LOCATION REPP MT+UT
Established Series
Rev. GLS-RJS
04/2013
REPP SERIES
The Repp series consists of very deep, well drained soils that formed in colluvium derived from argillite, quartzite, siltstone or limestone. These soils are on mountain slopes and hills. Slopes are 0 to 80 percent. Mean annual precipitation is about 480 mm, and mean annual air temperature is about 6.0 degrees C.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Calcic Haplustepts
TYPICAL PEDON: Repp very gravelly loam, forested (colors are for dry soil unless otherwise noted).
Oi--0 to 2 cm; slightly decomposed forest litter.
E1--2 to 15 cm; light brownish gray (10YR 6/2) very gravelly loam, dark grayish brown (10YR 4/2) moist; weak medium granular structure; soft, very friable, nonsticky and nonplastic; many very fine, fine, medium, and coarse roots; 40 percent gravel; slightly effervescent; slightly alkaline (pH 7.4); clear smooth boundary.
E2--15 to 33 cm; light brownish gray (10YR 6/2) very gravelly loam, dark grayish brown (10YR 4/2) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine, fine, and medium roots; 45 percent gravel; slightly effervescent; slightly alkaline (pH 7.4); clear smooth boundary. (combined thickness of the E horizons is 15 to 40 cm)
Bw--33 to 64 cm; pale brown (10YR 6/3) very gravelly loam, brown (10YR 4/3) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine, fine, and medium roots; few lime coatings on gravel, mainly on underside; 50 percent gravel; disseminated lime; violently effervescent; moderately alkaline (pH 8.4); gradual wavy boundary. (18 to 45 cm thick)
Bk1--64 to 104 cm; very pale brown (10YR 7/3) extremely gravelly loam, brown (10YR 5/3) moist; massive; soft, very friable, nonsticky and nonplastic; few fine roots; thin lime coatings on gravel, mainly on underside; 70 percent gravel; disseminated lime; violently effervescent; moderately alkaline (pH 8.4); gradual wavy boundary. (20 to 90 cm thick)
Bk2--104 to 152 cm; very pale brown (10YR 7/3) extremely gravelly loam, pale brown (10YR 6/3) moist; massive; soft, very friable, nonsticky and nonplastic; lime coating on gravel, mainly on underside; 65 percent gravel; disseminated lime; violently effervescent; moderately alkaline (pH 8.2).
TYPE LOCATION: Missoula County, Montana; 91 meters north and 122 meters east of the S 1/4 corner of Sec. 8, T14N, R21W.
RANGE IN CHARACTERISTICS:
Soil temperature - 6.5 to 8.0 degrees C.
Depth to calcic horizon - 33 to 90 cm
Note: Some pedons may have a E/Bw horizon.
E horizon
Hue: 10YR or 2.5Y; dry or moist
Value: 5 to 7 dry; 4 or 5 moist
Chroma: 2 or 3; dry or moist
Clay content: 10 to 20 percent
Rock fragments: 20 to 50 percent--20 to 50 percent gravel, 0 to 10 percent cobbles and stones
Reaction: pH 6.1 to 7.6
Bw horizon
Hue: 10YR or 2.5Y; dry or moist
Value: 5 to 7 dry; 4 or 5 moist
Chroma: 2 to 4; dry or moist
Clay content: 10 to 20 percent
Rock fragments: 35 to 60 percent--35 to 50 percent gravel, 0 to 10 percent cobbles
Reaction: pH 7.4 to 8.4
Bk horizons
Hue: 10YR or 2.5Y; dry or moist
Value: 6 to 8 dry; 4 to 6 moist
Chroma: 2 or 3; dry or moist
Clay content: 10 to 18 percent
Rock fragments: 60 to 85 percent--55 to 75 gravel, 0 to 10 percent cobbles
Calcium carbonate equivalent: 10 to 15 percent
Reaction: pH 7.8 to 8.4
COMPETING SERIES:
Lamedeer (MT) - have rock fragments that are channers and flagstones
Redfist (MT) - are moderately deep to a lithic contact
GEOGRAPHIC SETTING:
Landform - mountain slopes and hills
Elevation - 880 to 1,725 meters
Slope - 0 to 80 percent
Parent material - colluvium derived from argillite, quartzite, siltstone or limestone
Climate - long, cold winters; moist springs; warm summers
Mean annual precipitation - 430 to 650 mm
Mean annual temperature - 3.8 to 7.2 degrees C.
Frost-free period - 70 to 105 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: Repp soils are used mainly for timber production and understory grazing. Potential native vegetation is mainly Douglas-fir and ponderosa pine with an understory of bluebunch wheatgrass, elk sedge, pinegrass, common snowberry, and mallow ninebark.
DISTRIBUTION AND EXTENT: Repp soils are of small extent in western Montana and parts of Utah. MLRAs - 43A, 44A and 46.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Missoula County, Montana, 1970.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 33 cm (Oi, E1, E2 horizons);
Cambic horizon - 33 to 64 inches (Bw horizon);
Calcic horizon - 64 to 152 cm (Bk1, Bk2 horizon); and
Particle-size control section from 25 to 100 cm (part of E2, Bw, part of Bk1 horizons).
Repp soils have a frigid temperature regime and an ustic moisture regime.
ADDITIONAL DATA: Soil Interpretation Records - MT0155, MT8124.
This description reflects a change in classification from Loamy-skeletal, mixed, superactive, frigid Typic Haplustepts to Loamy-skeletal, mixed, superactive, frigid Calcic Haplustepts (10/03/2008).
National Cooperative Soil Survey
U.S.A.