LOCATION REBARROW ORTentative Series
TAXONOMIC CLASS: Ashy over loamy-skeletal, amorphic over isotic, frigid Alfic Udivitrands
TYPICAL PEDON: Rebarrow ashy silt loam - woodland, on a 37 percent, planar, north-facing slope at an elevation of 4,240 feet. (Colors are for moist soil unless otherwise noted. Soil textures are apparent field textures.)
Oi--0 to 0.5 inch; needles, twigs and logs
Oe--0.5 to 1 inch; decomposing needles and twigs
A--1 to 2 inches; dark reddish brown (5YR 2.5/2) ashy silt loam, brown (7.5YR 5/2) dry; weak medium subangular blocky structure parting to weak fine and very fine subangular or angular blocky; soft, friable, nonsticky, nonplastic and weakly smeary; common very fine and fine roots throughout; common fine tubular pores; slightly acid (pH 6.5); clear smooth boundary. (1 to 5 inches)
Bw--2 to 24 inches; brown (7.5YR 4/3) ashy silt loam, pale brown (10YR 6/3) dry; weak coarse subangular blocky structure parting to weak medium and fine subangular or angular blocky; soft, friable, nonsticky, nonplastic and weakly smeary; few very fine and common fine, medium and coarse roots throughout; common very fine and fine tubular pores; 5 percent gravel; slightly acid (pH 6.3); clear irregular boundary. (10 to 22 inches)
2Eb--24 to 33 inches; brown (10YR 4/3) very gravelly silt loam, light gray (10YR 7/2) dry; weak medium subangular blocky structure parting to weak fine subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; common fine, medium and coarse roots throughout; common very fine and fine tubular, and few very fine irregular pores; 35 percent gravel and 15 percent cobbles; neutral (pH 7.0); clear wavy boundary. (5 to 17 inches thick)
2Btb1--33 to 43 inches; brown (10YR 5/3) extremely cobbly loam, light yellowish brown (10YR 6/4) dry; weak medium subangular and angular blocky structure parting to weak fine subangular blocky; hard, friable, moderately sticky and moderately plastic; few coarse roots throughout; common very fine and fine tubular, few medium tubular, and few very fine irregular pores; 25 percent gravel, 25 percent cobbles, and 10 percent stones; neutral (pH 7.3) clear wavy boundary. (6 to 19 inches thick)
2Btb2--43 to 52 inches; brown (10YR 4/3) extremely stony clay loam, light yellowish brown (10YR 6/4) dry; weak medium subangular blocky structure parting to weak fine subangular blocky; hard, firm, moderately sticky and moderately plastic; few fine and medium roots throughout; common very fine and fine tubular, and common fine irregular pores; 15 percent gravel, 20 cobbles, and 30 percent stones; neutral (pH 7.3). (7 to 11 inches thick)
2BCb--52 to 61 inches; yellowish brown (10YR 5/4) extremely stony clay loam, very pale brown (10YR 7/3) dry; weak very fine subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few fine roots throughout; few very fine tubular pores; 20 percent gravel, 20 percent cobbles, and 30 percent stones; neutral (pH 7.3).
TYPE LOCATION: Union County, Oregon
Section 4 (SW , SE , SE ), T. 5 S., R. 41 E.
