LOCATION TERLOUGH OR
Tentative Series
IRD. RJO/RAW/DAL
05/2013
TERLOUGH SERIES
The Terlough series consists of very deep, somewhat poorly drained soils on low terraces of mountain valley floors. Terlough soils formed in alluvium from mixed rocks. Slopes are 0 to 5 percent. Mean annual precipitation is about 31 inches and mean annual temperature is about 42 degrees F.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Oxyaquic Hapludolls
TYPICAL PEDON: Terlough gravelly silt loam - conifer forest, on 0 percent slope at elevation of 3,840 feet. (Colors are for moist soil unless otherwise noted. Soil textures are apparent field textures.)
Oi--0 to 1 inches; slightly decomposed plant material consisting of leaves, needles, moss, twigs and logs
A--1 to 9 inches; very dark brown (7.5YR 2.5/2) gravelly silt loam, dark brown (7.5YR 3/3) dry; weak fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine, common medium and few coarse roots; few fine tubular and few very fine irregular pores; 25 percent gravel, 5 percent cobbles, and 2 percent stones; slightly acid (pH 6.5); clear wavy boundary
AB--9 to 14 inches; very dark brown (7.5YR 2.5/2) very gravelly loam, dark brown (7.5YR 3/2) dry; weak fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and common fine, medium and coarse roots; few fine tubular and very fine irregular pores; 35 percent gravel, 10 percent cobbles, and 5 percent stones; moderately acid (pH 6.0); clear wavy boundary. (A and AB horizons combined are 10 to 20 inches thick)
Bw--14 to 25 inches; dark brown (7.5YR 3/3) extremely gravelly sandy loam, brown (7.5YR 4/3) dry; common medium distinct strong brown (7.5YR 5/6) redox concentrations; single grain; loose, slightly sticky and slightly plastic; common very fine, fine and medium and few coarse roots; common very fine irregular pores; 45 percent gravel, 15 percent cobbles, and 10 percent stones; slightly acid (pH 6.2); gradual smooth boundary. (10 to 29 inches thick)
C--25 to 61 inches; very dark brown (7.5YR 2.5/2) extremely gravelly sandy loam, brown (7.5YR 4/2) dry; single grain; loose, nonsticky and nonplastic; common fine, few very fine and medium roots; many very fine irregular pores; 45 percent gravel, 15 percent cobbles, and 15 percent stones; slightly acid (pH 6.5).
TYPE LOCATION: Umatilla County, Oregon
Section 30 (NE , NW , NE ), T. 4 S., R. 33 E.
Latitude: 45 11 58 north; Longitude: 118 45 45.8 west
UTM Zone 11; 5,006,400 northing; 361,550 easting; NAD27
USGS Quadrangle: Owens Butte
RANGE IN CHARACTERISTICS:
Soil Temperature: frigid regime
Mean Annual Soil Temperature: 41 to 46 degrees F
Mean Summer Soil Temperature: 49 to 56 degrees F
Mean Winter Soil Temperature: 34 to 38 degrees F
Soil Moisture: udic regime, dry 25 to 45 days in summer
Particle-size control section: 10 to 40 inches below mineral soil surface
Clay content, weighted average: 5 to 15 percent
Rock fragment content, weighted average: 35 to 75 percent
Diagnostic Horizons and Features:
mollic epipedon: 10 to 20 inches thick
saturation with water, depth from mineral soil surface: 10 to 20 inches (redox concentrations without reduced matrix)
Major Horizons:
A horizon:
color, moist: 5YR 2.5/2, 3/2; 7.5YR 2.5/2, 3/2; 10YR 2/2
color, dry: 7.5YR 3/2, 3/3, 4/2, 4/3, 5/3; 10YR 4/3
texture: SIL, GR-SIL
clay content: 5 to 25 percent
rock fragment content: 0 to 35 percent
gravel: 0 to 25 percent
cobbles: 0 to 10 percent
stones: 0 to 2 percent
reaction: slightly acid to slightly alkaline; pH: 6.1 to 7.8
