LOCATION CHICKEN MT
Established Series
REV. KTS-RJS
01/2012
CHICKEN SERIES
The Chicken series consists of moderately deep, well drained soils that formed in colluvium and slide deposits derived from mixed igneous and interbedded sedimentary rock. These soils occur on hills, mountain slopes, ridges and landslides. Slopes are 8 to 50 percent. Mean annual precipitation is about 710 mm, and the mean annual air temperature is about 3 degrees C.
TAXONOMIC CLASS: Fine, smectitic Vertic Argicryolls
TYPICAL PEDON: Chicken clay loam, in forest on a 35 percent north slope at an elevation of 2277 meters (Colors are for dry soil unless otherwise noted).
Oi--0 to 6 cm; slightly decomposed forest litter; clear smooth boundary. (4 to 8 cm thick)
A--6 to 21 cm; dark grayish brown (10YR 4/2) clay loam, very dark brown (10YR 2/2) moist; moderate medium granular structure; slightly hard, friable, very sticky and moderately plastic; many very fine, fine, medium and coarse roots; many very fine and fine irregular pores; 5 percent gravel; slightly acid (pH 6.2); clear smooth boundary. (12 to 20 cm thick)
BA--21 to 39 cm; grayish brown (10YR 5/2) clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; slightly hard, friable, very sticky and moderately plastic; many very fine, fine, medium and coarse roots; many very fine and fine irregular pores; 5 percent gravel; moderately acid (pH 6.0); clear wavy boundary. (0 to 20 cm thick)
Bt--39 to 56 cm; light yellowish brown (2.5Y 6/3) gravelly clay loam, olive brown (2.5Y 4/3) moist; strong fine and medium subangular blocky structure; very hard, very firm, very sticky and very plastic; common very fine, fine, medium and coarse roots; common fine tubular pores; 15 percent gravel; 60 percent prominent continuous clay films on all faces of peds; moderately acid (pH 6.0); gradual wavy boundary.
Btss--56 to 84 cm; light yellowish brown (2.5Y 6/3) clay, light olive brown (2.5Y 5/3) moist; strong fine and medium subangular blocky structure; extremely hard, extremely firm, very sticky and very plastic; few very fine, fine, medium and coarse roots; common fine tubular pores; 5 percent gravel; 60 percent prominent continuous clay films on all faces of peds; 30 percent prominent slickensides; slightly acid (pH 6.2); abrupt wavy boundary. (combined thickness of Bt horizons - 35 to 70 cm)
Cr--84 to 152 cm; light yellowish brown (2.5Y 6/3) interbedded soft and moderately hard sandstone, olive brown (2.5Y 4/3) moist; crushes to medium and fine sand.
TYPE LOCATION: Beaverhead County, Montana; located at northwest corner of sec. 6, T. 15 S., R 4 W; Corral Creek topographic quadrangle; UTM 12T, 408879e., 4935338n. NAD 83.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 2 to 5 degrees C
Thickness of the mollic epipedon: 25 to 40 cm and may include part of the argillic horizon
Depth to the top of argillic horizon: 20 to 40 cm
Depth to paralithic contact: 50 to 100 cm
A horizon
Value: 3 to 5 dry; 2 or 3 moist
Chroma: 2 or 3; dry or moist
Clay content: 27 to 35 percent
Rock fragments: 0 to 15 percent--0 to 15 percent gravel, 0 to 5 percent cobbles
Reaction: pH 5.6 to 6.5
BA horizon
Value: 3 to 5 dry; 2 or 3 moist
Chroma: 2 or 3 dry or moist
Texture: clay loam or silty clay loam
Clay content: 27 to 35 percent
Rock fragments: 0 to 15 percent--0 to 15 percent gravel, 0 to 5 percent cobbles
Reaction: pH 5.6 to 6.5
Bt, Btss horizons
Hue: 10YR or 2.5Y
Value: 4 to 6 dry; 3 to 5 moist
Chroma: 2 to 4; dry or moist
Texture: clay loam, silty clay loam, silty clay or clay
Clay content: 35 to 50 percent
Rock fragments: Rock fragments: 0 to 20 percent--0 to 20 percent gravel, 0 to 5 percent cobbles
Reaction: pH 5.6 to 7.0
COMPETING SERIES:
Beaverdam (ID) - do not have bedrock within 100 cm
Buckskin (ID) - do not have bedrock within 100 cm
Cimarron (CO) - do not have bedrock within 100 cm
Cooperwash (NV) - do not have bedrock within 100 cm
Cucharas (CO) - do not have a horizon with slickensides
Gourley (CO) - do not have bedrock within 100 cm
Hairpin (MT) - do not have bedrock within 100 cm
Heathcoat (ID) - do not have bedrock within 100 cm
Helmet (CO) - do not have bedrock within 100 cm
Savar (WY) - do not have bedrock within 100 cm
Slights (ID) - do not have bedrock within 100 cm
Sudduth (CO) - do not have bedrock within 100 cm
Sudpeak (ID) - do not have bedrock within 100 cm
Toponce (ID) - do not have bedrock within 100 cm
Wetopa (CO) - do not have bedrock within 100 cm
Youman (CO) - do not have bedrock within 100 cm
GEOGRAPHIC SETTING:
Landform - hills, mountain slopes, ridges and landslides
Elevation - 2130 to 2750 meters
Slope - 8 to 50 percent
Parent material - colluvium and slide deposits derived from mixed igneous and interbedded sedimentary rock
Climate - long, cold winters; moist springs; short warm summers
Mean annual precipitation - 600 to 920 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: Chicken soils are used mainly for grazable woodland and timber. The vegetation is mainly Douglas-fir, subalpine fir, lodgepole pine, snowberry, buffaloberry, spirea, heartleaf arnica, pinegrass, and other miscellaneous grasses and forbs.
DISTRIBUTION AND EXTENT: Chicken 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, 2010.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from 6 to 39 cm (A and BA horizons)
Argillic horizon - from 39 to 84 cm (Bt and Btss horizons)
Particle-size control section - from 39 to 84 cm (Bt and Btss horizons)
Chicken soils have a cryic temperature regime and an udic moisture regime.
Taxonomic version: Eleventh Edition, 2010.
National Cooperative Soil Survey
U.S.A.