LOCATION RAPELJE MTEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, frigid Aridic Glossic Natrustalfs
TYPICAL PEDON: Rapelje silt loam, native grass cover (colors are for dry soil unless otherwise noted).
A2--0 to 5 inches; light brownish gray (10YR 6/2), top of plates, grayish brown (10YR 5/2) on bottom of plates, silt loam; very dark grayish brown (10YR 3/2) moist; many clean silt grains; weak fine platy structure; soft, friable, slightly sticky; abundant fine roots; noncalcareous, (pH 6.5); clear boundary. (3 to 7 inches thick)
A/B--5 to 8 inches; light brownish gray (10YR 6/2) top and vertical faces of peds, dark grayish brown (10YR 4/2) of ped interior, silty clay loam, dark brown (10YR 3/3, crushed 4/2) moist; many clean silt grains on tops and vertical faces of peds; weak prismatic parting to moderate fine blocky structure; hard friable, sticky and plastic; patchy distinct clay film on peds; abundant fine roots; noncalcareous, (pH 6.5); clear smooth boundary. (2 to 6 inches thick)
B2t--8 to 18 inches; dark grayish brown (10YR 4/2) silty clay loam, very dark grayish brown (10YR 3/2), crushed 4/2) moist; moderate medium and coarse prismatic parting to strong medium blocky structure; hard, friable, sticky and plastic; prominent clay film on peds, few gypsum crystals in lower portion of horizon; common fine roots between peds; noncalcareous, (pH 7.0); clear boundary. (4 to 16 inches thick)
B3cs--18 to 26 inches; mixed pale brown (10YR 6/3) and brown (10YR 5/3) silty clay loam, dark brown (10YR 4/3) moist and crushed; moderate fine blocky structure; hard, friable, sticky and plastic; prominent clay films on peds; few to common seams of gypsum; few fine roots; strongly calcareous; (pH 8.0); gradual smooth boundary. (5 to 12 inches thick)
C1ca--26 to 43 inches; light gray (10YR 7/2) silt loam, grayish brown (10YR 5/2) moist; massive; hard, friable, slightly sticky and nonplastic; few seams and threads of lime, very few fine roots; strongly calcareous; (pH 8.0); gradual smooth boundary. (10 to 20 inches thick)
IIC2--43 to 60 inches; light gray (10YR 7/2) fine sandy loam, brown (10YR 5/3) moist; single grain; soft, very friable, no roots; strongly calcareous; (pH 8.0).
TYPE LOCATION: Powder River County, Montana; 600 feet west and 600 feet north of the SE corner of sec. 23, T. 6 S., R. 46 E.
RANGE IN CHARACTERISTICS:
Soil temperature -
Moisture control section -
Mollic epipedon thickness -
Control section -
Rock fragments -
Depth to bedrock -
Depth to calcic horizon -
Soil phases -
NOTES-
A2 horizon - Hue: 10YR to 5Y
Value: 6 to 7 dry; 3, 4, or 5 moist
Chroma: 2 or 3
Texture, less than 2 mm:
Clay content:
Rock fragments:
Reaction: pH
NOTES:
A/B horizon - Hue: 10YR to 5Y
Value:
Chroma:
Texture, less than 2 mm:
Clay content:
Rock fragments:
Reaction: pH
NOTES:
B2t horizon - Hue: 10YR to 5Y
Value: 4, 5, or 6 dry; 3 to 4 moist
Chroma: 2
Texture, less than 2 mm:
Clay content: 25 to 35 percent
Rock fragments:
Reaction:
NOTES:
Bcs horizon - Hue: 10YR to 5Y
Value:
Chroma:
Texture, less than 2 mm:
Clay content:
Rock fragments:
Reaction: pH
NOTES:
C1ca horizon - Hue: 10YR to 5Y
Value:
Chroma:
Texture, less than 2 mm: silt loam
Clay content: 15 to 27 percent clay
Rock fragments:
Calcium carbonate equivalent: 5 to 10 percent
Reaction: pH
NOTES:
IIC2 horizon - Hue: 10YR to 5Y
Value:
Chroma:
Texture, less than 2 mm: silt loam
Clay content: 15 to 27 percent
Rock fragments:
Calcium carbonate equivalent: 5 to 10 percent
Reaction: pH
NOTES:
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: The Rapelje soils are on nearly level to sloping upland plains in southeastern Montana. Elevations are 3,000 to 4,000 feet. Slopes are 1 to 15 percent. These soils formed in weathered calcareous siltstone or locally transported silt loam materials. The climate is characterized by warm dry summers and cold winters. Mean annual precipitation is 10 to 16 inches. Mean annual air temperature is 40 to 45 degrees F. The frost-free period is 110 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS:
DRAINAGE AND PERMEABILITY: Well drained; moderately slow permeability.
USE AND VEGETATION: Rapelje soils are used mainly for native range and for production of small grains. Potential native vegetation is mainly green needlegrass, needleandthread, western wheatgrass, upland sedges, and sagebrush.
DISTRIBUTION AND EXTENT: Rapelje soils are moderately extensive in southeastern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Powder River Area Soil Survey, Montana, 1966.
REMARKS: Soil Interpretation Records: MT0445. The Rapelje series was formerly classified with Solodized-Solonetz soils group. The series will be put in the Glossic Aridic subgroup when it is approved.