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<br />Mountain Coal Company <br />West Elk Mine <br />Exhibit 27 <br />Characteristics of West Elk Mine Soil Mapping Units <br />Characteristic ToPosraphv <br />Soils of mapping unit number I8 occupy moderately to steeply sloping edges of mesa-like <br />areas believed to be remnants of old geomorphic fans. Slopes range from 10 percent to <br />60 percent and are usually relatively uniform. <br />Phvstcai Properties <br />The soils of mapping unit number 18 are mature soils havine a strong, stable. blocky and <br />granular structure. They are also fine-textured and contain at least ±~ percent gravel, <br />cobble, and stone. Structural properties which are essential to water, air, and plant root <br />movement are absent in these soils. Their steep slopes and composition of coarse <br />fragments make them poor choices for seedbed material. <br />The fine-textured portion of these soils have a high shrink/swel] ratio but this is offset <br />by the coarse fragment content. <br />No mass movement tendency was noticed in this unit; however, the potential for such <br />movement is moderate. Any changes in soil moisture at higher elevations can change <br />• this status. <br />in their native state, the soils of this unit are moderately susceptible to accelerated water <br />erosion, particularly where natural vegetation has been depleted. They are not very <br />susceptible to water erosion. If cleared or disturbed they are very susceptible to <br />accelerated water erosion and moderately susceptible to wind erosion. Activities <br />involving disturbance of these areas should include erosion control practices. <br />Chemical Properties and Natural Fertility - These are moderately weathered, mature <br />soils having distinct genetic horizonation including horizons of silicate clay accumulation <br />but lacking consistent horizons of secondary carbonates. The cation exchange complex <br />(ability of some parts of the soil to hold and exchange cations) is base saturated with a <br />predominance of calcium even though there is no free calcium or magnesium carbonate <br />in the solum (A and 62t horizons) or in at least the upper pan of the C horizon. No <br />evidence of deficiencies of any of the essential plant nutrients is apparent. <br />Natural fertility is slightly below normal for the area. Low organic matter levels seem <br />to be indicative of low nitrogen levels. This would probably indicate low soil moisture <br />which prevents heavy vegetative cover. Phosphorus also is deficient according to <br />indicated soil analysis (see Exhibit 26). Reclamation programs will be enhanced greatly <br />by supplemental fertilization including both nitrogen and phosphorus in early stages of <br />• plan[ growth. <br />Exhibit 27-14 <br />