LOCATION WEBBGULCH ORTentative Series
TAXONOMIC CLASS: Loamy-skeletal, isotic, frigid Vitrandic Haploxerolls
TYPICAL PEDON: Webbgulch very gravelly ashy loam - forested, on a 58 percent southfacing slope at an elevation of 6,000 feet. (Colors are for moist soil unless otherwise noted.)
Oi--0 to 1 inches; slightly decomposed needles and twigs
A--1 to 3 inches; dark brown (10YR 3/3) very gravelly ashy loam, brown (10YR 5/3) dry; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine roots; few fine irregular pores; 35 percent gravel; slightly alkaline (pH 7.5); clear wavy boundary. (2 to 7 inches thick)
Bw1--3 to 15 inches; dark brown (10YR 3/3) very gravelly ashy silt loam, brown (10YR 5/3) dry; weak very fine subangular blocky structure; soft, very friable, slightly sticky and nonplastic; many very fine and fine, and few medium and coarse roots; many fine irregular pores; 55 percent gravel; slightly acid (pH 6.5); clear smooth boundary. (4 to 17 inches thick)
Bw2--15 to 30 inches; brown (10YR 4/3) extremely gravelly loam, yellowish brown (10YR 5/4) dry; weak very fine subangular blocky structure; soft, very friable, moderately sticky and slightly plastic; few faint clay films on ped faces; few very fine, and common fine medium and coarse roots; common fine irregular pores; 60 percent gravel, and 5 percent cobbles; slightly acid (pH 6.5); abrupt smooth boundary. (7 to 15 inches thick)
R--30 inches; hard andesitic basalt
TYPE LOCATION: Baker County, Oregon
Section 6 (SW 1/4, SE 1/4, SW 1/4), T. 14 S., R. 36 E.
Latitude: 44 degrees, 22 minutes, 31 seconds N.
Longitude: 118 degrees, 20 minutes, 42 seconds W.
UTM coordinates: zone 11; north 494218.6 meters, east 392844.5 meters; NAD27
USGS Quadrangle: Rail Gulch
RANGE IN CHARACTERISTICS:
Soil Temperature: frigid regime
Mean Annual Soil Temperature: 40 to 46 degrees F
Mean Summer Soil Temperature: 49 to 54 degrees F
Mean Winter Soil Temperature: 30 to 35 degrees F
Soil Moisture: xeric regime; dry 60 to 75 consecutive days in summer
Particle-size Control Section:
clay content, average: 11 to 17 percent
rock fragment content, average: 50 to 75 percent; rock fragment shape: subangular
Diagnostic Horizons and Features:
vitrandic subgroup properties: upper boundary at the mineral surface, 11 to 19 inches thick
A1+1/2Fe (ammonium oxalate): 0.3 to 0.9 percent
P retention: 20 to 40 percent
glass content in the 0.02-2.0mm fraction: 5 to 15 percent
mollic epipedon: 11 to 19 inches thick
cambic horizon: 7 to 15 inches thick
ultic subgroup feature: base saturation less than 75 percent in Bw1 horizon
lithic contact, depth from mineral soil surface: 20 to 40 inches
A horizon:
color, moist: 10YR 2/2, 3/3
color, dry: 10YR 4/2, 4/3, 5/3
texture: GR-ASHY-L, STV-ASHY-SIL, CB-ASHY-L, CBV-ASHY-SIL, GRV-ASHY-L
clay content: 8 to 11 percent
rock fragment content: 25 to 55 percent
gravel: 15 to 35 percent
cobbles: 0 to 15 percent
stones: 0 to 10 percent
reaction: slightly acid to slightly alkaline; pH: 6.1 to 7.8
Bw1 horizon; AB in some pedons:
color, moist: 7.5YR 3/3; 10YR 3/3
color, dry: 7.5YR 5/6; 10YR 5/3, 5/4
texture: CBV-ASHY-L, STX-ASHY-SIL, CBV-ASHY-SIL, STV-ASHY-L, GRV-ASHY-SIL
clay content: 7 to 12 percent
rock fragment content: 40 to 75 percent
gravel: 10 to 55 percent
cobbles: 0 to 25 percent
stones: 0 to 20 percent
reaction: slightly acid to neutral; pH: 6.1 to 7.3
base saturation (sum of cations): 60 to 75 percent
Bw2 horizon; may include BC in some pedons:
color, moist: 7.5YR 4/6; 10YR 4/3, 4/4
color, dry: 7.5YR 5/6; 10YR 5/3, 5/4, 6/4
texture: STX-L, STX-SL, CBX-SL, GRX-L, CBX-L
