COAL FIELDS OF KENTUCKY AND TENNESSEE

By Dallas Bogan

Reprinted with Permission from Dallas Bogan. 
The following article is taken from The Cumberland Gap Coal Field of Kentucky and Tennessee as distributed by the United States Geology Survey of 1904

     The Cumberland Gap coalfield forms a part of the eastern edge of the Appalachian coalfield in southwestern Kentucky and northern Tennessee. It lies between Pine and Cumberland mountains, and extends from Fork Mountain to the heads of Poor and Clover forks of Cumberland River, having a length of 90 miles and a width of from 15 to 20 miles. Associated with Pine and Fork mountains are important faults (breaks in the Earth) making distinct breaks between this field and the coalfields to the west and north. While this field was originally part of the same general coalfield, as are the coals areas to the west and north, more detailed work than has yet been done will be required to connect the geography of this basin with that of the outside fields, or to associate the coals across the breaks made by the faults mentioned.

     Cumberland Mountain forms the eastern section of the Appalachian coalfield. All that part of the "coal measures" that may formerly have existed to the south having been removed by erosion.

     Work was done on these measures in the seasons of 1902 and 1903 over the central part of the basin, or the area lying between Log Mountains at the head of Yellow Creek to a north-south line about 10 miles east of Harlan.

     Pine and Cumberland mountains are formed by the edges of resistant sandstones upturned at angles from 20 degrees to 90 degrees from the horizontal, and, following the structure, run nearly straight on northeast/southwest lines. Between these two ranges lies a mass of mountains of irregular shapes, with irregular and usually narrow crests.

     The drainage of the area studied is empties entirely into the Cumberland River, which if formed by the union of there forks--Poor, Clover and Martins at Harlan, and which escapes from the basin by the gap at Pineville. Wallin, Puckett, Yellow, and Clear creeks are its principal tributaries below the forks. At the Pineville Gap Cumberland River has an elevation of about 980 feet above high tide, while the highest points in the area reach an elevation of 3,400 feet. The mountains rise 1,000 to 2,000 feet above adjacent drainages. The lower valleys have commonly broad bottoms with abruptly rising side slopes; the higher valleys are V-shaped.

     This basin is structurally a flat-bottomed trough with sharply bent slopes. The center of the trough lies near but a little southeast of the Cumberland River, running between Clover forks on the east and between Stony Fork of Yellow Creek and Clear Creek west of Middlesboro, Kentucky. In this belt were noted several minor faults in the gap at Pineville and the territory adjacent on the east. A fault with a down-throw to the west of over 1,200 feet along the west face of Rocky Face Mountain; a fault with apparently considerable horizontal movement. All the small hills in or immediately around the plain at Middlesboro give evidence of highly confused structure, as though the shales, which make up a large part of the exposed strata at that point, had given away with folding and probably faulting under the stresses which produced the faults just mentioned. The upturning of the rocks in Pine Mountain is in connection with the great Pine Mountain fault.

     The structure in Cumberland Mountain is part of the western limb of the Powell River valley.

     The projection of rocks of this basin consist of sandstones and shales with coal beds. So far as found, the fossils show that all of the coal-bearing rocks belong to the Pottsville group of the Pennsylvanian series. The lower part of the section is predominately sandy and often of a conglomerate nature.

     The upper part of the series of rocks shows an irregular succession of shales, sandstones, and coals, the shales and sandstones being in about equal proportions and showing little tendency toward segregation in particular parts of the section. In studying the coal content of the upper part of this series of rocks it will be convenient here to consider separately the Log Mountain area west of the fault belt from Cumberland Gap to Pineville, and the Harlan region east of that belt.