LOCATION CREED MTEstablished Series
TAXONOMIC CLASS: Fine, smectitic, frigid Aridic Natrustalfs
TYPICAL PEDON: Creed loam in grassland (colors are for dry soil unless otherwise noted).
A--0 to 5 inches; light brownish gray (10YR 6/2) loam, dark grayish brown (10YR 4/2) moist; weak thin platy structure parting to weak fine and very fine granular; slightly hard, very friable, slightly sticky and nonplastic; many fine roots; common fine pores; common unstained sand grains; slightly alkaline (pH 7.4); clear smooth boundary.
E--5 to 6 inches; light gray (10YR 7/2) loam, grayish brown (10YR 5/2) moist; weak thin platy structure parting to weak fine and very fine granular; slightly hard, very friable, slightly sticky and nonplastic; many fine roots; common fine pores; many unstained silt and sand grains; slightly alkaline (pH 7.4); abrupt wavy boundary. (The combined A and E horizons 4 to 10 inches thick)
Btn1--6 to 8 inches; grayish brown (2.5Y 5/2) silty clay, dark grayish brown (2.5Y 4/2) moist; strong fine and medium columnar structure parting to strong medium and fine angular blocky; very hard, firm, very sticky and plastic; common fine roots along prism faces; common very fine pores; common distinct clay films on faces of peds; light gray (10YR 7/2) skeletans on tops of columns, and common unstained sand and silt grains on vertical faces of peds; slightly alkaline (pH 7.6); clear wavy boundary.
Btn2--8 to 12 inches; grayish brown (2.5Y 5/2) silty clay loam, dark grayish brown (2.5Y 4/2) moist; moderate medium prismatic structure parting to strong medium and fine angular blocky; very hard, firm, very sticky and plastic; common fine roots; common very fine pores; continuous distinct clay films on faces of peds; moderately alkaline (pH 8.4); clear wavy boundary. (Combined thickness of the Btn horizons is 6 to 14 inches.)
Btnk--12 to 16 inches; light brownish gray (2.5Y 6/2) silty clay loam, dark grayish brown (2.5Y 4/2) moist; moderate medium prismatic structure parting to moderate medium subangular blocky; very hard, firm, sticky and plastic; common fine and very fine roots; common fine and very fine pores; common faint clay films on vertical faces of peds; common fine masses of lime; strongly effervescent; moderately alkaline (pH 8.4); gradual wavy boundary. (0 to 8 inches thick)
Bky--16 to 28 inches; light brownish gray (2.5Y 6/2) silty clay loam, dark grayish brown (2.5Y 4/2) moist; weak medium prismatic structure parting to weak medium subangular blocky; hard, firm, sticky and plastic; few to common fine and very fine roots; common fine and very fine pores; few to common fine seams of gypsum; common medium masses of lime; violently effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (10 to 15 inches thick)
Byz--28 to 60 inches; light brownish gray and light yellowish brown (2.5Y 6/2) silty clay loam stratified with lenses of loam, dark grayish brown (2.5Y 4/2) moist; hard, friable, sticky and slightly plastic; few to common fine seams of gypsum and other salts; disseminated lime; strongly effervescent; moderately alkaline (pH 8.4). (0 to 35 inches thick)
TYPE LOCATION: Blaine County, Montana; 1,500 feet west and 2,630 feet south of NE corner of sec. 12, T. 35 N., R. 20 E.
RANGE IN CHARACTERISTICS:
Soil temperature - 42 to 47 degrees F.
Moisture control section - between 4 and 12 inches; dry in all parts between four-tenths and five-tenths of the cumulative days per year when the soil temperature at 20 inches is 41 degrees F or above.
Depth to secondary lime - 10 to 20 inches.
Depth to gypsum and other salts - 16 to 30 inches.
Soil phase - sandy substratum; it is a loamy sand below a depth of 40 inches and has 2 to 8 percent clay.