clay content: 11 to 17 percent
rock fragment content: 65 to 85 percent
gravel: 20 to 60 percent
cobbles: 5 to 30 percent
stones: 0 to 25 percent
reaction: slightly acid to neutral; pH: 6.1 to 7.3
COMPETING SERIES:
Bearspring: very deep (>60 inches) in granitic colluvium; particle-size control section averages 35 to 50 percent angular rock fragments
Bigelk: very deep (>60 inches) in mixed till; mixed ash mantle, 7 to 14 inches thick (35 to 50 percent glass content) with discontinuity between mantle and buried cambic horizon; rock fragments are subrounded or rounded; dry 45 to 60 consecutive days in summer
Cassal: deep (40 to 60 inches) to densic contact (till); volcanic ash influenced layer (glass content 5 to 20 percent), 12 to 18 inches thick, with discontinuity between ashy layer and till substratum; distinct redoximorphic features at 30 to 45 inches
Cherrycreek: deep (40 to 60 inches) to a lithic contact (basalt); does not have an organic (O) horizon above surface of mineral soil (not forested); mixed mantle of volcanic ash and loess (glass content 15 to 30 percent), 35 to 50 inches thick; mollic epipedon is 20 to 35 inches thick
Coyotebluff: deep (40 to 60 inches) to a lithic contact (granite); mixed volcanic ash mantle (glass content 35 to 50 percent), 7 to 14 inches thick; mollic epipedon is 20 to 26 inches thick; particle-size control section averages 3 to 12 percent clay; dry 45 to 60 consecutive days in summer
Deck: moderately deep (20 to 40 inches) to a lithic contact (metavolcanic rock); mixed volcanic ash mantle (glass content 30 to 55 percent) with discontinuity between mantle and buried cambic horizon; particle-size control section averages 20 to 35 percent clay
Eastpine: moderately deep (20 to 40 inches) to a lithic contact (metasedimentary rock); minor volcanic ash influence (glass content 5 to 15 percent); dry 45 to 60 consecutive days in summer
Egyptcreek: moderately deep (20 to 40 inches) to a lithic contact (welded tuff); mollic epipedon is 7 to 14 inches thick; dry 75 to 90 consecutive days in summer
Fredonyer: moderately deep (20 to 40 inches) to lithic contact (andesite or basalt); does not have organic horizon above surface of mineral soil (not forested); mollic epipedon is 20 to 40 inches thick; dry more than 90 consecutive days in summer
Golfer: moderately deep (20 to 40 inches) to a paralithic contact (weathered granite); particle-size control section averages 2 to 10 percent clay
Grubcreek: moderately deep (20 to 40 inches) to a lithic contact (andesite, andesitic basalt or basalt); particle-size control section averages 18 to 33 percent clay
Kettlecreek: deep (40 to 60 inches) to a lithic contact (argillite)
Longs: deep (40 to 60 inches) to a lithic contact (basalt); mollic epipedon is 20 to 45 inches thick; subsoil has faint clay films on ped faces; particle-size control section averages 18 to 27 percent clay; dry 45 to 75 consecutive days in summer
Midpeak: moderately deep (20 to 40 inches) to a lithic contact (breccia); mixed volcanic ash mantle (glass content 5 to 20 percent) with discontinuity between mantle and buried cambic horizon; particle-size control section averages 5 to 15 percent clay
Mineral: moderately deep (20 to 40 inches) to a lithic contact (granitic rocks); rock fragments are sub-rounded or rounded
Peahke: moderately deep (20 to 40 inches) to a paralithic contact; volcanic ash mantle (glass content 20 to 30 percent), 7 to 14 inches thick; particle-size control section averages 18 to 30 percent clay, and has 60 to 70 percent channers; dry 45 to 60 consecutive days in summer
