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Coal Seams <br />• <br />Colowyo plans to mine coal from 7 major seams from the <br />upper ~•]illiams Fork formation of the Mesa Verde group, designated <br />by Colowyo by letters X, A, B, C, D, E and F, and several ,~:inor <br />seams above X seam, designated as Y2, Y3 and Y4 (See Figures 1 and <br />2). Seam thicknesses for the major seams vary betcaeen 3 ft. <br />and 13 ft. <br />Geological Cross-Sections <br />Figures 1 and 2, designated by Colowyo drawing nos. 5-22 <br />and S-23 are vertical cross-sectior~a'P maps showing the strati- <br />graphic structure of the interburden associated with the seams <br />or beds of coal at Colowyo mine. Figure 1 (5-22) was constructed <br />from drill hole logs G-42, G-43, G-44 and G-59; Figure 2 (S-23) <br />was constructed from drill hole logs G-52, G-57, G-59, G-56, <br />G-61 and G-70. Figure 1 (drawing no. 5-22) is a vertical • <br />cross-section for the east-west direction and Figure 2 presents <br />a cross-section for a north-south direction. The point of <br />intersection for the two cross-sections is drill hole no. 03-56-G13, <br />commonly designated G-59. The extent of area contiguous with <br />the too cross-sectioral' maps is illustrated within the inse~s, <br />upper right-hand corner. Incorporated as part of each cross- <br />section are columnar sections representing single measured <br />sections and average sequences for individual drill 'holes, such <br />as G-59. From the cross-sectior~-T~plots one can observe lateral <br />variations in bed thickness and lithology. Scale factor for the <br />horizontal axis is 1"=200' and on the vertical axis 1" = 50', <br />thus presenting•an exaggeration of vertical geological features. <br />In general, the lithology of the mine, within sections 2, <br />3 and 10, shows normal stratification of coal and sedimentary <br />rocks deposited as layers or beds in a cyclic process. The <br /> <br />