LOCATION BRUNCAN ID+OR

Established Series
Rev. PJS/ALH/CLM
10/2018

BRUNCAN SERIES

The Bruncan series consists of shallow to duripan, well drained soils with moderately slow permeability that formed in mixed silty alluvium and loess from basalt and volcanic ash. Bruncan soils are on tablelands, calderas, structural benches, plains and buttes. Slopes range from 0 to 15 percent. The average annual precipitation is about 250 mm and the average annual temperature is about 8.9 degrees C.

TAXONOMIC CLASS: Loamy, mixed, superactive, mesic, shallow Xeric Argidurids

TYPICAL PEDON: Bruncan gravelly loam -- on a slope of 2 percent, in native rangeland at 1,465 meter elevation. The surface has about 3 percent stone cover. (When described on July 1, 1980, the soil was dry throughout. Colors are for air-dry soil unless otherwise stated.)

A--0 to 8 cm; pale brown (10YR 6/3) gravelly loam, brown (10YR 4/3) moist; weak thin platy structure parting to moderate fine granular; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; common very fine irregular and vesicular pores; 10 percent gravel, 5 percent stones; moderately alkaline (pH 8.0); clear smooth boundary. (5 to 15 cm thick)

Bt--8 to 13 cm; pale brown (10Y 6/3) loam, dark yellowish brown (10YR 4/4) moist; moderate medium subangular blocky structure; soft, very friable, slightly sticky and nonplastic; common very fine and fine, few medium roots; common very fine irregular pores; common faint clay films on faces of peds; 10 percent gravel; moderately alkaline (pH 8.2); clear smooth boundary. (5 to 25 cm thick)

Btk1--13 to 20 cm; very pale brown (10YR 7/3) clay loam, yellowish brown (10YR 5/4) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine, few medium roots; common very fine irregular and tubular pores; common faint clay films on faces of peds; 10 percent gravel; strongly effervescent; moderately alkaline (pH 8.4); clear smooth boundary. (0 to 20 cm thick)

Btk2--20 to 28 cm; very pale brown (10YR 7/3) clay loam, yellowish brown (10YR 5/4) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine, few medium roots; few very fine irregular pores; few faint clay films on faces of peds; 10 percent gravel; violently effervescent; strongly alkaline (pH 8.5); clear smooth boundary. (0 to 10 cm thick)

Bkq--28 to 36 cm; very pale brown (10YR 7/3) extremely cobbly loam, light yellowish brown (10YR 6/4) moist; massive; hard, firm, nonsticky and nonplastic; common very fine, few fine and medium roots; 20 percent gravel, 40 percent cobbles; violently effervescent; strongly alkaline (pH 8.6); abrupt wavy boundary. (0 to 18 cm thick)

Bkqm--36 to 51 cm; very pale brown (10YR 7/4) to white (10YR 8/2) continuous, indurated siliceous laminae 1 mm thick over white (10YR 8/1) continuous, strongly cemented extremely cobbly loamy sand, light yellowish brown (10YR 6/4) moist; massive; extremely hard, brittle; 25 percent gravel, 50 percent cobbles; violently effervescent; abrupt smooth boundary. (3 to 30 cm thick)

2R--51 inches; basalt.

TYPE LOCATION: Owyhee County, Idaho; about 8 1/2 miles north and 5 miles west of Grasmere; about 2,560 feet south and 300 feet east of the northwest corner of section 3, T. 11 S., R. 4 E.; USGS Grassmere 7.5 minute topographic quadrangle; latitude 42 degrees, 29 minutes, 57 seconds North and longitude 115 degrees, 58 minutes, 52 seconds West; WGS84 Decimal Degrees 42.4991667 latitude, -115.9811111 longitude.

RANGE IN CHARACTERISTICS:

Particle-size control section - 5 to 35 percent rock fragments; 18 to 30 percent clay
Depth to duripan - 28 to 50 cm.
Depth to bedrock - 33 to 81 cm.
Average annual soil temperature - 8.3 to 12.2 degrees C.
Aridic moisture regime bordering on xeric.

