766 ABSTRACTS 



is located upon the westernmost of the sharp anticlines which charac- 

 terize the central division of the Appalachian province. In the eastern 

 part of the district the strata have suffered compression, which has 

 forced the originally horizontal strata into a series of long, narrow folds 

 whose axes extend in a northeast-southwest direction. In addition to the 

 folding, and as a further effect of the compression which produced it, 

 the strata have been fractured along many lines parallel with the folds, 

 and the rocks upon one side — generally the eastern — have been thrust 

 upward and across the broken edges of those on the other side. A 

 fault of this character passes along the western side of the Sequatchie 

 Valley, and several formations which would normally occur there are 

 entirely concealed. 



Mineral resources. — These consist of coal, iron ore, limestone, 

 building stone, and brick and tile clay. The productive coal -bearing 

 formations, the Lookout and Walden sandstones, occupy the surface of 

 the plateaus. They have an area within the district of about 400 

 square miles, and contain from one to three beds of workable coal. 

 The beds in the Lookout are generally variable in position, extent, and 

 thickness ; those in the Walden are constant over large areas, and are 

 worked on a considerable scale at various points along the eastern side 

 of Walden Ridge. About 200 square miles of area of these upper coals 

 occur within the district, on the Cumberland Plateau and in the east- 

 ern half of Walden Ridge. The most important iron ore in the dis- 

 trict is the red fossil or Clinton ore, which occurs as a regularly strati- 

 fied bed in the Rockwood shale. The bed is from three to five feet 

 thick in Sequatchie Valley, but considerably thinner in the vicinity of 

 Chattanooga and eastward. 



Geologic Atlas of the United States, Folio 8, Sewanee, Tennessee, i8g4. 



This folio consists of nearly four pages of text, signed by Charles 

 Willard Hayes, geologist; a topographic sheet (scale 1:125,000), a 

 sheet of areal geology, one of economic geology, one of structure 

 sections, and one giving columnar sections. 



Geography. — The map is bounded by the parallels 35° and 35° 30' 

 and the meridians 85° 30' and 86°, and the territory it represents is 

 wholly within Tennessee, embracing portions of Grundy, Sequatchie, 

 Marion, Franklin, and Coffee counties. The district lies almost wholly 

 within the western or plateau division of the Appalachian province. 

 Crossing its southeastern corner is the Sequatchie Valley, located upon 



