2016-08-29_PERMIT FILE - C1981035A (7)

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I • coal. If this relationship is correct, the "A" Seam coal will most likely continue to thin and disappeaz to the north as the tongue and Cliff House Sandstone merge. This trend appears to be present on the "A" Seam coal isopach map included in the "National King Coal, Inc. Geologic Report" (Henderson, 1995). The northern project area would correspond with the thin coal boundary (<4.0 feet thick) identified in the report to the northeast of the mine. This would result in a northwestlsoutheast trend for the tongue, with a strike of approximately 50-60 degrees. However, the tongue may have an irregulaz shape and while the general trend may be correct, the influence of the trend may vary with slight transgressions and regressions of the sand along en echelon lineaments or deeper structures (i.e., basinal compaction features). This may explain the presence of the isolated coal deposit up Roberts Canyon and extending to the old Hesperus Coal Mine, however correlation of the coal seams would need to be checked. b) "A" Seam Coal Deposition: It became evident that the "A" Seam coal had several strong depositional trends. Of extreme importance, it became evident that the National King Coal Mine is not mining within the thick coal pod of the "A" Seam, but is mining only the upper seam of the primary thick coal "pod" present to the northwest (figure 6 and 7). And second, that the higher sulfur trend along the eastern edge of National King Coal Mine is not present in the thicker central coal "pod" of the project area. 1) "A" Seam Coal "Pod": The presence of a thick "A" Seam coal "pod" to the • northwest of the National King Coal Mine (figure 7) was established. The formation of the thick coal "pod" was controlled by depositional features present in the Point Lookout Sandstone and the fluvial sandstones directly below, which created a stable depositional platform upon which the "A" Seam coal swamp was established. The "A" Seam "pod" (9-11 feet thick} splits into the Upper "A" Seam coal (4.5-6.0 feet thick) and the Lower "A" Seam coal (3.0-5.0 feet thick) towazds the National King Coal Mine. The lower split of the "A" seam quickly splits and thins within a distance of 2000-3000 feet to the southeast. Note: Thin remnants of the Lower "A"Seam are visible below the Upper "A"Seam as dirty coal bands 0.5-1.0 feet thick in many of the geophysical logs present at National King Coal Mine. The "A" Seam "pod" ranges in thickness from 7.9 to 11.7 feet thick, averaging 9.9 feet. The variation in thickness of the pod can be directly related to the immediate fluvial sandstone channels deposited below; the thinner 7.9 feet thick coal has only minor sandstone thickness (6.5 feet thick), while the thicker surrounding holes have 20-35 feet of sandstone present. This slight reduction in the sandstone platform allowed additional sediment into the swamp (drainages), generally reducing the coal thickness at the top and bottom of the bed. While the reduced coal thickness is not a mining concern, it is along the lower thickness trends that minor in-seam partings may also be encountered as thin, lenticular, meandering • bands.