LOCATION SHOTSPRINGS ORTentative Series
TAXONOMIC CLASS: Clayey-skeletal, smectitic, frigid Vitrandic Argixerolls
TYPICAL PEDON: Shotsprings ashy sandy loam -- upland forest, on a 55 percent convex slope, north aspect, at 5,100 feet elevation. (Colors are for dry soil unless otherwise noted; apparent field textures.)
Oi--0 to 2 inches, slightly decomposed Douglas-fir litter and duff.
A1--2 to 5 inches, brown (10YR 4/3) ashy sandy loam, very dark brown (10YR 2/2) moist: moderate thin to medium platy structure; very soft, very friable, nonsticky and nonplastic; many very fine, fine and medium roots; many very fine and fine vesicular pores; 5 percent gravel, 2 percent cobbles; slightly acid (pH 6.2); abrupt smooth boundary.
A2--5 to 12 inches, yellowish brown (10YR 5/4) ashy sandy loam, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure; soft, friable, nonsticky and nonplastic; many very fine, fine and medium, and common coarse roots; many very fine and fine tubular pores; 10 percent gravel, 2 percent cobbles; slightly acid (pH 6.4); clear smooth boundary. (Combined thickness of A horizons is 7 to 14 inches)
Bw--12 to 21 inches; yellowish brown (10YR 5/4) ashy sandy clay loam, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure; soft, friable, slightly sticky and slightly plastic; many very fine, fine and coarse roots; many very fine and fine tubular pores; 10 percent gravel, 2 percent cobbles; slightly acid (pH 6.4); clear smooth boundary. (6 to 10 inches thick)
2Bt--21 to 31 inches; yellowish brown (10YR 5/4) extremely cobbly sandy clay; dark brown (10YR 3/3) moist; moderate fine and medium angular blocky structure, slightly hard, firm, slightly sticky and moderately plastic; common fine and medium roots; common very fine and fine tubular pores; many distinct moderately thick clay films on ped faces and lining pores; 20 percent gravel, 50 percent cobbles, 2 percent stones; slightly acid (pH 6.4) abrupt smooth boundary. (6 to 22 inches thick)
2R--31 inches; basalt
TYPE LOCATION: Crook County, Oregon, on Ochoco Forest Road 1680-663 in central Maury Mountains
Section 27, (N1/2 of N1/2) T. 17 S, R. 20 E.
Latitude: 44 degrees, 3 minutes, 50.6 seconds N;
Longitude: 120 degrees, 18 minutes, 59.7 seconds W
UTM coordinates: zone 10; 4,882,272.5 northing; 714,917.8 easting; NAD 27
RANGE IN CHARACTERISTICS:
Soil temperature regime: frigid
Mean annual soil temperature: 37 to 41 degrees F.
Mean summer soil temperature: 44 to 49 degrees F.
Mean winter soil temperature: 32 to 36 degrees F.
Soil moisture: xeric regime, dry 45 to 60 consecutive days in summer and early fall
Particle-size control section: upper 20 inches of the argillic horizon
clay content (weighted average): 35 to 55 percent
rock fragment content (weighted average): 35 to 85 percent
Diagnostic horizons and features:
thickness of andic soil properties: 7 to 14 inches
mollic epipedon: 13 to 20 inches thick
lithic contact, depth below mineral surface: 20 to 40 inches
A horizons
andic soil properties
Al+1/2Fe: 0.4 to 1.0 percent (ammonium oxalate)
P retention: 25 to 50 percent
0.2 to 2.0 mm fraction: 60 to 80 percent of fine earth
glass content: 30 to 50 percent of 0.2 to 2.0 fraction
color, moist: hue 10YR; value 2 or 3; chroma 2 or 3
color dry: hue 10YR; value 3 to 5; chroma 2 to 4
texture: ASHY-SL, ASHY-LS
clay content: 10 to 18 percent
rock fragments: 5 to 15 percent
gravel: 5 to 15 percent
cobbles: 0 to 5 percent
reaction : moderately acid to slightly acid, pH: 5.8 to 6.4
Bw horizons
vitrandic soil properties
