LOCATION WETA SDEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Leptic Natrustolls
TYPICAL PEDON: Weta loam - on a slightly concave slope of 1 percent in native grass. When described the soil was dry throughout. (Colors are for dry soil unless otherwise stated.)
E--0 to 2 inches; light brownish gray (10YR 6/2) silt loam, very dark grayish brown (10YR 3/2) moist; weak thin platy structure parting to weak very fine and fine granular; soft, friable; many fine and medium roots; moderately acid; abrupt smooth boundary. (0 to 4 inches)
Btn1--2 to 5 inches; dark gray (10YR 4/1) silty clay, very dark grayish brown (10YR 3/1) moist; strong fine and medium columnar structure parting to moderate fine and medium subangular blocky; extremely hard, very firm, sticky and plastic; light brownish gray (10YR 6/2) coatings on tops of columns; many fine flat roots; neutral; clear wavy boundary.
Btn2--5 to 11 inches; dark gray (10YR 5/1) silty clay, very dark gray (10YR 3/1) moist; weak medium prismatic structure parting to moderate fine and medium subangular blocky; very hard, very firm, sticky and plastic; many fine flat roots; strong effervescence; slightly alkaline; clear wavy boundary. (Combined thickness of Btn horizon is 7 to 16 inches.)
Bkz1--11 to 20 inches; light gray (10YR 6/1) and light brownish gray (10YR 6/2) silty clay loam, dark brown (10YR 3/3) moist; dark grayish brown (10YR 4/2) crushed; weak fine and medium subangular blocky structure; hard, friable, sticky and plastic; few fine flat roots; common fine accumulations of salts; common fine accumulations of carbonate; strong effervescence; slightly alkaline; clear wavy boundary.
Bkz2--20 to 30 inches; light gray (10YR 7/2) silty clay loam; light brownish gray (10YR 5/3) moist; weak fine and medium subangular blocky stucture; hard, friable; common fine accumulations of salts; common fine accumulations of carbonate; strong effervescence; moderately alkaline; clear wavy boundary. (Combined thickness of the Bk horizons is 8 to 25 inches.)
C1--30 to 55 inches; light gray (10YR 7/2) silty clay loam, light brownish gray (10YR 5/3) moist; massive; weak bedding planes evident; hard, friable, strong effervescence; moderately alkaline; gradual wavy boundary.
C2--55 to 60 inches; light gray (10YR 7/2) silt loam, brown (10YR 5/3) moist; massive; weak bedding planes evident; slightly hard, friable; fine stratification evident; strong effervescence; moderately alkaline.
TYPE LOCATION: Jackson County, South Dakota; about 3 miles west and 1.5 miles north of Cactus Flat; 1,875 feet north and 900 feet west of the southeast corner of sec. 21, T. 2 S., R. 18 E.
RANGE IN CHARACTERISTICS: The depth to carbonates ranges from 0 to 12 inches. The thickness of the mollic epipedon ranges from 7 to 19 inches.
The E horizon has hue of 10YR, value of 4 to 6 and 3 to 5 moist, and chroma of 1 or 2. It is loam, very fine sandy loam, or silt loam. It ranges from strongly acid to slightly alkaline.
The Btn horizon has hue of 10YR or 2.5Y, value of 4 to 6 and 2 to 5 moist, and chroma of 1 to 3. It is clay, clay loam, or silty clay that averages between 35 and 55 percent clay with less than 15 percent fine sand or coarser. It ranges from neutral to moderately alkaline in the upper part and slightly to moderately alkaline in the lower part. The SAR ranges from 10 to 15 in the upper 10 inches and is 13 to 25 in some portion of the lower part of the Bt horizon.
The Bkz horizon has hue of 7.5YR, 10YR or 2.5Y; value of 5 to 8 and 4 to 6 moist; and value of 1 to 4. It is silty clay loam or clay is slightly alkaline or moderately alkaline. It has common to many accumulation of salts and carbonates.
The C horizons have hue of 7.5YR, 10YR, or 2.5Y; value of 5 to 8 and 4 to 6 moist; and chroma of 1 to 4. The C horizon typically is silty clay loam or silt loam stratified with layers of very fine sandy loam to clay. Bedding stratification is evident in most pedons. It ranges from slightly to strongly alkaline. Mudstone or siltstone are below a depth of 40 inches in some pedons.
COMPETING SERIES: These are the Gayville and Jerauld series. Gayville and Jerauld soils receive more rainfall. In addition, Jerauld soils have more than 15 percent fine sand and coarser in the Btn horizon.
GEOGRAPHIC SETTING: Weta soils are nearly level to moderately sloping on foot slopes, terraces, uplands, and alluvial fans. Surfaces are smooth or slightly concave and slope gradients range from 0 to 9 percent. Weta soils formed in clayey and silty sediments weathered from sodium enriched sedimentary rocks. Mean annual temperature ranges from 45 to 48 degrees F, and the mean annual precipitation ranges from 12 to 16 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the Absted, Cactusflat, Cedarpass, and Nunn soils. Absted soils are on similar landscapes and do not have a mollic epipedon. Cactusflat soils do not have a natric horizon and are on similar landscapes. Cedarpass soils contain less clay and are higher on the landscape than the Weta soils. Nunn soils do not have a natric horizon and contain more sand throughout than the Weta soils. They are slightly higher on the landscape.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is low or medium. Permeability is slow or very slow in the upper part of the subsoil and moderate or moderately slow in the lower part of the subsoil and in underlying material.
USE AND VEGETATION: Primarily as rangeland. Native vegetation is mainly buffalograss, western wheatgrass, blue grama, needlegrass, and cactus.
DISTRIBUTION AND EXTENT: Southwestern South Dakota. It is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Jackson County, South Dakota, 1981.
ADDITIONAL DATA: NSSL Lab data No. 82P825 is for the typical pedon. Other data: NSSL Lab data No. 82P834.
REMARKS: Diagnostic horizons and features recognized in this pedon are: Mollic epipedon - the zone from the surface of the soil to a depth of about 11 inches (E, Btn1, and Btn2 horizons); argillic (Natric) horizon - the zone from about 2 to 11 inches (Btn1 and Btn2 horizons).