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0 SAR =1.7 (nonsodic), OM =0.5 %; gradual wavy boundary. <br />Ck horizon — 38 to 54+ inches; light yellowish brown (10YR 6/4) clay (47% clay), yellowish <br />brown (10YR 4/4) moist; white carbonate streaks and spots; massive structure; very hard, <br />very firm, sticky and plastic consistence; moderately to strongly effervescent; from lab data: <br />pH =7.8 (slightly alkaline), EC =0.3 (nonsaline), SAR =2.3 (nonsodic), OM =0.5 %; gradual <br />wavy boundary; auger refusal at 54 inches — clay too hard and too dry to dig further down. <br />3.3.3 Map Unit 35E: Aaberg silty clay, 20 to 40% slopes <br />Aaberg was recently re- correlated to the Phippsberg soil series but the Aaberg name is <br />retained for potential surface- affected areas within the Sage Creek Mine project <br />because it is part of both the Seneca II Mine and Foidel Creek Mine soil legends. The <br />Phippsberg name is used for non - affected areas. Aaberg is an established soil series of <br />moderate extent mapped in the mountainous areas and valleys of north - central <br />Colorado, and is classified as a "Fine, smectitic frigid Leptic Udic Haplustert". <br />Diagnostic features for the typical pedon include a "Bss" horizon ( "B" horizon with <br />slickensides) from 7 to 37 inches in depth. The most recent official NRCS soil series <br />description for Aaberg, dated January 2006, is on file. Phippsberg is essentially the <br />same soil as Aaberg except it is considered to have an "ustic" soil moisture regime with <br />18 to 26 inches of average annual precipitation rather than about 12 inches for Aaberg. <br />• Phippsberg is classified as a "Fine, smectitic Chromic Haplocryert". <br />Aaberg Typical Sample "CC -3" Site and Profile Description: Aaberg clay was fully <br />described and sampled at one representative site, CC -3, located near the SE corner of <br />Section 11, T.5N., R.87W. The sample site is on an upland ridge sideslope with big <br />sagebrush and mixed grass vegetation, and is within the previous potential <br />transportation corridor in the hilly ridge "gap" area between the south end of the Seneca <br />II Mine permit area and the north end of Foidel Creek Mine permit area. Sample site <br />CC -3 has 12% slope, south aspect, slopewash alluvium over residuum from clay shale; <br />and stable surface with no erosion in the vicinity of the sample site location. An <br />evaluation of soil suitability indicates the sampled Aaberg pedon CC -3 is consistent with <br />the previous Seneca II Mine recommended topsoil salvage depth of 6 to 8 inches, with <br />an average recommended depth of 7 inches. Clay content is too high ( >40 %) below 7 <br />inches for salvage. <br />A horizon — 0 to 4 inches; grayish brown (10YR 5/2, 2.5YR 5/2) clay loam with 2% small <br />sandstone chips, dark grayish brown (10YR 4/2, 2.5YR 4/2) moist; strong fine granular <br />structure; slightly hard, friable, sticky and slightly plastic consistence; common medium, <br />fine, and very fine, and few coarse roots; noneffervescent; from lab data: pH =6.4 (slightly <br />acid), EC =0.3 (nonsaline), SAR =0.2 (nonsodic), OM =13.7% by weight -loss on ignition; <br />gradual smooth boundary. <br />• 10 <br />