LOCATION FOUREYES MT
Established Series
REV. GFB-RJS
01/2012
FOUREYES SERIES
The Foureyes series consists of very deep well drained soils that formed in colluvium derived from limestone. These soils occur on hills and mountain slopes. Slopes are 15 to 60 percent. Mean annual precipitation is about 330 mm and mean annual temperature is about 3 degrees C.
TAXONOMIC CLASS: Loamy-skeletal, carbonatic Ustic Calcicryepts
TYPICAL PEDON: Foureyes very gravelly fine sandy loam, in rangeland on a 40 percent slope at an elevation of 2121 meters (colors are for dry soil unless otherwise noted).
A--0 to 10 cm; brown (10YR 5/3) very gravelly fine sandy loam, dark grayish brown (10YR 4/2) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine, fine and medium roots; many very fine and fine dendritic tubular pores; 40 percent gravel; finely disseminated calcium carbonate; violently effervescent; moderately alkaline (pH 8.2); clear smooth boundary. (5 to 15 cm thick)
Bk--10 to 46 cm; pale brown (10YR 6/3) very gravelly sandy loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and fine, and few medium roots; many very fine tubular and irregular pores; 50 percent gravel; finely disseminated calcium carbonate, 5 percent soft masses of calcium carbonate, and 75 percent fine distinct irregular carbonate nodules on bottom of rock fragments; violently effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (20 to 40 cm thick)
BCk1--46 to 74 cm; very pale brown (10YR 7/3) extremely gravelly loam, light yellowish brown (10YR 6/4) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few very fine and fine roots; many very fine irregular pores; 65 percent gravel and 5 percent cobbles; finely disseminated calcium carbonate, 10 percent soft masses of calcium carbonate, and 60 percent medium distinct irregular carbonate nodules on rock fragments; violently effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (25 to 50 cm thick)
BCk2--74 to 152 cm; pale brown (10YR 6/3) extremely gravelly loam, grayish brown (10YR 5/2) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few very fine and fine roots; many very fine irregular pores; 65 percent gravel and 15 percent cobbles; finely disseminated calcium carbonate, 10 percent soft masses of calcium carbonate, and 50 percent medium distinct irregular carbonate nodules on rock fragments; violently effervescent; moderately alkaline (pH 8.4); clear wavy boundary.
TYPE LOCATION: Beaverhead County, Montana; located about 732 meters west and 732 meters north of the southeast corner of sec. 4, T. 15S, R. 10W; Caboose topographic quadrangle; UTM 12T, 355002e, 4935510n, NAD 83.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 2 to 5 degrees C.
Depth to calcic horizon - 5 to 15 cm
Control section - averages more the 40 percent calcium carbonate by weight
A horizon
Value: 5 or 6 dry; 3 or 4 moist
Chroma: 2 or 3; dry or moist
Clay content: 12 to 18 percent
Rock fragments: 15 to 45 percent--15 to 45 percent gravel, 0 to 5 percent cobbles
Calcium Carbonate Equivalent: 15 to 40 percent, including coarse fragments less than 20 mm in size
Reaction: pH 7.9 to 8.4
Bk horizon
Value: 6 to 8 dry; 4 or 5 moist
Chroma: 2 or 3; dry or moist
Texture: loam or sandy loam
Clay content: 12 to 18 percent
Rock fragments: 35 to 70 percent--35 to 70 percent gravel, 0 to 10 percent cobbles
Calcium Carbonate Equivalent: 40 to 60 percent, including coarse fragments less than 20 mm in size
Reaction: pH 8.0 to 8.4
BCk horizons
Value: 6 to 8 dry; 5 to 7 moist
Chroma: 2 to 4; dry or moist
Texture: loam, fine sandy loam or sandy loam
Clay content: 12 to 18 percent
Rock fragments: 60 to 80 percent--50 to 70 percent gravel, 5 to 20 percent cobbles
Calcium Carbonate Equivalent: 40 to 55 percent, including coarse fragments less than 20 mm in size
Reaction: pH 8.2 to 8.4
COMPETING SERIES:
Scudder (MT) - have an udic moisture subclass
GEOGRAPHIC SETTING:
Landform - hills and mountain slopes
Elevation - 1975 to 2450 meters
Slope - 15 to 60 percent
Parent material - colluvium derived from limestone
Climate - long, cold winters; moist springs; warm summers
Mean annual precipitation - 300 to 385 mm
Mean annual air temperature - 1 to 4 degrees C.
Frost-free period - 50 to 70 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: Foureyes soils are used mainly for rangeland and wildlife habitat. The vegetation is mainly bluebunch wheatgrass, kingspike fescue, POA (species), Indian ricegrass, sagebrush, rubber rabbitbrush, and other miscellaneous forbs.
DISTRIBUTION AND EXTENT: Foureyes 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:
Ochric epipedon - from 0 to 10 cm (A horizon)
Calcic horizon - from 10 to 152 cm (Bk, BCk1, BCk2 horizons)
Particle-size control section - from 25 to 100 cm (part of Bk, BCk1, part of BCk2 horizons)
Foureyes soils have a cryic temperature regime and an ustic moisture regime.
Taxonomic version: Eleventh Edition, 2010.
National Cooperative Soil Survey
U.S.A.