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Geology and Topography (2.04.5 and 2.04.6) <br /> The King Coal Mine lies at the northeastern corner of the Four Corners Plateau. The La <br /> Plata Dome and the larger San Juan Dome lie to the northeast. Southeast of the mine area lies <br /> the San Juan Basin, which extends southward into New Mexico. The Hogback monocline <br /> forms the boundary between the Four Corners plateau and the San Juan basin. <br /> Sedimentary rocks of the Upper Cretaceous Mesaverde Group are exposed throughout the <br /> area. The Lower Cretaceous Mancos shale forms the valley five miles to the north, through <br /> which U.S. Highway 160 has been constructed. The Mesaverde Group sits stratigraphically <br /> atop the Mancos shale, and is composed of three major units (in ascending order): the Point <br /> Lookout Sandstone, the coal-bearing Menefee Formation, and the Cliff House sandstone. The <br /> general dip of the strata is to the south, ranging from 2 to I I degrees. Locally, the Point <br /> Lookout is approximately 400 feet thick, the Menefee is 300 feet in thickness, and the Cliff <br /> House unit averages 350 feet. A stratigraphic section is provided in Appendix 4 of the PAP. <br /> Topography in the area consists of gently south-sloping upland surfaces, bisected by steep- <br /> sided drainages which generally flow to the south-southwest. Within the permit area, the <br /> Cliff House forms the top surface of the upland areas and is exposed, with the Menefee in <br /> some instances, in the sides of the drainages. The deeper Point Lookout unit is not exposed <br /> within the permit area. Quaternary sediments, both alluvial and colluvial, are present in the <br /> valley bottoms, and minor landslides have been mapped on the valley slopes. <br /> Of the two mineable coal seams exposed in the permit area, only the upper seam (Peacock, or <br /> "A") of the Menefee formation was developed at the King I Mine and is currently being <br /> developed at the King II Mine. Thickness of the upper seam ranges from less than 48 inches <br /> to more than 76 inches. The upper seam lies approximately 22 feet below the base of the <br /> Cliff House sandstone, and has 100 to 400 feet of overburden throughout much of the permit <br /> area. <br /> The lower ("B") coal seam is well exposed at the Burnwell Mine, located adjacent to the King <br /> I Mine. Operations began there in the 1940s, but the mine has long been abandoned and was <br /> never permitted under SMCRA. The lower coal seam of the Menefee Formation has an <br /> average thickness of 48 inches. This seam lies approximately 80 feet below the upper seam, <br /> with inter-bedded sandstone and shale between the two seams. To the north of the permit <br /> area, the interburden between the "A" and "B" seams may thin out, resulting in a single, <br /> thicker "A" seam. <br /> Ground Water Hydrology (2.04.5 and 2.04.7) <br /> The following four water-bearing stratigraphic units have been identified in the vicinity of the <br /> permit area: the alluvium of Hay Gulch; the Cliff House Sandstone; Menefee Formation <br /> (sandstone and coal deposits); and Point Lookout Sandstone. All but the alluvium (recent <br /> age) are Cretaceous units. <br /> The Hay Gulch alluvium consists of unconsolidated and poorly consolidated gravel, sand, <br /> 5 <br />