A horizon - Hue: 10YR, 2.5Y, or 5Y
Value: 5 or 6 dry; 3, 4 or 5 moist
Chroma: 2 or 3
Texture: sandy clay loam, silt loam, loam, clay loam, silty clay loam
Clay content: 10 to 35 percent
Rock fragments: 0 to 15 percent pebbles
Reaction: pH 6.1 to 8.4
E horizon - Hue: 10YR, 2.5Y, or 5Y
Value: 5, 6, or 7 dry; 4, 5, 6, or 7 moist
Chroma: 2 or 3
Texture: loam, sandy loam, sandy clay loam, clay loam, silt loam, silty clay loam
Clay content: 10 to 35 percent
Rock fragments: 0 to 15 percent pebbles
Reaction: pH 6.1 to 8.4
Btn horizons - Hue: 10YR, 2.5Y, or 5Y
Value: 4, 5, or 6 dry; 3, 4, or 5 moist
Chroma: 2 or 3
Texture: clay loam, silty clay loam, clay, silty clay
Clay contents: 35 to 55 percent
Rock fragments: 0 to 15 percent pebbles
Electrical conductivity: 2 to 4 mmhos/cm; sandy substratum phase 0 to 2 mmhos/cm
SAR: 8 to 20
Reaction: pH 6.6 to 9.0
Bkn, Bkny, Bknyz, Bky, or Btnk horizons - Hue: 10YR, 2.5Y, or 5Y
Value: 4, 5, 6, or 7 dry; 3, 4, 5, or 6 moist
Chroma: 2, 3, or 4
Texture: silty clay loam, clay loam, sandy clay loam, loam, silty clay or clay
Rock fragments: 0 to 15 percent pebbles
Clay content: 25 to 45 percent
Calcium carbonate equivalent: 5 to 15 percent
Electrical conductivity: 4 to 8 mmhos/cm
SAR: 13 to 20
Gypsum: 0 to 2 percent
Reaction: pH 7.9 to 9.0
Byz, BCy horizons - Hue: 10YR, 2.5Y, or 5Y
Value: 5, 6 or 7 dry; 4, 5 or 6 moist
Chroma: 2, 3, or 4
Texture: loam, clay loam, sandy clay loam, which are thinly stratified or stratified with thin layers of coarser material; and silty clay loam
Clay content: 25 to 35 percent
Rock fragments: 0 to 15 percent pebbles
Calcium carbonate equivalent: 5 to 10 percent
Electrical conductivity: 4 to 16 mmhos/cm
SAR: 13 to 25
Gypsum: 1 to 5 percent
Reaction: pH 7.9 to 9.0
COMPETING SERIES:
Elloam (MT) - formed in till that has a bulk density of 1.55 or greater above a depth of 40 inches.
Gerdrum (MT) - has A and E horizons which have a combined thickness of 4 inches or less and have slowly permeable Bt horizons.
Hydro (MT) - has an EB horizon at least 4 inches thick.
Oburn (MT) - is loamy-skeletal above a depth of 40 inches.
Talag (MT) - has a B/E horizon at least 4 inches thick.
Thoeny (MT) - formed in till that has a bulk density of 1.55 or greater above a depth of 40 inches.
Waltham (MT) - formed in till that has a bulk density of 1.55 or greater above a depth of 40 inches.
Weingart (MT) - has a paralithic contact of semiconsolidated shale at depths of 20 to 40 inches.
GEOGRAPHIC SETTING:
Landform - alluvial fans; drainageways; stream terraces; sedimentary plains.
Elevation - 2,000 to 5,200 feet.
Slope- 0 to 15 percent.
Parent material - alluvium or glaciofluvial deposits from mixed rock sources.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 10 to 14 inches, most of which falls during the spring and early summer.
Mean annual temperature - 40 to 45 degrees F.
Frost-free period - 95 to 135 days.
DRAINAGE AND PERMEABILITY: Well drained; slow permeability.
USE AND VEGETATION: Creed soils are used for rangeland, dryland crops, and to a lesser degree irrigated cropland. The potential native vegetation is mainly western wheatgrass, green needlegrass, winterfat, forbs, and shrubs.
DISTRIBUTION AND EXTENT: Central and eastern Montana, and possibly in adjacent states. Creed soils are moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Blaine County, Montana, 1976.
REMARKS: Soil interpretation records: MT0296, MT0765.
Diagnostic horizons and features recognized in this pedon are: ochric epipedon - from the soil surface to 6 inches (A, E horizons); albic horizon - from 5 to 6 inches (E horizon); natric horizon - from 6 to 12 inches (Btn1 and Btn2, Btnk horizons). Creed soils have a frigid temperature regime and an ustic moisture regime bordering on aridic.