LOCATION DOUBLECREEK OREstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Vitrandic Haploxerolls
TYPICAL PEDON: Doublecreek ashy silt loam - rangeland, on a 25 percent concave southeast-facing slope at an elevation of 2900 feet. (colors are for moist soil unless otherwise noted.)
A1--0 to 4 inches; black (10YR 2/1) ashy silt loam, very dark brown (10YR 2/2) dry; moderate fine granular and moderate very fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; common fine irregular and few fine tubular pores; slightly acid; (pH 6.5); gradual smooth boundary. (4 to 9 inches thick)
A2--4 to 10 inches; very dark brown (10YR 2/2) ashy silt loam, dark grayish brown (10YR 4/2) dry; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; many very fine and fine roots; common fine irregular and few fine tubular pores; 5 percent gravel, slightly acid (pH 6.5); gradual smooth boundary. (6 to 10 inches thick)
AB--10 to 16 inches; very dark grayish brown (10YR 3/2) ashy silt loam, brown (10YR 4/3) dry; weak fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; few fine and medium tubular pores; 5 percent gravel, slightly acid (pH 6.5); clear smooth boundary. (0 to 10 inches thick)
Bw1--16 to 22 inches; dark brown (10YR 3/3) cobbly loam, brown (10YR 5/3) dry; moderate medium and coarse subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine roots; few fine tubular pores; 5 percent gravel and 10 percent cobbles; neutral (pH 7.0); gradual smooth boundary.
Bw2--22 to 40 inches; brown (10YR 4/3) cobbly fine sandy loam, yellowish brown (10YR 5/4) dry; weak fine subangular blocky structure; hard, friable, nonsticky and nonplastic; common fine roots; few fine tubular pores; 5 percent gravel and 10 percent cobbles; neutral (pH 7.0); gradual smooth boundary. (Combined thickness of the Bw horizon is 20 to 40 inches)
C--40 to 61 inches; brown (10YR 4/3) cobbly fine sandy loam, yellowish brown (10YR 5/4) dry; massive; hard, friable, slightly sticky and slightly plastic; few fine roots; 10 percent gravel, 10 percent cobbles, and 5 percent stones; slightly alkaline (pH 7.5)
TYPE LOCATION: Wallowa County, Oregon; 1920 feet south and 960 feet east of the northwest corner of Section 35, T.1S., R.48E. (Latitude 45 degrees, 26 minutes, 37 seconds N; Longitude 116 degrees, 47 minutes, 20 seconds W).
RANGE IN CHARACTERISTICS: The soils are dry in all parts between 8 and 24 inches for 90 to 120 consecutive days during the summer. Mean annual soil temperature is 48 to 52 degrees F. Depth to bedrock is greater than 60 inches. The particle-size control section averages 10 to 18 percent clay with more than 15 percent fine sand and coarser of which less than 30 percent is medium and coarser. Solum thickness is 40 to 60 inches. The mollic epipedon is 20 to 30 inches thick.
The A1 horizon has value of 2 or 3 moist, 2 to 4 dry and chroma of 1 or 2 moist, 2 or 3 dry. Textures are ashy silt loam or extremely stony ashy silt loam. Volcanic glass content is 5 to 15 percent. Ammonium oxalate extractable Al plus one-half ammonium oxalate extractable Fe is 0.3 to 0.9 percent. Rock fragment content ranges from 0 to 5 percent gravel, 0 to 10 percent cobbles, and 0 to 70 percent stones. Reaction is slightly acid to slightly alkaline.
The A2 horizon and AB horizon, when present, has value of 2 or 3 moist, 4 or 5 dry and chroma of 2 or 3 moist or dry. Textures are ashy silt loam or ashy loam. Volcanic glass content is 15 to 30 percent. Ammonium oxalate extractable Al plus one-half ammonium oxalate extractable Fe equals 0.2 to 0.8 percent. Rock fragment content ranges from 0 to 5 percent gravel. Reaction is slightly acid to slightly alkaline.
