LOCATION YAWDIM ND+MT SDEstablished Series
TAXONOMIC CLASS: Clayey, smectitic, calcareous, frigid, shallow Aridic Ustorthents
TYPICAL PEDON: Yawdim silty clay - on a convex 3 percent northeast-facing slope in native grassland. (Colors are for dry soil unless otherwise stated. When described, the soil was moist to 25 inches and dry below 25 inches.)
A--0 to 3 inches; gray (N 5/) silty clay, dark grayish brown (2.5Y 4/2) moist; weak fine subangular blocky structure parting to moderate fine granular; very hard, friable, sticky and plastic; many roots; slightly alkaline; clear smooth boundary. (1 to 6 inches thick)
C1--3 to 9 inches; light brownish gray (2.5Y 6/2) silty clay, dark grayish brown (2.5Y 4/2) moist; few fine distinct light olive brown (2.5Y 5/4) moist mottles; weak coarse prismatic structure parting to moderate medium and fine subangular blocky; very hard, firm, sticky and plastic; common fine roots; common pores; slight effervescence; moderately alkaline; clear wavy boundary.
C2--9 to 15 inches; light gray (5Y 7/1) silty clay, gray (5Y 5/1) moist; weak medium angular blocky structure parting to weak fine platy; very hard, firm, sticky and plastic; few roots; few pores; few masses of carbonates; slight effervescence; moderately alkaline; clear wavy boundary. (Combined C horizons 9 to 14 inches thick)
Cr1--15 to 22 inches; light gray (5Y 7/2) partly weathered soft platy shale which crushes to silty clay; few roots between plates; slight effervescence; many gypsum crystals; few masses of carbonates; gradual boundary.
Cr2--22 to 60 inches; pale yellow (5Y 7/3) and light gray (5Y 7/1) platy shale; yellowish brown (10YR 5/4) and black (10YR 2/1) stains on faces of plates; slight effervescence.
TYPE LOCATION: Bowman County, North Dakota; about 14 miles south of Rhame; 910 feet south and 375 feet west of the northeast corner, sec. 34, T. 130 N., R. 104 W.
RANGE IN CHARACTERISTICS: Depth to shale or siltstone ranges from 10 to 20 inches. Depth to carbonates ranges from 0 to 6 inches. The soil throughout is silty clay loam, clay loam, silty clay or clay averaging between 35 and 50 percent clay.
The A horizon has hue of 10YR, 2.5Y or is neutral, value of 5 or 6 and 3 or 4 moist, and chroma of 2 or less. It is neutral or slightly alkaline.
The C horizon has hue of 10YR, 2.5Y or 5Y, value of 5 to 8 and 4 to 6 moist, and chroma of 1 to 4. It is slightly alkaline or moderately alkaline.
The Cr horizon is soft calcareous siltstone or shale.
COMPETING SERIES: These are the Lisam series in the same family and the Cabbart and Dilts series. Lisam soils have more than 50 percent clay. Cabbart soils are loamy. Dilts soils are strongly or very strongly acid throughout.
GEOGRAPHIC SETTING: Yawdim soils are on nearly level to very steep sedimentary upland hills and ridges. Slopes range from 2 to 70 percent. The soil formed in alluvium or colluvium over residuum or weathered from calcareous siltstone or shale. The mean annual precipitation is 10 to 16 inches, most of which falls during spring and summer. The mean annual air temperature is 40 to 47 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Cabbart and Lisam series and the Absher, Boxwell, Fleak, Marmarth, Rentsac, Rhame and Rhoades series. Cabbart and Lisam soils are on nearby sedimentary uplands. Absher and Rhoades soils are on nearby uplands and terraces and have natric horizons. Boxwell and Rhame soils are on nearby uplands and have mollic epipedons. Fleak soils have formed in sandstone and are sandy. Marmarth soils are on nearby uplands and have argillic horizons. Rentsac soils are on nearby uplands and are loamy-skeletal.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is slow to very rapid. Permeability is slow.
USE AND VEGETATION: Used mainly for range. A few areas are cropped to small grains. Native vegetation is bluebunch wheatgrass, blue grama, dryland sedges, western wheatgrass and forbs.
DISTRIBUTION AND EXTENT: Eastern Montana, western South Dakota, and western North Dakota. The series is extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Cascade County, Montana, 1969.
REMARKS: Diagnostic horizons and features recognized in this pedon are: ochric epipedon - the zone from the surface of the soil to a depth of 3 inches (A horizon).