LOCATION CRAMONT IDEstablished Series
TAXONOMIC CLASS: Fine, smectitic, frigid Vitrandic Haploxeralfs
TYPICAL PEDON: Cramont silt loam - on a 3 percent slope under coniferous forest at an elevation of 4,710 feet. (Colors are for dry soil unless otherwise noted. When described on August 8, 1991, the profile was moist throughout.)
Oi--1 inch to 0; very slightly decomposed moss, needles, and twigs.
A--0 to 2 inches; light brownish gray (10YR 6/2) silt loam, very dark grayish brown (10YR 3/2) moist; strong fine granular structure; soft, friable, slightly sticky and slightly plastic; many fine and very fine roots; common very fine tubular pores; moderately acid (pH 5.7); clear smooth boundary. (1 to 6 inches thick)
E--2 to 4 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; moderate thin platy structure; soft, friable, slightly sticky and slightly plastic; many fine and very fine and few medium roots; common very fine tubular pores; moderately acid (pH 5.6); clear smooth boundary.
EB--4 to 10 inches; light yellowish brown (10YR 6/4) silt loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and very fine and few medium roots; common very fine tubular pores; few faint pale brown (10YR 6/3) skeletans on faces of peds; strongly acid (pH 5.4); clear wavy boundary. (combined thickness of the E and EB horizons is 3 to 12 inches)
BE--10 to 14 inches; light yellowish brown (10YR 6/4) silt loam, dark yellowish brown (10YR 4/4) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and plastic; common fine and very fine and few medium roots; common fine and very fine tubular pores; many distinct pale brown (10YR 6/3) skeletans on faces of peds; strongly acid (pH 5.4); clear wavy boundary. (0 to 6 inches thick)
2Bt1--14 to 18 inches; dark yellowish brown (10YR 4/4), dark yellowish brown (10YR 4/6) crushed silty clay loam, dark yellowish brown (10YR 4/4) moist; moderate medium angular blocky structure; hard, firm, sticky and plastic; common fine and very fine and few medium roots; common fine and very fine tubular pores; many distinct pale brown (10YR 6/3) skeletans on faces of peds; common distinct dark yellowish brown (10YR 4/4) clay films on faces of peds and in pores; strongly acid (pH 5.5); gradual wavy boundary.
2Bt2--18 to 31 inches; brown (7.5YR 4/4), brown (7.5YR 5/4) crushed silty clay loam, dark yellowish brown (10YR 4/4) moist; moderate medium angular blocky structure parting to strong fine angular blocky; hard, firm, sticky and plastic; common fine roots; common fine and very fine tubular pores; common distinct pale brown (10YR 6/3) discontinuous skeletans on faces of peds; many prominent brown (7.5YR 4/4) clay films on faces of peds; 3 percent gravel; moderately acid (pH 5.8); gradual wavy boundary.
2Bt3--31 to 44 inches; brown (7.5YR 4/4), brown (7.5YR 5/4) crushed silty clay loam, dark yellowish brown (10YR 4/4) moist; weak coarse prismatic structure parting to strong medium and coarse angular blocky; hard, firm, sticky and plastic; few fine roots; many fine and very fine tubular pores; common distinct pale brown (10YR 6/3) skeletans on faces of peds; many prominent brown (7.5YR 4/4) clay films on faces of peds; 3 percent gravel; moderately acid (pH 5.9); diffuse wavy boundary. (Combined thickness of the 2bt1, 2Bt2, and 2Bt3 horizons is 20 to 55 inches)
2Bt4--44 to 65 inches; brown (7.5YR 4/4), brown (7.5YR 5/4) crushed silty clay loam, dark yellowish brown (10YR 4/4) moist; weak coarse prismatic structure parting to strong medium and coarse angular blocky; hard, firm, sticky and plastic; few fine roots; many fine and very fine tubular pores; common distinct pale brown (10YR 6/3) discontinuous skeletans on faces of peds; many prominent brown (7.5YR 4/4) clay films on faces of peds; 3 percent gravel; moderately acid (pH 6.0).
