LOCATION KURO MTEstablished Series
TAXONOMIC CLASS: Clayey, mixed, superactive, calcareous, frigid, shallow Typic Ustorthents
TYPICAL PEDON: Kuro clay loam, cultivated (colors are for dry soil unless otherwise noted).
Ap--0 to 7 inches; light reddish brown (5YR 6/3) clay loam, reddish brown (5YR 5/3) moist; weak very fine granular structure; slightly hard, friable, sticky and plastic; few fine roots; slightly effervescent; slightly alkaline (pH 7.4); clear wavy boundary. (3 to 9 inches thick)
C--7 to 15 inches; weak red (10R 4/3) pale yellow (5Y 7/3) clay loam, dusky red (10R 3/3) olive (5Y 5/3) moist; colors in very thin horizontal bands; weak coarse prismatic structure parting to strong thin platy; very hard, firm, sticky and plastic; few fine roots; slightly effervescent; with few fine threads of lime; moderately alkaline (pH 7.9); gradual wavy boundary. (6 to 10 inches thick)
Cr--15 to 60 inches; weak red (10R 4/3) and pale yellow (5Y 7/3) shale, slightly effervescent; strongly alkaline (pH 8.5).
TYPE LOCATION: Glacier County, Montana; 600 feet north and 400 feet west of the SE corner of sec. 18, T. 35 N., R. 10 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 42 to 47 degrees.
Moisture control section - between 4 and 12 inches.
Fragments - 0 to 35 percent shale chips in the control section.
Depth to bedrock - 10 to 20 inches.
Ap horizon - Hue: 10R, 5YR, or 2.5YR
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2, 3, or 4
Texture: clay loam or silty clay loam
Clay content: 30 to 40 percent
Rock fragments: 0 to 15 percent shale fragments
Reaction: pH 6.6 to 7.8
C horizons - Hue: 10R, 5YR, or 2.5YR
Value: 3, 4, 5, or 6 dry; 2, 3, or 4 moist
Chroma: 2, 3, or 4
Texture: clay loam, silty clay loam, or clay
Clay content: 35 to 45 percent
Rock fragments: 0 to 35 percent shale fragments
Reaction: pH 7.4 to 8.4
Cr horizon - this horizon consists of semiconsolidated shale which is extremely hard when dry and extremely firm when moist.
Reaction: pH 7.9 to 9.0
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform - hills and sedimentary plains.
Elevation - 2,500 to 4,600 feet.
Slope- 2 to 45 percent.
Parent material - residuum from semiconsolidated shale or in colluvium over the shale.
Climate - long, cold winters; moist springs; and warm summers.
Precipitation - 12 to 16 inches.
Mean annual air temperature - 40 to 45 degrees F.
Frost-free period - 90 to 135 days.
DRAINAGE AND PERMEABILITY: Well drained; slow permeability.
USE AND VEGETATION: Kuro soils are used mainly for grazing. Potential native vegetation is mainly western wheatgrass, blue grama, prairie junegrass, fringed sagewort, and threadleaf sedge.
DISTRIBUTION AND EXTENT: Kuro soils are inextensive, occurring throughout the unglaciated parts of northern and central Montana east of the Rocky Mountains.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Glacier County (Blackfeet Reservation-Cut Bank Area), Montana, 1969.
REMARKS: Soil interpretations record: MT0448. Diagnostic horizons and features recognized in this pedon are: an ochric epipedon from 0 to 7 inches (Ap horizon); a particle-size control section from 10 to 15 inches (C horizon); a paralithic contact at a depth of 15 inches (Cr horizon). Kuro soils have a frigid temperature regime and an ustic moisture regime.