LOCATION BAUX               WY+MT
Established Series


The Baux series consists of a thin soil mantle over fractured and displaced porcelanite. These soils are considered very deep and excessively drained. Baux soils formed in residuum and colluvium derived from weathered porcelanite and are on hillslopes, ridges, and escarpments. Slopes are both simple and complex and range from 3 percent on summits, to 100 percent on escarpments and ridges. The mean annual precipitation is about 16 inches, and the mean annual temperature is about 46 degrees F.

TAXONOMIC CLASS: Loamy-skeletal over fragmental, mixed, superactive, mesic Aridic Haplustolls

TYPICAL PEDON: Baux loam-rangeland. (Colors are for dry soil unless otherwise stated.)

A1--0 to 1 inch; reddish gray (5YR 5/2) loam, dark reddish brown (5YR 3/2) moist; weak very fine granular structure; soft, friable, slightly sticky and slightly plastic; common fine and very fine roots; mildly alkaline (pH 7.8); clear smooth boundary. (0 to 3 inches thick)

A2--1 to 12 inches; reddish gray (5YR 5/2) very channery loam, dark reddish brown (5YR 3/2) moist; weak very fine granular structure; soft, friable, slightly sticky and slightly plastic; common very fine and few fine roots; 50 percent fine and medium channers; mildly alkaline (pH 7.4); gradual smooth boundary. (5 to 17 inches thick)

2C--12 to 60 inches; fractured and displaced porcelanite with interstices larger than 3 mm. The rock fragments are angular and have thin, discontinuous crusts of carbonates on the undersides. Channers make up about 75 percent and angular cobble about 20 percent of this horizon. There are about 3 percent angular stones and a few boulder size clinkers present.

TYPE LOCATION: Sheridan County, Wyoming; about 75 feet east of road and 300 yards north of dam in SE1/4, NE1/4, sec. 33, T. 54 N., R. 82 W.

RANGE IN CHARACTERISTICS: The depth to fragmental substratum ranges from 12 to 20 inches. The mollic epipedon typically rests directly on the contrasting substrata but may range from 5 to 18 inches thick. These soils are typically noncalcareous throughout the loamy-skeletal part of the control section but some porcelanite chips may be calcareous. The mean annual soil temperature ranges from 47 to 54 degrees F. The strongly contrasting particle size control section consists of very channery or extremely channery loam and silt loam over fragmented porcelanite. The loamy-skeletal material has a matrix of loam or silt loam with 18 to 35 percent clay and more than 15 percent fine or coarser sand. Rock fragments range from 40 to 70 percent fine and medium channers and from 0 to 5 percent angular flagstones. The fragmental material contains interstices ranging from 2 mm. to over 2 cm.
in diameter. These are devoid of any fine earth material. Rock fragments range from 60 to 80 percent coarse channers, 15 to 35 percent angular cobbles and stone size porcelanite fragments. Coarse sand ranges from 0 to 5 percent.

The A horizon has hue of 7.5YR through 2.5YR, value of 4 or 5 dry, 2 or 3 moist, and chroma of 2 or 3. The upper few inches are typically free of coarse fragments, but the remainder of this horizon is skeletal as defined in the preceding paragraph. Reaction is neutral or mildly alkaline. A thin C horizon is present in some pedons immediately above the fragmental material where the soil exceeds 15 inches in thickness.

The 2C horizon consists of red, yellowish red, and brown fractured, displaced porcelanite. Only a few interstices in the upper few inches are partially filled with fine earth material; the rest are void. Carbonates in the form of thin crusts are present in about half the pedons but are discontinuous and even occur in pockets deep within the fragmental material.

COMPETING SERIES: There are no competing series in this family.

GEOGRAPHIC SETTING: Baux soils are on hillslopes, summits, ridges, and escarpments. These soils are complex with the upper part formed in residuum and colluvium derived from the underlying porcelanite which must be considered the lower part of the soil. The porcelanite beds are from 10 to over 100 feet thick. Slopes range from 3 to 100 percent. Elevations range from 3,900 to 5,200 feet. The mean annual precipitation ranges from 12 to 17 inches. The mean annual temperature ranges from 45 to 51 degrees F. The frost-free season is estimated to range from 100 to 130 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bauxson, Harlan, Kirtley, Shingle, and Spearman soils. The Bauxson, Harlan, and Kirtley soils have argillic horizons. The Bauxson soils occur intermixed on lower slopes with the Baux soils. Harlan and Kirtley soils occur on contiguous beds of unburned shale. The Shingle soils have ochric epipedons and occur over unburned shale. The Spearman soils are similar but have the fragmental substrata at 20 to 40 inches.

DRAINAGE AND PERMEABILITY: Excessively drained; slow to rapid runoff; moderate permeability in upper part, very rapid permeability in the fragmental substratum.

USE AND VEGETATION: Rangeland and wildlife habitat. Native vegetation consists of western wheatgrass, green needlegrass, Idaho fescue, bluebunch wheatgrass, and skunk brush.

DISTRIBUTION AND EXTENT: Northeastern and north central Wyoming. The series is of large extent.


SERIES ESTABLISHED: Sheridan County, Wyoming; 1987.

REMARKS: Diagnostic horizons and features recognized in thi pedon are:

Mollic epipedon - 0 to 12 inches (A1,A2)

Lithologic discontinuity - 12 to 60 inches (2C)

SIR- WY0625

National Cooperative Soil Survey