LOCATION HYSOOP MT
Established Series
Rev. JJU-RJS
01/2012
HYSOOP SERIES
The Hysoop series consists of very deep, well drained soils formed in slope alluvium and colluvium derived from red calcareous conglomerate or other red sedimentary rock. These soils occur on eroded fan remnants or hills. Slopes range from 4 to 35 percent. Mean annual precipitation is about 300 mm, and the mean annual air temperature is about 5 degrees C.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Calcidic Argiustolls
TYPICAL PEDON: Hysoop sandy loam, in rangeland (colors are for dry soil unless otherwise noted).
A--0 to 15 cm; brown (7.5YR 5/2) sandy loam, dark brown (7.5YR 3/2) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine roots throughout; many very fine irregular pores; 5 percent gravel, slightly alkaline (pH 7.6); clear smooth boundary. (8 to 18 cm thick)
Bt--15 to 30 cm; brown (7.5YR 5/3) sandy clay loam, dark brown (7.5YR 3/3) moist; moderate medium prismatic structure; hard, friable, moderately sticky and slightly plastic; many very fine and fine roots throughout; many very fine irregular pores; 5 percent gravel; 65 percent prominent clay films on faces of peds; slightly alkaline (pH 7.8); clear smooth boundary. (10 to 20 cm thick)
Btk--30 to 43 cm; reddish brown (5YR 5/4) loam, reddish brown (5YR 4/3) moist; moderate medium subangular blocky structure; very hard, firm, slightly sticky and slightly plastic; common very fine and fine roots throughout; many very fine irregular pores; 5 percent gravel; 10 percent faint continuous clay films on faces of peds; finely disseminated calcium carbonate and 1 percent very fine soft masses of calcium carbonate; strongly effervescent; moderately alkaline (pH 8.0); gradual wavy boundary. (0 to 20 cm thick)
Bk--43 to 75 cm; light reddish brown (2.5YR 7/3) sandy loam, light reddish brown (2.5YR 6/4) moist; weak coarse subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine and fine roots throughout; many very fine irregular pores; 5 percent gravel; 10 percent fine soft masses of calcium carbonate; violently effervescent; moderately alkaline (pH 8.4); gradual wavy boundary. (10 to 32 cm thick)
C1--75 to 98 cm; pale red (10R 7/4) sandy loam, pale red (10R 6/4) moist; massive; soft, very friable, nonsticky and nonplastic; 10 percent paragravel; finely disseminated calcium carbonate; strongly effervescent; moderately alkaline (pH 8.2); clear wavy boundary.
C2--98 to 152 cm; light red (2.5YR 6/6) paragravelly silty clay loam, reddish brown (2.5YR 5/4) moist; massive; very hard, firm, moderately sticky, moderately plastic; 25 percent paragravel; finely disseminated calcium carbonate; strongly effervescent; moderately alkaline (pH 8.2).
TYPE LOCATION: Beaverhead County, Montana; Dalys topographic quadrangle. UTM 12T, 0355474e, 4991779n, NAD83; 2400 feet north and 1000 feet east of the SW corner of sec.9, T. 20N., R. 10W.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 5 to 7 degrees C.
