PERMFILE54536 - Laserfiche WebLink

Home Browse Search

• Mountain Coal Company West Elk Ivfine Exhibit 27 Characteristics of West Elk Mine Soil Mapping Units No temperature distinction was made in this land type and mapping unit number 200 occurs at elevations both above and below 7.800 feet fapproximate ;9°F mean summer soil temperature isotherm). It occurs in greatest acreage be]ow 7.800 feet elevation. Above 7,800 feet it contains a component of soils similaz to those described for mapping unit number 6. These areas are of considerable importance in the evaluation of surface water flow and yields under differing degrees of wetness. Runoff yields during periods of high intensity rainfall are great. Mapping Unit Number 300: Land Type: Alluvial Land - This land [ype is used exclusively in [he portions of the mine area mapped by personnel of the Soil Conservation Service. It is confined to the low floodplains adjacent to the channel of the North Fork of the Gunnison River and consists of variable recent deposits of stream alluvium. Textures are usually sandy loams, loams, or clay loams but the soils of the unit are strongly stratified and both finer and coarser textures occur intermittently and within short distances. • Areas of this unit generally are only slightly above the stream channel, subject to frequent flooding, and have seasonally fluctuating water tables controlled by the river stage. Some are poorly drained more or less permanently by standing water tables at or near the surface. These soils occur in very small acreage. Mapping Unit Number 400: Land Type: Stony Alluvial Fans -This is a complex undifferentiated mapping unit used only in that part of the study area mapped by personnel of the Soil Conservation Service as part of the Paonia Area Soil Survey. It is described as an accumulation of deep, well drained stony and cobbly sediments from a variety of rock and upland soil materials deposited on the floodplains of narrow valleys, small fans, and tce slopes. It occurs along the edges of the uplands bordering the North Fork of the Gunnison River and has a small total acreage in the study area. Textures are variable ranging from sandy loams to clay loams in which are embedded considerable amounts of gravel, cobble, and boulders. The soils are subject to frequent flooding and the deposition of sediments. SOILS MORPHOLOGICAL GROUPS Morphological Group I Soils in morphological group 1 are undeveloped or very weakly developed, have light • colored surface horizons (A horizons), and occur in the dry lower elevations (below about 6,000 feet). This group includes mapping units 1. 4, and 5. Exhibit 27-33