LOCATION RIMLAP SDEstablished Series
TAXONOMIC CLASS: Fine, smectitic, frigid Vertic Argialbolls
TYPICAL PEDON: Rimlap silt loam on a concave slope of less than 1 percent in rangeland. When the soil was described it was moist to 59 inches and saturated below. (Colors are for moist soil unless otherwise stated)
A1--0 to 2 inches; black (10YR 2/1) silt loam, dark gray (10YR 4/1) dry; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; common medium and many very fine and fine roots throughout; common very fine tubular pores; slightly acid; clear smooth boundary.
A2--2 to 6 inches; very dark gray (10YR 3/1) silt loam, gray (10YR 5/1) dry; common fine prominent dark yellowish brown (10YR 4/4) redox concentrations; weak medium subangular blocky structure parting to moderate fine granular; soft, very friable, slightly sticky and slightly plastic; many very fine and fine roots throughout; common very fine tubular pores; slightly acid; clear smooth boundary. (Combined A horizons 2 to 6 inches thick)
E--6 to 10 inches; dark gray (10YR 4/1) silt loam, light gray (10YR 7/1) dry; many fine prominent dark yellowish brown (10YR 4/4) redox concentrations; moderate very thin and thin platy structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine roots throughout; common very fine tubular pores; few fine iron-manganese concretions; neutral; abrupt smooth boundary. (3 to 6 inches thick)
Bt1--10 to 17 inches; black (10YR 2/1) silty clay, dark gray (10YR 4/1) dry; weak medium columnar structure parting to moderate fine and medium angular blocky; very hard, very firm, very sticky and very plastic; common very fine roots between peds; few very fine tubular pores; light gray (10YR 7/1), dry, coats on tops of columns and clay films on vertical faces of peds; neutral; gradual smooth boundary.
Bt2--17 to 29 inches; black (10YR 2/1) silty clay, dark gray (10YR 4/1) dry; moderate medium prismatic structure parting to moderate fine and medium subangular blocky; very hard, very firm, very sticky and very plastic; common very fine roots between peds; few very fine tubular pores; clay films on vertical faces of peds; slightly alkaline; clear smooth boundary. (Combined Bt horizons 12 to 35 inches thick)
Btk--29 to 39 inches; very dark gray (2.5Y 2.5/1) silty clay loam, dark gray (2.5Y 4/1) dry; common fine prominent dark yellowish brown (10YR 4/4) redox concentrations; moderate medium prismatic structure parting to moderate medium subangular blocky; very hard, firm, sticky and plastic; few very fine roots throughout; few very fine tubular pores; clay films on vertical faces of peds; many medium and coarse masses of carbonate; strongly effervescent; moderately alkaline; gradual smooth boundary. (0 to 12 inches thick)
Bk--39 to 45 inches; dark grayish brown (2.5Y 4/2) silty clay loam, light brownish gray (2.5Y 6/2) dry; common fine prominent dark yellowish brown (10YR 4/4) redox concentrations and few fine distinct gray (10YR 5/1) redox depletions; weak medium prismatic structure parting to moderate medium subangular blocky; hard, firm, sticky and plastic; few very fine roots throughout; common very fine tubular pores; common medium masses of carbonate and few fine masses of iron-manganese; strongly effervescent; moderately alkaline; gradual smooth boundary. (5 to 25 inches thick)
C1--45 to 55 inches; grayish brown (2.5Y 5/2) loam, light gray (2.5Y 7/2) dry; many fine and medium prominent yellowish brown (10YR 5/6) redox concentrations and common fine distinct gray (10YR 5/1) redox depletions; massive; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots throughout; common very fine tubular pores; common fine masses of iron-manganese; slightly effervescent; strongly effervescent on ped faces; moderately alkaline; clear smooth boundary.
2C2--55 to 102 inches; olive brown (2.5Y 4/4) loam, light yellowish brown (2.5Y 6/4) dry; many fine and medium prominent dark yellowish brown (10YR 4/6) redox concentrations and many fine and medium prominent gray (10YR 6/1) redox depletions; massive; slightly hard, friable, slightly sticky and slightly plastic; common very fine tubular pores; strata of sandy loam 1 to 4 cm thick; slightly effervescent; 2 percent gravel; moderately alkaline.