The Bw horizon has value of 3 or 4 moist, 4 or 5 dry and chroma of 2 or 3 moist, 3 or 4 dry. Textures are cobbly loam, sandy loam, silt loam, or cobbly fine sandy loam. Rock fragment content ranges from 0 to 10 percent gravel and 0 to 10 percent cobbles. Reaction is neutral to slightly alkaline.
The C horizon has value of 4 or 5 moist, 5 or 6 dry and chroma of 3 or 4 moist or dry. Textures are sandy loam, cobbly fine sandy loam, silt loam, or fine sandy loam. Rock fragment content ranges from 0 to 15 percent gravel, 0 to 15 percent cobbles, and 0 to 5 percent stones. Reaction is neutral to slightly alkaline.
COMPETING SERIES:
Cabincreek - moderately deep to a lithic contact (metavolcanic rock); dry 75 to 120 consecutive days in summer
Conconully - moderately deep to a densic contact (till); mollic epipedon 10 to 14 inches thick
Deno - deep to a lithic contact (basalt); dry 60 to 90 consecutive days in summer
Fanal - very deep (colluvium and alluvium from mixed rocks); mollic epipedon 10 to 16 inches thick; moderately well drained with redox concentrations in the lower part of the control section; dry 45 to 60 consecutive days in summer (forested)
Phoebe - very deep (mixed outwash); lower part of particle-size control section is loamy sand or sand; dry 60 to 90 consecutive days in summer
Safety - moderately deep to a paralithic contact (weathered granite); mollic epipedon 10 to 16 inches thick; dry 75 to 90 consecutive days in summer
Stevens - moderately deep to a densic contact (mixed till); dry 60 to 90 consecutive days in summer
Uhlig - very deep (mixed outwash); has 2Bt horizons with clay films; dry 60 to 75 consecutive days in summer
GEOGRAPHIC SETTING: Doublecreek soils are on canyon foot slopes and toe slopes, and on alluvial terraces. Elevations are 1,700 to 4,000 feet. Slopes are 2 to 60 percent. The soils formed in colluvium and alluviuum from basalt with volcanic ash and loess mixed in surface soil. The climate is characterized by cool, wet winters and hot, dry summers. The mean annual precipitation is 14 to 20 inches. The mean annual temperature is 45 to 52 degrees F. The frost-free period is 100 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Lickskillet, Langrell, Phys, and Rockly soils. Langrell soils have greater than 35 percent rock fragments in the control section and are on outwash terraces. Lickskillet and Rockly soils are less than 20 inches deep to bedrock and are on side slopes of canyons. Phys soils have an argillic horizon, greater than 35 percent rock fragments in the particle-size control section, and are on fans.
DRAINAGE AND PERMEABILITY: Well drained; permeability is moderate.
USE AND VEGETATION: These soils are used for watershed, recreation, livestock grazing, forage crop production, and wildlife habitat. Native vegetation is bluebunch wheatgrass, Idaho fescue, Sandberg's bluegrass, rattlesnake brome, western hawkweed, twin arnica, yarrow, lupine and arrowleaf basalmroot.
DISTRIBUTION AND EXTENT: Northeast Oregon; MLRA 9. The soils are of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Wallowa County Area, Oregon 1998. The source of the name is Double Creek.
REMARKS: Diagnostic horizons and other features recognized in this pedon are:
Mollic epipedon - zone from 0 to 22 inches (A1, A2, AB, and Bw1 horizons)
Cambic horizon - zone from 22 to 40 inches (Bw2 horizon)
Particle-size control section - zone from 10 to 40 inches (AB, Bw1, and Bw2 horizons)
Vitrandic subgroup feature - zone from 0 to 16 inches (A1, A2 and AB horizons)
This revision (07/2008) recognizes volcanic ash in the upper part of the solum and corrects subgroup classification from coarse-loamy, mixed, superactive, mesic Pachic Haploxerolls to coarse-loamy, mixed, superactive, mesic Vitrandic Haploxerolls.