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2002 Soil Sampling: Seneca Mine, Hayden Colorado <br />• Lab Data- Lab data is located in Appendix II. Both the upper and lower topsoil <br />horizons, differing only in their mechanical treatment, have the same chemical <br />properties. pH ranges 6.1 to 7.4 and averages 6.6, which is neutral. Organic <br />matter averages 6.6 percent and ranges 4.3 to 7.9. These results and all <br />other lab data indicate topsoil in all sample pits is suitable (Appendix III, Table <br />1). <br />Subsoil- The same sample pits were sampled for subsoil/spoil from the bottom of <br />the topsoil horizon to the top of spoil material. Field descriptions are located in <br />Appendix IV and lab data is located in Appendix II. All subsoil in all sample pits <br />classify as suitable subsoil (Appendix III, Table 1). All sites are adry-land grass/forb <br />site. All sites are in their second year of growth. The results follow: <br />Depth- The average depth of the subsoil is 16.4 inches (1.4 feet) as <br />measured from the bottom of the topsoil to the top of the spoil. Subsoil depth <br />ranges 4 to 34 inches (.33 to 2.83 feet). Sample site S2-02-6 occurs in fill <br />over the blasted high wall (according to Seneca Mine personnel), indicating <br />the deep 34 inch subsoil. Site S2-02-10 had a subsoil that ended at 19 <br />inches, indicating that this site only had surface disturbance. <br />Textures- Textures are silt foams, foams, and clay foams. Clay content <br />averages 23 percent and ranges 14 to 31 percent, sand content averages 34 <br />percent and ranges 24 to 43 percent. Silt content averages 43 percent and <br />ranges 36 to 52 percent. <br />Rock Fragments- Rock fragments average 25 percent and range 10 to 30 <br />percent. Rock Fragments are predominantly gravel and cobble size (2mm to <br />250mm) of sedimentary origin, primarily sandstone with some fragments of <br />shale, siltstone, and coal. <br />Structure- Structure of the subsoil ranges from fine sub-angular blocky to <br />coarse sub-angular blocky. Such structure is typical of mechanically <br />redistributed subsoil. <br />Consistence- Dry consistence in the subsoil layer ranges from slightly hard <br />to very hard. Dry consistence indicates moderate compaction through the use <br />of mechanical equipment for subsoil redistribution. Moist consistence ranges <br />from friable to firm. <br />Lab Data- Lab data is located in Appendix II. The subsoil pH ranges 4.9 to <br />7.9 and averages 7.1, which is neutral. Organic matter averages 4.2 percent <br />and ranges 1.2 to 7.9. These results and all other lab data indicate subsoil in <br />• all sample pits as suitable (Appendix III, Table 1). <br />Page 3 of 5 01/28/03 <br />