LOCATION STREEK IDEstablished Series
TAXONOMIC CLASS: Fine, smectitic, frigid Vertic Argixerolls
TYPICAL PEDON: Streek silt loam, rangeland; on a 4 percent slope at 6,763 feet elevation. (Color is for air dry soil unless otherwise noted.)
A1--0 to 5 inches; dark grayish brown (10YR 4/2) silt loam, very dark brown (10YR 2/2) moist; moderate fine and very fine subangular blocky structure parting to moderate fine and very fine granular; slightly hard, friable, slightly sticky and slightly plastic; many fine and very fine and few medium roots; vertical cracks present, 1.5 to 4 cm wide; 5 percent gravel; slightly acid (pH 6.2); gradual wavy boundary. (4 to 8 inches thick)
A2--5 to 11 inches; dark grayish brown (10YR 4/2) silt loam, very dark grayish brown (10YR 3/2) moist; moderate coarse and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and very fine roots; vertical cracks present, 1.5 to 4 cm wide; 10 percent gravel; slightly acid (pH 6.2); gradual wavy boundary. (4 to 8 inches thick)
AB--11 to 16 inches; dark grayish brown (10YR 4/2) silty clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium angular blocky structure and moderate fine subangular blocky; slightly hard, friable, moderately sticky and moderately plastic; common fine and few coarse and medium roots; common silt coats on all faces of peds; vertical cracks present, 1 to 1.5 cm wide; 5 percent gravel; slightly acid (pH 6.2); gradual wavy boundary. (0 to 8 inches thick)
2Btss--16 to 45 inches; brown (10YR 5/3) silty clay, brown (10YR 4/3) moist; strong coarse and medium subangular blocky structure; hard, firm, very sticky and very plastic; few fine roots; common discontinuous distinct clay films on faces of peds; common discontinuous distinct slickensides on faces of peds; vertical cracks present, 1 to 1.5 cm wide; 5 percent gravel; slightly acid (pH 6.2); gradual wavy boundary. (25 to 40 inches thick)
2Btkss--45 to 60 inches; pale brown (10YR 6/3) silty clay, brown (10YR 5/3) moist; moderate coarse and medium subangular blocky structure; hard, firm, very sticky and very plastic; few fine roots; common discontinuous distinct clay films on faces of peds; common discontinuous distinct slickensides on faces of peds; strongly effervescent, common medium and fine carbonate masses; 2 percent gravel; slightly alkaline (pH 7.8). (0 to 20 inches thick)
TYPE LOCATION: Bear Lake County, Idaho; about 6 miles north of Liberty; about 1100 feet south and 700 feet east of the northwest corner of section 8, T.12 S., R.43 E.; USGS Nounan 7.5 minute topographic quadrangle; 42 degrees 23 minutes 52 seconds north latitude and 111 degrees 27 minutes 43 seconds west longitude, NAD 27.
RANGE IN CHARACTERISTICS:
Soil moisture control section - usually moist, 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 - 8 to 19 inches (may extend into the 2Btss horizon)
Depth to secondary carbonates - 40 to greater than 60 inches
Average annual soil temperature - 42 to 46 degrees F.
Particle-size control section:
Clay content average - 35 to 60 percent
Rock fragments - averages 1 to 14 percent
A horizons
Hue - 10YR
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 2 or 3 dry, 1 to 3 moist
Texture - loam or silt loam
Clay content - 18 to 27 percent
Rock fragments - 0 to 14 percent gravel
Reaction - slightly acid or neutral (pH 6.1 to 7.3)
AB horizon (when present)
Hue - 10YR or 7.5YR
Value - 4 or 5 dry, 2 to 4 moist
Chroma - 2 to 4 dry, 2 or 3 moist
Texture - silty clay loam or clay loam
Clay content - 28 to 40 percent
Rock fragments - 0 to 14 percent gravel
Reaction - slightly acid or neutral (pH 6.1 to 7.3)
2Btss horizon (some pedons may have a 2Btss2 horizon)
Hue - 10YR or 7.5YR
Value - 5 or 6 dry, 3 to 5 moist
Chroma - 3 or 4 dry, or moist
Texture - silty clay loam, clay loam, silty clay or clay
Clay content - 35 to 60 percent
Rock fragments - 0 to 10 percent gravel and 0 to 5 percent cobbles
Reaction - slightly acid or neutral (pH 6.1 to 7.3)
2Btkss (when present)
Hue - 10YR or 7.5YR
Value - 5 or 6 dry 4 to 6 moist
Chroma - 3 or 4 dry or moist
Texture - silty clay loam, clay loam, silty clay or clay
Clay content - 35 to 60 percent
Rock fragments - 0 to 10 percent gravel and 0 to 5 percent cobbles
Calcium carbonate equivalent - 5 to 15 percent
Reaction - slightly or moderately alkaline (pH 7.4 to 8.4)
COMPETING SERIES: These are the Cleymor, Laplatta, Mondey, Shar (T), Top and Wickiser series. Cleymor soils have a 20 to more than 60 inch thick mollic epipedon and are formed from volcaniclastic materials. Laplatta soils have a 24 to 40 inch thick mollic epipedon. Mondey soils have secondary carbonates at 31 inches and are formed in materials weathered from sandstone. Shar soils are moderately deep to bedrock and are formed in alluvium and loess over basalt. Top soils do not have slickensides. Wickiser soils have a mollic epipedon 25 to 35 inches thick.
GEOGRAPHIC SETTING:
Landform: hillslopes, mountain slopes, summits, alluvial fans and fan remnants
Elevation: 5,500 to 7,200 feet
Slope: 2 to 25 percent
Parent material: mixed alluvium over silty and clayey alluvium
Climate: long, cold winters; moist springs; warm, dry summers
Average annual precipitation: 16 to 24 inches
Average annual temperature: 39 to 45 degrees F.
Frost-free period: 70 to 90 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cleavage, Sagollow (T) and Swanpeak (T) series. Cleavage soils are shallow to bedrock and occur on higher landscape positions. Sagollow soils have a seasonal high water table at 10 to 40 inches and occur on lower landscape positions. Swanpeak soils have a clayey-skeletal particle-size control section and occur on similar landscape positions.
DRAINAGE AND PERMEABILITY: Well drained; high to very high runoff; slow permeability.
USE AND VEGETATION: Streek soils are used for rangeland and wildlife habitat. The present vegetation is mainly mules ear, prairie junegrass, bluebunch wheatgrass, Idaho fescue, oniongrass, snowberry, antelope bitterbrush, mountain big sage and small aspen groves.
DISTRIBUTION AND EXTENT: Southeastern Idaho. The soils are of small extent. MLRA 43B.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Bear Lake County, Idaho, 2008. The name is coined from nearby Stauffer Creek.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from the surface to 16 inches (the A1, A2 and AB horizons).
Argillic horizon - the zone from 16 to 60 inches (2Btss and 2Btkss horizons).
Depth to secondary carbonates - the zone from 45 to 60 inches (2Btkss horizon).
Vertic features - cracks from the surface to a depth of 40 inches that were 1.5 to 4 cm wide. Slickensides within 40 cm of the mineral soil surface.