Thickness of the mollic epipedon: 18 to 30 cm
Depth to top of argillic horizon: 8 to 30 cm
Depth to calcic horizon: 25 to 50 cm
A horizon
Hue: 10YR, 7.5YR or 5YR; dry or moist
Value: 4 or 5 dry; 2 or 3 moist
Chroma: 2 or 3; dry or moist
Clay content: 12 to 20 percent
Rock fragments: 0 to 15 percent--0 to 10 percent gravel, 0 to 5 percent cobbles
Reaction: pH 6.6 to 7.8
Bt horizons
Hue: 10YR, 7.5YR or 5YR; dry or moist
Value: 5 to 8 dry; 3 or 4 moist
Chroma: 1 to 3; dry or moist
Texture: sandy clay loam, loam or clay loam
Clay content: 20 to 35 percent
Rock fragments: 0 to 15 percent--0 to 10 percent gravel, 0 to 5 percent cobbles
Reaction: pH 6.6 to 7.8
Btk horizon
Hue: 7.5YR or 5YR; dry or moist
Value: 4 to 7 dry; 3 or 4 moist
Chroma: 2 or 4; dry or moist
Texture: sandy clay loam or loam
Clay content: 20 to 35 percent
Calcium carbonate equivalent: 1 to 10 percent
Rock fragments: 0 to 15 percent--0 to 10 percent gravel, 0 to 5 percent cobbles
Reaction: pH 7.8 to 8.4
Bk horizon
Hue: 5YR, 2.5YR or 10R; dry or moist
Value: 5 to 8 dry; 4 to 7 moist
Chroma: 3 to 8; dry or moist
Texture: sandy loam, sandy clay loam or loam
Clay content: 15 to 25 percent
Calcium carbonate equivalent: 15 to 25 percent
Rock fragments: 0 to 15 percent--0 to 10 percent gravel, 0 to 5 percent cobbles
Reaction: pH 7.9 to 8.4
C1 horizon
Hue 5YR, 2.5YR or 10R; dry or moist
Value: 5 to 8 dry; 4 to 7 moist
Chroma: 3 to 8; dry or moist
Texture: sandy loam or sandy clay loam
Clay content: 15 to 25 percent
Calcium carbonate equivalent: 5 to 15 percent
Rock fragments: 0 to 25 percent--0 to 25 percent gravel, 0 to 5 percent cobbles
Para fragments: 0 to 25 percent paragravel
Reaction: pH 7.9 to 8.4
C2 horizon
Hue 5YR, 2.5YR or 10R; dry or moist
Value: 5 to 8 dry; 4 to 7 moist
Chroma: 3 to 8; dry or moist
Texture: loam or silty clay loam
Clay content: 18 to 35 percent
Calcium carbonate equivalent: 5 to 15 percent
Rock fragments: 0 to 25 percent--0 to 25 percent gravel, 0 to 5 percent cobbles
Para fragments: 0 to 25 percent paragravel
Reaction: pH 7.9 to 8.4
COMPETING SERIES:
Cortyzack (CO) - precipitation is evenly distributed throughout the year
Eldgin (UT) - have a lithologic discontinuity
Emlin (CO) - precipitation is evenly distributed throughout the year
Fortlogan (MT) - are deep to a paralithic contact
Morval (NM) - have a lithologic discontinuity
Notter (UT) - average 35 to 65 percent rock fragments in the Bk horizons
Nuley (MT) - are deep to a lithic contact
Thunderhead (MT) - are moderately deep to a lithic contact
Varney (MT) - have a stratified BC horizon
Villa Grove (CO) - have secondary sulfate accumulation
GEOGRAPHIC SETTING:
Landform - eroded fan remnants or hills
Elevation - 1675 to 2075 meters
Slope - 4 to 35 percent
Parent Material - slope alluvium and colluvium derived from red calcareous conglomerate or other red sedimentary rock
Climate - long, cold winters; moist springs; short summers
Mean annual precipitation - 250 to 360 mm (the most precipitation occurs during May and June)
Mean annual temperature - 4 to 7 degrees C.
Frost-free period - 70 to 90 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well-drained; moderate permeability.
USE AND VEGETATION: Hysoop soils are used as native rangeland. Native vegetation is mainly mountain grasses and forbs dominated by bluebunch wheatgrass, needleandthread, western wheatgrass, prairie junegrass, pricklypear cactus and big sagebrush.
DISTRIBUTION AND EXTENT: Southwest Montana. The series is of small extent. 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, 2008.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Mollic epipedon - 0 to 30 cm (A, Bt horizons)
Argillic horizon - 15 to 43 cm (Bt, Btk horizons)
Calcic horizon - 43 to 75 cm (Bk horizon)
Particle size control section from 15 to 43 cm (Bt, Btk horizons)
Hysoop soils have a frigid temperature regime and an ustic moisture regime bordering on aridic.
National Cooperative Soil Survey
U.S.A.