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the No. 4 screen size (approximately 4 inch) and 50 percent <br />that would be retained on a No. 4 screen. No samples have been <br />screened to determine the exact gradings. The coarser fraction <br />contains all sizes of gravel, cobbles, and boulders but seems <br />to consist of a large amount of 6-inch to 36-inch rocks with <br />some boulders up to 10 feet across. The rocks are almost <br />entirely of hard, dense basalt which has originated from the <br />lava capping on Grand Mesa, with a few sandstone clasis. The <br />fragments range from angular to subrounded and are generally <br />unweathered with varying amounts of vesicles (gas holes) in <br />the basalts. <br />A generalized composite profile of the materials in the four <br />test pits consisted of one to 1.5 feet of dark brown topsoil, <br />1.5 to 5.5 feet of clayey sand with only a few cobbles and <br />boulders, and the underlying fan deposit of clay, sand, and <br />gravel with a high percentage of cobbles and boulders. The <br />estimate of plus 3-inch sizes in this layer in the four test <br />pits varied from 40 to 55 percent. The total thickness of the <br />material could not be determined due to the limitations of the <br />equipment used to excavate the pits; the final hole depths were <br />17 to 18 feet. A depth of 25 feet was used in the volume <br />calculations, which seems to be conservative based on exposures <br />and the topography. <br />Water Table <br />A high water table that would hinder mining of the gravelly <br />alluvial deposit under the subject property is not expected to <br />occur. The minable area is about 80 feet higher in elevation than <br />the nearby Rapid Creek. A water table was not reached in any <br />of the four test pits to final depths of 17 to 18 feet. <br />CONCLUSIONS <br />An appraisal of the clay, sand, gravel, cobble, and boulder <br />resource on a 14.03-acre parcel in Section 2 owned by Powder <br />Mountain Ranch has been prepared based principally on the results <br />of four test pits excavated in February, 2000. An estimate of <br />10,200 cubic yards of topsoil, 24,600 cubic yards of clay and <br />sand with only a few cobbles and boulders, and 170,700 cubic <br />yards of clay, sand, and gravel containing an estimated 40 to <br />55 percent of cobbles and boulders underneath the subject parcel <br />has been made using an estimate of 25 feet as average depth. <br />A number of drill holes to bedrock or pits using a very large <br />trackhoe would be necessary to refine the volume computation. <br />The area along Rapid Creek and the 50-foot wide north-south <br />portion of the property were considered too narrow to mine. <br />These alluvial materials have potential commercial value, after <br />processing, for riprap, roadfill, landscaping stone, and other <br />construction uses. Such materials are presently bein g mined <br />3 <br />