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9,000 feet ofMesozoie and 4,500 feet of Paleozoic sediments underlie these coal beds. The <br />Williams Fork Formation is estimated to be 1,600 feet thick in the permit azea and is underlain <br />bytheridge-forming Trout Creek Sandstone member of the Iles Formation. <br />Overburden material consists of a sequence of sedimentary claystones, siltstones, shales and <br />cazbonaceous-silty shales. These sediments are typical of the cyclothems deposited along the <br />western interior of North America during Late Cretaceous time: The site-specif c stratigraphy is <br />described in Exhibit 6 and on Map 8 of the PAP. There aze four coal seams below the "F" seam <br />which cannot be economically mined by surface mining methods. These seams are described in <br />the Northwest Colorado Environmental hnoact Statement, Site-~ecific Analysis. <br />3.2.6 Climate . . <br />.Climatic information is found. in Section 2.04.8 of the PAP. The region is characterized by a <br />semi-arid steppe climate regime. Precipitation averages 18 inches per yeaz with a significant <br />portion of this yearly precipitation occumng as snowfall. Prevailing winds over the permit area <br />aze from the southwest and average eight to nine miles per hour. High winds aze not common, <br />due to the protection afforded by local terrain. <br />327.Soils <br />Soils. information is found in Section B; Item N ofthis document, as well as in Section 2-04.9 <br />and Exhibit 9 of the PAP. The most prevalent soils, the Barnette and Work Loams, are moilisols <br />of the suborder boroll, which developed on gently sloping to rolling ridgetops, moderately steep <br />sideslopes, and in gently sloping, concave narrow stream valleys. Shallow, rocky soils of the <br />order entisol occur.ta a limiterT extentwithiathe areato be disturbed nn steep, south-facing <br />slopes. <br />The soils that developed on the gentle slopes and swales, including the Barnette and Work <br />Loams, are deep k>ams and clay foams with physical and chemical properties drat are generally <br />well suitedfor revegetation. One soil unit, the Campspass Fine Sandy Loam, which occupies <br />considerable acreage in the southern and western portions of the permit azea, is chazacterized by <br />subsoils high in clay content, These soils, if salvaged and redistributed duectly on the regraded <br />spoils, could hamper reclamation efforts-due. to the high runoff erosion hazard, slow. <br />perateability a~ droughty conditions associated with fine textured soils. <br />October 21, 2002 14 <br />