LOCATION DIRTYHEAD IDEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Typic Calcixerepts
TYPICAL PEDON: Dirtyhead very gravelly loam, rangeland; on a slope of 12 percent under grass and shrubs at 5,200 feet. (Colors are for dry soil unless otherwise noted.)
A--0 to 6 inches; light brownish gray (10YR 6/2) very gravelly loam, dark grayish brown (10YR 4/2) moist; weak very fine granular structure; soft, friable, nonsticky and nonplastic; common very fine, fine, and medium roots; common very fine tubular pores; strongly effervescent; 15 percent calcium carbonate equivalent; 40 percent gravel; slightly alkaline (pH 7.8); clear wavy boundary. (5 to 12 inches thick)
Bk1--6 to 16 inches; light brownish gray (10YR 6/2) very gravelly loam, grayish brown (10YR 5/2) moist; weak very fine subangular blocky structure; soft, friable, nonsticky and nonplastic; common very fine, fine, and medium roots; few very fine tubular pores; strongly effervescent; 20 percent calcium carbonate equivalent; 45 percent gravel; moderately alkaline (pH 8.0); clear smooth boundary. (8 to 13 inches thick)
Bk2--16 to 26 inches; light gray (10YR 7/2) very gravelly sandy loam, pale brown (10YR 6/3) moist; massive; slightly hard, friable, nonsticky and nonplastic; few very fine and fine roots; common very fine tubular pores; violently effervescent; 25 percent calcium carbonate equivalent; 55 percent gravel; moderately alkaline (pH 8.0); clear wavy boundary. (8 to 12 inches thick)
Bk3--26 to 38 inches; light gray (10YR 7/2) very gravelly sandy loam, brown (10YR 5/3) moist; massive; slightly hard, friable, nonsticky and nonplastic; few very fine tubular pores; violently effervescent; 20 percent calcium carbonate equivalent; 60 percent gravel; moderately alkaline (pH 8.2). (4 to 14 inches thick)
Cr--38 inches; weakly consolidated calcareous sandstone.
TYPE LOCATION: Franklin County, Idaho; about 6 miles northwest of Weston; 400 feet west and 1,900 feet north of the southeast corner of sec. 12, T.16S., R.37E.
RANGE IN CHARACTERISTICS:
Depth to calcic horizon - 5 to 12 inches
Average annual soil temperature - 43 to 47 degrees F.
Depth to paralithic contact - 25 to 40 inches
Particle-size control section
Clay content - 10 to 18 percent
Gravel content - 40 to 60 percent
A horizon
Value - 5 through 7 dry, 4 or 5 moist
Chroma - 2 or 3 dry or moist
Rock fragment content - 15 to 45 percent gravel and/or channers
Texture - silt loam or loam
Calcium carbonate equivalent - 10 to 25 percent
Reaction - slightly alkaline or moderately alkaline
Bk horizons
Hue - 10YR or 2.5Y
Value - 6 or 7 dry, 5 or 6 moist
Chroma - 2 or 3 dry or moist
Rock fragment content - 35 to 60 percent gravel and/or channers
Texture - silt loam, loam, or sandy loam
Calcium carbonate equivalent - 15 to 35 percent
Reaction - moderately alkaline
COMPETING SERIES:
Argora (T ID) - are very deep.
Chausse (T ID) - are very deep.
Cutoff (UT) - have hues redder than 10YR throughout the profile and the average annual soil temperature is less than 43 degrees F.
GEOGRAPHIC SETTING: Dirtyhead soils are on mountainsides, hills, and terraces. Slopes range from 1 to 60 percent. Elevations are 4,800 to 7,125 feet. The soils formed in slope alluvium and residuum derived dominantly from calcareous, siltstone, shale, and sandstone. Average annual precipitation is 14 to 20 inches. Average annual air temperature is 41 to 45 degrees F. The frost-free period is 70 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Collinston, Huffman, Wheelon, and Wursten soils. Collinston, Huffman, and Wheelon soils are fine-silty. Collinston and Huffman soils have a mollic epipedon. Wursten soils are coarse-loamy and have a mollic epipedon. Collinston, Huffman, and Wursten soils are on broad terraces and side slopes. Wheelon soils are on side slopes and ridges.
DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff; permeability is moderate.
USE AND VEGETATION: The soil is used principally for dryland crops and rangeland. Vegetation is mainly basin big sage, mountain sagebrush, low sagebrush, bluebunch wheatgrass, bitterbrush, and prairie junegrass.
DISTRIBUTION AND EXTENT: These soils are not extensive in southeast Idaho.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Franklin County, Idaho, 1997.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from 0 to 6 inches (A horizon).
Calcic horizon - The zone from 6 to 38 inches (the Bk1, Bk2, and Bk3 horizons)
Particle-size control section - The zone from 10 to 38 inches (part of the Bk1, the Bk2 and Bk3 horizons)