PERMFILE54536 - Laserfiche WebLink

Home Browse Search

Mountain Coal Company Exhibit 27 • West Elk Ivtine Characteristics of West Elk Mine Soil Mapping Units Characteristic Toooeraohv - Soils of this mapping unit occur on gently to moderately sloping foodplains and concave drainage channels. Slopes range from less than 1 percent to about 20 percent. Physical Properties -The soils of mapping unit number X26 have for the most part the same physical properties as mapping unit number 26, with the exception of mass movement. The major slide area for mapoine unit number 26 is east of Minnesota Reser.otr which does not apply to mapping unit number X26. Chemical Properties and Natural Fertility -The soils of mapping unit number X26 for the most part have the same chemical properties as mapping unit number '_6, with the exception of available nitrogen. Temporary shortages of available nitrogen may also occur during cold wet spring months when soil bacterial activity is low. These are naturally occurring phenomena in soils of higher elevations and are usually only temporary. Mappin Unit_Number 27 - Deep (more than 40 inches to bedrock), dark colored, moderately well drained, moderately coarse textured (less than 18 percent clay but finer • textured than loamy sand), weakly developed soils having no distinct soil horizonation other than a dark surface horizon (A horizon) occurring in parts of the study area where the mean summer soil temperature (June, July, and August mean temperature measured at 20 inches) is 59°F or warmer. Classification of Major Components -The components listed below comprise the major part of the mapping unit: A. Pachic Haploboroll (Chernozemic Regeosol). 1. Coarse-loamy, mixed, mesic. (Breese Series) Extent and Major Areas of Occurrence - Mapping unit number 27 has a small total acreage in the study area and occurs on the floodplains of the North Fork of the Gunnison River in the northern part of the study azea. Characteristic Topography -These soils occur on nearly level to gently sloping foodplains adjacent to major streams. Slopes range from 0 to about 6 percent in the study area. Physical Properties -The soils of mapping unit number 27 are immature. having no genetic soil horizonation other than a darkened surface horizon (A horizon). Soil • structure is weak and relatively unstable. However, their moderately coarse textures (sandy foams) insure good permeability and aeration to these soils or the materials derived from them without additional aggregation. Consequently, the soils of this group Exhibit 27-20