A horizon
Value - 5 to 7 dry, 3 to 5 moist
Chroma - 2 to 4 dry or moist
Reaction (pH) - neutral through moderately alkaline

Bt and Btk horizons
Hue - 10YR or 7.5YR
Value - 5 to 7 dry, 4 or 5 moist
Chroma - 2 to 4 dry or moist
Texture - L, CL, SICL, GR-CL, SIL, GR-SCL
Clay content - 20 to 33 percent
Rock fragments - 5 to 25 percent
Reaction (pH) - neutral through strongly alkaline
Calcium carbonate equivalent - 0 to 20 percent

Bkq horizon
Value - 6 or 7 dry, 5 or 6 moist
Chroma - 3 to 6 dry or moist
Texture - GRV-L, CBV-L, CBV-SIL, CBV-FSL, or CBV-VFSL
Rock fragments - 35 to 60 percent
Calcium carbonate equivalent - 15 to 40 percent
Reaction (pH) - moderately through very strongly alkaline

COMPETING SERIES: These are the Acana, Argalt, Ayres, Bartome, Chuckridge, Chuska, Colthorp, Dewar, Grassval, Handpah, Packwood, Pipeline, Roseworth, Thoms and Wellington series. Acana, Ayres, Bartome, Chuckridge, Chuska, Dewar, Handpah, Grassval, Pipeline, Roseworth, Thoms and Wellington soils lack bedrock above 100 cm. Argalt soils are less than 25 cm deep to bedrock. Colthorp soils have less than 25 percent rock fragments in the substratum. Packwood soils have hue of 7.5YR on 5YR in the B2t horizon and average 30 to 35 percent clay in the texture control section.

GEOGRAPHIC SETTING: Bruncan soils are nearly level to rolling on tablelands, calderas, structural benches, plains and buttes at elevations of 825 to 1,795 meters. Slopes range from 0 to 15 percent. These soils formed in mixed silty alluvium and loess from basalt and volcanic ash. The climate is cool and moist in the winter and warm and dry in the summer. Average annual precipitation ranges from 200 to 360 mm. Average annual temperature ranges from 7.2 to 11.1 degrees C. Frost-free period is 80 to 145 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Arbidge, Buncelvoir, Hardtrigger, Laped, Minveno, Snowmore and Troughs series. Arbidge and Snowmore soils are 50 to 100 cm deep to a duripan. Hardtrigger soils lack an indurated duripan. Laped soils have less organic matter in the surface horizon and are drier. Minveno soils lack an argillic horizon. Troughs soils have greater than 35 percent coarse fragments in the argillic horizon. Arbidge, Buncelvoir, Hardtrigger and Snowmore soils are on lower sideslopes and toeslopes. Laped, Minveno and Troughs soils are on similar landscape positions.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; slow to rapid runoff; moderately slow hydraulic conductivity.

USE AND VEGETATION: Bruncan soils are used mainly for rangeland and wildlife habitat. The dominant natural vegetation is Wyoming big sagebrush, bluebunch wheatgrass, and Thurber needlegrass with low sagebrush or black sagebrush in some areas.

DISTRIBUTION AND EXTENT: Southwestern Idaho and Southeastern Oregon. Bruncan soils are extensive. MLRA 25.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California

SERIES ESTABLISHED: Elmore County Area, Idaho, 1986.

REMARKS: This revision (6/95) changes the classification from Xerollic Durargids to Xeric Argidurids according to the 1994 edition of Keys to Soil Taxonomy. The remainder of the OSD has not been updated since 6/93.

Diagnostic horizons and other features recognized in this pedon:
Ochric epipedon - zone 0 to 8 inches (A horizon).
Argillic horizon - zone 8 to 28 cm (Bt, Btk1, and Btk2 horizons).
Calcic horizon - zone 13 to 28 cm (Btk1, Btk2, and Bkq horizons).

Duripan - zone 36 to 51 cm (Bkqm horizon).
Lithic contact- The boundary at 51 cm (R boundary).
Particle-size control section - The zone from the soil surface to 36 cm. (the A, Bt, Btk1, Btk2 and the Bkq horizons).

The superactive cation exchange activity class was added in 03/2003 to the taxonomic classification by the National Soil Survey Center on request of the Reno MLRA office, without review of the soil series property data. The remainder of this document has not been updated.

National Cooperative Soil Survey
U.S.A.