Summary:
The strata of the Tygart Valley in Taylor and Barbour Counties, West Virginia consists of Pennsylvanian age sedimentary strata of the Monongahela Group, the Conemaugh Group, and the Allegheny Formation. The gently dipping layered strata consists of shale, sandstone, claystone, fireclay, and coal seams. At present, economic sedimentary deposits are limited to coal.
The Monongahela Group includes the Sewickley, Redstone, and Pittsburgh coal seams. The Pittsburgh seam has been heavily surface-mined and deep-mined at higher elevations in the Tygart region.
The Conemaugh group coal seams include the Elk Lick, Harlem, Bakerstown and Brush Creek coal seams. These seams are generally thin and discontinuous on the Leer South property. No known mining has taken place in the Conemaugh group coal seams in the Leer South mine area.
The Allegheny Formation includes the Upper and Lower Freeport coal seams, Johnstown Limestone, Upper and Lower Kittanning coal seams, the Clarion and Brookville coal seams. The Upper Kittanning, Lower Kittanning and Clarion seams have been deep mined in the Leer South area. All other coal seams of the Allegheny Formation in the area occur in limited areal extent and are of insufficient thickness for mining. The Upper Kittanning coal seam has had limited mining in the area, often hampered by soft floor strata and high sulfur content.
Leer South is currently mining the Lower Kittanning seam.
Lower Kittanning Seam Distribution
The Lower Kittanning seam has been extensively mined in the region, with mine operators and mine names changing over time. The Leer South Lower Kittanning reserve is situated near Philippi, West Virginia, in the south and extends north to Rosemont, West Virginia. The reserve extends from US Route 119 on the east side to Glade Run on the west side of the Property. The reserve is approximately 9.5 miles in length (northwest to southeast) and approximately 5.9 miles wide, (northeast to southwest).
The Lower Kittanning seam consists primarily of a dual-bench horizon (tagged as 4600) with a thin boney coal or carbonaceous shale parting between the two benches, (typically less than 1 foot in thickness). An overlying Rider seam (tagged as 4650) is present primarily within the southern portion of the mine plan that can add an additional 2.7 feet of coal to the Lower Kittanning seam. Drill holes show the seam thickness within the reserve boundary ranging from 0.0 to 6.6 feet, (10.9 feet including the rider). The Lower Kittanning seam thins to less than 3.0 feet to the west of the Leer South mine plan.
Deposits
The coal produced at Leer South is typically High Volatile (>31% volatile matter) bituminous coal. Due to the historical value of the Lower Kittanning seams as high-volatile bituminous coal, it has been extensively mined in the region. Owing to relatively high sulfur and ash middling material, Leer South and its neighboring producers (including Arch’s Leer property) produce two products: (1) a low-ash coking coal and (2) a high-ash, high-sulfur thermal blend product.
Lower Kittanning Seam
The 4650 (Rider) and 4600 (Main seam) benches are splits of the Lower Kittanning horizon present on the Property and within the projected mining areas. Due to variations in the splitting and merging characteristics of these coal beds, two mining configurations are present within the Lower Kittanning horizon.
1. Main seam only (4600 bench), ranging from 0.00 feet to a maximum of 9.00 feet, typically from 4.50 to 5.00 feet within the longwall panel areas. The Lower Kittanning seam consists primarily of a dual-bench horizon (tagged as 4600) with a thin boney coal or carbonaceous shale parting between the two benches, (typically less than 1 foot in thickness). Main seam only mining occurs where the Rider is either not present or is located above the assumed 7.00-foot average cutting height of the longwall shearer.
2. Main seam with overlying Rider seam (4600 + 4650), or Full seam. Mining of the two benches occurs where the Rider is located within the 7.00-foot average cutting height of the longwall shearer. Under this scenario, the parting between the two benches ranges typically from 1.00 to 2.00 feet, and the resulting maximum mining height (assuming that the full extent of the Rider seam is excavated) approaches 10.90 feet.
The Lower Kittanning seam is situated below drainage throughout the Property and is accessible by existing slopes and shafts. Within the current longwall mine plan area, overburden thicknesses range from approximately 425 feet to more than 1,300 feet.
Composition of the mine floor varies across the projected mine area, consisting primarily of shale, sandy shale, and occasionally shaley fireclay. The lithologic composition of the immediate roof strata exhibits greater variability due to the presence (or absence) of the Rider seam but consists primarily of dark gray to black shale which coarsens upward to sandy shale. As noted above, the Rider seam can locally occur within 1-foot of the top of the Main seam where it is included within the mineable section however, it may occur more than 15 feet above the Main bench elsewhere.