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S~ 91~L'OLOGY --- - <br />STRATIGRAPHY <br />General. The strata that crop out on the Bourg property are <br />~• the Pierre Shale, the Coalmont Formation with the coal nearly at its <br />base, and some alluvial 5oi1. <br />Pierre Shale. This formation is about 4,000 feet thick in <br />this vicinity and consists of normal marine shale with some minor <br />amounts of siltstone and sandstone beds. It is overlain by the <br />Coalmont Formation. <br />Coalmont Formation. About 180 feet of the Coalmont Formation <br />crops out on the Bourg property. It includes two coal seams nearly <br />at the base of the formation and associated sandstones, siltstones <br />and shales. A columnar section of these beds is shown in Figure 2 <br />as well as a gamma ray-density log. The overburden consists about <br />half of tough siltstones, 36~ of rather hard, fine to coarse-grained <br />sandstones, and 148 of shales, including light grey shales and dark, <br />carbonaceous shales. Table 1 shows the Bourg drill hole data. Table <br />2 shows analyses of the coal and Table 3 of the overburden, along <br />with an analysis of the whitish siltstone which directly underlies <br />the lower coal seam. The lower seam is 25.5 feet thick on the <br />~• average and the upper seam 16.5 feet. They are about 80 feet apart. <br />Each stratigraphic unit of the overburden, interburden, and <br />first ten feet of strata below the lower coal seam has been analyzed <br />from two additional drill holes, 33B and 32A (Plate 1 and Appendix D}. <br />Conductivity, pH, saturation, particle size analysis, soluble Ca, Mg, <br />and Na, sodium absorption ratio, lime, selenium, boron, nitrate- ' <br />nitrogen, molybdenum, acid-based potential, exchangeable sodium <br />percentage, lead, arsenic, copper, cadmium, iron, manganese, zinc, <br />nickel, mercury, and ammonium nitrogen were the parameters analyzed <br />for in each of the two holes. To comply with the MLRB staff request <br />that analysis be made for whole rock sulfate, pyrite and marcasite, <br />whole rock analysis was also made for sulfate, sulfur and iron to <br />determine the percent content of. pyrite and/or marcasite. This <br />analysis was accomplished by analyzing a column through the core <br />sample by segments for the coal, the lithologic units immediately <br />adjacent to the coal and all partings in the coal, all for both <br />coal seams. These together with the drill logs showing each interval <br />sampled are shown in Appendix D. <br />~- <br />n <br />