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-4- <br />SITE (~70LClGY <br />The general subsurface geologic conditions below the refuse <br />disposal site are shown on Fig. 4. The coal refuse will be disposed <br />of along the gently sloping valley sides adjacent to the east trending <br />tributary to Red Wash. Test holes along the valley sides indicate <br />that from 4 to greater than 43 feet of residual and oolluvial soil <br />overlies interbedded sandstone, claystone and siltstone of the upper <br />unit of the Mesaverde Formation. The northern portion of the disposal <br />site lies along the northeastern limb of the Red Wash syncline. <br />Bedding planes in this area dip steeply about 50° towards the <br />southwest. The rtnre resistant beds form low northwest-trending <br />hogback ridges to the north of the disposal area. The southern <br />portion of the proosed disposal area is located on the southwestern <br />limb of the syncline. Bedding planes along this limb dip gently, <br />about 6° towards the northeast. Based on regional structure and <br />stratigraphy, it is estimated that interbedded sandstone, shale and <br />coal of the Mesaverde Formation extends tv depths ranging from about <br />2,400 to 3,000 feet below the disposal site. The Mesaverde is <br />underlain b~+ the Sego Sandstone, Budc Tongue of the Mancos Shale, and <br />the Castlegate Sandstone. 7Yiis sequence is about 400 feet thick and <br />is underlain b~+ the main body of the Manoos Shale, whidi extends to <br />depths of 7,500 to 8,000 feet below the site. The Dakota Sandstone <br />and older sedimentary rocks underlie the Manoos Shale. <br />SEISMIC E)~Y)SURE <br />The seismic exposure at the disposal site was evaluated based on <br />• <br />LJ <br />• <br />