LOCATION SKRAINKA MOEstablished Series
TAXONOMIC CLASS: Fine, mixed, active, mesic Oxyaquic Hapludalfs
TYPICAL PEDON: Skrainka silt loam - on a shoulder position of a high undulating terrace with 5 percent slope in fescue and clover pasture at an elevation of 830 feet. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 6 inches; dark brown (10YR 3/3) silt loam; dark yellowish brown (10YR 3/4) rubbed; brown (10YR 5/3) (dry), moderate very fine and fine granular structure; friable; many very fine and fine roots; few fine distinct dark yellowish brown (10YR 4/6) masses of iron accumulation along root channels; moderately acid (pH 5.6); abrupt smooth boundary. (4 to 10 inches thick)
Bt1--6 to 12 inches; brown (10YR 4/3) silty clay loam; moderate very fine subangular blocky structure; friable; common very fine and fine roots; very few distinct clay films on faces of peds; few fine distinct dark yellowish brown (10YR 4/6) masses of iron accumulation along root channels; strongly acid (pH 5.3); clear smooth boundary.
Bt2--12 to 21 inches; brown (10YR 4/3) silty clay loam; weak medium prismatic structure parting to moderate very fine and fine subangular blocky; firm; common very fine roots; common faint clay films and few distinct clay flows on faces of peds; few fine distinct dark yellowish brown (10YR 4/6) masses of iron accumulation along root channels; moderately acid (pH 5.9); clear smooth boundary.
Bt3--21 to 33 inches; brown (10YR 4/3) clay; moderate medium prismatic structure parting to moderate very fine and fine subangular blocky; firm; few very fine roots; many distinct clay films on faces of peds; common medium and coarse black stains (Mn/Fe); common fine distinct dark yellowish brown (10YR 4/6) masses of iron accumulation; neutral (pH 6.7); gradual wavy boundary. (Combined thickness of the Bt horizons is 27 to 52 inches)
2BC1--33 to 45 inches; dark yellowish brown (10YR 4/6) loam; moderate medium platy structure parting to weak fine subangular blocky; friable; very few very fine roots; few prominent clay flows on faces of peds; few prominent black masses of iron and manganese accumulation; few black specks (magnetite); neutral (pH 7.3); gradual wavy boundary.
2BC2--45 to 57 inches; dark yellowish brown (10YR 4/6) and yellowish brown (10YR 5/8) fine sandy loam; weak medium platy structure; friable; very few faint clay films on faces of peds; common black specks (magnetite); moderately alkaline (pH 8.0); gradual smooth boundary. (Combined thickness of the 2BC horizons is 8 to more than 36 inches)
2C1--57 to 68 inches; yellowish brown (10YR 5/8) and brownish yellow (10YR 6/8) sandy loam; massive; friable; many black specks (magnetite); few white lithochromic mottles; moderately alkaline (pH 8.1); gradual smooth boundary.
2C2--68 to 80 inches; yellowish brown (10YR 5/6) and brownish yellow (10YR 6/8) sandy loam; massive; friable; many black specks (magnetite); few white lithochromic mottles; moderately alkaline (pH 8.1).
TYPE LOCATION: Madison County, Missouri; about 7 miles west of Fredericktown; 3,500 feet south and 4,050 feet east of the northwest corner of sec. 36, T. 34 N., R. 5 E.; Rhodes Mt. USGS quadrangle. Latitude 37 degrees, 36 minutes, 13.0 seconds N., longitude 90 degrees, 25 minutes, 38.0 seconds W., NAD83.
RANGE IN CHARACTERISTICS:
Depth to the 2BC horizon is 24 to more than 60 inches. The rock fragments are
predominantly gravel size, but the A horizon can have larger sizes.
Ap or A horizon
Value: 2 to 3
Chroma: 2 or 3
Fine earth: silt loam, loam
Rock fragments: 0 to 15 percent
Reaction: neutral to strongly acid
Bt horizon
Hue: 10YR, 7.5YR, or 5YR
Value: 3 to 6
Chroma: 3 to 8
Fine earth: clay loam, silty clay loam, silty clay, and clay
Coarse fragments: 0 to 10 percent
Reaction: neutral to strongly acid
2BC horizon (upper part)
Hue: 10YR to 2.5YR
Value: 4 to 8
Chroma: 2 to 8
Fine earth: fine to coarse sandy loam, loam, clay loam
Coarse fragments: 0 to 7 percent
Reaction: neutral to moderately alkaline
2BC (lower part) and 2C horizon
Hue: 10YR or 7.5YR
Value: 5 to 8
Chroma: 3 to 8
Fine earth: fine to coarse sandy loam and loamy sand
Coarse fragments: 0 to 7 percent
Reaction: neutral to moderately alkaline
COMPETING SERIES: These are the Alsup, Goodson, Losantville, Miamian, Morrisville, Shircliff, Useful, and Vincent series. Alsup and Goodson soils have a paralithic contact from 40 to 60 inches. Losantville soils have free carbonates at 8 to 20 inches. Miamian soils have free carbonates from 18 to 40 inches.Morrisville soils have free carbonates at 10 to 30 inches. Shircliff soils have free carbonates at 30 to 60 inches. Useful soils have a lithic contact from 40 to 60 inches. Vincent soils formed in lacrustine deposits with a very low sand content in the Bt horizon.
GEOGRAPHIC SETTING: Skrainka soils are on basin-floor remnants and platforms consisting of terraces, footslopes, and ridges. Slopes range from 3 to 15 percent. The soils are primarily developed in colluvium and residuum derived from from basic igneous rocks. The upper material includes colluvial additions from arkose sandstone and acid igneous rocks. The lower material is derived from intrusive mafic rocks which include diabase, basalt, and gabbro. This material is colluvium which may grade with depth to highly weathered residuum below a former strath surface. Mean annual temperature is 54 to 58 degrees F., and mean annual precipitation is 38 to 48 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the Ashton, Delassus, Elk, Irondale, Lamotte, Nolin, Syenite, and Taumsauk series. Ashton and Elk soils are fine-silty and are on lower terraces. Delassus have a low base saturation, are fine-loamy and have a fragipan. They are commonly at higher elevations. Irondale, Syenite, and Taumsauk soils are at higher elevations and formed in materials primarily derived from acid igneous rocks. Syenite is fine loamy. Irondale, and Taumsauk are loamy-skeletal and are on steeper sideslopes. Lamotte soils formed in acid sandstone and are fine-loamy. They are at similar elevations on basin ridges. Nolin soils are fine-silty and are on flood plains.
DRAINAGE AND PERMEABILITY: Moderately well drained. Runoff potential is medium. Permeability is moderately slow. A wet zone is in this soil at a depth of 2 to 3.5 feet during parts of December through April in most years.
USE AND VEGETATION: Most areas are in grasses and legumes. The soils are used for pasture and hay. Other areas are in forest and a few areas are used for grain production. Native vegetation was native grasses and hardwoods.
DISTRIBUTION AND EXTENT: The St. Francis Mountains region of the Missouri Ozarks (MLRA 116C). The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Madison County, Missouri, 1998.
REMARKS: Diagnostic horizons and features recognized in this pedon are: Ochric epipedon - the zone from the surface to a depth of 6 inches. (Ap horizon)Argillic horizon - the zone from 6 to 33 inches (Bt1, Bt2, Bt3 horizons).This series was originally proposed as a Mollic Hapludalf, but the Oxyaquic subgroup supercedes the Mollic subgroup in the current Keys to Taxonomy.
ADDITIONAL DATA: Missouri University Laboratory sample number M9312314.These soils were previously included with Courtois, Lowell, and Syenite soils.