4l6 ABSTRACTS 



places on the head streams of Guyandotte River. Mining is restricted 

 to the Bluestone region and the valley of Elkhorn Creek. In these 

 two areas there are at present in operation thirty-seven distinct mines, 

 which in 1894 produced 3^096,867 long tons of coal. 



Geologic Atlas of the United States. Folio 25, Loudon, Tennessee, i8g6. 



The Loudon folio represents that portion of the Appalachian 

 province which is situated beween the parallels 35° 30' and 36° and the 

 meridians 84° and 84° 30'. This area contains 968 square miles, 

 divided among Blount, Monroe, Loudon, Knox, Roane and Morgan 

 counties, Tennessee. The folio consists of a topographic map, a 

 geologic map, structure sections, stratigraphic sections, a map of the 

 economic resources, and descriptive text. The author is Arthur 

 Keith. 



The text begins with a general description of the Appalachian 

 province, and points out the relations of this area to the general region, 

 with regard to its surface features. The local features of the drai.nage 

 by the Tennesse River and its tributaries, Emory, Clinch, Tellico, and 

 Little Tennessee, follow next in description. The various forms of 

 surface, such as the great valley of Tennessee and the portions of the 

 mountain district and the Cumberland plateau by which it is bounded, 

 are pointed out, and the relation between these forms and the under- 

 lying rocks is made clear. 



Under the heading " Stratigraphy," the geologic history of the 

 Appalachian province is presented in outline, and the local rock 

 groups are fully described in regard to composition, thickness, loca- 

 tion, varieties, and mode of deposition. The formations, thirty-three 

 in number, range in age from Cambrian, to Carboniferous ; being, 

 for the greater part, Cambrian and Silurian. The mountain district is 

 chiefly underlain by the Ocoee series, whose age is doubtful. Rocks 

 of Carboniferous and Devonian age occupy two small belts on either 

 side of the great valley, and Silurian and Cambrian strata are repeated 

 in narrow belts along it. Limestones, shales, and interbedded sand- 

 stones make up the Silurian and Cambrian strata; sandstones and 

 shales with coal seams and a limestone near the base constitute the 

 Carboniferous ; and the Ocoee rocks are conglomerates, sandstone, 

 slate, and limestone. 



The details of the strata are graphically represented in the colum- 



