LOCATION CLARKSBUTTE             OR

Tentative Series
Rev. ARR/TM
01/2019

CLARKSBUTTE SERIES

The Clarksbutte series consists of moderately deep over duripan, well drained soils that formed in mixed volcanic ash and loess over residuum weathered from basalt. Clarksbutte soils are on lava plateaus. Slopes are 2 to 15 percent. The mean annual precipitation is about 250 mm and the mean annual temperature is about 7 degrees C.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Vitrixerandic Argidurids

TYPICAL PEDON: Clarksbutte ashy silt loam, rangeland at an elevation of 1,320 meters. (Colors are for dry soil unless otherwise noted.) The surface is partly covered by 10 percent cobbles.

A--0 to 17 cm; pale brown (10YR 6/3) ashy silt loam, dark brown (10YR 3/3) moist; weak medium granular structure; soft, very friable, nonsticky and moderately plastic; many fine and very fine roots; many fine and common very fine interstitial pores; 10 percent cobbles; neutral (pH 7.2); clear wavy boundary. (5 to 10 cm thick)

Bt1--17 to 26 cm; dark brown (10YR 3/3) ashy clay, dark brown (10YR 3/3) moist; moderate medium prismatic structure parting to strong medium angular blocky structure; very hard, very firm, very sticky and very plastic; common fine and very fine roots; common fine and many very fine interstitial pores; 40 percent distinct pressure faces; slightly alkaline (pH 7.6); clear smooth boundary. (5 to 15 cm thick)

Bt2--26 to 42 cm; yellowish brown (10YR 5/4) clay loam, brown (10YR 4/3) moist; strong medium and fine subangular blocky structure; hard, firm, moderately sticky and moderately plastic; common very fine interstitial pores; 10 percent distinct pressure faces and 20 percent distinct clay films on faces of peds and along surfaces of pores; 10 percent cobbles; slightly alkaline (pH 7.8); clear smooth boundary. (15 to 25 cm thick)

Btk--42 to 54 cm; yellowish brown (10YR 5/4) clay loam, brown (10YR 4/3) moist; weak medium subangular blocky structure, and weak fine subangular blocky structure; hard, firm, moderately sticky and moderately plastic; 10 percent faint clay films on faces of peds and along surfaces of pores; 10 percent cobbles; strongly effervescent; moderately alkaline (pH 8.2); clear smooth boundary. (0 to 20 cm thick)

Bkqm1--54 to 70 cm; cemented material; light yellowish brown (10YR 6/4); massive; very hard, very firm; moderately cemented by secondary silica and calcium carbonate; 10 percent cobbles; strongly effervescent; moderately alkaline (pH 8.4); abrupt smooth boundary. (10 to 20 cm thick)

Bkqm2--70 to 90 cm; cemented material; massive; extremely hard, rigid; very strongly cemented by secondary silica and calcium carbonate; strongly effervescent; abrupt smooth boundary. (5 to 25 cm thick)

R--90 cm; indurated basalt

TYPE LOCATION: Malheur County, Oregon; Approximately 12 miles northeast of Jordan Valley, Oregon; about 1,580 feet south and 2,200 feet west of the northeast corner of section 17, T. 29 S., 44E. USGS Cow Lakes 7.5 minute quadrangle; latitude 43 degrees 2 minutes 31.1 seconds north and longitude 117 degrees 21 minutes 27.1 seconds west;
WGS84 Decimal Degrees 43.0419722 latitude, -117.3575278 longitude.


RANGE IN CHARACTERISTICS:

Soil Moisture - The soil moisture control section is dry throughout in summer and fall and moist in winter and spring; Aridic moisture regime that borders on xeric.
Soil Temperature - 8 to 9 degrees C.
Depth to Duripan - 50 to 100 cm.
Depth to Bedrock - 65 to 140 cm.

Control section - Clay content - Averages 27 to 35 percent.
Rock fragments - 10 to 30 percent; lithology of fragments is mainly basalt.

A horizon
Value: 7 and 6 dry, 3 and 4 moist.
Chroma: 3 dry, 2 and 3 moist.
Reaction: neutral through slightly alkaline.
Volcanic glass: Volcanic glass is estimated to range from 30 to 50 percent of the 0.2 to 2 mm fraction.

Bt horizons
Value: 3 to 6 moist and dry.
Chroma: 3 or 4 moist and dry.
Volcanic glass: Volcanic glass is estimated to range 5 to 25 percent of the 0.02 to 2 mm fraction in the zone from 17 to 26 cm (Bt1 horizon).
Clay content: Averages 27 to 30 percent, subhorizons range to 42 percent clay.
Texture: silty clay loam, clay loam; subhorizons of clay are in some pedons.
Rock fragments: 10 to 30 percent, mostly cobbles.
Reaction: neutral through slightly alkaline.

Btk horizon (when present)
Value: 3 to 6 moist and dry.
Chroma: 3 or 4 moist and dry.
Clay content: 27 to 35 percent.

Rock fragments: 5 to 10 percent, mostly cobbles.
Reaction: neutral through slightly alkaline.

Bkqm1 horizon
Rock fragments: 10 to 20 percent, mostly cobbles.
Reaction: moderately alkaline through strongly alkaline.
Effervescence: strongly effervescent to very strongly effervescent.
Cementation: weakly cemented to moderately cemented.

Bkqm2 horizon
Cementation: very strongly cemented through indurated.

COMPETING SERIES: This is the Ochoco soils, which is greater than 150 cm to bedrock.

GEOGRAPHIC SETTING: Clarksbutte soils are on lava plateaus. These soils are formed in mixed volcanic ash and loess over residuum weathered from basalt. Slopes are 2 to 15 percent. Elevations are 1,280 to 1,370 meters. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 200 to 280 mm; mean annual temperature is 7 to 8 degrees C, and the frost-free period is 80 to 100 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bogusrim and Wisher soils. Bogusrim soils have greater than 35 percent clay in the argillic horizon. Wisher soils are very deep and have a mollic epipedon.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained, slow to very slow permeability, moderately low saturated hydraulic conductivity.

USE AND VEGETATION: Rangeland and wildlife habitat. The present vegetation is mainly Wyoming big sagebrush and bluebunch wheatgrass.

DISTRIBUTION AND EXTENT: Southeast Oregon; the soil is of large extent. MLRA 25.

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

SERIES PROPOSED: Malheur County, Oregon, Southern Part, 2008.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon - The zone from the surface to about 17 cm (A horizon).
Argillic horizon - The zone from about 17 cm to 54 cm (Bt1, Bt2 and Btk horizons).
Vitrixerandic feature - Volcanic glass is 30 to 50 percent of the 0.02 to 2 mm fraction in the zone from 0 to 17 cm (A horizon) and 5 to 25 percent of the 0.02 to 2 mm fraction in the zone from 17 to 26 cm (Bt1 horizon).
Particle-size control section - The zone from 17 cm to 54 cm. (Bt1, Bt2 and Btk horizons).

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National Cooperative Soil Survey
U.S.A.