Summary:
The proposed mine site is situated within the Cumberland Block. The Cumberland Block is bounded by the Pine Mountain Fault Zone to the west, the Jacksboro Tear Fault to the south, the Cumberland Mountains to the east, and extends north into Kentucky.
Regionally, strata dips to the northwest, away from the Cumberland Mountains. South of Clear Fork Creek there is a northeast trending syncline that extends for about seven miles diagonally across the Eagan quadrangle, which is part of the Middlesboro Syncline. Paralleling this syncline is the Sand Lick Ridge Anticline, which extends for approximately the same distance as the adjacent syncline and is approximately 1.2 miles wide. Southeast of this anticline, along Tackett Creek, is an area of highly disturbed rock with numerous folds and near vertical bedding which is thought to be the surface exposure of a steeply dipping reverse fault. The local dip of the coal seams to be mined is approximately 0.4 degree to the southeast.
The mine site stratigraphy consists of sedimentary units within the Slatestone and Indian Bluff Groups. These units are within the middle Pennsylvanian age rocks and are a relatively flat lying and undisturbed rock group. The Slatestone Formation includes all strata between the top of the Poplar Creek Coal seam and the top of the Jellico (locally known as the Mingo or Mason) Coal seam. Included in this formation are the Poplar Creek, Ant, Coal Creek (locally known as the Kent), Petros, Blue Gem (locally known as the Rich Mountain), Terry Creek, and Jellico (locally known as the Mingo or Mason) coal seams. The Ant, Petros, and Terry Creek coal seams are not known to be present locally. Also included in this formation are several sandstone units, including the Stephens, Lower Petros, Upper Petros, Sand Gap, and Newcomb Sandstone, which is located only a few feet below the Jellico (Mason) coal seam. The Newcomb Sandstone is believed to be thirty to forty feet thick in this area. The Indian Bluff group includes all strata between the top of the Jellico (Mason) Coal seam and the top of the Pioneer Sandstone. Included in this formation are the Joyner, Stockstill, and Indian Fork coal seams. None of these coal seams are known to be present, locally. Also included in this formation are several sandstone units, including the Seeber Flats, Stockstill, Indian Fork, and Pioneer Sandstones.
The coal seams to be mined are the Jellico (locally known as the Mason or Mingo) coal seams. Both pre- and post SMCRA surface and underground mining of the Jellico (Mason) coal seams has occurred at this site. During the exploration conducted for this site, the permittee drilled 17 core holes and approximately 170 rotary drill holes to ascertain the extent and quantity of coal at the site. The depth to, and thickness of, the coal seams was recorded at each of the rotary holes. The core holes were logged and sampled for overburden analysis. Based upon the exploratory drilling conducted, the elevation of the Jellico (Mason) Coal seam varies from 1,847 feet at the western end of the permit area to 1742 feet at the eastern end of the permit area.