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The proposed refuse disposal site is blanketed by a large quantity of seedbed <br />quality, non-toxic cover. These soils consist of a topsoil "A" Horizon and a <br />colluvial "B" Horizon within the Absarokee loam soil type. See Table 2 of <br />the topsoil survey conducted by Kline and Bowman in 1981 entitled, <br />"Mt. Gunnison Mine -Topsoil Assessment - 1981," and submitted as part of <br />the Mt. Gunnison M and R Plan, for a description of the soil fertility. The <br />colluvium is moist but hard and well-compacted and exhibits low to high <br />plasticity. The total depth of these soils ranges up to 88 inches. For the <br />purpose of this discussion, al! soils including topsoil and colluvium of <br />seedbed quality will be referred to as soils or non-toxic cover. The above- <br />referenced topsoil survey showed seedbed quality soils at the refuse disposal <br />site to depths of between 39 and 88 inches, with an average depth of 65 <br />inches covering the 40 acre site. <br />Ge 1o~y <br />Approximately fifty borings, test pits, monitoring wells and exploration <br />holes were drilled and excavated on and near the proposed refuse disposal <br />• site. Some of the boring and test pit geologic and hydrologic information is <br />presented in Appendix B. The location of the borings, test pits and <br />exploration holes are shown in Drawing B1 of Appendix B. <br />Geologic structure of the bedrock in the area is relatively simple. The <br />regional strike and dip of the bedding is about N60W, and 3° -5° NE. There <br />are a few local variations from the regional strike and dip. Bedrock consists <br />predominantly of interbedded sandstone, shale and coal of the Cretaceous <br />Mesa Verde formation. The Mesa Verde formation in this area has been <br />divided into the Bowie shale, the Paonia shale and an undifferentiated <br />sandstone and shale member. The oldest member is the Bowie shale which <br />consists of dark-colored shale, coal and gray massive sandstone. The Paonia <br />shale, which lies conformably above the Bowie shale, contains alternating <br />beds of carbonaceous shale, poorly differentiated shale (locally known as <br />mudstone), coal and thin bedded sandstone. The undifferentiated member, <br />which unconformably overlies the Paonia shale, consists primarily of <br />massive sandstone with some interbedded shale. <br />n <br />LJ <br />colluvium is primarily a deposit .of gravelly, sandy clays with abundant <br />highly decomposed rock fragments of various sizes. The colluvial deposits <br />exist mainly on the gently sloping areas. Boring data show about 15 to 80 <br />-S- <br />