LOCATION TSCHAMMAN IDEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Chromic Durixererts
TYPICAL PEDON: Tschamman very stony silty clay loam - rangeland at an elevation of 5,150 feet. (Colors are for dry soil unless otherwise noted.)
A--0 to 3 inches; brown (10YR 5/3) very stony silty clay loam, dark brown (10YR 3/3) moist; weak fine and medium platy structure parting to weak fine subangular blocky; slightly hard, friable, sticky and plastic; common fine and very fine and few medium and coarse roots; many fine and very fine tubular pores; 20 percent gravel, 20 percent cobbles, 3 percent stones; 1 cm wide cracks; neutral (pH 7.0); abrupt broken boundary. (2 to 7 inches thick)
Bss1--3 to 14 inches; reddish brown (5YR 5/3) silty clay, dark reddish brown (5YR 3/3) moist; strong coarse prismatic structure parting to strong medium and coarse angular blocky and subangular blocky; extremely hard, very firm, very sticky and very plastic; few very fine, fine, medium and coarse roots in cracks; few fine very fine tubular pores; intersecting slickensides and pressure faces; 2 percent gravel; 1 cm wide cracks; neutral (pH 7.0); gradual wavy boundary. (7 to 15 inches thick)
Bss2--14 to 26 inches; reddish brown (5YR 5/3) silty clay, dark reddish brown (5YR 3/3) moist; strong coarse prismatic structure parting to strong medium and coarse angular blocky and subangular blocky; extremely hard, very firm, very sticky and very plastic; few very fine, fine, medium and coarse roots in cracks; few fine very fine tubular pores; intersecting slickensides and pressure faces; 2 percent gravel; 1 cm wide cracks; neutral (pH 7.0); clear wavy boundary. (0 to 20 inches thick)
Bss3--26 to 30 inches; yellowish red (5YR 5/6) clay, yellowish red (5YR 4/6) moist; strong fine and medium prismatic structure; very hard, firm, very sticky and very plastic; few very fine, fine, medium and coarse roots in cracks; few fine very fine tubular pores; intersecting slickensides and pressure faces; 2 percent gravel; 1 cm wide cracks; neutral (pH 6.8); abrupt smooth boundary. (0 to 7 inches thick)
Bqm--30 to 43 inches; pink (7.5YR 7/4) indurated duripan, brown (7.5YR 4/6) moist; massive; few very fine, fine, few fine and very fine roots matted at the top of the horizon; 2 percent gravel, 10 percent cobbles, 10 percent stones (cemented into the duripan); silica cap (l mm thick) is underlain by strongly cemented material; abrupt broken boundary. (1 to 15 inches thick)
2R--43 inches; basalt bedrock
TYPE LOCATION: Gooding County, Idaho; about 13 miles north of Bliss, 1.350 feet south and 250 feet east of the northwest corner of Sec. 26, T3S, R12E. Lat. 43 degrees North, 8 minutes, 16 seconds; Long. 115 degrees West, 0 minutes, 7 seconds.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 47 to 50 degrees F.
Thickness of mollic epipedon - 10 to 26 inches
Depth to duripan - 20 to 40 inches
Depth to bedrock - 40 to 60 inches
Clay (control section average) - 40 to 60 percent
Reaction - slightly acid to neutral
Cracks - open July through October; closed during winter; 1 to 3 cm wide extending from the surface to 50 to 75 cm.
Present in some pedons - Bkqm and Bq horizons
A horizon
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 3 or 4 dry or moist
Rock fragments - 5 to 20 percent gravel, 5 to 40 percent cobbles, 1 to 3 percent stones
Bss horizons
Hue - 5YR or 7.5YR
Value - 4 through 7 dry, 3 through 6 moist
Chroma - 3 through 6 dry or moist
Texture - SIC, C
Clay content - 40 to 60 percent
Rock fragments - 0 to 10 percent gravel, 0 to 5 percent cobbles Intersecting slickensides - few to common
Bqm horizon
Hue - 10YR of 7.5YR
Value - 5 through 8 dry or moist
Chroma - 2 through 5 dry or moist
Distance between indurated silica caps - .5 mm to 3 inches
Thickness of indurated silica caps - .5 mm to 2 mm thick
Cementation between caps - weak to strong
Effervescence - noneffervescent to slightly effervescent
Calcium carbonate content - 0 to 5 percent
COMPETING SERIES: This is the Peasley series. Peasley soils have a weakly cemented duripan.
GEOGRAPHIC SETTING: Tschamman soils are on basalt plateaus and mesas. Tschamman soils are underlain by basalt and developed in loess. Slopes are 2 to 8 percent. Elevations range from 3,900 to 5,200 feet. The average annual precipitation is 11 to 13 inches. The average annual air temperature is 45 to 48 degrees F. and the frost-free period is 90 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hobby soils on ridges and the Bray soils in concave positions. Hobby soils are moderately deep to bedrock and lack a duripan. Bray soils have an ochric epipedon and an argillic horizon and do not crack.
DRAINAGE AND PERMEABILITY: Well drained; runoff is rapid; permeability is very slow.
USE AND VEGETATION: Tschamman soils are used for rangeland. Potential native vegetation is low sagebrush and bluebunch wheatgrass.
DISTRIBUTION AND EXTENT: Tschamman soils are of moderate extent in south central Idaho.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Gooding County, Idaho, 1993.
REMARKS: This revision changes the classification from Haplic Durixerolls to Chromic Durixererts.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: the zone from 0 to 26 inches (A, Bss1, and Bss2 horizons)
Cambic horizon: the zone from 26 to 30 inches (Bss3 horizon)
Duripan: the zone from 30 to 43 inches (Bqm horizon)
Particle-size control section: zone from 10 inches to 30 inches (Part of the Bss1, the Bss2, and the Bss3 horizons)