LOCATION PERITSA MT+WYEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, frigid Typic Haplustolls
TYPICAL PEDON: Peritsa silt loam - grassland. (Colors are for dry soil unless otherwise noted.)
A--0 to 3 inches; reddish brown (5YR 4/3) silt loam, dark reddish brown (5YR 3/2) moist; moderate medium granular structure; slightly hard, friable, slightly sticky, slightly plastic; few very fine roots; few very fine interstitial pores; neutral; clear smooth boundary. (2 to 5 inches thick)
Bw1--3 to 6 inches; reddish brown (5YR 4/3) silty clay loam, dark reddish brown (5YR 3/3) moist; moderate medium prisms that separate to moderate medium blocky structure; hard, friable, slightly sticky, moderately plastic; many very fine roots; few very fine pores; neutral; clear smooth boundary. (3 to 5 inches thick)
Bw2--6 to 9 inches; reddish brown (2.5YR 5/4) silty clay loam, dark reddish brown (2.5YR 3/4) moist; moderate medium prisms that separate to medium coarse blocky structure; hard, friable, moderately sticky, moderately plastic; many very fine roots; common very fine tubular pores; neutral; clear smooth boundary. (3 to 5 inches thick)
Bw3--9 to 14 inches; red (2.5YR 5/6) silty clay loam, reddish brown (2.5YR 4/4) moist; moderate medium prisms that separate to moderate medium blocky structure; hard, friable, moderately sticky, moderately plastic; many very fine roots; many very fine tubular pores; 2 percent fine unweathered shale chips; strongly calcareous; moderately alkaline; clear wavy boundary. (4 to 8 inches thick)
BCk--14 to 24 inches; light reddish brown (2.5YR 6/4) silty clay loam, reddish brown (2.5YR 4/4) moist; massive; very hard, firm, moderately sticky, moderately plastic; few fine roots; many very fine tubular pores; 2 percent fine shale chips; many fine and medium white lime threads; strongly calcareous; moderately alkaline; gradual boundary. (6 to 15 inches thick)
C1--24 to 31 inches; light red (2.5YR 6/6) silty clay loam, red (2.5YR 4/6) moist; massive; very hard, firm, moderately sticky, moderately plastic; few very fine roots and many very fine tubular pores; few fine white lime threads; strongly calcareous; moderately alkaline; gradual boundary. (5 to 10 inches thick)
C2--31 to 38 inches; light red (2.5YR 6/6) partially weathered shale; strongly calcareous; moderately alkaline; diffuse boundary.
Cr--38 to 68 inches; soft, red, calcareous, platy shale.
TYPE LOCATION: Big Horn County, Montana; 275 feet north of trail and 320 feet southeast from center of sec. 34, T.6S., R.28E.
RANGE IN CHARACTERISTICS: Depth to a paralithic contact ranges from 20 to 40 inches. Thickness of solum is 12 to 20 inches and depth to calcareous soil is 6 to 14 inches. The 10- to 40-inch control section is silty clay loam or heavy silt loam, with 25 to 35 percent clay and 5 to 15 percent fine and coarser sand. Mean annual soil temperature ranges from 40 to 46 degrees F. and average summer soil temperature ranges from 59 to 63 degrees F. Hue of the entire soil is 5YR through 10R.
The A horizon has value of 4 or 5 dry and 2 or 3 moist and chroma of 2 or 3.
The Bw horizon has value of 5 or 6 dry and 4 or 5 moist and chroma of 2 through 6.
The BCk horizon has about 8 to 14 percent CaC03 equivalent.
COMPETING SERIES: These are the Amsterdam, Bryant, Golva, Omio, Sen, and Temvik series. Amsterdam, Bryant, Golva, and Sen soils have hues yellower than 7.5YR and lack a paralithic contact within depths of 40 inches. In addition, the Amsterdam soils have average summer temperature ranging from 44 to 46 degrees F. Omio and Temvik soils have hue of 10YR or yellower.
GEOGRAPHIC SETTING: The Peritsa soils are on smooth strongly sloping to steep mid slopes of the grass covered uplands at elevations of 4,000 to 5,000 feet. The soils formed in residuum from red calcareous silty shales of the Chugwater formation. The climate is cool dry-subhumid with a mean annual temperature of less than 47 degrees F. The annual rainfall is from 15 to 19 inches. The growing season ranges from 90 to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Abac and Harvey soils and the competing Rottulee soils. Abac soils have no B horizon. Harvey soils have a white calcic horizon.
DRAINAGE AND PERMEABILITY: Well-drained; medium runoff; moderate permeability.
USE AND VEGETATION: Rangeland. Native vegetation is bluegrass, silver sage, western wheatgrass, broom snakeweed and fringed sagewort.
DISTRIBUTION AND EXTENT: South-central Montana. The Peritsa series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Big Horn County (Big Horn Area), Montana, 1970.