LOCATION SALHEUR ORTentative Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid, shallow Abruptic Xeric Argidurids
TYPICAL PEDON: Salheur gravelly ashy silt loam at an elevation of 1,475 meters, rangeland.(Colors are for dry soils unless otherwise noted.) The surface is covered with 20 percent gravel and 5 percent cobble.
A--0 to 10 cm; pale brown (10YR 6/3) gravelly ashy silt loam, brown (10YR 4/3) moist; weak fine and very fine subangular blocky structure; slightly hard, friable, nonsticky, nonplastic; common fine and very fine roots; common fine and very fine tubular and common fine interstitial pores; 5 percent fine gravel and 15 percent gravel; slightly alkaline (pH 7.4); clear smooth boundary.(5 to 15 cm thick)
Bt1--10 to 30 cm; brown (10YR 5/3) very cobbly ashy silt loam, dark yellowish brown (10YR 4/4) moist; moderate medium and fine subangular blocky structure; slightly hard, friable, nonsticky, nonplastic; common fine and very fine roots; common fine and very fine tubular pores; 5 percent faint clay films; 20 percent gravel and 25 percent cobbles; slightly alkaline (pH 7.4); abrupt wavy boundary. (10 to 20 cm thick)
Bt2--30 to 37 cm; dark yellowish brown (10YR 4/4) cobbly clay, dark yellowish brown (10YR 4/4) moist; strong fine and medium angular blocky structure; very hard, extremely firm, very sticky, very plastic; common fine and very fine roots; common very fine tubular pores; 30 percent distinct clay films on all faces of peds; 10 percent gravel and 15 percent cobbles; slightly alkaline (pH 7.4); abrupt smooth boundary. (5 to 15 cm thick)
2Bqm--37 to 39 cm; cemented material; massive; extremely hard, rigid, very strongly cemented by secondary silica; slightly alkaline (pH 7.4); abrupt smooth boundary. (2 to 10 cm thick)
2Ck--39 to 150 cm; very cobbly sandy loam; dark yellowish brown (10YR 4/6) moist; massive structure; very hard, firm, nonsticky, nonplastic; 25 percent rounded basalt gravel and 25 percent rounded basalt cobbles; strongly effervescent; slightly alkaline (pH 7.8).
TYPE LOCATION: Malheur County, Oregon; Approximately 10 miles south of Jordan Valley, Oregon; UTM 486029 easting, UTM 4736073 northing, zone 11 NAD83 on the USGS Juniper Ridge 7.5 minute quadrangle, latitude 42 degrees 46 minutes 37.00 seconds north and longitude 117 degrees 10 minutes 15.00 seconds west, NAD83.
RANGE IN CHARACTERISTICS:
Soil moisture - The soil moisture control section is dry throughout in summer and fall and moist in winter and spring; the soil surface is wet in April due to snowmelt; Aridic moisture regime that borders on xeric.
Soil temperature - The mean annual soil temperature is 7 to 8 degrees C.
Depth to duripan 35 to 50 cm.
Other features - Abrupt textural change is present between Bt1 and Bt2 horizons.
Control section - Clay content - 25 to 35 percent.
Rock fragments 35 to 60 percent, mainly gravel and cobbles with basalt or tuff lithology.
A horizon -
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 or 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.
Bt1 horizon
Value: 4 or 5 dry.
Chroma: 2 to 4 moist or dry.
Texture: ashy silty clay loam, ashy silt loam.
Clay content: 25 to 35 percent.
Rock fragments: Averages 25 to 55 percent, mainly cobbles.
Reaction: Neutral through slightly alkaline.
Volcanic glass: Volcanic glass is estimated to range from 5 to 25 percent of the 0.2 to 2 mm fraction.
Bt2 horizon
Value: 4 or 5 dry.
Chroma: 3 or 4 moist or dry.
Texture: Silty clay loam, clay.
Clay content: 40 to 55 percent.
Rock fragments: Averages 35 to 55 percent, mainly cobbles.
Reaction: Neutral through slightly alkaline.
Bqm horizon
Reaction: Neutral through slightly alkaline.
Cementation: very strongly cemented or indurated.
Ck horizon
Value: 5 or 6 dry, 4 or 5 moist.
Chroma: 4 or 5 dry, 4 to 6 moist.
Clay content: 8 to 15 percent.
Rock fragments: Averages 35 to 75 percent, mainly cobbles.
Reaction: Slightly alkaline through moderately alkaline.
Effervescence: Strongly effervescent through very strongly effervescent.
COMPETING SERIES: There are no competing soils.
GEOGRAPHIC SETTING: Salheur soils are on pediments and fan remnants. These soils formed in alluvium. Slopes are 2 to 15 percent. Elevations are 1,430 to 1,585 meters. The climate is semiarid with cold, moist winters and warm, dry summers. The mean annual precipitation is 300 to 400 mm; mean annual temperature is 5 to 7 degrees C, and the frost free season is 50 to 80 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Littlegrass soils. Littlegrass soils have less than 35 percent rock fragments in the particle size control section.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Moderately well drained, very slow permeability, and low saturated hydraulic conductivity.
USE AND VEGETATION: Rangeland and wildlife habitat. The present vegetation is mainly low sagebrush, and Idaho fescue.
DISTRIBUTION AND EXTENT: Southeast Oregon; the soil is of small extent. MLRA 25.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES PROPOSED: Malheur County, Oregon, Southern Part, 2008.
REMARKS: This soil was originally proposed as Aritolla series, but was too similar in spelling and pronounciation to the existing Arritola series. Changed 11/19/2008.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to about 0 to 10 cm (A horizon).
Argillic horizon - The zone from about 10 to 37 cm (Bt1 and Bt2 horizons).
Duripan The zone from about 37 to 39 cm.
Ashy textures - Volcanic glass is 30 to 50 percent of the 0.02 to 2 mm fraction in the zone from 0 to 10 cm (A horizon). Volcanic glass is 5 to 25 percent of the 0.02 to 2 mm fraction in the zone from 10 to 30 cm (Bt1 horizon).
Abrupt textural boundary Between the Bt1 and Bt2 horizons, at approximately 30 cm.
Particle-size control section - the zone from 10 to 37 cm (Bt1 and Bt2 horizons).