LOCATION EEP IDEstablished Series
TAXONOMIC CLASS: Ashy-skeletal, glassy, frigid Vitrandic Argixerolls
TYPICAL PEDON: Eep very cobbly sandy loam - on a west facing slope of 25 percent under rangeland vegetation at 6,080 feet elevation. When described on April 15, 1981, the soil was slightly moist throughout. (Colors are for dry soil unless otherwise noted.)
A--0 to 9 inches; dark grayish brown (10YR 4/2) very cobbly sandy loam, very dark brown (10YR 2/2) moist; weak medium granular structure; soft, friable; many roots; many very fine tubular pores; 20 percent gravel, 30 percent cobbles, 5 percent stones; neutral (pH 6.6); gradual wavy boundary. (4 to 12 inches thick)
Bt1--9 to 17 inches; brown (10YR 5/3) very gravelly loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; slightly hard, friable, sticky and plastic; many roots; many very fine tubular pores; common distinct clay films on faces of peds and in pores; 40 percent gravel, 15 percent cobbles; slightly acid (pH 6.4); gradual wavy boundary. (5 to 15 inches thick)
Bt2--17 to 26 inches; brown (10YR 5/3) extremely gravelly loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many roots; many very fine tubular pores; few faint clay films on faces of peds and in pores; 40 percent gravel, 20 percent cobbles, 5 percent stones; neutral (pH 6.6); gradual wavy boundary. (8 to 25 inches thick)
BC--26 to 38 inches; pale brown (10YR 6/3) very cobbly sandy loam, brown (10YR 4/3) moist; massive; slightly hard, friable; common very fine to medium roots; many very fine tubular pores; 20 percent gravel, 30 percent cobbles; neutral (pH 7.0); clear wavy boundary. (0 to 14 inches thick)
C--38 to 76 inches; white (10YR 8/1) unconsolidated loamy sand volcanic ash, light gray (10YR 7/2) moist; single grain; loose; few very fine roots; abrupt wavy boundary. (30 to 60 inches thick)
Cr--76 to 78 inches; very pale brown (10YR 7/3) consolidated ash, light yellowish brown (10YR 6/4) moist; massive; very hard, very firm.
TYPE LOCATION: Twin Falls County, Idaho; about 21 miles southwest of Rogerson, Idaho; in the northeast 1/4, southeast 1/4, southeast 1/4 section 7, T. 15 S., R. 13 E.
RANGE IN CHARACTERISTICS:
Base saturation upper 40 inches - 65 to 75 percent
Mollic epipedon - 10 to 20 inches (O.C. i. less than 0.6 percent below 20 inches.)
Clay percent in control section - 20 to 30 percent
Coarse fragments in control section - 40 to 70 percent
Average annual soil temperature - 42 to 46 degrees F.
A horizon
Chroma - 1 or 2 dry or moist
Reaction - slightly acid through neutral
Volcanic glass content - 75 to 85 percent
Bt horizons
Value - 5 or 4 dry
Value - 3 or 2 moist
Chroma - 2 or 3 dry or moist
Texture - GRV-CL, CBX-L, or CBV-L
Gravel - 25 to 40 percent
Cobbles - 10 to 20 percent
Stones - 0 to 10 percent
Volcanic glass content - 65 to 85 percent
Reaction - slightly acid or neutral
BC horizon
Value - 5 through 8 dry
Value - 3 through 7 moist
Chroma - 1 through 4 dry or moist
Texture - CBV-SL, GRV-SL, GRX-SL
Gravel - 30 to 60 percent
Cobbles - 10 to 30 percent
Volcanic glass content - 85 to 95 percent
COMPETING SERIES: This is the Monasterio series. Monasterio soils are moderately deep.
GEOGRAPHIC SETTING: Eep soils are on breaks, hillslopes, and scarps. The slope ranges from 6 to 75 percent. The soils formed in colluvium from volcanic ash and welded tuff. Elevations are 5,800 to 6,800 feet. The average annual precipitation ranges from 16 to 22 inches. The average annual temperature is 40 to 44 degrees F. The frost free season is 60 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Amboat, Brose, Dehana, Howcree, Keman, and Mug soils. Amboat soils are clayey-skeletal and occur on summits. Brose soils are shallow to bedrock and occur on summits. Dehana soils are not skeletal, are cryic, and occur on the same landscape, but on wetter exposures. Keman soils are loamy-skeletal and occur on summits.Mug soils are moderately deep to bedrock. Howcree and Mug soils occur on terraces. Howcree soils are clayey-skeletal.
DRAINAGE AND PERMEABILITY: Well drained, medium or rapid runoff; moderate permeability.
USE AND VEGETATION: Eep soils are used for rangeland. Native vegetation is mountain big sagebrush, antelope bitterbrush, bluebunch wheatgrass, Sandberg bluegrass, needleandthread, Idaho fescue, lupine, and stoneseed.
DISTRIBUTION AND EXTENT: Eep soils are of moderate extent in south central Idaho.
MLRA OFFICE RESPONSIBLE: Reno, Nevada
SERIES ESTABLISHED: Twin Falls County, Idaho, 1992.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from 0 to 17 inches (A and Bt1 horizons)
Argillic horizon - the zone from 9 to 26 inches (Bt1 and Bt2 horizons)
ADDITIONAL DATA: This soil has been sampled by the NSSL at Lincoln Lab. The laboratory sample number is 81P572.