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<br /> <br />• coal bearing horizon is scoured to where the upper coal seam, so <br /> prevalent in the Hay Gulch area, is complete absent. <br />The Menefee formation is of nonmarine origin throughout the <br />Hespexvs area. The petrographic impression of the formation varies with <br />its lithologic ctraracter, but over rmst of the area it is slightly less <br />x•csistant than the overlying and underlying formations. <br />Cliff House :a.ndstone <br />'Phe Cliff house sandstone is the upper formation of the Mesa <br />Verde Gmup in the Hesperus area and is of rnarine origin. It generally <br />consists of irregular to lenticular ledges of hard fine to ^,ediwrr <br />grainer] calcareous sandstone enclosed in softer argillaceous fine <br />s~urdstune, mudstune, and silty shale. <br />Like the 1-bint Lookout sandstone, the Cliff House sandstone is <br />• reported to decrease in gx•ain size in an eastward direction. Ten to <br />fifteen miles east of the project area, the formation is composed of <br />soft darl:-gray mudstone and finely sandy silt-shale with an occasional <br />very thin lentil of fine sandstone in the lower part. <br />The Cliff House sandstone has an average thickness of 35C feet <br />thuughout oust of the project area. It shows a slight eastward <br />thinning, probably due W the decrease in roars elastics and the <br />increase in compactible fine sediments. <br />- 5 - <br />• <br />