LOCATION CURRYCREEK MT
Established Series
REV. JJU-RJS
01/2012
CURRYCREEK SERIES
The Currycreek series consists of very deep, well drained soils that formed in landslide deposits and colluvium derived from igneous and sedimentary sources. These soils occur on landslides and mountain slopes. Slopes are 4 to 35 percent. Mean annual precipitation is about 700 mm, and the mean annual air temperature is about 3 degrees C.
TAXONOMIC CLASS: Fine, smectitic Pachic Argicryolls
TYPICAL PEDON: Currycreek silty clay loam, forested. (Colors are for dry soil unless otherwise noted).
Oi--0 to 10 cm; forest litter, slightly decomposed. (3 to 15 cm thick)
A1--10 to 30 cm; dark gray (10YR 4/1) silty clay loam, black (10YR 2/1) moist; moderate medium and fine granular structure; moderately hard, very friable, slightly sticky and moderately plastic; many fine, medium, and coarse roots; many very fine and fine irregular pores; 5 percent gravel; slightly acid (pH 6.4); clear smooth boundary.
A2--30 to 52 cm; dark grayish brown (10YR 4/2) clay loam, very dark gray (10YR 3/1) moist; moderate medium and coarse granular structure; moderately hard, friable, moderately sticky and moderately plastic; many fine, medium and coarse roots; many very fine and fine irregular pores; 5 percent gravel; slightly acid (pH 6.4); clear smooth boundary. (combined thickness of A horizons - 30 to 50 cm thick)
Bt1--52 to 79 cm; dark grayish brown (10YR 4/2) clay loam, very dark grayish brown (10YR 3/2) moist; strong coarse subangular blocky structure; moderately hard, friable, moderately sticky and moderately plastic; many fine and medium roots; common fine irregular pores; 45 percent distinct clay films on faces of peds; slightly acid (pH 6.4); clear wavy boundary. (15 to 30 cm thick)
Bt2--79 to 104 cm; brown (10YR 4/3) clay, very dark grayish brown (10YR 3/2) moist; strong coarse subangular blocky structure; hard, firm, very sticky and very plastic; many very fine and fine roots; common fine irregular pores; 75 percent prominent clay films on faces of peds; slightly acid (pH 6.4) clear wavy boundary. (20 to 35 cm thick)
BC--104 to 152 cm; brown (10YR 4/3) clay loam, dark grayish brown (10YR 4/2) moist; weak fine subangular blocky; moderately hard, friable, moderately sticky and moderately plastic; few very fine and fine roots; few very fine irregular pores; neutral (pH 6.6).
TYPE LOCATION: Beaverhead County, Montana; located about 189 meters north and 244 meters east of the southwest corner of sec. 21, T. 14 N., R 2 W; Slide Mountain topographic quadrangle; UTM 12T, 432726e., 4938840n. NAD 83.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 2 to 6 degrees C.
Thickness of mollic epipedon - 40 cm or greater
Depth to top of the argillic horizon - 45 to 60 cm
Particle-size control section - averages 35 to 45 percent clay
Note: Some pedons may have a transitional Bt/E horizon
A horizons
Value: 3 or 4 dry; 2 or 3 moist
Chroma: 1 or 2; dry or moist
Texture: clay loam or silty clay loam
Clay content: 27 to 35 percent
Rock fragments: 0 to 15 percent gravel
Reaction: pH 5.6 to 6.5
Bt1 horizon
Value: 3 or 4 dry; 2 or 3 moist
Chroma: 1 or 2; dry or moist
Texture: clay loam or silty clay loam
Clay content: 27 to 40 percent
Reaction: pH 5.6 to 7.0
Bt2 horizon
Value: 3 or 4 dry; 2 or 3 moist
Chroma: 2 or 3; dry or moist
Texture: clay loam, clay, silty clay loam or silty clay
Clay content: 35 to 50 percent
Reaction: pH 5.6 to 7.0
BC horizon
Value: 4 or 5 dry or moist
Chroma: 2 or 3; dry or moist
Texture: clay loam or silty clay loam
Clay content: 27 to 40 percent
Reaction: pH 5.6 to 7.0
COMPETING SERIES:
Bischoff (ID) - have a xeric moisture regime
Burnette (MT) - have secondary calcium carbonate accumulation
Cochetopa (CO) - have an ustic moisture regime
Faim (UT) - have a lithologic discontinuity
Fulcher (CO) - have secondary calcium carbonate accumulations
Grouseville (ID) - have a xeric moisture regime
Guero (CO) - have greater than 15 percent rock fragments in the substratum
Leemorris (OR) - have a lithic contact at depths of less than 100 cm
Lintim (CO) - dry in some part for greater than 45 days (cumulative)
Mancos (CO) - have a lithic contact at depths of less than 100 cm
Mayflower (MT) - have a paralithic contact at depths of less than 100 cm
Paulson (WY) - have secondary calcium carbonate accumulations
Perinos (UT) - have hues redder than 7.5YR in the Bt horizon.
Richens (UT) - have a lithic contact at depths of less than 150 cm
Runlett (CO) - have a lithic contact at depths of less than 100 cm
Skutum (UT) - have a lithic contact at depths of less than 150 cm
Winridge (ID) - have a lithic contact at depths of less than 100 cm
GEOGRAPHIC SETTING:
Landform - landslides and mountain slopes
Elevation - 2040 to 2700 meters
Slope - 4 to 35 percent
Parent material - landslide deposits and colluvium derived from igneous and sedimentary sources
Climate - long, cold winters; moist springs; short warm summers
Mean annual precipitation - 600 to 900 mm
Mean annual air temperature - 1 to 4 degrees C.
Frost-free period - 30 to 70 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: well drained; slow permeability.
USE AND VEGETATION: Currycreek soils are used mainly for understory grazing and timber. The vegetation is mainly aspen, Douglas-fir, subalpine fir, lodgepole pine, snowberry, heartleaf arnica, pinegrass, western meadowrue and other miscellaneous grasses and forbs.
DISTRIBUTION AND EXTENT: Currycreek soils are of small extent in southwestern Montana. MLRA - 43B.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Horse Prairie-South Valley Area - Part of Beaverhead County, Montana, 2011; proposed in Beaverhead County, Montana, 2011.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from 10 to 79 cm (A1, A2 and Bt1 horizons)
Argillic horizon - from 52 to 102cm (Bt1 and part of the Bt2 horizons)
Particle-size control section - from 52 to 102 cm (Bt1 and part of Bt2 horizons)
Currycreek soils have a cryic temperature regime and an udic moisture regime.
Taxonomic version: Eleventh Edition, 2010.
National Cooperative Soil Survey
U.S.A.