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Stratigraphy <br />• The Sudduth Coal seam lies at the bottom of the Tertiary <br />Coalmont formation. Overlying the coal on the Lease tract <br />is the lowermost 500 feet of the Coalmont sediments. As <br />demonstrated on the correlated section, Plate II, the <br />Coalmont section overlying the Sudduth seam can be <br />generalized to consist of two units. Immediately overlying <br />the coal is a sandy siltstone sequence 70 to 120 feet thick. <br />Overlying this unit and extending to the weathered surface <br />is a sequence of clay-rich and highly interbedded shales, <br />siltstoaes and mudstones with extremely little sand content. <br />Although the Sudduth seam and a few of the larger siltstone- <br />shale beds can be followed for distances of a few miles, <br />most beds in the lower Coalmont are highly lenticular and <br />• cannot be laterally correlated for long distances. <br />Directly underlying the Sudduth seam lies a 40-50 foot <br />shale zone which separates the Coalmont from the underlying <br />Pierre formation. The Pierre formation consists of a fine <br />grained silty to muddy sandstone approximately 200 feet in <br />thickness. Underlying this sand member is a massive, clay <br />rich grey shale of undetermined thickness. <br />Structure <br />The Wyoming Fuel Co. Lease lies on the McCallum anticline <br />near its southern terminus. At this location, the anti- <br />cline is breached such that the older rocks oP the Pierre <br />• Formation are exposed in the center and the younger strata <br />3 <br />