LOCATION METRE SDEstablished Series
TAXONOMIC CLASS: Very-fine, smectitic, mesic Aridic Leptic Haplusterts
TYPICAL PEDON: Metre clay - on a slightly concave slope having less than 3 percent gradient in native grass. (Colors are for dry soil unless otherwise stated.)
A--0 to 4 inches; gray (10YR 5/1) clay, very dark gray (10YR 3/1) moist; weak fragile vesicular crust in upper 1 inch over weak fine and medium subangular blocky structure; very hard, very firm, slightly sticky and very plastic; cracks 1/2 to 1 inch wide; slightly alkaline; abrupt smooth boundary. (4 to 6 inches thick)
Bss1--4 to 10 inches; gray (10YR 5/1) clay, very dark grayish brown (2.5Y 3/2) moist; weak coarse blocky structure; extremely hard, extremely firm, very sticky and very plastic; cracks 1/2 to 1 inch wide; few intersecting slickensides; strong effervescence; moderately alkaline; clear smooth boundary.
Bss2--10 to 17 inches; gray (10YR 5/1) clay, dark gray (10YR 4/1) moist; weak coarse blocky structure; extremely hard, extremely firm, very sticky and very plastic; cracks 1/2 to 1 inch wide; few intersecting slickensides; common tongues of very dark grayish brown (2.5Y 3/2); few fine accumulations of carbonate; strong effervescence; moderately alkaline; gradual smooth boundary. (Combined Bss horizons is 10 to 22 inches thick.)
Bk--17 to 22 inches; dark gray (10YR 4/1) and light gray (10YR 7/2) clay, dark gray (10YR 4/1) and light brownish gray (10YR 6/2) moist; weak coarse blocky structure; extremely hard, extremely firm, very sticky and very plastic; cracks 1/2 inch wide; many medium and fine accumulations of carbonate; strong effervescence; moderately alkaline; gradual smooth boundary. (4 to 10 inches thick)
C--22 to 30 inches; light gray (2.5Y 7/2), white (2.5Y 8/2), and grayish brown (2.5Y 5/2) silty clay, light gray (2.5Y 7/2) and dark grayish brown (2.5Y 4/2) moist; weak coarse blocky structure parting to weak very fine blocky; very hard, very firm, sticky and plastic; few dark colored tongues 1/4 inch wide; few medium accumulations of carbonates; strong effervescence; moderately alkaline; gradual smooth boundary.
Cr--30 to 60 inches; white (2.5Y 8/2) and gray (10YR 5/1) soft mudstone; strong effervescence.
TYPE LOCATION: Mellette County, South Dakota; about 8 miles north and 1 3/4 miles west of Cedar Butte; 1,200 feet east and 1,580 feet north of the southwest corner of sec. 18, T. 43 N., R. 31 W.
RANGE IN CHARACTERISTICS: The depth to beddock ranges from 20 to 40 inches. Carbonates are within 10 inches of the surface. Gilgai microrelief is in most areas. The mollic epipedon ranges from 8 to 20 inches in thickness.
The A horizon has hue of 10YR, 2.5Y, or is neutral; value of 3 to 5 and 2 or 3 moist; and chroma of 0 to 2. It contains carbonates when plowed or disturbed. It ranges from neutral to moderately alkaline.
The Bss horizon has hue of 2.5Y to 5YR or is neutral, value of 3 to 6 and 2 to 5 moist, and chroma of 0 to 4. It ranges from slightly alkaline to moderately alkaline.
The Bk horizon is multicolored and has hue of 5YR to 5Y, value of 4 to 8 and 3 to 7 moist, and chroma of 1 to 4. It has few to many, fine to coarse accumulations of carbonates. It ranges from slightly alkaline to strongly alkaline.
The C horizon has hue of 10R to 5Y, value of 4 to 8 and 3 to 7 moist, and chroma of 1 to 4 and reflects the varigated colors of the parent material. It is clay or silty clay. It ranges from slightly alkaline to strongly alkaline.
The Cr horizon is variegated and has color similar to the C horizon. It is soft mudstone or clayey shale having varying degrees of weathering.
COMPETING SERIES: This is the Larvie sereis. The Larvie series does not have a mollic epipedon.
GEOGRAPHIC SETTING: The Metre soils are on nearly level to strongly sloping uplands. Surfaces are plane to slightly concave and slope gradients range from 0 to 15 percent. Gilgai microrelief is in most areas. These soils formed in clayey residuum weathered from mudstone or shale. Mean annual air temperature ranges from 43 to 48 degrees F, and the mean annual precipitation from 12 to 18 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hisle, Larvie, Norrest and Conata soils. All of these soils do not have a mollic epipedon. Hisle soils have a natric horizon and are in shallow depressions. Larvie soils are on ridges of a gilgai landscape and Conata and Norrest soils are on nearby convex slopes.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is medium to very high depending on slope. Permeability is very slow.
USE AND VEGETATION: Most areas are in native grass. The native vegetation is western wheatgrass, green needlegrass, blue grama, buffalograss, sedges, and forbs.
DISTRIBUTION AND EXTENT: Inextensive, mostly in southwestern South Dakota and possibly adjacent areas in Wyoming and Nebraska.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Mellette County, South Dakota, 1971.
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 10 inches (A, Bw1 horizons).