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MINING PLAN , 5 EXHIBIT D(CONT) <br /> encountered in the Piney Creek alluvium are a result of water <br /> erosion and redeposition of rock materials from the front range <br /> of the Rocky Mountains . The deposition of this material occurred <br /> during a time when the river was much larger than it is now. <br /> ACCORDING TO THE US GS GEOLOGIC MAPS FOR THIS AREA THE MATERIAL UNDERLYING THE <br /> GRAVEL TO BE MINED IS A PART OF THE DENVER FORMATION. IT IS A DENSE, GREY <br /> SHALE, SILTY CLAYSTONE AND INTERBEDDED SILTSTONE FORMATION OF THE UPPER <br /> CRETACEOUS AGE THAT IS FROM 800 TO 1000 FEET THICK. <br /> This type of material is typically found from south of Denver to <br /> the Colorado state line along the South Platte River. Along this <br /> section of the river, the deposit has a 60% rock, 40% sand ratio <br /> and averages 30 feet deep . <br /> There are two zones of gravel on this property, The upper or <br /> terrace deposit along the eastern half of the permit area and the <br /> alluvial gravels lying on the western part of the site. The <br /> upper 30+ feet of the terrace deposit is dry while the lower 15+ <br /> feet are below groundwater due to what we believe is a ridge of <br /> shale running north/south or parallel to the base of the <br /> escarpment that divides the site . This ridge impedes the flow of <br /> groundwater from the east to west until it reaches 5072 and <br /> overtops the ridge . Drilling data provided by the landowners <br /> show the shale bedrock rises to within 3 feet of the surface in <br /> the area between the base of the hillside and the old lake or <br /> approximately where we placed the Stage Line separating the two <br /> stages . The ditch constructed by past owners along this line <br /> collects the water and diverts it to the old hatchery area. <br /> SOILS AND OVERBURDEN <br /> See the soils and vegetation information in EXHIBITI/J for detailed <br /> information regarding the soils on this site. The soil <br /> information is not site specific, it describes in general terms <br /> the nature of the soils found at this site and was obtained from <br /> the USDA soil survey for Adams County. <br /> Approximately 3 . 17 acres of this site is covered by structures <br /> and associated parking and driveways where there is little soil <br /> in and around them. Of the remaining 50 . 00 acres, 10 . 15 acres is <br /> pre-law mining area, 1 .24 acres is abandoned fish rearing <br /> raceways, 0 . 38 acres is the Bull Seep and associated water ways <br /> on the west side of the property. Overlying the gravel deposit <br />