LOCATION RUBICK MT
Established Series
Rev. TJK-EMM-KLS
09/2022
RUBICK SERIES
The Rubick series consists of very deep, somewhat excessively drained soils that formed in colluvium and slope alluvium derived from coarse-grained igneous and metamorphic rocks. These soils are on ridges and sideslopes of mountains. Slopes are 25 to 60 percent. Mean annual precipitation is about 510 mm and mean annual air temperature is about 3 degrees C.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Ustic Haplocryepts
TYPICAL PEDON: Rubick cobbly coarse sandy loam, very stony, forested (colors are for dry soil unless otherwise noted).
Oi--0 to 5 cm; forest litter of partially decomposed needles, twigs and moss roots. (3 to 8 cm thick)
E1--5 to 13 cm; light brownish gray (10YR 6/2) cobbly coarse sandy loam, brown (10YR 4/3) moist; moderate very fine granular structure; slightly hard, very friable, nonsticky and slightly plastic; 10 percent gravel, 10 percent cobbles and 5 percent stones; many very fine, fine, medium and coarse roots; many very fine, fine and medium pores; slightly acid (pH 6.4); abrupt wavy boundary.
E2--13 to 26 cm; light brownish gray (10YR 6/2) very cobbly coarse sandy loam, brown (10YR 5/3) moist; weak fine subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; 15 percent gravel, 20 percent cobbles and 5 percent stones; many very fine, fine and medium and common coarse roots; many very fine, fine and medium pores; neutral (pH 7.0); clear wavy boundary. (Combined thickness of E horizons - 8 to 30 cm).
Bw--26 to 74 cm; pale brown (10YR 6/3) very stony coarse sandy loam, brown (10YR 5/3) moist; moderate fine and medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; 20 percent gravel, 10 percent cobbles and 20 percent stones; many very fine, fine and medium and common coarse roots; many very fine, fine and medium pores; neutral (pH 7.2); gradual wavy boundary (35 to 75 cm thick).
BC--74 to 158 cm; light gray (10YR 7/2) extremely stony loamy coarse sand, pale brown (10YR 6/3) moist, single grain; loose, nonsticky and nonplastic; 25 percent gravel, 15 percent cobbles and 30 percent stones; few fine, medium and coarse roots; many very fine, fine and medium pores; neutral (pH 7.0).
TYPE LOCATION: Jefferson County, Montana; about 730 meters south and 610 meters west of the NE corner of sec. 20, T. 7 N., R. 3 W.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--2 to 6 degrees C
Moisture control section--20 to 60 cm
Surface stones or boulders--0 to 3 percent
A thin A horizon is allowed.
E horizons
Hue--10YR or 2.5Y
Value--5 or 6 dry; 4 or 5 moist
Chroma--2 or 3
Texture--loam, sandy loam or coarse sandy loam
Clay content--8 to 20 percent
Rock fragment content--10 to 50 percent--0 to 25 percent cobbles and stones; 10 to 25 percent gravel
Reaction--pH 5.6 to 7.3
Bw horizon
Hue--10YR or 2.5Y
Value--5 or 6 dry; 4 or 5 moist
Chroma--2 or 3
Texture--loam, coarse sandy loam or sandy loam
Clay content--8 to 18 percent
Rock fragment content--35 to 60 percent--20 to 35 percent cobbles and stones; 15 to 25 percent gravel
Reaction--pH 5.6 to 7.3
BC horizon
Hue--10YR or 2.5Y
Value--6 or 7 dry; 5 or 6 moist
Chroma--2 or 3
Texture--sandy loam, coarse sandy loam, loamy coarse sand or loamy sand
Clay content--5 to 15 percent
Rock fragment content--35 to 70 percent--25 to 45 percent cobbles and stones, 15 to 25 percent gravel
Reaction--pH 5.6 to 7.3
COMPETING SERIES:
Danavore (CO) - 50 to 100 cm to a paralithic contact
Ellena (MT) - 50 to 100 cm to granite bedrock
Elve (MT) - has an E horizon 25 to 65 cm thick; has more than 60 percent coarse fragments in the Bw horizon
Hiore (MT) - has less than 15 percent cobbles and stones throughout the profile; does not have E horizons
Millswitch (CO) - 100 to 150 cm to a paralithic contact
Pergrin (CO) - 50 to 100 cm deep to granite bedrock
Scout (UT) - has a udic moisture regime
Shadow (MT) - has 15 to 40 percent mica in the particle-size control section
Taglake (WY) - formed in glacial till; has less than 25 percent very coarse sand
Vandamore (CO) - 50 to 100 cm to a lithic contact
GEOGRAPHIC SETTING:
Landform--ridges and sideslopes of mountains
Elevation--1675 to 2425 meters
Slope--5 to 60 percent
Parent material--colluvium and slope alluvium derived from coarse-grained igneous rocks
Climate--long, cold winters; cool, moist springs; short cool summers
Mean annual precipitation--380 to 760 mm
Mean annual air temperature--2 to 4 degrees C
Frost-free period--30 to 70 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; moderately rapid permeability
USE AND VEGETATION: Rubick soils are used primarily for timber production, watersheds and wildlife habitat. The potential vegetation is mainly Douglas-fir, lodgepole pine, pinegrass, common juniper, heartleaf arnica, Oregon grape, strawberry, woods pussytoes and elk sedge.
DISTRIBUTION AND EXTENT: Rubick soils is moderately extensive in the mountains of southwestern Montana; MLRA 43B
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Jefferson County, Montana, 1998
REMARKS: Soil interpretation record: MT3033.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon--5 to 26 cm (E1 and E2 horizons)
Cambic horizon--26 to 74 cm (Bw horizon)
Particle-size control--25 to 100 cm (part of the E2, all of the Bw and part of the BC horizon)
Rubick soils have a cryic temperature regime and have an ustic soil moisture regime.
The 3/2008 description reflects a change in classification from Loamy-skeletal, mixed, superactive Ustic Eutrocryepts to Loamy-skeletal, mixed, superactive Ustic Haplocryepts due to revision of the cryepts great groups and subgroups. The competing series section was not updated and should be reviewed after all the cryepts have been re-classified.
Converted to metric, updated formatting, and O horizons were updated to start at zero. Competing series section was not updated. 9/2022
National Cooperative Soil Survey
U.S.A.