LOCATION AABERG COEstablished Series
TAXONOMIC CLASS: Fine, smectitic, frigid Leptic Udic Haplusterts
TYPICAL PEDON: Aaberg clay - grassland. (Colors are for dry soil unless otherwise noted.)
A--0 to 4 inches; grayish brown (2.5Y 5/2) clay, very dark grayish brown (2.5Y 3/2) moist; strong fine granular structure; soft, friable, moderately sticky and moderately plastic; slightly alkaline (pH 7.6); clear smooth boundary. (3 to 6 inches thick)
Bw--4 to 23 inches; light olive brown (2.5Y 5/3) clay, olive brown (2.5Y 4/3)) moist; weak medium prismatic structure parting to moderate medium angular blocks; slightly hard, friable, moderately sticky and moderately plastic; peds are extremely hard; few thin glossy patches on faces of peds; cracks 1 to 2 cm. wide when dry; few slickensides; slightly alkaline (pH 7.6); gradual wavy boundary. (10 to 37 inches thick)
BC--23 to 30 inches; light olive brown (2.5Y 5/3) clay, olive brown (2.5Y 4/3) moist; weak coarse angular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; peds are extremely hard; few slickensides; cracks 1 to 2 cm. wide when dry; strongly effervescent; moderately alkaline (pH 8.0); gradual wavy boundary. (0 to 10 inches thick)
TYPE LOCATION: Jackson County, Colorado; about 10 miles east of Walden; 1/4 mile east and 1/8 mile north of the south 1/4 corner of Sec. 35, T. 9 N., R. 78 W. Johnny Moore Mountain USGS quad; lat. 40 degrees 42 minutes 02 seconds N. and long. 106 degrees 06 minutes 41 seconds W., NAD 83.
RANGE IN CHARACTERISTICS: Mean annual soil temperature is 39 degrees F., and mean summer soil temperature ranges from 55 to 59 degrees F. Exchangeable sodium ranges from 0 to 15 percent in the control section. The solum is calcareous in some pedons. Depth to the paralithic contact ranges from 20 to 40 inches. The particle size control section is typically clay but averages 35 to 60 percent clay, 15 to 45 percent silt, and 15 to 45 percent sand with more than 15 percent fine or coarser sand. Rock fragments range from 0 to 15 percent in the major part of the control section and are mainly 0 to 10 inches in diameter. In some pedons subhorizons redder than 7.5YR occur, but a major part of the solum and C horizons above the bedrock has hue of 7.5YR or yellower. Mottling ranges from none to few faint mottles. These soils crack widely on drying and have a high shrink-swell potential.
The A horizon has hue of 5Y through 7.5YR, value of 5 or 6 dry, and 3 or 4 moist, with chroma of 2 through 4. It is neutral or slightly alkaline.
The Bw horizon has hue of 5Y through 7.5YR, value of 5 through 7 dry, and 3 through 6 moist, with chroma of 2 through 4. It ranges from neutral to moderately alkaline.
A Ck horizon is present in some pedons but is absent or discontinuous in others.
The C horizon has hue of 5Y through 7.5YR. It ranges from neutral to strongly alkaline.
COMPETING SERIES: These are the Abor, Barkof, Bascovy, (T)Bickerdyke, Binco, Bulkley, Dutton, Gerber, Linnet, Marias, and Marvan series, all of which have a frigid temperature regime except Binco. In addition, Binco soils lack a paralithic contact within a depth of 40 inches.
GEOGRAPHIC SETTING: Aaberg soils are on upland hills and ridges where shale occurs above a depth of 40 inches. Slopes typically range from 2 to 65 percent. The soil formed in fine textured, noncalcareous or weakly calcareous parent sediments weathered from underlying clay shale beds. The average annual precipitation ranges from 9 to 12 inches with peak periods of precipitation during the spring and early summer. The average annual air temperature is 37 degrees F., and the average summer temperature is 57 degrees F. Elevation ranges from 8,200 to 8,600 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Barishman and Bundyman soils. Barishman soils lack a paralithic contact above a depth of 40 inches. Bundyman soils have continuous horizons of secondary calcium carbonate accumulation above the bedrock.
DRAINAGE AND PERMEABILITY: Moderately well drained; high runoff; slow permeability.
USE AND VEGETATION: These soils are used principally for native pastureland. Native vegetation consists of alkali sage, western wheatgrass, and pine needlegrass.
DISTRIBUTION AND EXTENT: High mountain valleys of north-central Colorado. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Jackson County Area, Colorado, 1973.
The original concept of this series when correlated and established in 1973 was a cryic temperature regime and an aridic moisture regime.