LOCATION SHAM ND+MT PAEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, calcareous, frigid Aridic Ustorthents
TYPICAL PEDON: Sham loam - grassland. (Colors are for dry soil unless otherwise stated)
A1--0 to 4 inches; grayish brown (2.5Y 5/2) loam, dark grayish brown (2.5Y 4/2) moist; weak medium and fine granular and weak thin platy structure; hard, friable; many roots; moderately alkaline; clear wavy boundary.
A2--4 to 10 inches; light brownish gray (2.5Y 6/2) loam, dark grayish brown (2.5Y 4/2) moist; weak medium and fine subangular blocky structure; hard, friable; common roots; few pores; slight effervescence; moderately alkaline; clear wavy boundary. (Combined A horizons 1 to 16 inches thick)
C1--10 to 14 inches; light brownish gray (2.5Y 6/2) stratified fine sandy loam, grayish brown (2.5Y 5/2) moist; massive; very hard, friable; few roots; few pores; strong effervescence; strongly alkaline; clear wavy boundary.
C2--14 to 60 inches; light olive gray (5Y 6/2) stratified loam, silt loam, very fine sandy loam and fine sandy loam, olive gray (5Y 5/2) moist; massive; very hard, friable; few fine roots in upper part; few masses of carbonates; strong effervescence; strongly alkaline.
TYPE LOCATION: Bowman County, North Dakota; about 9 miles west of Rhame; 2,210 feet south and 400 feet east of the northwest corner, sec. 8, T. 132 N., R. 105 W.
RANGE IN CHARACTERISTICS: The particle-size control section averages loam, silt loam or very fine sandy loam with 10 to 18 percent clay and more than 15 percent fine sand or coarser sand. It is stratified with 2 to 10 mm thick lenses but some lenses are as thick as 5 cm.
The A horizon has hue of 10YR or 2.5Y, value of 5 or 6 and 4 moist. It ranges from slightly to strongly effervescent. It is moderately alkaline or strongly alkaline. Some pedons have a thin A1 horizon with a moist chroma of 3.
The C horizon has hue of 2.5Y or 5Y. It has very hard or extremely hard consistence and ranges from slightly to strongly effervescent. It is strongly alkaline. In some pedons thin lenses of silty clay loam are at various depths and coarser or finer textures are below depths of 40 inches in other pedons. The upper part of the C horizon is usually massive, but some pedons have weak or moderate grades of coarse or very coarse prismatic or blocky structure. The prisms or blocks break into plates along strata lines.
COMPETING SERIES: There are no series in the same family. Other competing series are Benz, Glendive and Patent series. Benz and Patent soils are fine-loamy. Glendive soils have an irregular decrease in organic carbon with depth and do not have hard or very hard C horizons.
GEOGRAPHIC SETTING: Sham soils are on level to strongly sloping fans immediately below sedimentary uplands and on floodplains and terraces. Slopes range from 0 to 15 percent. The substratum is stratified local alluvium from alkaline sandstone and shale. The climate is cool, semiarid, and the mean annual precipitation is 11 to 14 inches. The mean annual temperature is about 38 to 45 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Benz and Patent soils on nearby landscapes.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is medium or rapid. Permeability is slow.
USE AND VEGETATION: Used mainly for range. A few small areas are cropped to small grains and hay. Native vegetation is blue grama, needleandthread, silver sagebrush, and western wheatgrass.
DISTRIBUTION AND EXTENT: Southwestern North Dakota, and possibly eastern Montana and northwestern South Dakota. It is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Hill County, Montana, 1969.
REMARKS: Revised 11/92.
Diagnostic horizons and features recognized in this pedon are: ochric epipedon - the zone from the surface of the soil to a depth of 10 inches (A1 and A2 horizons).