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e <br />ESPEY, HUSTON & ASSOCIATES, INC. <br />L_J <br />Z.0 GEOLOGIC AND GEOGRAPHIC SETTING <br />2.1 GENERAL GEOLOGY <br />Coal seams and the encompassing sedimentary rocks to be affected <br />during the underground coal mining by Northern Coal Company occur in upper <br />Cretaceous age rocks of the Williams Fork Formation. Structurally, the mining area <br />is confined to the Sulfur Creek syncline which represents the northern terminus of <br />the Grand Hogback monocline and the Danforth Hills anticline and coalfield. These <br />geologic structures effect control net only on the surface and subsurface drainage <br />patterns, but also on the altitude of the ground surface. <br />Northern Coal Company intends to mine, via subsurface mining methods, <br />• 83.3 million tons of high volatile bituminous B-rank coal from five seams within the <br />Williams Fork Formation. <br />2.2 STRATIGRAPHY AND GEOLOGIC STRUCTURE <br />2.2.1 General StratiQraphy <br />The coals and encompassing sedimentazy rocks of the azea surrounding <br />Northern Coal Company's underground coal mines occur in the Upper Cretaceous <br />age Williams Fork Formation. A few thin coals are present in the underlying IIes <br />Formation, however, they aze quite dirty and not of commercial significance. The <br />Williams Fork Formation, the IIes Formation and, underlying Mancos Shale comprise <br />the Mesaverde Group in the Meeker, Colorado area. The Trout Creek Sandstone <br />Member, 75-90 feet thick, comprises the uppermost portion of the IIes and is easily <br />recognizable both in outcrop and in cores by its conspicuous white color, thickness <br />and massive lithologic texture. Overlying the Mesaverde Group aze Quaternazy and <br />Recent age deposits consisting of alluvial and coazse colluvial material weathered <br /> <br />F-3 <br />