TYPE LOCATION: Spink County, South Dakota; about 10 miles west and 6 miles north of Redfield; 1,850 feet east and 1,150 feet south of the northwest corner Sec. 7, T. 117 N. - R. 65 W.; USGS Topographical Quadrangle - ZELL, S. DAK.; Latitude: 45 degrees, 58 minutes, 0 seconds N; Longitude: 98 degrees, 42 minutes, 34 seconds W.
RANGE IN CHARACTERISTICS: Depth to carbonates typically is 24 to 38 inches, but, ranges from 24 to 50 inches. These are also the maximum depths to which mollic colors extend. The depth to till typically ranges from 40 to 60 inches, but is below 60 inches in some pedons. The combined A and E horizons thickness and depth to the Bt horizon is 7 to 12 inches.
The A horizon has hue of 10YR, value of 2 or 3 and 3 to 5 dry, and chroma of 1 or 2. It typically is silt loam, but some pedons are loam or silty clay loam. It is slightly acid to neutral.
The E horizon has hue of 10YR, value of 4 or 5 and 5 to 7 dry, and chroma of 1 or 2. It typically is silt loam, but some pedons are loam or silty clay loam. It has few to many distinct or prominent redox features. It is slightly acid to neutral.
The Bt horizon has hue or 10YR or 2.5Y, value of 2 or 3 and 3 to 5 dry and chroma of 1 or 2. It is silty clay, clay or silty clay loam with clay content ranging from 35 to 55 percent. It is neutral to moderately alkaline. The Bt1 horizon typically has columnar or degraded columnar structure. Redox features are usually only evident in the lower part of the Bt horizon. They range from common to many and faint to prominent.
The Bk horizon has hue or 10YR, 2.5Y, or 5Y, value of 3 to 5 and 4 to 6 dry and chroma of 2 or 3. It is silty clay loam, clay loam or silty clay. It is neutral to moderately alkaline. It has few or common, fine to coarse accumulations of carbonates in most pedons. Some pedons have accumulations of gypsum. Redox features range from few to many and faint to prominent. BC horizons are in some pedons.
The C and 2C horizons have hue of 2.5Y or 5Y, value of 4 or 5 and 5 to 7 dry and chroma of 2 to 4. They are clay loam, silty clay loam or loam. They are slightly or moderately alkaline. Redox features range from common to many and faint to prominent. Some pedons have accumulations of gypsum. Some pedons do not have C horizons above the 2C horizon. Some pedons do not have 2C horizons.
COMPETING SERIES: This is the Galchutt series. Galchutt soils are somewhat poorly drained and are deeper than 12 inches to the Bt horizon.
GEOGRAPHIC SETTING: Rimlap soils are in depressions. Slopes ranges from 0 to 1 percent. The soils formed in local alluvial sediments overlying till. The mean annual air temperature ranges from 34 to 45 degrees F, and the mean annual precipitation ranges from 14 to 20 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Arnegard, Bowbells, Heil, Max, Niobell, Noonan, Parnell, Tonka and Williams soils. Arnegard, Bowbells, Niobell and Noonan soils are moderately well drained and are in swales and nearly level upland positions. In addition, Niobell and Noonan soils have a natric horizon. Heil, Parnell and Tonka soils are on similar landscapes. Heil soils have a natric horizon and are less than 5 inches to the Bt horizon. Parnell soils do not have an albic horizon. Tonka soils have a depth to the Bt horizon greater than 12 inches and lack an abrupt textural change from the albic to the argillic horizon. Max and Williams are well drained and are on higher parts of the landscape.
DRAINAGE AND PERMEABILITY: Poorly drained. Runoff is ponded. Permeability is slow or very slow.
USE AND VEGETATION: Mostly in pasture and hayland. Native vegetation is mainly prairie cordgrass and sedges.
DISTRIBUTION AND EXTENT: North central South Dakota and possibly south central North Dakota. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Spink County, South Dakota, 1997.
REMARKS: Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface of the soil to a depth of 7 inches after mixing (A1, A2 and E horizons); albic horizon - the zone from 6 to 10 inches (E horizon); argillic horizon - the zone from 10 to 39 inches (Bt1, Bt2, and Btk horizons).
Soils with a depth to the Bt horizon from 5 to 7 inches are included in this series in mapping.
The soil may have a natric horizon. Several pedons have been sampled for laboratory characterization. If the date indicates the classification will be changed.
ADDTIONAL DATA; Laboratory characterization (NSSL) - S96SD115019