648 



SCIENCE. 



[N. S. Vol. III. No. 70. 



called the Apison shale, Eome sandstone 

 and Conasauga shale. Above these forma- 

 tions is a great thickness of siliceous mag- 

 nesian limestone, the Knox dolomite, the 

 lower portion probably being Cambrian and 

 the upper portion Silurian. The remaining 

 Silurian formations are the Chickamauga 

 limestone and the Eockwood sandstone. 

 The Devonian is either wholly wanting or 

 is represented by a single thin bed of car- 

 bonaceous shale, not over 35 feet in thick- 

 ness. Above the Chattanooga black shale 

 are the Fort Payne chert, Floyd shale and 

 Bangor limestone forming the lower Car- 

 boniferous, and the Lookout and Walden 

 sandstones forming the Coal Measures. 

 Most of the formations thicken eastward, 

 and at the same time the proportion of 

 calcareous matter decreases, showing that 

 the land from which the materials com- 

 posing the rocks were derived lay to the 

 east. 



The region has been subjected to com- 

 pression in a northwest-southeast direction, 

 and the originally horizontal strata have 

 been thrown into a series of long, narrow 

 folds, whose axes extend at right angles to 

 the direction of the compression, or north- 

 east and southwest. The effects of com- 

 pression were greatest in the eastern por- 

 tion of the district, where the strata are 

 now all steeply inclined and the basal beds 

 form sharp ridges, while in the western 

 portion considerable areas of strata remain 

 nearly horizontal and form plateaus. 

 Where the folding was greatest there was 

 also much fracturing of the rocks, and the 

 strata on the eastern side of a fracture are 

 in many places thrust upward and across 

 the broken edges of the corresponding 

 strata on the west. Most of the ridges in 

 the district have thrust faults of this char- 

 acter along their eastern bases. 



Mineral resources. — These consist of coal, 

 iron ore, mineral paint, manganese ore, 

 limestone, building stone and brick and tile 



clay. The productive coal-bearing forma- 

 tions, the Lookout and Walden sandstones, 

 occupy the upper portions of Pigeon, Look- 

 out and Sand mountains, having an area in 

 in this district of 116 square miles. The 

 Lookout generally contains one, and in 

 some places two or three, workable coal 

 seams, but they are variable in position, 

 extent and thickness. The Walden sand- 

 stone forms a considerable area on Lookout 

 mountain, and contains at least one valu- 

 able seam of coal, which is extensively 

 worked at the Durham mines. Two vari- 

 eties of iron ore ai-e found in workable quan- 

 tities. The first is the red fossil or ' Clin- 

 ton ' ore, which occurs as a regularly strati- 

 fied bed in the Eockwood formation, and is 

 worked at various places along the base of 

 Lookout mountain. The second variety is 

 limonite, which occurs as a pocket deposit 

 at the base of several of the ridges along 

 the eastern border of the district. Associ- 

 ated with the latter, particularly along the 

 faults, are deposits of manganese, generally 

 as nodules scattered through the surface 

 soil. 



FOLIO 4, KINGSTON, TENNESSEE, 1894. 



This folio consists of three and one-half 

 pages of text, signed by C. Willard Hayes, 

 geologist ; a topographic sheet ("scale 1 : 

 125,000), a sheet of areal geologj', one 

 of economic geology, one of structure sec- 

 tions and one giving columnar sections. 



Geography. — The map is bounded by the 

 parallells 35° 30' and 36° and the meridi- 

 ans 34° 30' and 35°. The district repre- 

 sented lies wholly within the State of Ten- 

 nessee, and includes portions of Cumber- 

 land, Morgan, Eoane, Ehea, Loudon, Meigs 

 and McMinn counties. Its area is approxi- 

 mately 1,000 square miles, and it forms a 

 part of the Appalachian province, being 

 about equally divided between the vallej-- 

 and plateau divisions of the province. The 

 northwestern half of the district is a portion 