UTM Zone 11; Northing: 4,999,000; Easting: 446,300
Latitude: 45 degrees 08 minutes 33 seconds
Longitude: 117 degrees 40 minutes 59 seconds
USGS Quadrangle: Little Catherine Creek
RANGE IN CHARACTERISTICS:
Soil Temperature: frigid regime
Mean Annual Soil Temperature: 40 to 43 degrees F
Mean Summer Soil Temperature: 48 to 52 degrees F
Mean Winter Soil Temperature: 32 to 36 degrees F
Soil Moisture: udic regime, dry 35 to 45 days in summer
Particle-size Control Section: mineral soil surface to 40 inches below mineral surface
Upper part (ashy): 14 to 21 inches thick
Clay content: 2 to 8 percent
Rock fragment content: 0 to 10 percent
Lower part (loamy-skeletal): 13 to 26 inches thick
Clay content: 18 to 30 percent
Rock fragment content: 35 to 60 percent
Rock fragment shape: subangular to angular
Diagnostic Horizons and Features:
andic soil properties: upper boundary at the mineral surface; 14 to 21 inches thick
Al+1/2Fe(aox): 1.0 to 3.0 percent
bulk density: 0.65 to 1.0 g/cc
P retention: 40 to 90 percent
0.02-2.0 mm fraction: 40 to 60 percent of fine earth
glass content in the 0.02-2.0 mm fraction: 60 to 90 percent
water content at 1500 kPa (air dried): 5 to 12 percent
8Si + 2Fe(aox): 5 to 12 percent
8Si - 2Fe(aox): 4 to 8 percent
ochric epipedon: 1 to 5 inches thick
cambic horizon: 10 to 22 inches thick
argillic horizon: 13 to 20 inches thick
Major Horizons:
A horizon:
color, moist: 5YR 2.5/2; 7.5YR 2.5/2, 3/4; 10YR 2/2, 4/4
color, dry: 7.5YR 5/2; 10YR 5/3, 5/4, 6/4
texture: ASHY-SIL
clay content: 2 to 8 percent
rock fragments content: 0 to 5 percent
gravel: 0 to 5 percent
reaction: slightly acid or neutral; pH: 6.1 to 7.3
organic carbon: 1.0 to 5.0 percent
Bw horizon:
color, moist: 7.5YR 4/3, 4/4; 10YR 4/4, 5/4, 5/6, 6/4
color, dry: 10YR 6/3, 6/4, 7/3, 7/4, 8/4
texture: ASHY-SIL
clay content: 2 to 8 percent
rock fragments content: 0 to 10 percent
gravel: 0 to 10 percent
reaction: slightly acid or neutral; pH: 6.1 to 7.3
organic carbon: 0.6 to 1.0 percent
2Eb horizon:
color, moist: 5YR 3/3; 7.5YR 4/3; 10YR 3/3, 4/3
color, dry: 7.5YR 5/5; 10YR 5/4, 5/5, 6/3, 7/2
texture: STV-SIL, GRV-L, GRV-SIL
clay content: 11 to 20 percent
rock fragments: 35 to 50 percent
gravel: 10 to 35 percent
cobbles: 0 to 15 percent
stones: 0 to 20 percent
reaction: slightly acid or neutral; pH: 6.1 to 7.3
2Btb horizons:
color, moist: 5YR 4/3; 7.5YR 3/4; 10YR 3/4, 4/3, 5/3, 5/4
color, dry: 7.5YR 4/6, 5/4; 10YR 5/6, 6/4, 7/4
texture: GRV-SICL, STV-L, STV-CL, CBX-L, GRV-L, GRV-CL, GRV-SCL, STX-CL, STX-L
clay content: 22 to 35 percent
rock fragments: 35 to 75 percent
gravel: 10 to 40 percent
cobbles: 5 to 25 percent
stones: 0 to 30 percent
reaction: slightly acid to slightly alkaline; pH: 6.1 to 7.8
2BCb horizon:
color, moist: 7.5YR 3/3, 4/3; 10YR 3/4; 5/4
color, dry: 7.5YR 5/4; 10YR 5/3, 6/2, 6/3, 6/4, 7/3
texture: GRV-SL, GRX-SCL, GRV-CL, GRV-L, CBX-SL , STX-CL
clay content: 12 to 35 percent
rock fragments: 35 to 80 percent
gravel: 20 to 50 percent
cobbles: 0 to 35 percent
stones: 0 to 30 percent
reaction: neutral or slightly alkaline; pH: 6.6 to 7.8
COMPETING SERIES:
Rebarrow (T)-- very deep (>60 inches) to a lithic contact: volcanic ash is ashy silt loam and has 60 to 90 percent glass; rock fragments in the loamy-skeletal part of the pscs are subangular or angular; 2Bt has 22 to 35 percent clay, is <20 inches thick, and is slightly acid to slightly alkaline; dry for 35 to 45 consecutive days; soil formed in ash over colluvium from andesitic basalt
Courvash--very deep (>60 inches); volcanic ash is ashy silt loam and has 12 to 30 percent glass; rock fragments in the loamy-skeletal part of the pscs are rounded or well rounded; 2Bt is strongly acid or moderately acid; soil formed in volcanic ash over till
