LOCATION THIESSEN                WA+OR

Established Series
Rev. HRG/RJE/KWH/RWL
09/2019

THIESSEN SERIES

Landscape--plateaus, hills, canyonlands
Landform--summits, structural benches, hillslopes, canyons
Slope--2 to 90 percent
Parent material--loess and colluvium derived from basalt
Mean annual precipitation--about 410 mm
Mean annual air temperature--about 9 degrees C
Depth class--moderately deep
Drainage class--well drained
Soil moisture regime--xeric
Soil temperature regime--mesic
Soil moisture subclass--typic

TAXONOMIC CLASS: Clayey-skeletal, smectitic, mesic Pachic Argixerolls

TYPICAL PEDON: Thiessen very stony silt loam in an area of rangeland, on a 70-percent, southeast-facing slope at an elevation 575 m

A--0 to 8 cm; very stony silt loam, brown (10YR 4/3) dry, very dark grayish brown (10YR 3/2) moist; moderate fine and medium granular structure; hard, friable, moderately sticky and moderately plastic; many very fine and few medium roots; many very fine irregular pores; 25 percent gravel, 15 percent cobbles, and 10 percent stones; neutral (pH 7.2); clear wavy boundary

Bt1--8 to 23 cm; very cobbly clay loam, brown (10YR 4/3) dry, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; many very fine and few medium roots; many very fine irregular pores; many faint stress cutans and clay films on faces of peds; 20 percent gravel, 25 percent cobbles, and 5 percent stones; neutral (pH 7.2); clear wavy boundary

Bt2--23 to 43 cm; very cobbly clay loam, brown (10YR 5/3) dry, very dark grayish brown (10YR 3/2) moist; moderate fine and medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; common very fine roots; common very fine irregular pores; many faint stress cutans and clay films on faces of peds; 20 percent gravel, 25 percent cobbles, and 5 percent stones; slightly alkaline (pH 7.5); clear wavy boundary

Bt3--43 to 56 cm; extremely cobbly clay loam, brown (10YR 5/3) dry, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; common very fine roots; common very fine irregular pores; continuous faint stress cutans and clay films on faces of peds; 30 percent gravel, 30 percent cobbles, and 5 percent stones; slightly alkaline (pH 7.5); abrupt irregular boundary

2R--56 cm; basalt

TYPE LOCATION: Asotin County, Washington, about 8 km northeast of Anatone; about 75 m north and 800 m west of the southeast corner of section 2, T. 8 N., R. 46 E.

RANGE IN CHARACTERISTICS:
Depth to a lithic contact--50 to 100 cm
Mean annual soil temperature--8 to 11 degrees C
Soil moisture--usually moist, but dry in all parts 75 to 90 consecutive days between depths of 10 and 30 cm following summer solstice
Particle-size control section--averages 40 to 65 percent angular basalt fragments, by volume; 35 to 45 percent clay in fine-earth fraction
Thickness of mollic epipedon--51 to 89 cm; includes all or part of argillic horizon
Thickness of argillic horizon--46 to 89 cm

A horizon
Hue--7.5YR, 10YR
Value--3 to 5 dry, 2 or 3 moist
Chroma--1 to 3 dry or moist
Texture--loam, silt loam
Clay content--18 to 27 percent
Thickness--5 to 15 cm

AB horizon (where present)
Color--similar to that of A horizon

Bt1 and Bt2 horizons
Hue--7.5YR, 10YR
Value--3 to 5 dry, 2 or 3 moist
Chroma--1 to 3 dry or moist
Texture--very cobbly clay loam, very gravelly clay loam, very gravelly silty clay loam, very gravelly clay
Clay content--35 to 45 percent
Reaction--6.1 to 7.3

Bt3 horizon (where present)
Hue--5YR, 7.5YR, 10YR
Value--3 to 5 dry, 2 or 3 moist
Chroma--2 or 3 dry or moist
Texture--very cobbly clay, extremely cobbly clay loam, extremely gravelly clay loam, very gravelly clay loam, very cobbly clay loam, extremely cobbly clay
Clay content--35 to 45 percent
Reaction--6.1 to 7.3

Combined thickness of Bt horizon--43 to 89 cm

BCt horizon (where present)
Hue--7.5YR, 10YR
Value--4 or 5 dry, 3 or 4 moist
Chroma--3 or 4 dry or moist
Texture--very cobbly clay, very gravelly clay loam, extremely cobbly clay loam, very cobbly clay loam
Reaction--6.1 to 7.8

COMPETING SERIES:
Dosie--100 to 150 cm (deep) to a lithic contact (basalt); dry more than 90 consecutive days following summer solstice (aridic [border xeric])
Drakce--100 to 125 cm (deep) to a lithic contact (basalt)
Gurdane--dry 60 to 75 consecutive days following summer solstice; argillic horizon 15 to 35 cm thick
Kishwalk--15 to 50 percent stones and no stress-oriented material in particle-size control section
Mallory--dry 60 to 75 consecutive days following summer solstice
Tablerock--more than 150 cm (very deep) to a paralithic contact (sandstone)
Zweygardt--no lithic contact within a depth of more than 150 cm

GEOGRAPHIC SETTING:
Elevation--275 to 1225 m
Climate--hot, dry summers; cool, moist winters
Mean annual precipitation--330 to 480 m
Mean annual air temperature--7 to 10 degrees C
Frost-free season--100 to 150 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Laufer--on canyon walls; 25 to 50 cm (shallow) to a lithic contact (basalt)
Matheny--on canyon walls; 100 to 150 cm or more (deep, very deep) to a lithic contact (basalt)
Pataha, Stember--on plateaus; less than 35 percent clay in particle-size control section

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Saturated hydraulic conductivity (Ksat)--moderately high or moderately low

USE AND VEGETATION:
Use--livestock grazing, wildlife habitat
Native vegetation--bluebunch wheatgrass, western yarrow

DISTRIBUTION AND EXTENT: Southeastern Washington and northeastern Oregon; MLRAs 8 and 9; moderate extent

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Asotin County, Washington; 1984

REMARKS:
Diagnostic horizons and other features recognized in this pedon
*Mollic epipedon--zone from the surface to a depth of 56 cm
*Argillic horizon--zone from 8 to 56 cm
*Depth to lithic contact--56 cm
*Particle-size control section--zone from 8 to 56 cm

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National Cooperative Soil Survey
U.S.A.