Laserfiche WebLink
for coal that was mined at Roadside, was located west of the mine site along Interstate 70. The <br /> Cameo power plant has been decommissioned and demolished. <br /> Geology <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 /> 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 /> 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 /> 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 /> Ground Water Hydrology <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 /> The strata in the Roadside Mine area dip NE beneath the Colorado River. The Cameo Coal Seam <br /> 8 <br />