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• direction as the coal seams, but to a slightly lesser degree, <br />resulting in a relatively small difference between the dip of the <br />coal and the average elope of the topographic surface. <br />Specifically, within the mining area, the difference between the <br />dip of the coal and the slope of the land surface was approaia~ately <br />2 degrees. From the Wedge outcrop near the crest of the dip slope <br />to the base of the dip-elope, overburden thicknesses increased to <br />100 feet. The predominant Land form is characterized by long, Low <br />hills and narrow valleys. Overburden isopach contours are shown on <br />Nap 2, , Mine No. 3 Geology. <br />Stratigraphy <br />• For this discussion, reference should be made to Figure 2, <br />General Stratigraphic Columa. More detailed stratigraphy is shove <br />on the lithologic logs in Eahibit 1, Drill Hole Logs, and on Map 3, <br />Mine No. 3 Geologic Cross Sections A, B and C. The only coal seam <br />mined by the surface operations is the Wedge Sena. This seam lies <br />within a sequence of sedimentary rocks characterized by shales, <br />clayatonea, siltstones, sandstones and minor coal seams in the Dpper <br />Cretaceous Mesaverde Group. This sedimentary sequence is about 75 <br />million years old and is composed of terrigenous clastics deposited <br />in offshore, shallow and near-marine environments at the western <br />edge of an epeiric seaway which was located in interior western <br />North America during late Early Cretaceous and moat of Late <br />Cretaceous time. <br />• <br />The sandstones were formed in beach enviro~ents and are <br />2.04-25 <br />