2010-12-17_REVISION - C1981019 (156)

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r I - A - -? T-5 BASELINE SURVEY OF SOIL RESOURCES COLLUM MINING AREA MAP UNIT DESCRIPTIONS • Map Unit Slope Pct. Components % Surf Text Topsoil Subsoil Limiting Factors Inclusions Comment >- This unit occurs on old terraces and outwash F Silty Clay to Variable soil with stratified Other non-limiting Haplustolls and Haplargids on plains at the extreme north end of the project area. 18 O-5 Fine-Loamy Aridic Haplustolls 70 Loam 12 22 deposits. Generally less the upland fringes of the unit. The soils developed from old alluvial deposits and development lower in profile. therefore have variable coarse fragment content in stratified layers. This unit occurs on wind and sun sheltered north- 19 20-50 Evanot 80 Loam 9 24 Higher coarse fragments and Other non-limiting Haplustolls and Haplargids on facing slopes and hollows in the northern portion lime at depth. the upland fringes of the unit. of the project area. The soil formed from loess deposited over colluvium and residuum. This unit occurs in a variety of positions not typical Loam & Silt High rock and clay content Non-limiting inclusions are soils without Mollic of other units exhibiting more profile development. 20 0-35 Fine-Loamy Typic Haplustolls 65 Loam 6 12 below subsoil. epipedons (Haplustepts) and with argillic horizons Most of the soils develop from thin loess deposits (Alfisols). over weathered bedrock. Occurs in the northern portion of the study area where conditions are dry. Deeper pachic soils (Shawa) are found in this unit Loam and The subsoil generally has very to a limited extent. Soils with argillic horizons and This soil is generally very shallow and developed 21 4-20 Duffymont 70 Channery- 12 var. high rock content. more prominent clay/shale influence (Nortez) are in loess deposits and weathered sandstone Loam also likely present. Rock outcrop occurs in less bedrock. than 5% of the unit. Duffymont 35 Loam 4 10 Bedrock within 20 inches. Similar lithic Mollisols (Tolman) and deeper This complex is difficult to map due to the 22 0-20 com n ts (W r d t C i interbedded nature of the sandstone and shale High clay content in subsoil and po en ee ) a e presen . ampspass s also present to a limited extent and may limit use. parent materials and the fact that much of this unit Nortez 35 Clay Loam 6 20 has been burned, eliminating climax vegetation. below. Shawa 60 This unit occurs in drainage bottoms with sheet 23 0 10 L 30 30 Some of the soils in this unit F i l i li iti wash from adjacent slopes and high moisture l l lti f t d - oam may be too wet to salvage . ew nc ons, none m us ng. eve s resu ng rom a jacen springs. Soils in the channel bottom may be difficult to salvage. Very Fluventic Haplustoll 40 good soil may be available below 60 inches. Pinridge 60 This unit occurs on terraces and floodplains in 24 0 10 Loam & Clay 10 30 Generally more clay, less Some soils with heavy influence from adjacent major drainage bottoms in the north end of the - Loam nutrients with depth. slope wash may lack mollic colors (Battlement). study area. Soils are very deep and show Shawa 40 evidence of historical flooding and deposition. 25 Same as 2 4, but veg etation shows evidence of sub irrigation. T here is likely some redox activity in these soils. High rock content or clay from Mollisols with argillic horizons (Weed and This unit developed from weathered sandstone 26 0-35 Shawa 70 Loam 18 22 shale deeper in the profile. Morapos) are likely present. and siltstone residuum. Smaller units on leeward slopes show evidence of loess influence. This soil occurs on ridge crests in the north portion Channery- Soils without a Mollic epipedon are common in of the study area where sedimentary rocks have 27 0-20 Tolman 55 Loam & 6 6 High rock content in subsoil. this unit but are very similar to the primary soil. been weathered to shallow depths with some Loam Rock outcrops occur in less than 5% of the unit. loess influence. The subsoil has extremely high rock content. N:\TYPING\ENV-FAC\5520068\Collum Soil Data\Table B-5 Page 3 of 7