LOCATION HYSOOP MTTentative Series
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; disseminated lime and 1 percent very fine soft masses of lime; 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 lime; 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 lime; 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 lime; 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.20 N., R 10 W.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 5 to 7 degrees C.
Moisture control section - between 10 and 30 cm
Depth to argillic horizon: 8 to 30 cm
Depth to calcic horizon: 25 to 50 cm
Thickness of the mollic epipedon: 18 to 30 cm
Surface rock fragments: 0 to 10 percent stones or boulders
A horizon
Hue: 10YR, 7.5YR or 5YR,
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 5 percent cobbles, 0 to 10 percent gravel
Reaction: pH 6.6 to 7.8
Bt horizons
Hue: 10YR, 7.5YR or 5YR
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 5 percent cobbles, 0 to 10 percent gravel
Reaction: pH 6.6 to 7.8
Btk horizon
Hue: 7.5YR or 5YR
Value: 4to 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 5 percent cobbles, 0 to 10 percent gravel
Reaction: pH 7.4 to 8.4
Bk horizon
Hue: 5YR, 2.5YR or 10R
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 5 percent cobbles, 0 to 10 percent gravel
Reaction: pH 7.9 to 8.4
C horizons
Hue 5YR, 2.5YR or 10R
Value: 5 to 8 dry; 4 to 7 moist
Chroma: 3 to 8, dry or moist
Texture: sandy loam, sandy clay loam, loam or silty clay loam
Clay content: 15 to 35 percent
Calcium carbonate equivalent: 5 to 15 percent
Rock fragments: 0 to 25 percent paragravel or gravel
Reaction: pH 7.9 to 8.4
COMPETING SERIES:
Cortyzack (CO) - receives 15 to 20 inches of precipitation.
Emlin (CO) - does not have a C horizon.
Morval (NM) - has a 2Bt horizon at depths greater than 46 inches.
Notter (UT) - the Bk horizon averages 35 to 65 percent rock fragments.
Nuley (MT) -has a lithic contact at a depths of 40 to 60 inches.
Thunderhead (MT) - has a paralithic and lithic contact at depths of less than 40 inches.
Varney (MT) - has a stratified BC horizon.
Villa Grove (CO) - has exchangeable sodium percent of 5 to 20 in the argillic horizon.
GEOGRAPHIC SETTING:
Landform - eroded fan remnants or hills.
Elevation - 1675 to 2072 meters
Slope - 4 to 35 percent
Parent Material - slope alluvium and colluvium weathered from red calcareous conglomerate or other sedimentary rock
Climate - long, cold winters; moist springs; short summers.
Mean annual precipitation - 254 to 356 mm.
Mean annual temperature - 4 to 7 degrees C.
Frost-free period - 70 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS:
DRAINAGE AND PERMEABILITY: Well-drained; medium runoff; 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, big sagebrush.
DISTRIBUTION AND EXTENT: Southwest Montana. The series is of small extent. MLRA 43B.
MLRA OFFICE RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Beaverhead County, Montana, 2008. Hysoop is a Native American word for sagebrush.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Mollic epipedon - 0 to 30 cm (A and Bt horizons);
Argillic horizon - 15 to 43 cm (Bt and Btk horizons);
Calcic horizon - 43 to 75 cm (Bk horizon);
Particle size control section from 15 to 43 cm (Bt and Btk horizons);
Hysoop soils have a frigid temperature regime and an ustic moisture regime bordering on aridic.