Al+1/2Fe: 0.2 to 0.4 percent (ammonium oxalate)
P retention: 15 to 25 percent
glass content: 15 to 30 percent of 0.2 to 2.0 fraction
color, moist: hue 10YR; value 2 or 3; chroma 2 or 3
color dry: hue 10YR; value 3 to 5; chroma 2 to 4
texture: ASHY-SCL, GR-ASHY-SCL, CB-ASHY-SCL
clay content: 20 to 26 percent
rock fragments: 5 to 25 percent
gravel: 5 to 20 percent
cobbles: 0 to 10 percent
reaction : moderately acid to slightly acid, pH: 5.8 to 6.4
2Bt horizons
color moist: hue 10YR, value 2 or 3, chroma 2 to 4
color dry: hue 10YR, value 3 to 5, chroma 3 or 4
texture: CBX-SC, CBX-C, CBV-SC, CBV-C
clay content: 35 to 55 percent
rock fragments: 35 to 85 percent
gravel: 25 to 30 percent
cobbles: 10 to 50 percent
stones: 0 to 5 percent
reaction: slightly acid to neutral, pH: 6.2 to 6.6
COMPETING SERIES: These are the;
Breeseranch - deep; dry for 75 to 90 consecutive days in summer;
Dupratt - mollic epipedon 20 to 30 inches thick; dry for 70 to 90 consecutive days in summer;
Erakatak lacks an O horizon
Finsel - lacks an O horizon; mollic epipedon 20 to 40 inches thick; dry 75 to 90 consecutive days in summer;
Hamtah - very deep; lacks an O horizon; mollic epipedon is 20 to 26 inches thick
Home Camp - moderately deep to paralithic contact, lacks an O horizon
Humarel - dry 60 to 75 consecutive days in summer
Lamulita - deep to a lithic contact,
Maule - dry 60 to 90 consecutive days in summer
Menbo lacks an O horizon; dry 100 to 120 consecutive days in summer
Squatterflat - very deep; dry 60 to 75 consecutive days in summer
GEOGRAPHIC SETTING:
Landform: mountain backslopes and ridges
Slope gradient: 20 to 70 percent
Parent Material: volcanic ash over mixed ash and colluvium over residuum
Lithology: basalt and rhyolite
Elevation: 4,000 to 6,000 feet
Climate: cold, wet winters and hot, dry summers
Mean annual precipitation: 20 to 25 inches
Mean annual temperature: 40 to 45 degrees F.
Frost free period: 60 to 90 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Hafmau - on mountain sideslopes and benches; shallow to bedrock; under Douglas-fir, ponderosa pine, elk sedge and heartleaf arnica
Maule - on plateau tops and mountain sideslopes; under ponderosa pine, Idaho fescue, Ross's sedge, mountain brome and yarrow
Maucros - on sideslopes and plateau tops; deep; with ash mantle 14 to 20 inches thick, under grand fir, ponderosa pine, heartleaf arnica, pinegrass and pine bluegrass
Norlo - on sideslopes and benches; very deep; with ash mantle 14 to 20 inches thick, under grand fir, Douglas-fir, ponderosa pine, pinegrass and elk sedge
DRAINAGE AND PERMEABILITY:
Drainage: well drained
Runoff: medium
Permeability: rapid in ashy surface and slow in clayey subsoil
USE AND VEGETATION:
Use: timber production, range, wildlife habitat and water supply
Natural Vegetation: Douglas-fir, ponderosa pine and pinegrass
DISTRIBUTION AND EXTENT:
Distribution: MLRA 43c; Central Oregon
Ecological region: Blue Mountains, John Day-Clarno Highlands
Extent: moderate
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Crook County, Ochoco National Forest, Oregon, 2008.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
andic soil properties: 2 to 12 inches
vitrandic subgroup properties: 12 to 21 inches
mollic epipedon: 2 to 21 inches
argillic horizon: 21 to 31 inches
lithic contact: 31 inches
Lab data: NSSL pedon number: S93OR013-007
Plant Association: CPS1-12. Douglas-fir/pinegrass. (Hall, 1989, Plant Association and Management Guide for the Ochoco and Southern Blue Mountain Areas)
Plant Association Group: Douglas-fir (moist)