LOCATION WORTHENTON              WY

Established Series
Rev.PJL-PSD-KLS
01/2023

WORTHENTON SERIES

The Worthenton series consists of very deep, poorly drained soils that formed in alluvium derived from shale and interbedded siltstone. They are on flood plains and depressed positions within meander belts. Slopes are 0 to 3 percent. The mean annual precipitation is about 410 mm, and the mean annual air temperature is about 8 degrees C.

TAXONOMIC CLASS: Fine, smectitic, mesic Typic Argiaquolls

TYPICAL PEDON: Worthenton clay loam-pasture. (Colors are for dry soil unless otherwise stated.)

Oe--0 to 5 cm; partially decomposed root mat.

A--5 to 25 cm; gray (10YR 5/1) clay loam, very dark grayish brown (10YR 3/2) moist; common fine and medium redox concentrations yellowish brown(10YR 5/6); moderate fine and medium angular blocky structure; hard, very friable, sticky and plastic; many very fine and common coarse roots; slightly effervescent; calcium carbonate disseminated; moderately alkaline (pH 8.0); clear smooth boundary. (18 to 28 cm thick)

Btg--25 to 53 cm; gray (5Y 6/1) silty clay loam, dark brown (10YR 3/3) moist; common fine and medium redox concentrations yellowish brown (10YR 5/6); strong medium and coarse angular blocky structure parting to strong fine angular blocky; extremely hard, firm, sticky and plastic; common fine and very fine and few coarse roots; many prominent clay films on faces of peds; slightly effervescent; calcium carbonate disseminated; moderately alkaline (pH 8.2); clear smooth boundary. (15 to 33 cm thick)

Bkg1--53 to 96 cm; greenish gray (5GY 6/1) clay, dark brown (10YR 3/3) moist; many fine and medium redox concentrations yellowish brown (10YR 5/6); strong medium angular blocky structure; extremely hard, firm, sticky and plastic; few very fine roots; strongly effervescent; calcium carbonate as common medium and large soft masses; common fine lignite chips; moderately alkaline (pH 8.2); clear smooth boundary. (23 to 46 cm thick)

Bkg2--96 to 157 cm; light greenish gray (5GY 7/1) clay loam, dark gray (N 4/ ) moist; many medium and large redox concentrations dark yellowish brown(10YR 4/4); massive; hard, friable, sticky and plastic; strongly effervescent; calcium carbonate as common large soft masses; common very fine lignite chips; moderately alkaline (pH 8.4);

TYPE LOCATION: Sheridan County, Wyoming; north end of old oxbow; NE1/4, SW1/4 of sec. 14, T. 51 N., R. 85 W.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--8 to 12 degrees C
Thickness of mollic epipedon--18 to 50 cm
Depth to endosaturation--25 to 100 cm
Depth to base of argillic--33 to 60 cm
Depth to horizon of maximum secondary carbonate accumulation--33 to 60 cm
These soils are flooded for brief durations during May through July.
Lignite chips are common throughout the soil in most horizons.

A horizon
Hue--10YR through 5Y
Value--3 through 5 dry, 2 or 3 moist
Chroma--1 or 2
Redoximorphic features are present in most pedons.
There is typically an organic mat of partially decomposed material on the surface.

Btg horizon
Hue--10YR through 5Y
Value--4 through 6 dry, 3 or 4 moist
Chroma--1 through 3
Texture-- clay, silty clay, or silty clay loam
Clay content--35 to 50 percent

Bkg horizon
Hue--10YR through 5GY
Value--5 through 7 dry, 3 or 4 moist or N 4/ moist
Chroma--0 through 4
Texture--clay, silty clay, clay loam, or silty clay loam
Clay content--30 to 50 percent
Reaction--pH 7.9 to 8.4 in the upper part and ranges up to 9.0 in the lower part
Calcium carbonate equivalent--10 to 20 percent, but typically less than 15 percent
Electrical conductivity--2 to 8 mmhos below 90 cm

COMPETING SERIES: These are the Bremer, Chancellor, Crossplain, Edinburg, Gregory, Haig, Lodgepole, Mazaska, Minnetonka, Taintor, Virden, Winterset, and Worthing series. The Bremer, Chancellor, Crossplain, Gregory, Lodgepole and Mazaska soils have reactions of pH 4.5 through pH 7.8 in the Bt horizon. The Bremer, Edinburg, Gregory, Haig, Lodgepole, Taintor, Virden, and Winterset soils do not have free carbonates above 100 cm. The Minnetonka soils contain more carbonates and formed in lacustrine deposits. The Worthing soils are nonflooded and have mollic epipedons more than 90 cm thick.

GEOGRAPHIC SETTING:
Landform--floodplains and in oxbows
Elevation--1075 to 1375 meters
Slope--0 to 3 percent
Parent material--alluvium derived from shale and interbedded siltstone
Mean annual precipitation--310 to 430 mm, however this soil receives additional water during brief flooding in May, June, and July
Mean annual air temperature--7 to 9 degrees C
Frost-free period--110 to 120 days

GEOGRAPHICALLY ASSOCIATED SOILS: None listed

DRAINAGE AND PERMEABILITY: Poorly drained; slow runoff; slow permeability. Flooding occurs in the spring with brief durations.

USE AND VEGETATION: Wildlife habitat and livestock grazing. Native vegetation is Nebraska sedge, slender wheatgrass, northern reedgrass, and cattails.

DISTRIBUTION AND EXTENT: Worthenton soils are of small extent in northcentral Wyoming; MLRA 58B

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Sheridan County Area, Wyoming; 1987

REMARKS: SIR - WY0708
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon--5 to 25 cm (A horizon)
Argillic horizon--25 to 53 cm (Btg horizon)
Particle-size control section--25 to 53 cm (Btg horizon)

Converted to metric and O horizons were updated to start at zero. Competing series section was not updated. 01/2023

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National Cooperative Soil Survey
U.S.A.