“Partnership” refers to PA Mining Complex LP (formerly known as CONSOL Coal Resources LP), a Delaware limited partnership that is a wholly-owned subsidiary of the CONSOL Energy Inc. and holds an undivided interest in, and is the sole operator of, the Pennsylvania Mining Complex.
Summary:
Pennsylvania Mining Complex (PAMC) operations currently consist of three active underground mines Bailey, Enlow Fork, and Harvey.
Pennsylvania Mining Complex (PAMC) is situated in the Allegheny Plateau of the NAPP coal fields region. Near-surface geology of this area primarily consists of Pennsylvanian and Lower Permian coal-bearing strata. Coal seams mined in this region are generally classified as high- to low-volatile bituminous, characterized by low-to-high sulfur content and high heating value.
The Pittsburgh Seam is the only coal seam of economic interest on the property. The Pittsburgh Seam is relatively flat-lying, typically dipping less than one degree, and is located at depths ranging from approximately 300 ft to 1,400 ft below ground surface within the PAMC area.
The Pittsburgh Seam coal bed is composed of three distinct and relatively consistent intervals, in order of deposition being the thick “main bench” coal, an overlying “draw slate”, and one or more “roof coal” zones. Mining methods employed at the PAMC generally necessitate extraction of the first (lowermost) roof coal zone, along with the draw slate and main bench coal.
The main bench coal thickness across the PAMC area is generally between the 5.0 ft to 6.0 ft range, averaging 5.5 ft over most of the mine plan area. Isolated pockets of both thinner and thicker coal do exist, and extreme but generally isolated occurrences may range from below 1 ft to above 11 ft thick.
The draw slate is a prominent, laterally persistent shale parting that immediately overlies the main bench coal. Thickness generally ranges from 0 to 2.0 ft, averaging less than 1.0 ft across much of the PAMC area. Isolated drilling within the study area have recorded instances of the draw slate being over 4-ft thick.
The roof coals tend to be of lesser quality when compared to the main bench coal, as well as being highly inconsistent in depositional nature. In some areas the roof coal may be completely absent; present as a solid interval of relatively thick coal; or split into several plies separated by shale, clay, and/or impure coal partings. Average roof coal zone thickness across the PAMC area is just under 2-ft thick.
The immediate roof overlying the Pittsburgh Seam coal bed consists of two different assemblages of strata:
1. A “normal roof”, composed of interbedded shales and sandy shales, with one to several rider or roof coals.
2. A “sandstone roof”, composed of paleochannel sandstone fill, known as the Pittsburgh Sandstone, which scoured and replaced part or all of the normal roof strata.
The Pittsburgh Sandstone represents a major fluvial system that flowed north-northwest from West Virginia, through Greene and Washington counties, depositing sandstone in an elongated body up to 80-ft thick and several miles wide. The Pittsburgh Sandstone is a result of several instances of paleochannelization eroding the typical roof strata, and in some localized areas eroding some of the main bench of the Pittsburgh Seam. Areas of the deposit with sandstone channels in close proximity to the Pittsburgh Seam commonly exhibit discontinuities and rolls in the coal bed. Poor roof conditions are also common along margins of the channels, where the roof type transitions between the sandstone roof and normal shale roof.
The immediate floor beneath the Pittsburgh Seam coal bed consists of an interval of typically 1 ft or less of underclay. The underclay provides a generally competent floor, however poor floor conditions can develop when the underclay is exposed to water.
The Pittsburgh Seam coal bed is located at depths ranging from approximately 300 ft to over 1,400 ft below ground surface within the PAMC area. Seam structure shows a general seam dip of less than 1 degree to the south-southwest, with slightly steeper areas dipping up to 4 degrees in a southeast-northwest trend. There are not any major structural faulting or tectonic features known to occur in the deposit. Small-displacement faults and compaction-related faults may be present, but are not expected to materially affect mine plans.
The structural setting for the deposit is generally considered to be simple in terms of geological complexity. Some areas exhibit evidence of localized channelization; as such, isolated areas of the deposit may be considered moderate in geological complexity. Having been widely studied and extensively mined, the Pittsburgh Seam is well-known and widely-accepted to be a very uniform deposit.
Overall, the Pittsburgh Seam coal bed is a high-rank, high-volatile bituminous, medium-ash, and medium-to high-sulfur coal that is used for both thermal and metallurgical purposes. The roof coal zones exhibit overall higher sulfur and ash contents, combined with lower calorific value; however, this is offset by the consistently superior quality of the main bench coal.