LOCATION DUNSTAN OR
Established Series
IRD. JWL/DAL/KMS
11/2018
DUNSTAN SERIES
Landscape--mountains
Landform--mountain slopes, landslides on mountain slopes, mass failures on mountain slopes
Slope--0 to 90 percent
Parent material--thin mantle of mixed volcanic ash over colluvium derived from basalt or tuff breccia
Mean annual precipitation--about 600 mm
Mean annual air temperature--about 5 degrees C
Depth class--deep to lithic bedrock
Drainage class--well drained
Soil moisture regime--xeric
Soil temperature regime--frigid
Soil moisture subclass--typic
TAXONOMIC CLASS: Clayey-skeletal, smectitic, frigid Vitrandic Haploxeralfs
TYPICAL PEDON: Dunstan ashy silt loam, forested, on a 42-percent, west-facing slope at an elevation of 1554 m
Oi--0 to 3 cm; slightly decomposed needles, grasses, and leaves
A--3 to 13 cm; ashy silt loam, brown (7.5YR 5/2) dry, dark brown (7.5YR 3/2) moist; weak medium subangular blocky structure parting to weak fine subangular blocky; soft, very friable, slightly sticky and slightly plastic; common very fine, fine, and medium roots; common fine and very fine irregular pores; 5 percent gravel; slightly acid (pH 6.1); clear wavy boundary
Bw--13 to 28 cm; ashy silt loam, pinkish gray (7.5YR 6/2) dry, brown (10YR 4/3) moist; weak medium subangular blocky structure parting to weak fine subangular blocky; slightly hard, very friable, slightly sticky and slightly plastic; common very fine, fine, and medium roots; common fine and very fine irregular pores; 10 percent gravel; slightly acid (pH 6.5); abrupt wavy boundary
2Eb--28 to 51 cm; very gravelly clay loam, pinkish gray (7.5YR 6/2) dry, brown (7.5YR 4/2) moist; weak medium subangular blocky structure parting to moderate fine and very fine subangular blocky; slightly hard, friable, slightly sticky and moderately plastic; common very fine and fine and few medium roots; common very fine and few fine tubular pores and few very fine irregular pores; 25 percent gravel and 10 percent cobbles; slightly acid (pH 6.5); clear irregular boundary
2Btb--51 to 114 cm; very gravelly clay loam, brownish yellow (10YR 6/6) dry, dark yellowish brown (10YR 4/6) moist; weak medium subangular blocky structure parting to moderate fine and very fine subangular blocky; very hard, firm, moderately sticky and moderately plastic; common thin clay films on ped faces; few fine and very fine roots; common very fine tubular pores and common very fine and few fine irregular pores; 45 percent gravel and 10 percent cobbles; neutral (pH 7.0); abrupt irregular boundary
2R--114 cm; andesitic tuff breccia of the Clarno Formation
TYPE LOCATION: Grant County, Oregon; 342 m east and 147 m south of the northwest corner of section 25, T. 8 S., R. 35 E.; Granite U.S. Geological Survey quadrangle; latitude 44.8488626, longitude -118.4504092, datum WGS 84 (coordinates estimated from pin prick on hard copy map)
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--5 to 7 degrees C
Mean summer soil temperature--9 to 11 degrees C
Mean winter soil temperature--1 to 2 degrees C
Soil moisture --dry 45 to 60 consecutive days in summer
Depth to lithic contact--100 to 150 cm
Thickness of ash-influenced layers--25 to 35 cm
Estimated properties of layers influenced by volcanic ash
*Ammonium oxalate extractable Al + 1/2 Fe--0.4 to 1.2 percent
*0.02- to 2.0-mm fraction--30 to 40 percent
*Glass content in 0.02- to 2.0-mm fraction--25 to 55 percent
*1/3-bar bulk density--0.90 to 1.20 g/cm3
*Phosphate retention--30 to 55 percent
Particle-size control section
*Clay content--35 to 44 percent
*Total rock fragment content--35 to 65 percent
A horizon
Moist color--5YR 3/2, 7.5YR 3/2, 10YR 3/3, 10YR 4/2
Dry color--5YR 5/2, 7.5YR 4/2, 7.5YR 5/2, 10YR 6/2
Fine-earth texture--ashy silt loam
Clay content--12 to 20 percent
Sand content--25 to 32 percent
Organic matter content--1 to 5 percent
Total rock fragment content--2 to 10 percent
Gravel content--2 to 10 percent
Reaction--6.1 to 7.3
Thickness--8 to 15 cm
Bw horizon
Moist color--5YR 4/3, 7.5YR 4/4, 10YR 4/2, 10YR 4/3
Dry color--5YR 5/2, 7.5YR 5/2, 7.5YR 5/4, 7.5YR 6/2
Fine-earth texture--ashy silt loam
Clay content--12 to 22 percent
Sand content--25 to 32 percent
Organic matter content--1 to 3 percent
Total rock fragment content--2 to 20 percent
Gravel content--2 to 15 percent
Cobble content--0 to 5 percent
Reaction--5.6 to 7.3
Thickness--15 to 25 cm
2Eb horizon, and 2EBb horizon (where present)
Moist color--5YR 4/2, 7.5YR 4/2, 10YR 4/3
Dry color--5YR 5/3, 7.5YR 5/3, 7.5YR 6/2, 10YR 6/2, 10YR 6/3
Fine-earth texture--loam, clay loam
Clay content--26 to 28 percent
Sand content--30 to 35 percent
Organic matter content--1 to 2 percent
Total rock fragment content--20 to 40 percent
Gravel content--10 to 25 percent
Cobble content--5 to 15 percent
Reaction--5.6 to 7.3
Thickness--8 to 25 cm
2Btb horizon, and 2BCb horizon (where present)
