LOCATION NATHAN AREstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, semiactive, thermic Typic Paleudults
TYPICAL PEDON: Nathan silt loam, 1 to 8 percent slopes in woodland (Colors are for moist soil unless otherwise stated.)
A--0 to 18 cm (0 to 7 in); very dark grayish brown (10YR 3/2) silt loam; moderate medium granular structure; friable; many fine and medium roots and common coarse roots; very slightly acid; clear wavy boundary.
E--18 to 36 cm (7 to 14 in); light yellowish brown (10YR 6/4) silt loam; moderate medium granular structure; friable; many fine, medium, and coarse roots; slightly acid; clear wavy boundary.
Bt1--36 to 48 cm (14 to 19 in); brownish yellow (10YR 6/6) silt loam; few medium distinct very pale brown (10YR 7/3) iron depletions and few medium prominent yellowish red (5YR 5/8) iron accumulations; weak and moderate medium subangular blocky structure; friable; common fine and medium roots and few coarse roots; slightly acid; clear wavy boundary.
Bt2--48 to 66 cm (19 to 26 in); strong brown (7.5YR 5/8) silty clay loam; few medium distinct very pale brown (10YR 7/3) iron depletions; moderate coarse subangular blocky structure; firm; medium fine and common coarse roots; many patchy distinct clay films on all faces of peds; moderately acid; gradual wavy boundary.
Bt3--66 to 89 cm (26 to 35 in); yellowish red (5YR 5/8) silty clay loam; few medium distinct dark red(2.5YR 3/6) iron accumulations; moderate medium subangular blocky structure; firm; few fine and medium roots and common coarse; fragments of rounded chert make up 5% by volume; many patchy distinct clay films on all faces of peds; strongly acid; gradual wavy boundary.
Bt4--89 to 127 cm (35 to 50 in); strong brown (7.5YR 5/6) silt loam; moderate medium few medium prominent red(2.5YR 4/8) iron accumulations, few medium prominent light gray(10YR 7/1) and few coarse and medium distinct yellow (10YR 7/6) iron depletions; moderate coarse subangular blocky structure; firm; few medium and very few coarse roots; fragments of shale and soft sandstone make up 10% by volume; few patchy faint clay films on all faces of peds; strongly acid, gradual irregular boundary.
C--127 to 203 cm (50 to 80 in); yellow (10YR 7/6) silt loam; common coarse prominent light gray(10YR 7/1), common coarse prominent red (2.5YR 4/8), and common coarse prominent yellowish red (5YR 4/6) iron accumulations; moderate coarse subangular blocky structure; firm; few fine roots; few patchy distinct pressure faces on vertical faces of peds; strongly acid.
TYPE LOCATION: Pike County, Arkansas; SE1/4, SW1/4, NE1/4 Sec 10, R26W, T.8 S.,USGS Nathan quadrangle, Latitude, 34 degrees, 4 minutes, 25 seconds North; Longitude, 93 degrees, 45 minutes, 41 seconds West.Latitude, 34 degrees, 4 minutes, 25 seconds N., Longitude, 93 degrees, 45 minutes, 41 seconds W.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 152 to more than 203 cm (60 to more than 80 in).
A horizon:
Hue: 10YR
Value: 4
Chroma: 2 or 3
Texture: silt loam
Reaction: moderately acid or slightly acid.
E horizon:
Hue: 10YR
Value: 5 or 6
Chroma: 2 or 4
Texture: silt loam
Reaction: moderately acid or slightly acid.
BE horizon:
Hue: 7.5YR or 10YR
Value: 4 to 6
Chroma: 4 or 6
Texture: silt loam
Reaction: ranges from strongly acid to slightly acid.
Upper Bt horizon:
Hue: 5YR or 7.5YR
Value: 5
Chroma: 6
Redoximorphic features: Some pedons have few to many mottles in shades of red and brown.
Texture: silt loam or silty clay loam.
Reaction: ranges from very strongly acid to moderately acid.
Lower Bt horizon:
Hue: 7.5YR or 5YR
Value: 5 or 6
Chroma: 6 or 8
Redoximorphic features: few to common and occur below a depth of 30 inches. Iron-manganese nodules range from none to few. Texture: silt loam, loam or fine sandy loam.
Rock fragments: Some pedons have chert, quartz, or ironstone gravel that constitute as much as 10 percent of the volume. Reaction: ranges from very strongly acid to moderately acid.
C horizon:
Hue: 10YR
Value: 7
Chroma: 6
Redoximorphic features: few to common in shades of red, brown, or gray are common.
Texture: loam or silt loam.
Reaction: very strongly acid.
COMPETING SERIES: This is the
Pickwick series.
Pickwick soils are on stream terraces and formed form alluvium.
GEOGRAPHIC SETTING: Nathan soils are on hillslopes and ridgetops in dissected uplands of the Cretaceous Western Gulf Coastal Plain. The slope range is from 1 to 8 percent. These soils formed in thick beds of loamy marine or fluvial deposits. The climate is warm and humid with mean annual temperature of 60 degrees F, and mean annual precipitation of 47 inches near the type location.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Antoine,
Kizzia,
Peanutrock,
Pikecity, and
Tiak soils.
Antoine soils are moderately well drained
Kizzia and Pikecity soils have a fine-loamy control section and Kizzia soils are moderately well drained.
Peanutrock soils have a loamy-skeletal control section.
Pikecity soils are fine-loamy and have a siliceous mineralogy.
Tiak soils have a fine control section and are moderately well drained.
DRAINAGE AND PERMEABILITY: Well drained; slow to very rapid runoff; moderate permeability.
USE AND VEGETATION: Most areas of the Biggs soils are used for woodland, principally loblolly, longleaf, and shortleaf pines. Cleared areas are used mainly for growing pasture.
DISTRIBUTION AND EXTENT: Cretaceous Western Gulf Coastal Plain of Arkansas and possibly Oklahoma. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Pike County, Arkansas; 2006.
REMARKS: These soils were formerly included in the Smithdale series.
Diagnostic features and horizons recognized in this pedon:
ochric epipedon-The zone from the surface to 14 inches
argillic horizon-The zone from 14 inches to 50 inches
ADDITIONAL DATA: Characterization of the typical pedon by the National Soil Survey Laboratory: S03AR-109-010.
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