LOCATION SILVERCLIFF COEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Calcic Haplocryolls
TYPICAL PEDON: Silvercliff cobbly sandy loam - grassland, on twenty percent southwest aspect. (Colors are for dry soil unless otherwise noted.)
A--0 to 8 inches; grayish brown (10YR 5/2) cobbly sandy loam, very dark grayish brown (3/2) moist; moderate very fine granular structure; soft, very friable; 20 percent pebbles, 15 percent cobbles; slightly alkaline; clear smooth boundary. (7 to 15 inches thick)
Bw--8 to 14 inches; brown (7.5YR 5/4) very gravelly sandy loam, dark brown (7.5YR 4/4) moist; weak fine subangular blocky structure; hard, friable, slightly sticky and slightly plastic; 25 percent pebbles, 15 percent cobbles; slightly alkaline; abrupt wavy boundary. (3 to 18 inches thick)
Bk--14 to 34 inches; white (N 8/) stratified very gravelly sandy and cobbly loam, sand, and very gravelly sandy loam, pinkish gray (7.5YR 6/2) moist stratified with light brown (7.5 YR 6/4) and brown (7.5YR 5/4) massive; slightly hard, very friable, nonsticky and slightly plastic; 40 percent pebbles, 15 percent cobbles; disseminated lime with many fine lime concretions and pendants on lower surface of rock fragments; strongly effervescent; moderately alkaline; clear irregular boundary. (10 to 30 inches thick)
2C--34 to 43 inches; light reddish brown (5YR 6/4) loamy sand, reddish brown (5YR 5/4) moist; single grained; loose, soft; 5 percent pebbles; slightly effervescent; mildly alkaline; clear irregular boundary. (8 to 15 inches thick)
2Ck--43 to 60 inches; white (N 8/) gravelly loam, pinkish gray (5YR 7/2) moist; massive; slightly hard, friable, slightly sticky and plastic; 10 percent pebbles, 10 percent cobbles; secondary calcium carbonate well disseminated throughout horizon and many fine lime concretions; violently effervescent; moderately alkaline.
TYPE LOCATION: Custer County, Colorado; 2,000 feet south and 2,400 feet east NW corner Sec. 2, T. 23 S., R. 72 W. U.S.G.S. Aldrich Gulch quad.; Lat. 38 degrees, 5 minutes, 18 seconds N.; and long. 105 degrees, 24 minutes, 38 seconds W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 40 to 44 degrees F. Mean summer soil temperature is 47 to 58 degrees F. Depth to bedrock is more than 60 inches. The particle-size control section averages less than 18 percent clay in the fine earth fraction, and stratified layers of sand are common. Rock fragments range from 35 to 80 percent and are dominantly less than 3 inches in diameter, but cobble-size fragments are common.
The A horizon has hue of 7.5YR or 10YR, value of 4 or 5 dry, 2 or 3 moist, and chroma of 2 or 3. This horizon is cobbly sandy loam, very cobbly sandy loam, or gravelly sandy loam.
The B horizon has hue of 5YR through 10YR, value of 5 or 6 dry, 4 or 5 moist, and chroma of 4 or 5. This horizon is typically sandy loam or loam in the fine earth fraction.
The C horizon has hue of 5YR through 7.5YR, value of 5 through 8 dry, 5 through 7 moist, and chroma of 0 through 4. The Cca horizon has 20 to 35 percent calcium carbonate equivalent.
COMPETING SERIES: These are the Antrobus (CO), Basinpeak (NV), Broad Canyon (UT), Decram (NV), Fairydell (NV), Farlow (WY), Foxmont (NV), Gaia (NV), Grafen (CO), Greyback (WY), Handran (CO), Kamack (UT), Klug (ID), Krackle (OR), Lag (ID), Maurice (MT), McCort (WY), Middlehill (ID), Midelight (WY), Midfork (WY), Parachute (CO), Rockabin (NV), Sebud (MT), Sup (NV), Supervisor (NM), Teemat (WY), Thornburg (CO), Tiban (MT), Timmercrek (NV), Tineman (WY), and Wareagle (ID) series.
Decram, Krackle, Middlehill, Parachute, and Supervisor soils have a lithic contact at a depth of 20 to 40 inches. Broad Canyon soils are slightly and or medium acid in the control section. Fairydell, Farlow, Kamack, Midelight, Midfork, Sebud, and Tiban soils have more than 18 percent clay in the particle-size control section. Also, Farlow and Midelight soils have channery coarse fragments and have a lithic contact at a depth of 40 to 60 inches. Greyback and Midfork soils lack a calcic horizon. Foxmont, Grafen, and Rockabin soils have a paralithic contact at a depth of 20 to 40 inches. Handran, Klug, Lag, Maurice, McCort, Sup, Thornburg, Tineman, and Wareagle soils lack continuous horizons of secondary carbonate accumulation. Basinpeak, Gaia, and Timmercrek soils lack Bw and k horizons. Teemat lacks Bw horizons.
GEOGRAPHIC SETTING: Silvercliff soils are on fans and terraces. Elevations range from 7,500 to 8,600 feet. The soils formed in coarse textured gravelly alluvium. Slopes range from 1 to 50 percent. The soils are in a cold and dry climate with precipitation ranging from 14 to 18 inches. Mean annual temperature is 40 to 44 degrees F. The frost-free season is about 55 to 75 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Feltonia, Hoodle, and Coutis soils. Feltonia soils have a mollic epipedon more than 16 inches thick, and average less than 35 percent coarse fragments. Hoodle soils have an argillic horizon. Coutis soils have a mollic epipedon thicker than 16 inches, and contain less than 15 percent rock fragments through the profile.
DRAINAGE AND PERMEABILITY: Well to somewhat excessively drained; medium runoff; moderately rapid to rapid permeability.
USE AND VEGETATION: These soils are used for rangeland. Native vigitation is Arizona fescue, western wheatgrass, blue grama, and fringed sage.
DISTRIBUTION AND EXTENT: Outwash fans and terraces of high mountain valleys of Colorado. The soils are moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Custer County, Colorado, 1979.
REMARKS: Silvercliff was initially classified in the loamy-skeletal, mixed family of Calcic Cryoborolls. Diagnostic features include a mollic surface from 0 to 8 inches; a cambic horizon from 8 to 14 inches; a Bk horizon from 14 to 34 inches; a lithologic continuity at 34 inches; and a 2Ck horizon at 43 to 60 inches. Last updated by the state on 4/94.