LOCATION UNITYLAKE ORTentative Series
TAXONOMIC CLASS: fine, smectitic, frigid Vertic Palexeralfs
TYPICAL PEDON: Unitylake ashy silt - forested, on a 4 percent northeastfacing slope at 4,500 feet elevation. (Colors are for moist soil unless otherwise noted.)
Oi--0 to 1 inches; slightly decomposed leaves and moss.
A--1 to 4 inches; very dark gray (10YR 3/1) ashy silt, light brownish gray (10YR 6/2) dry; moderate fine granular and weak fine and very fine subangular blocky structure; soft, friable, slightly sticky and nonplastic; many very fine and fine, and few medium and coarse roots; common fine irregular and few fine tubular pores; moderately acid (pH 5.6); clear wavy boundary. (2 to 7 inches thick)
Bw--4 to 14 inches; dark grayish brown (10YR 4/2) ashy silt, light gray (10YR 7/2) dry; weak fine and medium subangular blocky structure; soft, friable, slightly sticky and nonplastic; few very fine and common fine, medium, and coarse roots; common fine tubular pores; moderately acid (pH 6.0); abrupt wavy boundary. (6 to 10 inches thick)
2Eb--14 to 16 inches; dark grayish brown (10YR 4/2) silt, white (10YR 8/1) dry; weak very fine subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common fine and few medium and coarse roots; common fine and few medium tubular pores; slightly acid (pH 6.1); abrupt wavy boundary. (1 to 11 inches thick)
2Btb1--16 to 31 inches; dark brown (10YR 3/3) clay, brown (10YR 5/3) dry; weak to moderate fine and medium angular blocky structure; extremely hard, firm, moderately sticky and very plastic; many moderately thick clay films on ped faces; few fine roots in cracks; few fine tubular pores; neutral (pH 7.0); gradual smooth boundary. (13 to 29 inches thick)
2Btb2--31 to 61 inches; brown (10YR 5/3) silty clay loam, brown (10YR 5/3) dry; moderate fine and very fine angular to subangular blocky structure; hard, firm to friable, moderately sticky and moderately plastic; many thin clay films on ped faces; neutral (pH 7.3).
TYPE LOCATION: Baker County, Oregon
Section 26 (SE 1/4, SW 1/4, SW 1/4), T. 10 S., R. 35 1/2 E.
Latitude; 44 degrees, 39 minutes, 32 seconds North
Longitude: 118 degrees, 23 minutes, 26 seconds West
UTM coordinates: zone 11; North 4,945,782 meters; East 389,751 meters; NAD27
USGS Quadrangle: Greenhorn
RANGE IN CHARACTERISTICS:
Soil Temperature: frigid regime
Mean Annual Soil Temperature: 42 to 45 degrees F
Mean Summer Soil Temperature: 50 to 54 degrees F
Mean Winter Soil Temperature: 34 to 37 degrees F
Soil Moisture: xeric regime; dry 60 to 75 consecutive days in summer
Particle-size Control Section: upper 20 inches of argillic horizon
clay content, average: 40 to 75 percent
rock fragment content, average: 0 to 20 percent
Diagnostic Horizons and Features:
andic soil properties: upper boundary at the mineral surface; 7 to 13 inches thick
Al+1/2Fe (ammonium oxalate): 1.0 to 2.2 percent
bulk density: 0.65 to 1.00 g/cc
P retention: 60 to 85 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 85 percent
cambic horizon: 6 to 10 inches thick
argillic horizon: 22 to 45 inches thick
clay increase (absolute): 20 to 40 percent from 2Eb to 2Btb horizon
linear extensibility, upper 100 cm of mineral soil (estimated): 6.0 to 8.0 cm
A horizon:
color, moist: 10YR 3/1, 3/2, 4/2, 5/3
color, dry: 10YR 5/2, 6/2, 6/3
texture: ASHY-SIL, ASHY-SI, CB-ASHY-SIL
clay content: 6 to 12 percent
rock fragment content: 0 to 25 percent
gravel: 0 to 10 percent
cobbles: 0 to 10 percent
stones: 0 to 5 percent
reaction: moderately acid to neutral; pH: 5.6 to 7.3
Bw horizon:
color, moist: 10YR 4/2, 5/3, 6/3
color, dry: 10YR 6/3, 7/2, 7/3
texture: ASHY-SIL, ASHY-SI, CB-ASHY-SIL
clay content: 5 to 14 percent
rock fragment content: 0 to 30 percent
gravel: 0 to 15 percent
cobbles: 0 to 10 percent
stones: 0 to 5 percent
reaction: moderately acid to neutral; pH: 5.6 to 7.3