Hugus--very deep (>60 inches); volcanic ash is ashy silt loam and has 15 to 60 percent glass; 2Bt has 12 to 24 percent clay, is >20 inches thick, and is very strongly acid to slightly acid; dry for 25 to 35 consecutive days; soil formed in volcanic ash over colluvium, residuum and/or old alluvium from metasedimentary rock or gneiss
Honeymooncan (T)--deep (40 to 60 inches) to a lithic contact; volcanic ash is ashy silt loam and has 60 to 90 percent glass; rock fragments in the loamy-skeletal part of the pscs are angular or subangular; 2Bt is neutral to moderately alkaline; soil formed in volcanic ash over colluvium from metavolcanic rock
Limberjim--deep (40 to 60 inches) to a lithic contact; volcanic ash is ashy silt loam; 2Bt is moderately acid to neutral; soil formed in volcanic ash over colluvium from basalt and andesite
Syrupcreek--moderately deep (20 to 40 inches) to a lithic contact; volcanic ash is ashy silt loam; formed in ash and loess over colluvium from basalt and andesitic basalt
GEOGRAPHIC SETTING:
Landform: backslopes of mountains
Slope gradient: 0 to 90 percent
Parent material: volcaniclastic volcanic ash overlying colluvium
Lithology: Mazama ash over andesitic basalt
Elevation: 4,200 to 6,000 feet
Climate: wet winters and cool, moist summers
Mean annual precipitation: 15 to 30 inches
Mean annual air temperature: 38 to 41 degrees F
Frost-free period: 35 to 75 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Pinuscreek (T)--occur on more convex mid to upper slope positions; 40 to 60 inches to a lithic contact; <14 inch volcanic ash mantle; 45 to 60 dry days
Balmcreek (T)--occur on convex upper slopes and ridges, 3 to 20 inches to a lithic contact; has an influence of volcanic ash; has and ochric epipedon and a cambic layer
Syrupcreek--occur on ridge tops and side slopes; 20 to 40 inches to a lithic contact
Tamara (T)--occur on backslopes; >60 inches to bedrock; <35 percent rock fragments in lower part of pscs
Thirstygulch--occur on convex stable ridge tops and side slopes; 10 to 20 inches to a lithic contact; has mollic epipedon; has cambic epipedon; has mixed volcanic ash throughout profile; 60 to 75 dry days
Wonder (T)--occur on ridges and shoulder slopes; 20 to 40 inches to a lithic contact; <14 inch volcanic ash mantle; has cambic epipedon; 45 to 60 dry days
DRAINAGE AND PERMEABILITY:
Drainage: well drained
Permeability: moderate over moderately slow
USE AND VEGETATION:
Use: timber production, watershed, recreation and wildlife habitat.
Native vegetation: grand fir, western larch, lodgepole pine, Douglas fir, ponderosa pine, grouse whortleberry, longtube twinflower, Oregon boxwood, birchleaf spirea, sitka alder, Utah honeysuckle, prince's pine, bearberry, braken fern, sidebells pyrola, white flowered hawkweed, roundleaf violet, woods strawberry, pinegrass and northwest sedge.
Ecological site: Dominant: grand fir/ longtube twinflower; ABGR/LIBOL2 in Union County; but others may include: ABGR/CLUN2, ABGR/VASC-LIBOL2, ABGR/VAME and ABGR/VASC.
DISTRIBUTION AND EXTENT:
MLRA-E43
Distribution: Blue Mountains of northeastern Oregon
Extent: small
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Union County, Oregon 2003. The name is derived from a College Experimental Forest southwest of La Grande.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
ochric epipedon: 1 to 2 inches A
cambic horizon: 2 to 24 inches Bw
argillic horizon: 33 to 52 inches 2Btb1, 2Btb2
particle-size control section:
ashy part - 1 to 24 inches A, Bw
loamy-skeletal part - 24 to 41 inches 2Eb, 2Btb1