LOCATION EPSIE MT+SDEstablished Series
TAXONOMIC CLASS: Clayey, smectitic, calcareous, mesic, shallow Aridic Ustorthents
TYPICAL PEDON: Epsie clay, in grassland (colors are for dry soil unless otherwise noted).
E--0 to 2 inches; light gray (5Y 7/1 and 6/1) clay, light gray (5Y 6/1) moist; weak very fine platy structure parting to strong very fine granular with a thin vesicular surface crust that has a thickness range of 1/4 to 1 inch; very hard, firm, sticky and plastic; common fine roots; strongly acid (pH 5.4); clear smooth boundary. (1 to 4 inches thick)
Bky--2 to 18 inches; light brownish gray (2.5Y 6/2) clay; grayish brown (2.5Y 5/2) moist; moderate medium and coarse subangular blocky structure; extremely hard, very firm, sticky and very plastic; common fine roots; few pores; common medium seams and rounded soft nodules of lime and gypsum below 6 inches with few fine and medium seams and soft masses of gypsum above 6 inches; strongly effervescent; moderately alkaline (pH 8.0); abrupt boundary. (6 to 18 inches thick)
Cr--18 to 60 inches; light brownish gray (2.5Y 6/2), olive brown (2.5Y 4/4) semiconsolidated shale that crushes to clay; few fine roots and gypsum crystals in cracks and between plates in the upper few inches; noncalcareous; neutral (pH 7.2).
TYPE LOCATION: Powder River County, Montana; 1,200 feet west and 100 feet south of NE corner of sec. 12, T. 3 S., R. 50 E.
RANGE IN CHARACTERISTICS:
Soil temperature - 47 to 52 degrees F.
Moisture control section - approximately between the depths of 4 and 12 inches.
Control section - 50 to 60 percent clay
Depth to bedrock - 12 to 20 inches.
Depth to Bky horizon - 1 to 4 inches.
E horizon - Hue: 5Y, 2.5Y
Value: 6 or 7 dry; 5 or 6 moist
Chroma: 1 or 2
Texture, less than 2 mm: clay
Clay content: 40 to 50 percent
EC: 4 to 8 mmhos/cm
Reaction: pH 5.1 to 7.8
Bky horizon - Hue: 5Y, 2.5Y, 10YR
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 1 or 2
Texture, less than 2 mm: clay
Clay content: 50 to 60 percent
EC: greater than 16 mmhos/cm
Reaction: pH 6.1 to 9.0
Some horizons lack lime in the profile.
Cr horizon - Hue: 5Y, 2.5Y, 10YR
Value: 4, 5, or 6 dry; 4 or 5 moist
Chroma: 1 or 2
Texture, less than 2 mm: weakly consolidated shale that textures to clay
Clay content: 50 to 60 percent
Reaction: pH 6.1 to 9.0
Shale is massive or thick and very thin plates.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform - hills, sedimentary plains.
Elevation - 2,300 to 3,600 feet.
Slope- 3 to 45 percent.
Parent material - residuum derived from semiconsolidated shale.
Climate - long, cold winters; moist springs; and hot, dry summers.
Mean annual precipitation - 10 to 16 inches.
Mean annual temperature - is 45 to 52 degrees F.
Frost-free period - 105 to 150 days.
DRAINAGE AND PERMEABILITY: Well drained; very slow permeability.
USE AND VEGETATION: Epsie soils are used mainly as rangeland. Potential native vegetation is mainly western wheatgrass, green needlegrass, thickspike wheatgrass, Nuttall saltbush, greasewood, and sagebrush.
DISTRIBUTION AND EXTENT: Epsie soils are of moderate extent in southeastern Montana and western South Dakota.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Butte County, South Dakota, 1970.
REMARKS: Soil Interpretation Record: MT0443. Diagnostic horizons and features recognized in this pedon are: a paralithic contact at a depth of 18 inches; a particle-size control section from 10 inches to the paralithic contact (Bky horizon). Epsie soils have a mesic temperature regime and an ustic moisture regime bordering on aridic.
Classification changed from Ustic Torriorthents to Aridic Ustorthents in 1995.