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<br /> <br /> <br /> 10 C1981-041 RN7 findings <br />Geology <br /> <br />Nearly the entire surface of the permit area consists of the Mesaverde Formation, a sequence of <br />interbedded shales, siltstones and sandstones, indicative of a marine/alluvial depositional <br />environment. Further to the south, the Wasatch and Ohio Creek Formations outcrop on the surface. <br /> <br />The Roadside operation mined the Cameo coal seams found in the Mount Garfield Formation of <br />the Mesaverde Formation of sandstones, coal and shales. The Mount Garfield Formation is an <br />example of the transitory nature of many oceanic transgressions and regressions from the <br />Cretaceous geologic period. <br /> <br />The Mount Garfield Formation ranges in thickness from 472 to 536 feet in the permit area and <br />consists of three coal zones intertonguing with three prominent sandstone members. From the top <br />to the base, the formational sequence is as follows: the Carbonera coal seam, (stratigraphic marker <br />of the top of the Mount Garfield sequence), a 64-foot sandstone/shale sequence, the Cameo coal <br />seam, 9 to 12 feet thick, Rollins sandstone member, about 114 feet thick, another shale/sandstone <br />sequence, followed by the cliff-forming Palisade sandstone which is 139 feet thick. Beneath the <br />Palisade sandstone member, named for the town nearby, is the Palisade coal seam and then the <br />Sego sandstone which forms the base of the Mount Garfield Formation. The stratigraphic column <br />can be found in Exhibits 14, 24 and 40 of the permit application. <br /> <br />The Cameo coal seam was the zone of interest at the Roadside Mines. Of the three coal seams in <br />the Bookcliffs Mount Garfield Formation, only the "B" and "C" Cameo seams are recognized as <br />economically recoverable. The Cameo "B" seam was the primary seam extracted, and was mined <br />via the North Portals on the west side of the Colorado River and the South Portals on the east side <br />of the river. The South Portals were permanently idled in January, 1997. Some limited mining of <br />the “C” seam occurred through the North Portals in late 1998 and 1999. The Cameo "B" seam in <br />the permit area varies in thickness from a minimum of four feet to a maximum of eleven feet, with <br />an average minable thickness of six feet. The coal has been classified as bituminous, with a low <br />sulfur and high ash content. Coal extraction ceased on December 2, 1999, and the operator <br />submitted official notice of permanent cessation of operations in March 2000. Further information <br />on the geology of the permit area can be found in Tab 6, Volume 2, of the permit application. <br /> <br />Ground Water Hydrology <br /> <br />The water table in the Roadside permit area is controlled by a combination of local precipitation, <br />topography, stratigraphy and geologic structure. The nature of the rock strata in the upper portion <br />of the Mesaverde Formation creates a discontinuous water table. Localized perched aquifers are <br />found in the coal overburden which measures between 0 to 1900 feet in thickness. Groundwater <br />moves slowly through and between these perched aquifers via the network of interconnected <br />sandstone lenses. <br /> <br />The strata in the Roadside Mine area dip NE beneath the Colorado River. The Cameo Coal Seam <br />outcrops at approximately the location and elevation of the South Portals and dips at approximately <br />3 degrees beneath the river to the northeast. The seam mined at the North Portals is below the <br />elevation of the river, but “cross dip” from the river. The entire sequence of Mesaverde that