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• <br />Mountain Coal Compatry <br />West Elk Mine <br />Exhibit 27 <br />Characteristics of West Elk Mine Soil Mapping Units <br />Soils of this group are the least developed in the area. Normally they have thin granular. <br />calcareous surface horizons three to five inches thick that are grayish brown to light <br />brownish gray when dry and grayish brown to dark grayish brown when moist. Below <br />the surface horizon the soil is massive, calcareous, and only slightly lighter colored than <br />the surface horizon. A few small concretions of calcium carbonate or crystals of calcium <br />sulfate may occur at any depth but there is no distinct zone of concentration. In a few <br />instances subsurface horizons about 20 inches in depth may have weak prismatic to <br />blocky structure and brighter colors. but such development is still very weak and occurs <br />only occasionally. <br />There are many soi]s occurring on recently deposited or weakly weathered residual <br />materials in the dryer parts of the mine area. Largest areas of the soils of morphological <br />group 1 occur in the area of Minnesota Creek in the western part of the mine area and <br />in the valleys of [he North Fork of the Gunnison River and its tributaries in the northern <br />part of the study area. <br />Morphological Group 2 <br />Soils in morphological group 2 are mature, have light colored surface horizons (A <br />• horizons), and occur in the dry lower elevations (below about 6,800 feet). This group <br />includes mapping units l6, 17, and 18. <br />The soils of morphological group 2 aze the mature soil associates of group 1. Group 2 <br />soils occur in the same landscapes and in the same parts of the study area as those of <br />group 1 but occupy the older more stable parts of those landscapes where soil <br />development has been active for a sufficient period of time to form distinct soil <br />horizonations. <br />Normally, these soils are characterized by friable, granular, noncalcazeous. neutral to <br />mildly alkaline surface horizons (A horizons) four to six inches thick that are light <br />brownish gray to grayish brown when dry and grayish brown to dazk grayish brown <br />when moist. The surface horizon grades into noncalcareous, somewhat finer textured, <br />prismatic to blocky subsurface horizons (B2t horizons) 10 to 24 inches thick in which <br />there is cleaz evidence of the translocation and accumulation of silicate clay as clay tilms <br />and flow surfaces on pad faces and in root channels. <br />The soils of this group normally become calcareous at depths of 12 to 18 inches and have <br />weak but distinct horizons of visible calcium cazbonate accumulation above 30 inches. <br />Mapping unit 18 of this group is an exception in that it is noncalcazeous and has no <br />carbonate accumulation above 60 inches. <br />• <br />Exhibit 27-34 <br />