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Mountain Coal Company Exhibit 27 <br />• West Elk Kline Characteristics of West Elk [vfine Soil Mapping Units <br />hfapping Unit Number 33 - Moderately deep (20 to ~0 inches to bedrock) and deep <br />(more than 40 inches to bedrockl, dark colored, well drained, maturely developed, eery <br />gravelly, and cobbly clayey soils (more than 35 percent clay in the tine earth), having <br />an Al, B2t. C soil horizon sequence with well developed horizons of silicate clay <br />accumulation (B2t horizons) occurring in parts of the mine area where the mean summer <br />soil temperature (June. July, and August mean temperature measured at 20 inches) is <br />59°F or warmer. <br />Classification of Major Components -The components listed below comprise the major <br />part of the mapping unit: <br />A. Aridic Argiustoll (Chesnut Soils). <br />1. Clayey-skeletal, montmorillonitic, mesic family. <br />(Series unidentified) <br />B. Aridic Argiboroll (Chetnozem). <br />1. Clayey-skeletal, montmorillonitic family. <br />(Radersburg Series) <br />• Extent and Major Areas of Occurrence - Mapping unit number 33 has a small total <br />acreage and occurs in the western part of the mine area at elevations less than 7,800 feet. <br />Characteristic Toooeraohv - The soils of this unit occur on moderately to steeply <br />sloping hills and ridges. Slopes range from about 4 to 60 percent. <br />Physical Propgrties - The soils of mapping unit number 33 are mature soils having <br />strong, stable, blocky, and granular structure. They are also fine textured and contain <br />at least 35 percent gravel, cobble, and stone by volume. Although with careful <br />management these soils could be used as seedbed material without loss of the structural <br />properties essential to water, air, and plant root movement, their steep slopes and content <br />of coarse fragments make them poor choices for seedbed materials. <br />The fine earth portion of these soils has a wide shrink swell ratio but this is partially <br />offset by the content of coarse fragments. Tonal potential extensibility of a 40-inch <br />section with 50 percent gravel and cobble is about 0.8 to 1.6 inches. <br />No tendency toward mass movement is seen in this unit in the mine area; however, the <br />potential for such movement is moderate because of the character of the landforms on <br />which the unit occurs. Practices involving large amounts of water on these soils or on <br />adjacent soils will enhance this potential for mass movement. <br /> <br />Exhibit 27-29 <br />