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'. <br />An unnamed syncline and the Wolf Creek anticline are located to the west of <br />the mines. The Wolf Creek anticline plunges to the north, northwest. The <br />sedimentary beds on the eastern limb of the unnamed syncline (in the area of <br />the mines) dip 25 to 34 degrees to the west. <br />Most faults along the Grand Hogback are perpendicular to the strike of the <br />strata and trend east-west. The faults in the area of the mines are low <br />displacement normal faults. The displacements of faults increase in faults <br />located south of the mines. <br />Sedimentary rock units within the permit and adjacent areas of the mines and <br />loadout range in age from Pennsylvanian to Tertiary Formation. The <br />formations, in ascending order, are the Maroon Formation, Entrada Formation, <br />Morrison Formation, Dakota Sandstone, Mancos Shale, Iles Formation, Williams <br />Fork formation, and Wasatch Formation. The most significant sandstones and <br />coals in the permit and adjacent areas of the mines are contained in the Iles <br />and Williams Fork Formations. <br />The mined resources included the A seam and the Anderson seam. The A seam is <br />a seven- to ten-foot-thick coal that lies above the Rollins Sandstone of the <br />Iles Formation and is approximately 3,300 to 3,500 feet below the ground <br />surface. The Anderson seam is approximately nine to ten feet thick and lies <br />approximately 2,400 feet below the ground surface. <br />Ground Water Hydrology <br />There are three major bedrock aquifers within the mine area: the Upper <br />Sandstone, the Middle Sandstone, and the Rollins Sandstone. These are <br />regional aquifers and are relatively thick and laterally extensive throughout <br />the mine area. The Rollins Sandstone is below the lowest coal seam that was <br />mined (A seam) and is within the Iles Formation. The A coal seam, the Middle <br />Sandstone and the Upper Sandstone all lie within the Bowie member of the <br />Williams Fork Formation. The Anderson coal seam lies within the Paonia <br />member. The North Thompson Creek No. 1 Mine is in the A seam, while the No. 3 <br />Mine is in the Anderson seam. In addition to the sandstone aquifers mentioned <br />above, several other potential sandstone aquifers exist above and below the <br />Anderson seam. However, these sandstones are thin and laterally discontinuous. <br />A shallow and discontinuous alluvial aquifer exists on portions of the permit <br />area adjacent to North Thompson Creek. The loadout site, located adjacent to <br />the Roaring Fork River, is situated on an ancient valley floodplain. The <br />alluvium adjacent to the river at this point is laterally extensive with <br />thicknesses from 50 to 100 feet in many areas. The alluvial aquifer along the <br />Roaring Fork River has good quality water. <br />Surface Water Hydrology <br />Two perennial streams are in the permit area: North Thompson Creek and Middle <br />Thompson Creek. The watersheds of both drainages are very similar. E~evation <br />ranges from 7,600 feet at the mine office to over 11,000 feet in the headwater. <br />-3- <br />