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Mayo and Assodales, LC <br />• In most locations, the mine roof above the E-Seam consists of asequence ofthinly-bedded <br />carbonaceous shales which are frequently silty to sandy in nature. Locally, thick sandstone <br />paleochannels form the immediate roof or closely overlie it. The F-Seam is the highest of the <br />mineable coal seams in the West Elk Mine permit area and was previously mined by MCC. <br />Sandstone paleochannels are common in the F-Seam roof. The F-Seam outcrop is burned in <br />limited areas, predominately on south- and west-facing slopes. <br />The Upper Coal Member displays sequences of disturbed bedding attributed to differential <br />compaction and bioturbation in the non-coal units. The shale to sandstone ratio increases <br />relative to the Lower Coal Member, and the sandstones appear to be less continuous than <br />those in the Lower Coal Member. This is probably due to a greater fluvial influence in the <br />• depositional regime of the Upper Coal Member. <br />Barren Member <br />The Barren Member of the Mesaverde Formation lies above the F-Seam and is approximately <br />1,000 feet thick in the West Elk Mine area. II consists of interbedded sandstone, siltstone, <br />and shale with a few thin and discontinuous coals of no commercial importance. The Barren <br />Member caps the highlands in the western, central and southern portions of the mine <br />property. The lenticular sandstones of the Barren Member commonly form the uppermost <br />cliffs in outcrop. On the highest mesas occurring in the easternmost portions of the West Elk <br />Mine area, the Ohio Creek Member overlies the Barren Member. <br />• <br />Characterization of Groundwater Systems in the Vicinity of the west Elk Mine, Somerset, Colorado <br />29 January 1999 <br />Page 19 <br />