LOCATION WOOLSTED IDTentative Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive Xeric Haplocryolls
TYPICAL PEDON: Woolsted silt loam, on a south-facing slope of 1 percent under sagebrush and grass at an elevation of 1,935 meters (Colors are for dry soil unless otherwise noted.)
A1--0 to 5 cm; dark grayish brown (10YR 4/2) silt loam, very dark grayish brown (10YR 3/2) moist; weak fine and medium granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine irregular and few very fine tubular pores; neutral (pH 6.8); clear wavy boundary.
A2--5 to 33 cm; brown (10YR 4/3) silt loam, dark brown (10YR 3/3) moist; weak fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and common fine roots; common very fine tubular pores; neutral (pH 6.6); gradual wavy boundary. (Combined thickness of A horizons is 25 to 36 cm.)
Bw1--33 to 64 cm; brown (10YR 5/3) silt loam, brown (10YR 4/3) moist; moderate fine and medium subangular blocky structure; very hard, friable, sticky and plastic; many very fine and fine roots; common very fine tubular pores; slightly acid (pH 6.4); gradual wavy boundary.
Bw2--64 to 91 cm; brown (10YR 5/3) silt loam, brown (10YR 4/3) moist; moderate fine and medium subangular blocky structure; very hard, friable, sticky and plastic; few very fine and fine roots; common very fine tubular pores; few distinct very pale brown (10YR 7/3) silt coats on ped faces; 2 percent gravel; neutral (pH 6.6); gradual wavy boundary.
Bw3--91 to 150 cm; brown (10YR 5/3) silt loam, brown (10YR 4/3) moist; weak fine and medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few very fine roots; common very fine and few fine tubular pores; few distinct very pale brown (10YR 7/3) silt coats on ped faces; 2 percent gravel; neutral (pH 6.7); gradual wavy boundary. (Combined thickness of Bw horizons is 35 to 143 cm.)
C--150 to 183 cm; brown (10YR 5/3) silt loam, brown (10YR 4/3) moist; massive; hard, friable, slightly sticky and slightly plastic; few fine and medium tubular pores; few distinct very pale brown (10YR 7/3) silt coats on ped faces; 1 percent gravel; neutral (pH 6.7).
TYPE LOCATION: Caribou County, Idaho; 7 miles northeast of Conda;1,900 feet west and 100 feet south of the northeast corner of sec. 28, T. 7 S., R. 43 E; Lower Valley topographic quadrangle; lat. 42 degrees 47 minutes 37.5 seconds N. and long. 111 degrees 26 minutes 5.2 seconds W., NAD 83.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 1.7 to 4.4 degrees C
Mean summer soil temperature: 12.8 to 15 degrees C
Soil moisture control section: between 10 and 30 cm; dry in all parts for 45 consecutive days or more in the four months following the summer solstice. Xeric moisture regime.
Thickness of mollic epipedon: 25 to 36 cm
Particle-size control section:
Clay content: 18 to 27 percent
Rock fragment content: 0 to 10 percent
A horizons
Value: 3 to 5 dry; 2 or 3 moist
Chroma: 2 or 3 dry; 1 to 3 moist
Clay content: 12 to 18 percent clay
Rock Fragments: 0 to 5 percent gravel
Reaction: 6.1 to 7.8
Bw horizons
Hue: 10 YR or 7.5YR
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2 to 4, dry or moist
Clay content: 18 to 27 percent clay
Rock Fragments: 0 to 5 percent gravel
Reaction: 6.1 to 7.3
C horizon
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2 to 4, dry or moist
Clay content: 14 to 20 percent clay
Rock Fragments: 0 to 10 percent gravel
Reaction: 6.6 to 7.3
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landscape: Mountains
Landform: Fan remnants
Elevation: 1,830 to 2,075 meters
Slope: 1 to 20 percent
Parent material: Loess and silty alluvium
Mean annual precipitation: 450 to 560 mm
Mean annual air temperature: 0.6 to 4.0 degrees C
Frost-free period: 30 to 65 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Lanark and Rin soils. Lanark soils are pachic and are on mountain slopes and alluvial fans. Rin soils are coarse-silty and pachic, and are on foothills, mountain slopes, and stream terraces.
DRAINAGE AND PERMEABILITY:
Drainage class: Well drained
Runoff: Low to medium
Permeability: Moderate
USE AND VEGETATION:
Major use: Rangeland
Vegetation: Mountain big sagebrush, Idaho fescue, and bluebunch wheatgrass
DISTRIBUTION AND EXTENT: Woolsted soils are of limited extent in southeastern Idaho. MLRA 43B.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Caribou County, Idaho, 1980.
REMARKS: Diagnostic horizons and other features recognized in this pedon:
Mollic epipedon: 0 to 33 cm (A1 and A2 horizons)
Cambic horizon: 33 to 150 cm (Bw1, Bw2, and Bw3 horizons)
Particle-size control section: the zone from 25 to 100 cm (part of the A2, Bw1, Bw2, and part of the Bw3 horizons)
Woolsted soils have a cryic temperature regime and a xeric moisture regime.
This description reflects an update in classification from Fine-silty, mixed, superactive Xeric Argicryolls to Fine-silty, mixed superactive Xeric Haplocryolls.