LOCATION BILLSTOWN AREstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Vertic Paleudalfs
TYPICAL PEDON: Billstown loam in pasture. (Colors are for moist soil.)
Ap--0 to 18 cm (0 to 7 in); dark grayish brown (10YR 4/2) loam; weak medium subangular blocky structure; friable; many common fine roots; slightly acid; abrupt smooth boundary.
E--18 to 33 cm (7 to 13 in); yellowish brown (10YR 5/4) loam; few medium distinct light brownish gray (10YR 6/2) and common medium faint pale brown (10YR6/3) iron depletions; weak medium subangular blocky structure; friable; common fine roots; about 10 percent by volume subrounded sandstone fragments less than 8 cm (3 in) in diameter; strongly acid; clear wavy boundary.
Bt1--33 to 56 cm (13 to 22 in); red (2.5YR 4/6) clay; few fine prominent light brownish gray (10YR 6/2) iron depletions and common medium prominent strong brown (7.5YR 5/6) masses if iron accumulation on faces of peds and within matrix; moderate medium subangular blocky structure; firm; common fine distinct continuous clay films on faces of peds; few fine and medium roots; distinct pressure faces on surfaces of peds; very strongly acid; gradual wavy boundary.
Bt2--56 to 81 cm (22 to 32 in); red (2.5YR 4/6) clay; few fine prominent light brownish gray (10YR 6/2) and common medium prominent light yellowish brown (10YR 6/4) iron depletions within matrix; moderate medium subangular blocky structure; firm; common fine distinct continuous clay films on faces of peds; few fine roots; distinct pressure faces on surfaces of peds; very strongly acid; clear wavy boundary.
Btssg--81 to 124 cm (32 to 49 in); gray (10YR 6/1) clay; moderate medium subangular blocky structure; very firm; common fine and medium roots; common medium pressure faces and common large intersecting slickensides having distinct polished and grooved surfaces; common medium distinct light yellowish brown (10YR 6/4) and common fine and medium prominent red (2.5YR 4/6) masses of iron accumulation on faces of peds and within the matrix; common fine distinct continuous clay films on faces of peds; very strongly acid; clear smooth boundary.
2Bkss1--124 to 163 cm (49 to 64 in); light olive brown (2.5Y 5/4) clay; moderate medium subangular blocky structure; very firm; common fine and medium roots throughout; common medium pressure faces and common large intersecting slickensides having prominent polished and grooved surfaces; common medium prominent gray (10YR 6/1) iron depletions within matrix; common fine and medium rounded soft masses of calcium carbonate and few fine rounded calcium carbonate nodules; violently effervescent; moderately alkaline; gradual smooth boundary.
2Bkss2--163 to 203 cm (64 to 80 in); olive yellow (2.5Y 6/6) clay; moderate medium subangular blocky and angular blocky structure; very firm; few fine roots; common medium pressure faces and common large intersecting slickensides having prominent polished and grooved surfaces; many fine and medium rounded soft masses of calcium carbonate and few fine rounded calcium carbonate nodules; violently effervescent; moderately alkaline.
TYPE LOCATION: Billstown silt loam in an area of Billstown loam, 3 to 8 percent slopes; located in an area of pasture ; NW1/4,NW1/4,SW1/4 Sec. 5, T. 9 South, R. 23 West, Pike County, Arkansas; PINEY GROVE USGS topographic quadrangle; Latitude: 33 degrees, 59 minutes, 29.80 seconds N., Longitude: 93 degrees, 29 minutes, 25.20 seconds W.
RANGE IN CHARACTERISTICS: Depth to horizons with secondary carbonates ranges from 76 to more than 152 cm (30 to more than 60 in). Depth to chalk bedrock characterized as a paralithic contact is more than 152 cm (60 in).
A or Ap horizon:
Hue: 5YR to 10YR
Value: 3 to 6
Chroma: 2 to 4
Texture: silt loam
Rock fragments: subrounded and rounded sandstone less than 8 cm (3 in) in diameter range from 0 to 35 percent by volume
Reaction: ranges from very strongly acid to moderately alkaline
E horizon:
Hue: 7.5YR to 10YR
Value: 5 or 6
Chroma: 3 to 5
Texture: fine sandy loam, very fine sandy loam, loam, clay loam, or silty clay loam
Rock fragments: subrounded and rounded sandstone less than 8 cm (3 in) in diameter range from 0 to 35 percent by volume
Reaction: ranges from very strongly acid to moderately alkaline
Bt horizon(s):
Hue: 2.5YR, 5YR, or 7.5YR
Value: 4 or 5
Chroma: 6 or 8
Redoximorphic features: iron depletions in shades of gray and iron accumulations in shades of brown and red range from none to common, generally increasing with depth. Some pedons have few to common soft masses and/or concretions of iron and manganese.
