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• ILS <br />The soils range from shallow (less than 20 inches), poorly <br />developed units derived from interbedded sandstone and shale <br />(Lithic Ustic Torriorthents) to deep (greater than 40 inches) <br />eolian derivatives (Ustollic Haplargids). The shallow soils <br />are associated with numerous rock outcrops. <br />The land within the application area does not consist of prime <br />or unique farmlands, or alluvial valley floors. An alluvial <br />valley floor may exist southwest of the modification <br />application area where Pine Gulch merges into Hay Gulch. It <br />is not anticipated that mining in the area will affect the <br />possible alluvial valley floor at Hay Gulch. However, final <br />determination will be made by Colorado DMG during the review <br />of the lessee's permit application for the modification <br />application area. <br />GEOLOGY AND MINERAL RESOURCES <br />The only known mineral resource contained in the application <br />area is coal. The coal deposits occur within the Menefee <br />Formation of the Cretaceous Mesa Verde Group and is within the <br />Durango Known Recoverable Coal Resource Area (KRCRA). <br />National King Coal is the only operating mine in the area at <br />this time. There are no known oil and gas deposits in the <br />proposed modification area. However, oil and gas is known to <br />occur in the Point Lookout, Gallup, Dakota Sandstone and the <br />Paradox Formations. <br />The proposed modification area is characterized by hilly <br />plateau tops cut by one ephemeral drainage. The altitude <br />ranges from about 7,000 to 8,500. The geologic formation <br />outcropping in the area is the Cliff House Formation of the <br />Cretaceous Mesa Verde Group and the overlying Quaternary <br />alluvial deposits. The coal proposed for mining is coal bed <br />1 in the Menefee Formation which outcrops about 1'b miles north <br />of the proposed modification area in the Hay Gulch drainage. <br />No quantitative data exists for subsidence on the proposed <br />modification area; however, the surface effects of subsidence <br />have been recorded on Federal lease P-058300 approximately <br />one-half mile northeast of the proposed modification area. <br />The overburden thickness consistently ranges from 300 to 400 <br />feet above coal bed 1 throughout the area of the existing <br />leases as well as in the proposed modification area. <br />Subsidence is directly affected by the thickness of the coal <br />seam mined (4 to 6 feet), the overburden thickness, and <br />overburden composition. <br />r1 <br />U <br /> <br />9 <br />