2Eb horizon:
color, moist: 10YR 4/2, 5/3, 5/4
color, dry: 10YR 6/2, 6/3, 7/1, 8/1
texture: SIL, L, ST-SIL, SI
clay content: 12 to 25 percent
rock fragment content: 0 to 20 percent
gravel: 0 to 10 percent
cobbles: 0 to 5 percent
stones: 0 to 5 percent
reaction: slightly acid to neutral; pH: 6.1 to 7.3
2Btb horizon:
color, moist: 10YR 3/3, 4/4, 5/2, 5/3
color, dry: 10YR 5/2, 5/3, 5/4, 6/4, 7/2
texture: C, SIC, SICL, GR-SICL, ST-C
clay content: 40 to 60 percent
rock fragment content: 0 to 20 percent
gravel: 0 to 20 percent
cobbles: 0 to 5 percent
stones: 0 to 5 percent
reaction: neutral to slightly alkaline; pH: 6.6 to 7.8
2BCb or 2C horizon; present within 60 inches in some pedons:
color, moist: 2.5Y 5/4; 10YR 4/3, 4/6, 5/3, 5/4, 6/2, 6/6
color, dry: 2.5Y 7/2; 10YR 5/4, 6/4, 7/2
texture: SICL, GR-SIC, GR-SIL, CBV-SIL, GRV-SCL
clay content: 25 to 40 percent
rock fragment content: 0 to 45 percent
gravel: 0 to 40 percent
cobbles: 0 to 10 percent
stones: 0 to 5 percent
reaction: neutral; to slightly alkaline; pH: 6.6 to 7.8
COMPETING SERIES:
Inferno: formed in alluvium and colluvium from volcanic rocks; does not have volcanic ash mantle with andic soil properties, has secondary carbonates in lower Bt horizons; dry 90 to 120 consecutive days in summer
GEOGRAPHIC SETTING:
Landform: valley floors and swales of rolling hills
Slope gradient: 0 to 60 percent
Parent material: volcanic ash overlying colluvium and residuum
Lithology: soft tuffs
Elevation: 4,000 to 5,000 feet
Climate: cold, wet winters and warm, dry summers
Mean annual precipitation: 19 to 28 inches
Mean annual air temperature: 40 to 43 degrees F
Frostfree period: 40 to 80 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Bennettcreek: on lower backslopes and footslopes, moderately deep to bedrock with a mixed mantle of ash and colluvium over loamy-skeletal argillic horizon; under grand fir, Douglas-fir, ponderosa pine, birchleaf spiraea, and pinegrass
Getaway: on mountain backslopes and canyon walls; deep to basalt with mollic epipedon and loamy-skeletal argillic horizon; under Douglas-fir, ponderosa pine, mallow ninebark, common snowberry and elk sedge
Klicker: on backslopes, moderately deep, mollic epipedon without an argillic horizon and minor ash influence under Douglas-fir or ponderosa pine forest
Tolo: on gently sloping basalt plateaus with thick ash mantle over loamy buried argillic horizon; under grand fir and Douglas-fir forest
DRAINAGE AND PERMEABILITY:
Drainage: well drained
Permeability: slow
USE AND VEGETATION:
Use: watershed, wildlife habitat, timber production, livestock grazing and recreation
Native vegetation: ponderosa pine, Douglas-fir, lodgepole pine, common snowberry, creeping Oregon grape, birchleaf spiraea, bearberry, showy aster, Rocky Mountain iris, sticky cinquefoil, blueleaf strawberry, prairie smoke, lupines, pinegrass, elk sedge and northwestern sedge
Plant Association: PSME/SYAL (Douglas-fir/common snowberry); may include PSME/CAGE (Douglas-fir/elk sedge) or PSME/SPBE (Douglas-fir/birchleaf spiraea).
DISTRIBUTION AND EXTENT:
Distribution: MLRA: 43c; Blue Mountains of northeastern Oregon
Extent: minor
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Wallowa-Whitman National Forest, Oregon 2008. The name is from a town and reservoir in southern Baker County.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
ochric epipedon: 1 to 4 inches; A horizon
cambic horizon: 4 to 14 inches; Bw horizon
andic soil properties: 1 to 14 inches; A, Bw horizons
eluvial horizon: 14 to 16 inches; 2Eb horizon
argillic horizon: 16 to 61 inches; 2Btb1, 2Btb2 horizons
particle-size control section: 16 to 36 inches; 2Btb1, 2Btb2 horizons
linear extensibility of 7.7 in upper 100 cm of mineral soil
abrupt clay increase from 14 percent to 60 percent at contact between 2Eb and 2Btb1 horizons