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Sandstone, Mancos Shale, the coal- bearing Mesaverde Group, and the Wasatch and Ohio Creek <br />formations. <br />The stratigraphy of the Mesaverde Group includes interbedded and lenticular sandstones, shale, <br />siltstone, and coal beds. In ascending order (oldest to youngest), the Group contains (1) the <br />Corcoran Sandstone, a marine shale sequence, and the Rollins Sandstone; (2) the Bowie (coal - <br />bearing) member; (3) the Paonia (coal - bearing) member; and (4) the Upper (non -coal bearing) <br />member. The Corcoran and Rollins Sandstones are the bottom and top, respectively, of the Iles <br />Formation, and the upper three members belong to the Williams Fork Formation [see Figure <br />3.3 -3 in the Permit Application Package (PAP)]. <br />The Wheeler coal seam, which was planned to be mined at the Coal Ridge No. 1 Mine, is in the <br />Williams Fork Formation within the Bowie member. Coal seams in the Bowie member are the <br />most continuous of any of the Mesaverde coals. Their cumulative thickness is 33 to 54 feet. <br />The Wasatch and Ohio Creek formations unconformably overlie the Mesaverde Group. These <br />formations consist of red and buff shale, red sandstone, and red to gray conglomerate and form <br />the ridge bluffs of the Grand Hogback. <br />Quaternary unconsolidated sediments in the mine area, as represented by surface features, fall <br />into three geomorphic categories: <br />1) Alluvium: These Quaternary deposits include all sediments associated directly with the <br />active portions of the various stream channels and alluvial fans. <br />2) Terraces: Sediments associated with the inactive portions of the stream channels, <br />particularly those at much higher levels, have been categorized as Quaternary Terraces. <br />3) Colluvium: Colluvial deposits are considered to be loose, heterogeneous rock masses <br />composed of soils and rock fragments which have been deposited chiefly by mass - wasting, <br />usually at the base of steep slopes. <br />Surface Water <br />The Coal Ridge No. 1 Mine permit area is located in the Upper Colorado River Basin, in <br />portions of three watersheds: the Colorado River, Alkali Creek, and South Canyon Creek. <br />Proposed mining operations beneath portions of the Alkali and South Canyon Creek watersheds <br />did not occur. <br />Water from the Colorado River is of good quality and is used for domestic and irrigation <br />purposes. Salinity concerns have resulted in the establishment of standards for the upper and <br />lower Colorado River basin (including the Colorado River and Alkali Creek). Water has been <br />monitored since 1981 on Alkali Creek and 1983 on the Colorado River. The Colorado <br />Department of Public Health and Environment receiving stream standards for some metals have <br />occasionally been exceeded in both the Colorado River and Alkali Creek, but the elevated metals <br />were not determined to be mine related. See PAP pages 3 -40 through 3 -49 for more information <br />on surface hydrology. <br />Coal Ridge No. 1 Mine <br />Permit Renewal 6 5 31 October 2011 <br />