LOCATION CRAMONT                 ID

Established Series
Rev. PNP/TWH/KLS
11/2022

CRAMONT SERIES

The Cramont series consists of very deep, well drained soils that formed in loess and volcanic ash over material weathered from basalt. Cramont soils are on basalt plateaus and have slopes of 2 to 20 percent. Permeability is slow. The average annual precipitation is about 690 mm, and the average annual air temperature is about 6 degrees C.

TAXONOMIC CLASS: Fine, smectitic, frigid Vitrandic Haploxeralfs

TYPICAL PEDON: Cramont silt loam - on a 3 percent slope under coniferous forest at an elevation of 1425 meters. (Colors are for dry soil unless otherwise noted. When described on August 8, 1991, the profile was moist throughout.)

Oi--0 to 3 cm; very slightly decomposed moss, needles, and twigs.

A--3 to 8 cm; 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. (3 to 15 cm thick)

E--8 to 13 cm; 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--13 to 28 cm; 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 - 8 to 30 cm)

BE--28 to 38 cm; 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 15 cm thick)

2Bt1--38 to 48 cm; 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--48 to 81 cm; 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--81 to 114 cm; 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 - 50 to 140 cm)

2Bt4--114 to 167 cm; 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 1600 meters south of Soldiers Meadow Reservoir; about 280 meters south and 220 meters west of the northeast corner of section 5, T. 32 N., R. 3 W. USGS Winchester West topographic quadrangle; Lat. 46 degrees, 08 minutes, 54 seconds N; Long. 116 degrees, 43 minutes, 30 seconds W.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--6 to 7 degrees C
Depth to cobbly material--100 to 150 cm or more

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--pH 5.6 to 7.3

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--pH 5.1 to 6.5

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
Rock fragment content--less than 5 percent gravel
Clay content--32 to 42 percent
Base saturation--55 to 75 percent
Reaction--pH 5.1 to 6.5

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:
Landform--undulating loess-covered and volcanic ash-covered basalt plateaus
Elevations--1250 to 1525 meters
Slope--2 to 20 percent
Parent material--loess and volcanic ash over material weathered from basalt
Mean annual precipitation--640 to 710 mm
Mean annual air temperature--5 to 6 degrees C
Frost-free--60 to 85 days

GEOGRAPHICALLY ASSOCIATED SOILS: None listed

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: Cramont soils are moderately extensive in the Lewis and Nez Perce area of northcentral Idaho; MLRA 9

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Nez Perce County, Idaho, 1995

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon--3 to 8 cm (A horizon)
Vitrandic feature--3 to 28 cm (A, E, and EB horizons)
Argillic horizon--38 to 167 cm (all 2Bt horizons)
Particle-size control section--38 to 86 cm (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.

The classification was changed from Fine, montmorillonitic Mollic Cryoboralfs, and the type location of the pedon sampled by NSSL was updated. 7/1996

Converted to metric, updated formatting, and O horizons were updated to start at zero. Competing series section was not updated. 11/2022

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National Cooperative Soil Survey
U.S.A.