Moist color--7.5YR 4/2, 7.5YR 4/4, 10YR 4/4, 10YR 4/6
Dry color--5YR 5/3, 7.5YR 4/4, 7.5YR 5/6, 10YR 5/3, 10YR 5/6, 10YR 6/6
Fine-earth texture--clay loam, clay
Clay content--35 to 45 percent
Sand content--22 to 35 percent
Organic matter content--0 to 2 percent
Total rock fragment content--35 to 55 percent
Gravel content--25 to 50 percent
Cobble content--5 to 20 percent
Stone content--0 to 10 percent
Reaction--6.6 to 7.3
Thickness--50 to 80 cm
COMPETING SERIES:
Cotay--moderately deep (50 to 100 cm) to lithic contact (metavolcanic rock, serpentine)
Cougarrock--moderately deep (50 to 100 cm) to lithic contact (soft tuff, basalt); paralithic material 8 to 25 cm thick above lithic contact
Stithum--no lithic contact within a depth of 150 cm; alluvium; no cambic (Bw) horizon; dry 60 to 75 consecutive days in summer
Tamarackcanyon--moderately deep (50 to 100 cm) to lithic contact (basalt); clay loam or silty clay loam cambic (Bw) horizon that has 25 to 35 percent clay; no eluvial (2Eb) horizon
GEOGRAPHIC SETTING:
Elevation--1020 to 1830
Climate--cold, wet winters; warm, dry summers
Mean annual precipitation--380 to 1020 mm
Mean annual air temperature--3 to 7 degrees C
Frost-free period--30 to 100 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Btree--on stable, concave mountain slopes; deep (100 to 150 cm) to lithic contact (tuff); thick ash mantle over buried argillic horizon; under grand fir, lodgepole pine, western larch,
Douglas-fir, twinflower, prince's pine, sidebells pyrola, roundleaf violet, pinegrass, and northwestern sedge
Cougarrock--on backslopes; moderately deep (50 to 100 cm) to lithic contact (andesitic tuff breccia); mixed volcanic ash and colluvium over buried clayey-skeletal argillic horizon; under grand fir, lodgepole pine, western larch, big huckleberry, birchleaf spirea, and pinegrass
Fivebit--on plateaus and backslopes; shallow (25 to 50 cm) to lithic contact (rhyolitic tuff, andesite, basalt); minor influence of volcanic ash in loamy-skeletal colluvium; under ponderosa pine,
Douglas-fir, birchleaf spirea, common snowberry, and pinegrass
Kamela--on ridge crests and shoulder slopes; moderately deep (50 to 100 cm) to lithic contact (basalt); mixed mantle of ash and loess over loamy-skeletal colluvium; under grand fir,
Douglas-fir, ponderosa pine,
Rocky Mountain maple, ninebark, heartleaf arnica, and prince's pine
Larabee--on backslopes and shoulders of hills and on canyons of dissected basalt plateaus; mollic epipedon and argillic horizon; under
Douglas-fir, ponderosa pine, mallow ninebark, common snowberry, and elk sedge
Meaufun--on mountain backslopes; mollic epipedon of ash mixed with colluvium; argillic horizon; under
Douglas-fir and ponderosa pine forest
Melhorn--on backslopes and footslopes; no lithic contact within a depth of 150 cm (very deep); mixed ash mantle; under
Douglas-fir, ponderosa pine, or grand fir forest
Payraise--on backslopes; no lithic contact within a depth of 150 cm (very deep); colluvium and a thin volcanic ash mantle; loamy-skeletal argillic horizon; under grand fir, pinegrass, and birchleaf spirea
Pinuscreek--on planar to concave backslopes; deep (100 to 150 cm) to lithic contact (basalt); thin undisturbed ash mantle over loamy-skeletal argillic horizon; under grand fir,
Douglas-fir, western larch, lodgepole pine, grouse huckleberry, pinegrass, and Ross' sedge
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Saturation during normal years--none
Flooding--none
Ponding--none
Saturated hydraulic conductivity (Ksat)--high over moderately low or moderately high
USE AND VEGETATION:
Use--timber production, livestock grazing, recreation, wildlife habitat, watershed
Potential native vegetation--Douglas-fir, grand fir, ponderosa pine, western larch, lodgepole pine, western juniper, subalpine fir, pinegrass, grouse huckleberry, white spirea, elk sedge, common snowberry, sagebrush rockcress, northwestern sedge, big huckleberry, Virginia strawberry, heartleaf arnica, baldhip rose, pinemat manzanita, woodland strawberry, white hawkweed, myrtle pachystima, prince's pine, Scouler's willow, tailcup lupine, low Oregon grape, russet buffaloberry, western fescue, common yarrow, blue wildrye, American vetch, showy aster
DISTRIBUTION AND EXTENT: South-central Blue Mountains in the area of the Middle Fork and North Fork of the John Day River, Oregon; MLRA 10; moderate extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Umatilla National Forest, Oregon; 2018
REMARKS:
Diagnostic horizons and other features recognized in this pedon
*Ochric epipedon
*Cambic horizon--zone from 13 to 28 cm
*Vitrandic subgroup properties (mixed ash mantle)--zone from 3 to 28 cm
*Buried eluvial horizon--zone from 28 to 51 cm
*Buried argillic horizon--zone from 51 to 114 cm
*Particle-size control section--zone from 51 to 101 cm
National Cooperative Soil Survey
U.S.A.