TYPE LOCATION: Nez Perce County, Idaho; about 1 mile south of Soldiers Meadow Reservoir; about 930 feet south and 720 feet west of the northeast corner of section 5, T. 32 N., R. 3 W. USGS Winchester West topographic quadrangle; Latitude - 46 degrees, 08 minutes, 54 seconds N; Longitude - 116 degrees, 43 minutes, 30 seconds W.
RANGE IN CHARACTERISTICS:
Depth to cobbly material - 40 to 60 inches or more Average annual soil temperature - 43 to 45 degrees F
Particle-size control section (weighted average) Clay content - 35 to 40 percent
A horizon Value - 4 or 5 dry Chroma - 2 or 3, dry or moist Volcanic glass content in the 0.02 to 2.0 mm fraction - 10 to 30 percent Coarse silt plus sand content - 30 to 45 percent Acid-oxalate extractable Al plus 1/2 Fe - 0.4 to 1.2 percent Reaction - moderately acid through neutral
E and EB horizons Value - 6 or 7 dry, 4 or 5 moist Chroma - 3 or 4, dry or moist Clay content - 14 to 24 percent Volcanic glass content in the 0.02 to 2.0 mm fraction - 5 to 30 percent Coarse silt plus sand content - 30 to 45 percent Acid-oxalate extractable Al plus 1/2 Fe - 0.4 to 1.2 percent Reaction - strongly acid through slightly acid
2Bt horizon Hue - 7.5YR or 10YR Value - 4 or 5 dry Chroma - 4 to 6, dry or moist Texture - silty clay loam or silty clay Gravel content - less than 5 percent Clay content - 32 to 42 percent Base saturation - 55 to 75 percent Reaction - strongly acid through slightly acid
Present in some pedons: 3Bt horizon Hue - 7.5YR or 10YR Chroma - 4 to 6, dry or moist Clay content - 32 to 40 percent Rock fragment content - 5 to 25 percent
COMPETING SERIES: There are no other series recognized in this family. The Talmaks series in a closely related family has a fine-silty particle-size class.
GEOGRAPHIC SETTING: The Cramont soils are on undulating loess- and volcanic ash-covered basalt plateaus at elevations of 4,100 to 5,000 feet and have slopes of 2 to 20 percent. The soils formed in loess and volcanic ash over material weathered from basalt. The average annual precipitation is 25 to 28 inches. Average annual temperature is 41 to 43 degrees F. The frost-free period is 60 to 85 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Seddow and Culdesac soils. Seddow soils are on south- and west-facing hillsides and are deep and fine-loamy. Culdesac soils are on north- and east-facing hillsides and have a thick volcanic ash mantle.
DRAINAGE AND PERMEABILITY: Well drained, medium to rapid runoff; slow permeability.
USE AND VEGETATION: Used mainly for woodland, woodland grazing, recreation, and wildlife habitat. The natural vegetation is mainly grand fir, Douglas-fir, western larch, ponderosa pine, longtube twinflower, big blueberry, goldthread, and elk sedge.
DISTRIBUTION AND EXTENT: North central Idaho. The series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Nez Perce County, Idaho, 1995.
REMARKS: This revision changes the classification from Fine, montmorillonitic Mollic Cryoboralfs, and moves the type location to the pedon sampled by NSSL.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - from the surface to 2 inches (the A horizon)
Vitrandic feature - from the surface to 10 inches (the A, E, and EB horizons)
Argillic horizon - from 14 to 65 inches (all 2Bt horizons)
Particle-size control section - from 14 to 34 inches (2Bt1, 2Bt2, and upper part of the 2Bt3 horizons)
ADDITIONAL DATA: This soil has been sampled for characterization by the NSSL. Laboratory sample number 91P1097, soil survey sample number S91ID-069-032.