Piersonte: very deep (>60 inches) in colluvium from shale; mollic epipedon is 20 to 35 inches thick; particle-size control section averages 18 to 30 percent clay, rock fragments are mostly shale channers; dry 60 to 90 consecutive days in summer
Porch: moderately deep (20 to 40 inches) to lithic contact (argillite); rock fragments are angular
Scoap: very deep (>60 inches) in mixed till or outwash materials; mollic epipedon is 20 to 30 inches thick
Shalrock: moderately deep (20 to 40 inches) to a lithic contact (sandstone); mixed volcanic ash mantle (glass content 5 to 15 percent); with discontinuity between mantle and substratum; particle-size control section averages 5 to 12 percent clay,
Shilling: very deep (greater than 60 inches) in colluvium from basalt; particle-size control section averages 18 to 27 percent clay; dry 45 to 75 consecutive days in summer
Umatilla: very deep (> 60 inches) in colluvium from basalt; mollic epipedon is 20 to 30 inches thick (mollic colors throughout); discontinuity between ashy layer and subsoil horizons; particle-size control section averages 25 to 35 percent clay
Yellcreek: very deep (>60 inches) in mixed colluvium; minor volcanic ash influence (glass content 5 to 20 percent) with discontinuity between volcanic ash influence zone and substratum; mollic epipedon is 7 to 15 inches thick; particle-size control section averages 5 to 15 percent clay; rock fragments are angular
GEOGRAPHIC SETTING:
Landform: ridges and shoulders of mountains
Slope gradient: 0 to 90 percent
Parent material: colluvium with a small amount of volcanic ash
Lithology: andesitic basalt or basalt
Elevation: 4,000 to 6,200 feet
Climate: cold, wet winters and warm, dry summers
Mean annual precipitation: 24 to 40 inches
Mean annual air temperature: 36 to 43 degrees F
Frost-free period: 25 to 80 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Pinuscreek: on planar to concave backslopes, deep to basalt bedrock; thin undisturbed ash mantle over loamy-skeletal argillic horizons; under grand fir, Douglas-fir, western larch, lodgepole pine, grouse huckleberry, pinegrass and
Ross sedge
Thirstygulch: on convex sideslopes and shoulders near rock outcrop; shallow to bedrock with minor amount of volcanic ash mixed with loess and colluvium from basalt; under ponderosa pine, Douglas-fir, common snowberry, and elk sedge
DRAINAGE AND PERMEABILITY:
Drainage: well drained
Permeability: moderate
USE AND VEGETATION:
Use: watershed, wildlife habitat, timber production, livestock grazing and recreation
Native vegetation: Douglas-fir, ponderosa pine, western juniper, birchleaf spiraea, common snowberry, creeping Oregon grape, curlleaf mountain mahogany, heartleaf arnica, woods strawberry, white flowered hawkweed, sticky cinquefoil, wayside gromwell, elk sedge, pinegrass and mountain brome.
Plant Association: PSME/SYAL (Douglas-fir/common snowberry); may include PSME/SPBE (Douglas-fir/birchleaf spiraea), PSME/CARU (Douglas-fir/pinegrass), and PSME/CELE/CAGE (Douglas-fir/curlleaf mountain mahogany/common snowberry)
DISTRIBUTION AND EXTENT:
Distribution: MLRA: 43c; Blue Mountains in eastern Oregon
Extent: small
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Wallow-Whitman National Forest, Oregon 2008. The name is from a gulch near Unity.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
mollic epipedon: 1 to 15 inches; A, Bw1 horizons
cambic horizon: 15 to 30 inches; Bw2 horizons
vitrandic subgroup properties: 1 to 15 inches; A, Bw1 horizon
particle-size control section: 11 to 30 inches; Bw1, Bw2 horizons