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2.04.5(1) • The Rollins Sandstone forms a 100 to 140 foot high pink to tan sandstone cliff, approximately one half mile south of the Red Canyon # 1 D1ine and proposed # 2 Mine entrance. Topograthically above, and primarily west of the Red Canyon #1 Mine and proposed #2 Mine entrance, the surface is covered by Quaternary Aqe younger glacial deposits (Pinedale age) consisting of sand, sediment, and other alluvial gravels composed largely of basalt boulders derived from the basalt flows capping Grand Mesa to the north. These gravels cover a large percentage of the permit area and are significant because they contain large amounts of ground water affecting, to a large degree, the water in the Red Canyon #1 i Mine itself, The coal which is to be mined by Grand Mesa Coal Company consists of the "D" and "E" coal seams. They are above the Rollins Sandstone • in the lower Williams Fork Formation, referred to by some researchers as the Howie Shale :fember and by others as the Cameo Shale Member. The "D" coal seam is the thickest and most commerically mineable coal deposit in this area, attaining a thickness of eleven feet. Stratigraphically, the "D" seam exists approximately 150 feet above the Rollins Sandstone and 130 feet below the "E" coal seam. The Geology Map, 2.04.5-1, illustrates the outcrop and approximate subcrop of both coal seams and their relationship to the other stratigraphic units in the area. STRUCTURAL GEOLQGY The outcrop of the contact between the .+lesaverde Group and the Mancos Shale generally defines the southern flank of the Piceance Creek Basin. This very large northwest-southeast trending structural depression represents the largest structural basin in northwestern Colorado and contains 28,000 feet of accumulated sediments within its boundaries. stratigraphic units within the basin dip towards a center axis, and at this location the dip is approximately three to five degrees • north, slightly northeast. ptear the surface, the beds tends to dip more steeply in the same direction due to the erosion and unloading d2