James C. Hower, James D. Pollock, Jeffrey G. Klapheke
The Middle Pennsylvanian/Westphalian B Pond Creek Coal is an important low-sulfur resource in Pike and Martin Counties, Kentucky. The Breathitt Formation seam, also known as the lower Elkhorn coal, accounted for nearly 40% of Pike County's 1983 production of 22 million tons. Although the coal is nearly mined out through central Pike County, substantial reserves still exist in the northern part of the county. Past studies of the seam by the U.S. Bureau of Mines concentrated on the utility of the seam as a coking blend, with additional consideration of the megascopic and microscopic coal petrology. Our research has focused on the regional variations in the Pond Creek seam, with emphasis on the petrographic variations.
The main bench of the Pond Creek seam in central Pike County contains a dull zone; variously appearing as bone, durain, or dull clarain. This attrital layer, which can be followed through several quadrangles, is less distinct to the north in Martin County. To the southwest, its position in the seam may be replaced by a siltstone parting. Several other dull, attrital zones can be followed for long distances, but none are as thick or persistent. Microscopically, the attrital zones are inertodetrinite-rich and have detrital mineral assemblages. The attrital zone often contributes a significant amount of mineral matter to the otherwise low-ash coal. The remainder of the seam consists of clarain and bright clarain. The brighter lithotypes generally have 65-80% vitrinite with some lithotype exceeding 90% vitrinite. The mineable thickness of the coal increases to over 10 ft (3 m) in mines where a lower bench/leader and a rider are separated from the main seam by relatively thin partings. The Pond Creek rider often has a high sulfur content. The overlying strata becomes more marine toward the top and, includes nodules of the Campbell Creek Limestone, particularly in the western and southwestern portions of Pike County.
AAPG Search and Discovery Article #91043©1986 AAPG Annual Convention, Atlanta, Georgia, June 15-18, 1986.