Geological Setting, Deposit Types and Mineralization.
The coal deposits in the eastern USA are the oldest and most extensively developed coal deposits in the country. The coal-bearing formations on the properties are Carboniferous in age, being in the Pennsylvanian system, which includes the Monongahela, Conemaugh, Alleghany, and Upper Pottsville groups. These coal-bearing formations contain two-fifths of the nation’s bituminous coal deposits, extend over 900 miles from northern Alabama to Pennsylvania, and are part of what is known as the Appalachian Basin. The Appalachian Basin is more than 250 miles wide and in some portions, contains over 60 coal seams of varying economic significance. Seams are typically between 1 foot and 6 feet in thickness, with relatively little structural deformation. Coal in the region is classified as high- to low-volatile bituminous with rank increasing to the east. Coals are typically characterized as low to medium sulfur and high heat content.

Mineralization.
Mineable coal seams within the properties are typically low-ash, low to high-sulfur, and high- thermal content bituminous coals. Regionally, the coals are typically low-volatile in rank, with rank increasing from west to east. The maximum seam thickness may reach over 6.0 feet where multiple coal benches occur in proximity to one another; however, the average mineable thickness of the seams in this evaluation generally ranges from 1 foot to 4 feet. Seams are generall ........

Schrock Run (including the associated Schrock Run Extension area) is currently the only active surface mining operation on the Property; however, Corsa has numerous idled and planned surface mines within its operational plan.

The proposed surface mines are planned to be operated by a mobile equipment spread built around Hitachi EX3600 or Komatsu PC 2000 shovels as the principal excavators. The surface mine operations are linked in the financial model by the progression of equipment spreads and crews from resource area to resource area. The configuration of this equipment spread, or fleet is projected to be maintained for the future mine projections. Surface-mining activities are projected to occur from 2021 through 2037 at annual production rates up to 217,000 tons. Equipment replacements are scheduled at appropriate times over the period for the equipment.

The Hitachi and Komatsu shovels are supported with a fleet of equipment including:
- Caterpillar 785 and 777 Rock Trucks;
- Caterpillar D11 Tractors;
- Caterpillar 16M Road Graders; and
- Other support equipment including backhoes and service trucks.

The mine model generally targeted overburden strip ratio limits of 16 to 20 bcy of overburden per ton. Tractor contribution to production may drop due to shorter panel lengths and rock truck haul distances are likely to increase to provide void space for highwall miner activity in the Upper Kittanning seam. Productivity will ........

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