LOCATION RUMSEY MTEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Ustic Calcicryepts
TYPICAL PEDON: Rumsey gravelly ashy silt loam, 15 to 35 percent slopes, in woodland (colors are for dry soil unless otherwise noted).
Oi--0 inches to 2 inches; slightly decomposed forest litter.
Oe--2 inches to 3; decomposed forest litter.
Bw1--3 to 11 inches; light brown (7.5YR 6/4) gravelly ashy silt loam, dark brown (7.5YR 4/4) moist; moderate fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine roots; 20 percent gravel; high amount of volcanic ash; moderately acid (ph 5.6); clear wavy boundary. (7 to 14 inches thick)
2Bw2--11 to 19 inches, light yellowish brown (10YR 6/4) very gravelly loam, yellowish brown (10YR 5/4) moist; weak fine granular structure; soft, friable, slightly sticky and slightly plastic; many very fine and fine and few medium and coarse roots; 10 percent cobbles, 45 percent gravel; slightly acid (ph 6.2); clear wavy boundary. (2 to 10 inches thick)
2Bk1--19 to 32 inches; pale brown (10YR 6/3) extremely gravelly sandy loam, brown (10YR 5/3) moist; weak medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; many very fine and fine and common medium roots; 55 percent gravel, 10 percent cobbles; few faint lime casts on all sides of coarse fragments; strongly effervescent; slightly alkaline (ph 7.6); clear wavy boundary. (10 to 15 inches thick)
2Bk2--32 to 41 inches; light yellowish brown (10YR 6/4) extremely gravely loam, yellowish brown (10YR 5/4) moist; weak medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; many very fine and fine and few medium roots; 20 percent cobbles, 50 percent gravel; common distinct lime casts on all sides of coarse fragments; disseminated lime; strongly effervescent; slightly alkaline (ph 7.8); gradual wavy boundary. (9 to 15 inches thick)
2Bk3--41 to 63 inches; light yellowish brown (10YR 6/4) extremely gravelly loam, yellowish brown (10YR 5/4) moist; weak medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; many very fine and fine and few medium roots; 20 percent cobbles, 55 percent gravel; many prominent lime casts on all sides of coarse fragments; disseminated lime; strongly effervescent; slightly alkaline (ph 7.8).
TYPE LOCATION: Granite County, Montana; 1,550 feet west and 1,600 feet south of the NE corner of sec. 12, T. 5 N., R. 14 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 36 to 41 degrees F.
Moisture control section - between 4 and 12 inches.
Depth to the Bk horizon: 9 to 24 inches
Some pedons have an E horizon
Bw1 horizon - Hue: 10YR or 7.5YR
Value: 5 or 6 dry, 3 or 4 moist
Chroma: 4 or 6
Clay content: 18 to 27 percent
Content of rock fragments: 5 to 35 percent--0 to 10 cobbles, 5 to 25 percent gravel
Reaction: pH 5.6 to 7.8
Moist bulk density: .85 to 1.0 gm/cm3
Acid Oxalate extractable Al + 1/2 Fe: greater than 1.0 percent
2Bw2 horizon - Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4
Clay content: 18 to 27 percent
Content of rock fragments: 15 to 60 percent--0 to 15 percent cobbles, 15 to 45 percent gravel
Reaction: pH 6.1 to 7.8
2Bk horizons - Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4
Texture: loam or sandy loam
Clay content: 18 to 27 percent
Content of rock fragments: 35 to 80 percent--10 to 20 percent cobbles, 25 to 60 percent gravel
Calcium carbonate equivalent: 15 to 30 percent
Reaction: pH 7.4 to 8.4
COMPETING SERIES:
Ashworth (MT) - has an albic horizon; does not have a 2Bw horizon.
Buhrig (WA) - has a lithic contact at depths of 20 to 40 inches.
Buttoncreek (WA) - has a xeric moisture regime.
Devore (WA) - has a lithic contact at depths of 20 to 40 inches; has a xeric moisture regime.
Finney (WA) - has a xeric moisture regime; has a lithic contact at 40 to 60 inches.
Gatewall (WA) - has a xeric moisture regime.
Holloway (MT) - does not have a horizon of secondary calcium carbonate accumulation.
Hun (ID) - has a xeric moisture regime; does not have a horizon of secondary calcium carbonate accumulation; has a paralithic contact of weathered granite at depths of 40 to 60 inches.
Moses (WA) - has a paralithic contact of quartz monzonite at depths of 20 to 40 inches.
Otwin (OR) - has a lithic contact at depths of 20 to 40 inches; has a xeric moisture regime.
Petty (MT) - does not have a horizon of secondary calcium carbonate accumulation.
Phillcher (MT) - does not have a horizon of secondary calcium carbonate accumulation.
Prouty (WA) - has a paralithic contact at depths of 20 to 40 inches.
Remmel (WA) - has a xeric moisture regime.
Rubycreek (ID) - does not have horizons of secondary carbonate accumulation.
Surgh (WA) - has a lithic contact of gneiss at depths of 40 to 60 inches; has a xeric moisture regime.
Sweetbutte (WA) - has a lithic contact at 40 to 60 inches; has a xeric moisture regime.
Venson (WA) - has a lithic contact at 20 to 40 inches; has a xeric moisture regime.
Waldbillig (MT) - has a very hard 2E and Bt horizon; does not have a horizon of secondary calcium carbonate accumulation.
GEOGRAPHIC SETTING:
Landform- mountains; glacial moraines.
Elevation - 5,800 to 7,800 feet.
Slope - 8 to 60 percent.
Parent material - volcanic ash over colluvium derived from calcareous argillite, limestone and glacial till.
Climate - long, cold winters; cool, moist springs; short, cool summers.
Mean annual precipitation - 15 to 22 inches.
Mean annual air temperature - 34 to 39 degrees F.
Frost-free period - 30 to 70 days.
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained, moderate permeability.
USE AND VEGETATION: Rumsey soils are primarily used for woodland. The potential native vegetation is mainly lodgepole pine, grouse whortleberry, pine grass, lupine, and dwarf huckleberry.
DISTRIBUTION AND EXTENT: Rumsey soils are of small extent in southwestern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Granite County, Montana, 1997.
REMARKS: Soil interpretation record: MT1498. Diagnostic horizons and features recognized in this pedon are: an ash influenced ochric epipedon from 0 to 8 inches (Bs horizon); a cambic horizon from 8 to 16 inches (2Bw horizon); a particle-size control section from 10 to 40 inches (2Bw, Bk1, Bk2, Bk3 horizons). Rumsey soils have a cryic temperature regime and an ustic moisture regime.
The 3/2008 description reflects a change in classification from Loamy-skeletal, mixed, superactive Andic Eutrocryepts to Loamy-skeletal, mixed, superactive Ustic Calcicryepts due to revision of the cryepts great groups and subgroups. This series would also meet Haplustandic subgroup criteria. The competing series section was not updated and should be reviewed after all the cryepts have been re-classified.