Texture: silty clay loam, silty clay or clay.
Reaction: ranges from extremely acid to moderately alkaline.
Btss horizon(s):
Hue: 2.5YR to 7.5YR
Value: 4 to 6
Chroma: 4 to 8
or Hue of 2.5Y
Value: 5 or 6
Chroma: 4 to 6
or has no dominant matrix color and is multicolored in shades of red, brown, and gray.
Redoximorphic features: Iron depletions in shades of gray and iron accumulations in shades of brown and red range from few to many, generally increasing with depth. Some pedons have few to common soft masses and/or concretions of iron and manganese.
Texture: silty clay or clay.
Slickensides: range from few to many.
Reaction ranges from extremely acid to slightly acid or moderately alkaline in lower Btss horizons.
Btssg horizon(s):
Hue: 10YR
Value: 5 or 6
Chroma: 1 ro 2
Redoximorphic features: Iron depletions in shades of gray and iron accumulations in shades of brown and red range from few to many, generally increasing with depth. Some pedons have few to common soft masses and/or concretions of iron and manganese.
Texture: silty clay or clay.
Slickensides: range from few to many.
Reaction ranges from extremely acid to slightly acid or moderately alkaline.
Bkss horizon(s):
Hue: 10YR, 2.5Y, or 5Y
Value: 4 to 6
or Hue: 7.5YR or 5YR
Value: 5 or 6. Chroma: 4 to 8 in ped interiors and from 2 to 4 on exterior faces of peds or slickenside faces.
Some pedons do not have a dominant matrix color and are variegated in shades of olive, brown, and gray.
Redoximorphic features: Iron depletions in shades of gray and iron accumulations in shades of brown range from few to many and are most common on surfaces of peds or slickensides. Some pedons have few to common soft masses and/or concretions of iron and manganese.
Texture: clay or silty clay.
Slickensides: range from few to many.
Calcium Carbonate: Soft masses of calcium carbonate range from common to many and concretions or nodules of carbonate range from few to many.
Reaction: commonly slightly alkaline or moderately alkaline, but ranges to neutral.
2C horizon (where present):
Marl or highly weathered chalk
Reaction: slightly alkaline or moderately alkaline.
2Cr horizon (where present):
Occus below a depth of 60 inches that is weathered chalk bedrock. It is massive or has platy rock structure. It can be dug with difficulty with hand tools and is rippable by light machinery
COMPETING SERIES: These are the
Annona,
Bryarly,
Kipling,
Susquehanna, and
Woodville series.
Annona soils are located on Pleistocene Age terraces.
Bryarly soils do not have an abrupt texture change between the A and Bt horizons.
Kipling, Susquehanna, and Woodville soils somewhat poorly drained.
GEOGRAPHIC SETTING: Billstown soils are on ridges and side slopes interfluves of the Cretaceous Western Gulf Coastal Plain (MLRA 135B). Slopes are generally 1 to 15 percent, but may be as steep as 35 percent in some places. These soils formed in clayey sediments overlying marl or chalk. The average annual air temperature ranges from 16 to 18 degress C (60 to 65 degrees F), and the average annual precipitation ranges from 1220 to 1420 mm (48 to 56 in).
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Delight,
Japany,
Marietta,
Ochlockonee,
Peanutrock and
Tiak soils.
Delight soils are on similar landscapes.
Japany soils are somewhat poorly drained and are on lower landscape positions.
Marietta and Ochlockonee soils are on flood plains.
Peanutrock soils are loamy-skeletal and are on higher landscape positions
Tiak soils lack slickensides and are more acid thoughout.
DRAINAGE AND PERMEABILITY: Moderately well drained; medium to rapid runoff; very slow permeability. No free water has been observed in these soils but soil morphology suggests that they may be saturated within a depth of 46 to 107 cm (1.5 to 3.5 ft) of the surface for short periods during winter and spring.
USE AND VEGETATION: Principal use is woodland. Some areas are in pasture, hayland, or cultivated crops. Common trees in wooded areas include loblolly pine, shortleaf pine, southern red oak, post oak, sweetgum, and hickory.
DISTRIBUTION AND EXTENT: The Cretaceous Western Gulf Coastal Plain of southwest Arkansas and possibly Oklahoma. It 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 Oktibbeha series. Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from the surface to a depth of about 33 cm (13 in).
Argillic horizon - the zone from about 33 to 124 (13 to 49 in).
Vertic features - intersecting slickensides beginning at about 61 cm (32 in) and continuing to a depth of 203 cm (80 in) (Bss and Bkss horizons).
ADDITIONAL DATA: Characterization of the typical pedon by the National Soil Survey Laboratory S03AR-109-006.
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