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The Lower Coal Bearing (Bowie) Member consists of 260 to 350 feet of interbedded gray <br /> shales, thin to thick lenticular beds of buff-colored, fine- to medium-grained sandstones, and <br /> coals. Three coal horizons exist in this member, the A (Old King) horizon, the B (Somerset) <br /> horizon, and the C (Bear) horizon. The A horizon is immediately above the Rollins <br /> Sandstone and is not currently mined at any operation in the vicinity. The B horizon contains <br /> two coal seams and occurs about 20 to 120 feet above the Rollins Sandstone and will be <br /> mined by MCC during this permit term. This horizon has been mined and is currently being <br /> mined at the Somerset Mine. The C horizon contains one coal seam that occurs 50 to 100 <br /> feet above the B horizon. This horizon has been mined at U.S. Steel's Elk Creek Mine (now <br /> within the Sanborn Creek Mine permit area) and the Bear No. I and 2 Mines, and is currently <br /> mined at the Bear No. 3 Mine. The top of the member is usually capped by a massive <br /> buff-colored sandstone up to 90 feet in thickness. This sandstone, however, appears not to be <br /> a single persistent bed, but is actually several thick lenticular sandstones occurring at <br /> progressively lower stratigraphic horizons from east to west. <br /> The Upper Coal Bearing (Paonia) Member consists of 200 to 500 feet of gray shales, <br /> interbedded, buff-colored, lenticular sandstones, and coals. The top of this member is <br /> generally considered to be capped by a massive, cliff-forming sandstone. Three coal horizons <br /> have been identified in the Upper Coal Member, the D (Oliver) horizon, the E (Hawk's Nest) <br /> horizon, and the F horizon. The D horizon occurs directly above the massive sandstone of <br /> the Lower Coal Bearing Member and contains three seams. This horizon is currently mined <br /> in the Orchard Valley Mine. The E horizon occurs about 130 feet above the D horizon and <br /> contains two coal seams. This horizon has been mined at the Hawk's Nest Mine and was <br /> mined at the Blue Ribbon Mine. The West Elk Mine plans to mine the E Seam in the future. <br /> It will not be mined on Jumbo Mountain because the E Seam is split and comprised of <br /> several thin (< 5 ft.) coal benches which are separated by rock partings. The F horizon <br /> contains two coal seams and has been mined at the West Elk Mine. At the mine site, the <br /> coal is immediately overlain and underlain by shale. Coal seams of the F horizon do not <br /> exist to the north of the North Fork of the Gunnison River in thicknesses sufficient for <br /> mining. In the Jumbo Mountain area, the F Seam thins to less than five feet in thickness and <br /> is of limited aerial extent. Therefore, MCC does not plan to mine this seam in Jumbo <br /> Mountain. <br /> Overlying the Upper Coal Member is the Barren Member of the Mesaverde Formation. This <br /> unit consists of interbedded sandstones, siltstones, shales, and coals. The unit is not thought <br /> to be of marine origin and, as a result, the sandstones and the coals are highly lenticular, <br /> discontinuous, and of limited lateral extent in outcrop. This unit ranges up to 1,500 feet thick <br /> and outcrops throughout most of the five-year permit area. <br /> The Ohio Creek Member is the uppermost member of the Mesaverde Group. This unit is <br /> approximately 700 feet thick and consists primarily of interbedded sandstone, mudstone, and <br /> shale. The sandstones range from a few feet to more than 100 feet in thickness and are <br /> generally lenticular in nature. Although typically fine to coarse grained, the sandstones may <br /> locally be conglomeratic. <br /> The Mesaverde Formation is unconformably overlain by the Tertiary Age Rudy or Wasatch <br /> Formation. This formation consists of red to buff-colored shales, red sandstones, and red to <br /> gray conglomerates. The sediments of this formation are weathered volcanic rocks. <br /> 8 <br />