LOCATION BOLTUS WYEstablished Series
TAXONOMIC CLASS: Clayey, smectitic, calcareous, frigid, shallow Typic Torriorthents
TYPICAL PEDON: Boltus silty clay - grassland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 3 inches; gray (5Y 6/1) light silty clay, olive gray (5Y 4/2) moist; strong fine granular structure; soft, very friable, plastic, sticky; crystalline calcium sulfate throughout the horizon; calcareous; moderately alkaline, pH 8.2; clear smooth boundary. (2 to 6 inches thick)
C--3 to 12 inches; gray (5Y 6/1) light silty clay, olive gray (5Y 4/2) moist; moderate very fine subangular blocky structure that parts to moderate coarse granules; slightly hard, very friable, plastic, sticky; visible calcium sulfate occurring as large crystals and in seams and streaks throughout the entire horizon; calcareous; pH 8.4 (Bt); gradual wavy boundary. (2 to 8 inches thick)
IIC--12 to 40 inches; gypsiferous calcareous gray shale.
TYPE LOCATION: Carbon County, Wyoming. The SE 1/4 of the SE 1/4 of sec. 21, T. 19 N., R. 87 W.
RANGE IN CHARACTERISTICS: Unless otherwise noted the entire range of properties permissible for the subgroup and family in which the series has been placed applies to the series as well. Depth to uniformly calcareous material ranges from 0 to 10 inches. Depth to the paralithic contact ranges from 10 to 20 inches. Weighted average gypsum content of the control section ranges from 5 to 35 percent. Exchangeable sodium ranges from 0 to 15 percent and conductivity ranges from 0 to 14 millimhos in the control section. Continuous subhorizons of genetically concentrated visible secondary calcium carbonate and/or sulfate should not occur within the control section although visible calcium sulfate and/or carbonate occurs throughout the control section as a natural feature of the parent materials. Content of coarse fragments ranges from 0 to 35 percent and coarse fragments ranging from 1/2 to 10 inches in diameter predominate. Mottling within the control section not due to segregated lime may range from no mottling to a few fain mottles but if the soil is consistently mottled the base chroma of the matrix material must be more than 2. The control section should be uniform with only minor stratification. Color of the A horizon may range in hue from 5Y to 7.5YR, in value from 5 to 7 dry or 3 to 6 moist, and in chroma from 2 to 4. Reaction normally ranges from mildly alkaline to moderately alkaline (1:5 dilution unbuffered organic dye). Hue of the C horizon ranges from 5Y to 7.5YR. Reaction normally ranges from moderately to strongly alkaline (1:5 dilution unbuffered organic dye). Texture is usually a loam or silt loam ranging to clay loam or silty clay loam averaging 18 to 35 percent clay, 10 to 50 percent silt, and 20 to 50 percent sand.
COMPETING SERIES: There are no series presently in this subgroup and family. Similar and related series include the Chipata and Coaldraw series. The Chipata series differs in lacking the high content of gypsum, in having mixed mineralogy, and in being in a mesic family. The Coaldraw series differs in being coarser textured with less than 35 percent clay.
GEOGRAPHIC SETTING: The Boltus series occurs on gently to steeply sloping upland hills and ridges. Slopes typically range from 2 percent to about 40 or more percent. The soil is developing in thin, calcareous, gypsiferous materials weathered from gypsiferous shales. At the type location the average annual precipitation is 8 inches with peak periods of precipitation occurring in the spring and early summer months. Mean annual air temperature is 42 degrees F., mean summer air temperature is 65 degrees F., mean annual soil temperature is 46 degrees F., and mean summer soil temperature is 64 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: these include the Beamton and Coaldraw series. The Beamton series differs in being in a fine silty family. the coaldraw series differs in being in a loamy family and in having bedrock below 20 inches.
DRAINAGE AND PERMEABILITY: Well to moderately well drained. Runoff is slow to rapid. Permeability is moderate to slow.
USE AND VEGETATION: These soils are used mainly as native pastureland. Native vegetation includes Gardnera saltbush, snakewood, and birdsfoot sage.
DISTRIBUTION AND EXTENT: Present known distribution limited to central Wyoming. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Sage Creek Watershed area, Carbon County, Wyoming. Series name is a coined name.
OSED scanned by NSSQA. Last revised by state on 12/71.