organic carbon: 1.5 to 4.7 percent
AB horizon:
color, moist: 5YR 3/3; 7.5YR 2.5/2, 3/2; 10YR 3/2, 3/3
color, dry: 7.5YR 3/3; 10YR 5/3
texture: GR-SL, GRV-L
clay content: 5 to 18 percent
rock fragment content: 20 to 50 percent
gravel: 15 to 35 percent
cobbles: 0 to 10 percent
stones: 0 to 5 percent
reaction: moderately acid to slightly alkaline; pH: 5.6 to 7.8
organic carbon: 0.9 to 1.8 percent
Bw Horizon:
color, moist: 5YR 2.5/2, 3/3; 7.5YR 3/3; 10YR 2/2, 3/2, 3/3
color, dry: 5YR 4/3; 7.5YR 4/3; 10YR 4/3, 5/3
texture: STX-SL, GRV-SL, GRX-SL, CBX-LS, GRV-LS
clay content: 3 to 18 percent
rock fragment content: 55 to 80 percent
gravel: 10 to 50 percent
cobbles: 5 to 25 percent
stones: 0 to 30 percent
reaction: moderately acid to neutral; pH: 5.6 to 7.3
organic carbon: 0 to 0.6 percent
redox concentrations: common, medium, distinct, strong brown or yellowish red masses and nodules
C Horizon:
color, moist: 5YR 3/3; 7.5YR 2.5/2; 10YR 2/2, 3/4
color, dry: 5YR 5/3; 7.5YR 4/2, 4/4; 10YR 4/3, 4/4, 5/3
texture: GRX-LS, CBX-LS, GRX-SL, STX-LS
clay content: 3 to 10 percent
rock fragment content: 60 to 80 percent
gravel: 15 to 50 percent
cobbles: 15 to 25 percent
stones: 10 to 40 percent
reaction: slightly acid to neutral; pH: 6.1 to 7.3
organic carbon: 0 to 0.6 percent
COMPETING SERIES: there are no competing series in the same family
GEOGRAPHIC SETTING:
Landform: low terraces on mountain valley floors
Slope gradient: 0 to 5 percent
Parent material: alluvium
Lithology: mixed rocks
Elevation: 3,600 to 5,200 feet
Climate: cold, wet winters and warm, moist summers
Mean annual precipitation: 24 to 38 inches
Mean annual air temperature: 39 to 44 degrees F
Frost-free period: 40 to 80 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Dardry (T) - on intermediate terraces of mountain valley floors, under
Douglas fir and ponderosa pine;
Getaway - on mountains slopes, influence of volcanic ash, under
Douglas fir and ponderosa pine;
Klickson - on mountain footslopes, mixed loess and ash mantle, under
Douglas fir and ponderosa pine;
Larabee - on mountain footslopes, mixed loess and ash mantle, under
Douglas fir and ponderosa pine;
Melloe (T): in depressions on floodplains of mountain valley floors, under wet meadow;
Tertoo (T): on upper relict terraces of mountain valley floors, volcanic ash mantle, under grand fir, elk sedge and pinegrass;
DRAINAGE AND PERMEABILITY:
Drainage: somewhat poorly drained
Permeability: moderate over moderately rapid.
USE AND VEGETATION:
Use: woodland, watershed, wildlife habitat and recreation
Native vegetation: grand fir, Douglas fir, Engelmann spruce, lodgepole pine, twinflower, common snowberry, Rocky mountain maple, side-flowered mitrewort, heartleaf arnica, queens cup beadlily, mountain sweet-cicely, blue wildrye, western fescue and northwest sedge.
Plant Associations: Dominant: ABGR/LIBO2; may include: ABGR/TABR/CLUN, ABGR/VAME and PIEN/BRVU
DISTRIBUTION AND EXTENT:
MLRA 10
Distribution: Blue Mountains and Wallowa Mountains of northeastern Oregon
Extent: small
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Umatilla County, Oregon 2007. The name is coined.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
mollic epipedon: 1 to 14 inches; A, AB horizons
particle-size control section: 11 to 41 inches; AB, Bw, C horizons
oxyaquic feature: redoximorphic concentrations (without depletions or reduced matrix), 14 to 25 inches; C1 horizon
National Cooperative Soil Survey
U.S.A.