LOCATION HAYESCREEK MT
Established Series
Rev. JJU-KTS-RJS
01/2012
HAYESCREEK SERIES
The Hayescreek series consists of moderately deep, well drained soils that formed in volcanic ash and zeolite influenced colluvium and/or slope alluvium over residuum derived from calcareous rhyolitic bedrock. These soils occur on mountain slopes, hills and escarpments. Slopes are 2 to 50 percent. Mean annual precipitation is about 300 mm, and mean annual air temperature is about 6 degrees C.
TAXONOMIC CLASS: Ashy-skeletal, glassy, frigid Aridic Calciustepts
TYPICAL PEDON: Hayescreek very gravelly ashy sandy loam, in rangeland on a 40 percent slope at an elevation of 1798 meters (colors are for dry soil unless otherwise noted).
A--0 to 12 cm; grayish brown (10YR 5/2) very gravelly ashy sandy loam, dark grayish brown (10YR 4/2) moist; weak very fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine roots; many very fine and fine irregular pores; 25 percent gravel and 15 percent cobbles; finely disseminated calcium carbonate and 60 percent fine distinct irregular calcium carbonate coats around rock fragments; slightly effervescent; slightly alkaline (pH 7.8); clear smooth boundary. (10 to 20 cm thick)
Bk1--12 to 47 cm; light brownish gray (10YR 6/2) very gravelly ashy sandy loam, dark grayish brown (10YR 4/2) moist; weak fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine and fine irregular pores; 30 percent gravel and 20 percent cobbles; finely disseminated calcium carbonate and 70 percent fine distinct irregular calcium carbonate coats around rock fragments; strongly effervescent; moderately alkaline (pH 8.0); clear wavy boundary.
Bk2--47 to 72 cm; light brownish gray (2.5Y 6/2) extremely gravelly ashy sandy loam, grayish brown (2.5Y 5/2) moist; weak very fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and fine roots; few fine irregular pores; 45 percent gravel and 25 percent cobbles; finely disseminated calcium carbonate and 75 percent fine distinct irregular calcium carbonate coats around rock fragments; violently effervescent; moderately alkaline (pH 8.2); gradual wavy boundary. (combined thickness of Bk horizons - 40 to 65 cm thick)
BCk--72 to 94 cm; white (2.5Y 8/1) extremely gravelly ashy loamy sand, light gray (2.5Y 7/2) moist; single grain; loose, nonsticky and nonplastic; 50 percent gravel and 20 percent cobbles; finely disseminated calcium carbonate and 80 percent fine distinct irregular calcium carbonate coats around rock fragments; violently effervescent; moderately alkaline (pH 8.4) clear smooth boundary. (15 to 27 cm thick)
R--94 to 152 cm: calcareous fractured volcanic ash influenced rhyolite bedrock.
TYPE LOCATION: Beaverhead County, Montana; located about 800 feet west and 2600 feet north of the SE corner of sec. 35, T. 9S., R. 10W.; Dalys topographic quadrangle; UTM 12T, 358048e. 4985197n. NAD 83
RANGE IN CHARACTERISTICS:
Soil temperature - 4 to 7 degrees C.
Volcanic glass - 30 to 50 percent in the .02 to 2.0 mm fraction
Depth to a calcic horizon - 10 to 30 cm
Depth to a lithic contact - 50 to 100 cm
Soil surface - strongly effervescent when mixed to 18 cm
Note: Some pedons may have a C horizon.
A horizon
Hue: 10YR or 2.5Y; dry or moist
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2 or 3; dry or moist
Texture: ashy sandy loam or ashy loam
Clay content: 12 to 22 percent
Rock fragments: 15 to 45 percent--15 to 40 percent gravel, 0 to 15 percent cobbles and stones
Calcium carbonate equivalent: 1 to 8 percent
Reaction: pH 7.6 to 8.2
Bk1, Bk2 horizons
Hue: 10YR or 2.5Y; dry or moist
Value: 6 or 7 dry; 4 or 5 moist
Chroma: 2 or 3; dry or moist
Texture: ashy sandy loam or ashy loam
Clay content: 10 to 18 percent
Rock fragments: 35 to 70 percent--20 to 55 percent gravel, 5 to 25 percent cobbles
Calcium carbonate equivalent: 15 to 35 percent
Reaction: pH 7.9 to 8.4
BCk horizon
Hue: 10YR or 2.5Y; dry or moist
Value: 7 or 8 dry; 6 or 7 moist
Chroma: 1 or 2; dry or moist
Texture: ashy loamy sand or ashy sandy loam
Clay content: 5 to 15 percent
Rock fragments: 45 to 75 percent--30 to 55 percent gravel, 10 to 40 percent cobbles
Calcium carbonate equivalent: 15 to 25 percent
Reaction: pH 7.9 to 8.4
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform - mountain slopes, hills and escarpments
Elevations - 1520 to 2140 meters
Slopes - 2 to 50 percent
Parent material - volcanic ash and zeolite influenced colluvium and/or slope alluvium over residuum derived from calcareous rhyolitic bedrock
Climate - long, cold winters; moist springs; warm summers
Mean annual precipitation - 250 to 360 mm
Mean annual air temperature - 4 to 7 degrees C.
Frost-free period - 70 to 90 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained; moderately rapid permeability.
USE AND VEGETATION: Hayescreek 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: Hayescreek soils are of small extent in southwestern Montana. MLRAs - 43B, 44B.
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, 2009.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - from 0 to 12 cm (A horizon)
Calcic horizon - from 12 to 94 cm (Bk1, Bk2, BCk horizons)
Lithic contact - at 94 cm (R horizon)
Particle-size control section - from 25 to 94 cm (part of Bk1, Bk2, BCk horizons)
Hayescreek soils have a frigid temperature regime and an ustic moisture regime that borders on aridic.
National Cooperative Soil Survey
U.S.A.