LOCATION OSTIN NCEstablished Series
TAXONOMIC CLASS: Sandy-skeletal, mixed, mesic Typic Udifluvents
TYPICAL PEDON: Ostin loamy sand on a 1 percent slope at 950 feet in elevation in a flood plain--pastured. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 6 inches; dark brown (10YR 4/3) loamy sand; yellowish brown (10YR 5/4) dry; weak medium granular structure; very friable; many very fine and fine roots; 5 percent gravel and 5 percent cobbles by volume; common fine and medium flakes of mica; slightly acid; clear smooth boundary. (2 to 10 inches thick )
C1--6 to 11 inches; dark yellowish brown (10YR 4/6) loamy sand; many thin lenses of strong brown (7.5YR 5/6) sand; single grained; loose; common very fine and fine roots; 10 percent gravel by volume; common fine and medium flakes of mica; neutral; clear smooth boundary.
C2--11 to 22 inches; yellowish brown (10YR 5/4) very cobbly coarse sand; single grained; loose; few very fine and fine roots; 25 percent gravel and 30 percent cobbles by volume; few fine and medium flakes of mica; neutral; abrupt smooth boundary.
C3--22 to 28 inches; yellowish brown (10YR 5/4) gravelly coarse sand; single grained; loose; few very fine roots; 15 percent gravel by volume; few fine and medium flakes of mica; neutral; clear smooth boundary.
C4--28 to 60 inches; yellowish brown (10YR 5/6) extremely gravelly coarse sand; single grained; loose; 55 percent gravel and 20 percent cobbles by volume; few fine and medium flakes of mica; neutral.
TYPE LOCATION: Polk County, North Carolina; about 0.1 mile north of Mill Spring on NC Highway 9; 5.2 miles northwest on Secondary road 1138; 0.9 mile west on Secondary road 1155; 0.9 mile west on 1155; 120 feet north of road in a pasture.
RANGE IN CHARACTERISTICS: Depth to bedrock is greater than 5 feet. Rock fragment content ranges from 5 to 50 percent by volume in the A horizon and from 5 to 80 percent by volume throughout the C horizon. Rock fragment content averages more than 35 percent by volume in the control section. Fragments are dominantly gravel and cobbles but occasionally include stones. Reaction is very strongly acid to neutral. Content of mica flakes ranges from few to many.
The A or Ap horizon has hue of 10YR, value of 3 to 5, and chroma of 1 to 6. Surfaces having value of 3 and chroma of 1 to 3 are less than 7 inches thick. Texture of the fine-earth fraction is loamy sand, sandy loam or sand. Some pedons have a thin Ab horizon that has the same color and texture range as the A horizon.
The C horizon has hue of 10YR or 7.5YR, value of 4 to 6, and chroma of 3 to 8, or is multicolored. Some pedons have redoximorphic features of iron depletions with chroma of 2 or less below a depth of 24 inches. Texture of the fine-earth fraction is loamy sand, sand, loamy coarse sand, or coarse sand.
COMPETING SERIES: These are the Huel, Juno and Potomac in the same family. Huel and Juno soils are in wet marine climates of the Pacific northwest. Huel soils have hue of 2.5Y or 5Y and an annual precipitation range of 120 to 160 inches. Juno soils contain glacial erratics and have an annual precipitation range of 70 to 100 inches. Potomac soils have an annual precipitation range of 32 to 44 inches and formed in alluvium washed from soils derived from sedimentary rocks such as sandstone, siltstone, shale and limestone, and contains fragments of those rocks.
GEOGRAPHIC SETTING: Ostin soils are on narrow flood plains of fast flowing streams in the Southern Appalachian Mountains. These flood plains are adjacent to the lower slopes of steep and very steep mountain escarpments and large fan shaped areas of very stony colluvium. The soils formed in coarse textured alluvium containing large amounts of sand, gravel and cobbles. The alluvium has washed from nearby soils that formed in residuum and colluvium weathered from metamorphic and igneous rocks. These rocks include gneiss, schist, amphibolite, granite, phyllite and quartzite. Elevation ranges from about 950 to 2,100 feet. Slopes are commonly 1 to 3 percent, but range from 0 to 5 percent. Mean annual temperature ranges from about 50 to 57 degrees F., and mean annual precipitation ranges from about 50 to 65 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the Ashe, Arkaqua, Biltmore, Brevard, Buladean, Chestnut, Cleveland, Cliffield, Colvard, Cowee, Cullowhee, Dellwood, Edneyville, Evard, Fannin, French, Greenlee, Iotla, Nikwasi, Reddies, Rosman and Tate soils. Dellwood is the only one of these soils that occurs on similar landscapes and is in a sandy-skeletal family. However, Dellwood soils have an umbric epipedon. Colvard soils are coarse-loamy and are in similar landscapes. Reddies soils are in a related coarse-loamy over sandy or sandy-skeletal family on similar landscapes. The somewhat poorly drained Cullowhee and French soils, and the poorly drained Nikwasi soils are in the wetter depressions and backwater areas of flood plains in similar geographic settings. Arkaqua, Biltmore, Colvard, Iotla and Rosman soils have less than 35 percent rock fragments by volume in the control section and are on flood plains of larger, or slower moving streams. Ashe, Buladean, Chestnut, Cleveland, Cliffield, Cowee, Edneyville, Evard and Fannin soils formed in residuum that is affected by soil creep and are on adjacent mountain side slopes and nearby ridgetops. Brevard, Greenlee and Tate soils formed in colluvium and are on adjacent toe slopes, benches and fans in coves.
DRAINAGE AND PERMEABILITY: Well drained and moderately well drained. Runoff is slow. Permeability is moderately rapid to rapid in the upper part and rapid to very rapid in the lower part. Most areas are occasionally flooded but flooding ranges to frequent.
USE AND VEGETATION: Most areas are in pasture. The rest is mainly in woodland. The major forages are tall fescue and ladino clover. Yellow poplar, American sycamore, river birch, red maple, black locust, black cherry, eastern hemlock, Virginia pine and eastern white pine are common canopy trees. Understory plant species include ironwood, doghobble, flowering dogwood, rhododendron, grape, green briar, trillium and Christmas fern.
DISTRIBUTION AND EXTENT: North Carolina, and possibly Georgia, South Carolina, Virginia and Tennessee. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Polk County, North Carolina; 1992. The name is from Ostin Creek in Polk County.
REMARKS: Ostin soils were formerly included with the Potomac series. However, Potomac soils formed in alluvium washed from soils derived from sedimentary rocks such as sandstone, shale, siltstone, and limestone, and contain fragments of those rocks. At lower elevations, this soil occurs adjacent to Southern Piedmont MLRA 136 and may be marginal to thermic in some areas.
Diagnostic features and horizons recognized in this pedon are:
Ochric Epipedon - the zone from 0 to 6 inches (Ap horizon)
Sandy-skeletal feature - average content of more than 35 percent rock fragments by volume, and sandy fine-earth textures in the 10 to 40 inch control sections (C1, C2, C3, and C4 horizons)
MLRA: 130 SIR: NC0260