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-5- <br />The western part of the tract consists of medium brown soil material of fine <br />to very fine grain size and a surface concentration of lag gravel. The <br />material immediately below the lag gravel consists of the following: <br />Fine Quartz and Feldspar Sand - 35 to 45 percent <br />V. Fine Sand as above - 25 to 35 percent <br />Silt Size Particles - 15 to 20 percent <br />1~`-, Inch Rock Fragments - 5 to 10 percent <br />The Bureau of Reclamation apparently excavated two test pits on the tract. <br />The pits were subsequently filled but material remaining on the surface is <br />identical to that which will be described from the existing pits. <br />Both existing pits were examined in order to project the type of deposit which <br />could be expected at depth on the subject tract. The gravels consist of <br />sedimentary, igneous and metamorphic rocks. The majority of the larger size <br />material consists of Conglomerate derived from the the Crestone Conglomerate <br />which outcrops over a wide area in the San Isabel drainage. There was some <br />material consisting of igneous or metamorphic rocks possibly derived from <br />larger boulders in the Crestone Conglomerate since areas of precambrian <br />outcrops are uncommon in this area. The potential source rocks are the <br />Pennsylvanian-Permian Sangre de Cristo formation consisting of Sandstone, <br />Siltstone, and Conglomerate, and [he Minturn and Belden formations (Permian) <br />consisting of Sandstone, Siltstone, and Shale. These formations were in turn <br />derived from older igneous, metamorphic, and sedimentary rocks during erosion <br />of the ancestral Rocky Mountains. <br />The active pit to the northeast of the subject tract consists of 1.0 to 1.5 <br />feet of immature soil profile underlain by at least 10 feet of poorly sorted <br />t'o unsorted material from clay size to approximately 1 foot in diameter. The <br />size fractions of the deposit is approximately as follows: <br />