORGIA 169 



This group of altered sediments has been studied in detail only 

 in one section of the state, namely, the area covered by the Ellijay 

 Folio. In that locality the rocks have been described by La Forge 

 and Phalen under the following formation names : (i) Great Smoky 

 formation, (2) Nantahala slate, (3) Tusquitee quartzite, (4) Brass- 

 town schist, (5) Valleytown formation, (6) Murphy marble, (7) 

 Andrews schist, and (8) Nottely quartzite. 



The Great Smoky formation^ in the Ellijay quadrangle along its 

 eastern margin, lies upon the Carolina gneiss, although the imme- 

 diate contact is difficult to define, as in that section the latter is 

 made up largely of graywacke and conglomerate, which are very 

 similar in lithological character to the base of the Great Smoky. 

 The formation consists of a great thickness of conglomerate, gray- 

 wacke, sandstone, quartzite, slate, mica schist, garnet schist, and 

 staurolite schist. The conglomeratic phase is best developed to 

 the east and north, while to the west and south the mica schist, 

 quartzite schist, and slates prevail. The Great Smoky formation 

 is a part of Safford's Ocoee series and has been provisionally corre- 

 lated with the Cochran and the Thunderhead conglomerates of 

 Tennessee and North Carolina. West of the Ellijay quadrangle and 

 below the Great Smoky formation occur considerable areas of the 

 Wilhite slate and the Gilmer formation, but their detailed struc- 

 ture and relations have not yet been worked out. 



The Nantahala slate, near the Georgia-North Carolina line, 

 includes principally blackish and dark-gray slates, though white 

 quartzite and staurolitic schist are also more or less plentiful. 

 Farther south in the vicinity of Ellijay and beyond, the formation is 

 mainly graphitic schist with but few siliceous beds. Its distribu- 

 tion is confined to the eastern margin of the metamorphic area, 

 where it forms narrow belts rarely over a mile in width. 



The Tusquitee quartzite, which is apparently confined to the 

 Ellijay quadrangle, consists almost entirely of white quartzite 

 with an occasional bed of conglomerate. Owing to the persistent 

 character of the formation and its difference in color from the 

 associated rock, it is an excellent guide in working out the strati- 

 graphy of the region, which is much complicated by numerous 

 faults and folds. 



