2010-12-17_REVISION - C1981019 (142)

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Baseline Survey of Soil Resources - Collom Mining Area July, 2006 Figure 2 shows the dominant soil temperature and moisture regimes in the Survey Area. The extreme north end was determined to be frigid and aridic while higher elevations in the southern portion of the Survey Area were determined to be cryic and ustic. Entisols (soils exhibiting no profile development) were not classified by regime and are shown as their own class (entic). Transitional temperature regimes occurred along cryic canyon walls and shaded slopes to the north and frigid plateaus to the south. The boundary between moisture regimes generally coincided with the prominent ridge and high elevations in the extreme southern end of the Survey Area. Transitional moisture zones include aridic ridge tops and south-facing slopes, and ustic valley bottoms and steep north-facing slopes. Entisols were present throughout the Survey Area on steep slopes, in areas of active alluvial deposition, and areas of bedrock exposure or extremely shallow depth-to-bedrock. During preparation of this report, many of pedons in these transitional zones were reclassified to better correlate with the temperature and moisture regimes of the mapped soil units. Some field forms were not updated with the most recent classifications prior to finalizing this report. The correct and final classification for all pedons can be found in Appendix B, Table B-I. Soil Series _The series present in the Survey Area compare well with the official series descriptions, with few exceptions affecting interpretations for mining and reclamation. Soils with characteristics differing from the established series were identified as series taxadjuncts and variants to acknowledge these differences. Taxadjuncts have properties outside the range of the recognized series that do not significantly affect the interpretations or limit the use of the soil for reclamation. Variants have characteristics outside the range of the recognized series that may affect certain uses for reclamation. In Appendix B, Table B-I these are uniformly identified by the field name followed by a "v" (e.g., Campspass v.). The following section presents each of the 30 identified series and generally describes their dominant characteristics and limitations for use. Major deviations from the standard series descriptions are noted in each description. These descriptions, supplemented by the data presented elsewhere in this report, provide valuable information regarding the suitability and limitations of the soils in the Survey Area. Representative photographs of the series and other soils in the Survey Area are presented in Appendix C. The official taxonomic classifications of these series and a list of the most common un-named soil families are presented in Appendix B, Table B-2. Adderton Clay Loam The Adderton series consists of very deep, well-drained soils formed in alluvium on low slopes. Adderton soils are on flood plains, stream terraces, fans, and toe slopes. This soil occurs as a primary component along major drainages in the southern portion of the Survey Area and as an inclusion in the lowland units of minor tributaries. This soil has few limiting factors and has very high nutrient content relative to other soils in the Survey Area. However, the stratified nature of this soil can make determining optimal soil depths difficult. Lab data for this series confirmed that organic matter content and nutrients vary with the stratified layers. Battlement Fine Sandy Loam The Battlement series consists of very deep, well-drained or moderately well-drained soils formed in colluvial and alluvial (co-alluvial) material on flood plains, low stream terraces and narrow valley floors. The soil is primarily found in the northern portions of the Survey Area where alluvial soils are heavily influenced by eroded materials from nearby inceptic and entic slope soils. This soil is limited by its low organic matter content, high sand percentage and attendant high erodibility. Nutrient content of this soil ranks among the lowest of those tested. Blazon Channery Clay Loam The Blazon series consists of well-drained soils that are shallow to shale and siltstone. These soils form in slope alluvium and colluvium over residuum on convex hillslopes and ridges throughout the Survey Area. Tetra Tech, Inc. 4