LOCATION BLACKSPAR IDEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Lithic Mollic Haploxeralfs
TYPICAL PEDON: Blackspar very cobbly loam - on a 36 percent south-facing slope at an elevation of 6,080 feet in rangeland. When described on June 25, 1979, the soil was dry throughout. (Colors are for dry soil unless otherwise noted.)
A--0 to 3 inches; brown (10YR 5/3) very cobbly loam, dark brown (10YR 3/3) moist; moderate fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine and fine interstitial pores; about 20 percent gravel and 20 percent cobbles; neutral (pH 6.8); clear wavy boundary. (3 to 6 inches thick)
Bt1--3 to 7 inches; yellowish brown (10YR 5/4) very cobbly loam, dark yellowish brown (10YR 4/4) moist; moderate very fine and fine subangular blocky structure; hard, firm, slightly sticky and slightly plastic; common very fine and fine roots; common very fine and fine tubular pores; about 35 percent cobbles and 20 percent gravel; few faint clay films on ped faces and in pores; neutral (pH 6.8); clear wavy boundary. (4 to 7 inches thick)
Bt2--7 to 17 inches; light yellowish brown (10YR 6/4) extremely cobbly loam, dark yellowish brown (10YR 4/4) moist; moderate very fine and fine angular blocky structure; hard, firm, slightly sticky and slightly plastic; few very fine and fine roots; common very fine and fine tubular pores; about 30 percent cobbles and 35 percent gravel;
common faint clay films on ped faces and in pores; neutral (pH 7.2); abrupt wavy boundary. (3 to 10 inches thick)
2R--17; quartzitic sandstone
TYPE LOCATION: Blaine County, Idaho about 2 miles east and 6 miles north of the Fish Creek Reservoir; 900 feet north and 400 feet east of the southwest corner of sec. 6, T. 2 N., R. 23 E. Latitude - 43 degrees, 26 minutes, 32 seconds North; Longitude - 113 degrees, 38 minutes, 9 seconds West.
RANGE IN CHARACTERISTICS:
Depth to unfractured bedrock - 10 to 20 inches
Mean annual soil temperature - 42 to 45 degrees F.
Soil moisture - dry 90 to 120 days cumulative when above 41 degrees F. but not continuously dry for over 90 days
A horizon
Color value, dry - 5 or 6
Color value, moist - 2 or 3
Rock fragments - 35 to 60 percent
Organic carbon - 0.7 to 1.5 percent
Bt horizon
Color hue - 10YR or 7.5YR
Color value, dry - 4 through 6
Texture - CBV-L, CBV-CL, CBX-L
Clay content - 20 to 30 percent
Rock fragments - 35 to 75 percent
COMPETING SERIES: These are Avtable, Thorn and Wassit series. Avtable soils are dry for less than 90 days cumulative. Thorn soils are dry for 60 to 90 consecutive days after the summer solstice and have a 4 to 7 inch thick surface layer of sandy loam ash. Wassit soils are dominated by gravel size rock fragments and have hue of 10YR ot 2.5Y in the subsoil.
GEOGRAPHIC SETTING: Blackspar soils are on mountainsides. Slopes range from 30 to 75 percent. Elevation ranges from 5,200 to 8,500 feet. The soil formed in colluvium from quartzitic sandstone and conglomerate. The mean annual precipitation is 12 to 18 inches, most of which falls as snow and early spring rain. The mean annual temperature is 30 to 44 degrees F. The frost-free season is 50 to 90
days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dollarhide, Lavacreek, Milligan, Povey, and Vitale soils. Dollarhide, Lavacreek, and Povey soils have mean summer temperatures less than 59 degrees F and are on north-facing and east-facing slopes. Milligan and Vitale soils have bedrock at depths of 20 to 40 inches. Milligan and Vitale soils occur on the same landscape.
DRAINAGE AND PERMEABILITY: Well drained, rapid to very rapid runoff. Moderate permeability.
USE AND VEGETATION: Mainly used for rangeland. Vegetation is low sagebrush, bluebunch wheatgrass, and Sandberg bluegrass.
DISTRIBUTION AND EXTENT: South-central Idaho. This series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Blaine County, Idaho, 1985.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipdeon goes from the soil surface to approximately 3 inches (A horizon)
Argillic horizon is the zone from 3 to 17 inches (Bt1 and Bt2 horizons)