LOCATION COWTON OKEstablished Series
TAXONOMIC CLASS: Fine, mixed, active, thermic Ultic Hapludalfs
TYPICAL PEDON: Cowton loam, on a 6 percent slope, in native
grass meadow.
(Colors are for moist soil unless otherwise
stated.)
A1--0 to 8 inches; very dark grayish brown (10YR 3/2) loam;
weak fine granular structure; friable; fragments of sandstone from
2 mm to 76 mm in diameter make up 10 percent by volume; medium
acid; gradual smooth boundary. (6 to 12 inches thick)
B21t--8 to 14 inches; yellowish red (5YR 4/6) clay loam; moderate fine subangular blocky structure; friable; patchy clay
films on faces of peds; fragments of sandstone from 2 mm to 76 mm
in diameter make up 15 percent by volume; strongly acid; gradual smooth boundary. (0 to 11 inches thick)
IIB22t--14 to 27 inches; dark red (2.5YR 3/6) silty clay;
common fine distinct yellowish red mottles and coatings on faces
of peds; moderate fine and medium blocky structure; firm;
continuous clay films on faces of peds; very strongly acid;
gradual smooth boundary. (6 to 15 inches thick)
IIB3--27 to 34 inches; coarsely mottled red (2.5YR 4/6),
reddish yellow (7.5YR 6/6), and light gray (10YR 7/1) silty clay; weak fine blocky structure; firm; continuous clay films on faces
of peds; fragments of shale from 2 mm to 76 mm in diameter make up
15 percent by volume; very strongly acid, gradual irregular
boundary. (4 to 12 inches thick)
IICr--34 to 40 inches; yellowish brown and gray soft shale.
TYPE LOCATION: LeFlore County, Oklahoma; about 2 miles south of Cowlington, Oklahoma; 500 feet north and 2,565 feet west of the southeast corner of sec. 5, T. 9 N., R. 24 E.
RANGE IN CHARACTERISTICS: Solum thickness is 20 to 40 inches. Reaction ranges from strongly acid to neutral in the A1 horizon,
from very strongly acid to medium acid in the B21t horizons, and
from very strongly acid to strongly acid in the IIB22t and IIB3 horizons.
The A1 horizon has hue of 7.5YR or 10YR, value of 3 or 4, and
chroma of 2 or 3. It is gravelly loam, loam, gravelly silt loam, silt loam, gravelly fine sandy loam, or fine sandy loam.
Fragments of sandstone from 2 mm to 76 mm in diameter make up 0 to
20 percent by volume.
In some pedons there is a 3 to 5 inch thick A12 horizon similar to the A11 horizon.
The B21t horizon has hue of 2.5YR to 7.5YR, value of 4 to 6, and chroma of 4 to 8. It is gravelly clay loam, gravelly silty clay loam, clay loam, or silty clay loam. Fragments of sandstone from
2 mm to 76 mm in diameter make up 0 to 30 percent by volume and fragments 76 mm to 25 cm make up 0 to 10 percent by volume.
The IIB22t horizon has hue of 2.5YR to 10YR, value of 3 to 7, and chroma of 6 to 8, with few to common mottles in shades of red,
brown, and gray. The gray mottles are inherited from the
underlying material. It is clay loam, silty clay loam, clay, or silty clay with a clay content ranging from 35 to 70 percent but averaging 35 to 60 percent clay in the upper 20 inches of the argillic horizon. Sandstone fragments 2 mm to 76 mm in diameter
make up 0 to 10 percent by volume and shale fragments 2 mm to 76
mm in diameter make up 0 to 15 percent by volume.
The IIB3 horizon is mottled in hue of 2.5YR to 10YR, value of 4 to
7, and chroma of 1 to 8. It is shaly silty clay, shaly clay,
silty clay, or clay. Shale fragments 2 mm to 76 mm in diameter
make up 5 to 25 percent by volume.
The Cr horizon is soft shale that is commonly gray and brown, but
is also red in some pedons.
COMPETING SERIES: These are the Brantley, Canton Bend, Capshaw, Enon, Hampshire, Maben, Mecklenburg, and Zion series in the same family and the Barnsdall, Bolivar, Bosville, Carnasaw, Counts,
Homa, McKamie, Porum, Stigler, Tamaha, Toine, Vinita, White Store, and Wister series of similar families. Brantley and Capshaw soils have a solum 40 to 60 inches thick. Canton Bend and Maben soils
have flakes of mica in the solum. Enon and Mecklenburg soils are formed over saprolite, and are medium acid to mildly alkaline in
the lower part of the B horizon. Hampshire soils are formed over interbedded limestone and shale at depth of 40 to 65 inches. In addition, Hampshire and Zion soils are moist for longer periods of time. Barnsdall soils have a fine-silty control section. Bolivar and Toine soils have a fine-loamy control section. Bosville,
Counts, Porum, Stigler, and Tamaha soils have a solum more than 60 inches thick and have wetness mottles within 30 inches of the soil surface. Carnasaw and Vinita soils have a lower base saturation. Homa soils have a very-fine control section and wetness mottles within 30 inches of the soil surface. McKamie and White Store
soils have a COLE or 0.09 or more and cracks 1 cm or more wide at
a depth of 20 inches below the soil surface. Wister soils have wetness mottles within 30 inches of the soil surface and have an abrupt textural change between the A and B2t horizons.
GEOGRAPHIC SETTING: Cowton soils are on very gently sloping to moderately steep convex slopes and crests of low ridges in the
valley of the Ouachita Mountains and the Arkansas Valley and
Ridges. They are formed in material weathered from interbedded sandstone and shale of Pennsylvanian age. Slopes are mainly 3 to
10 percent but range from 2 to 15 percent. Mean annual
precipitation ranges from 40 to 50 inches. Mean annual
temperature ranges from 60 degrees to 66 degrees F. Thornthwaite annual P-E indices are greater than 64.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Stigler
and Wister series and the Vian and Wing series. They are all downslope from Cowton soils. Stigler and Wister soils are
generally on concave slopes. Vian soils have a fine-silty control section, are moderately well drained, and occur on convex slopes. Wing soils commonly occur adjacent to drainageways and have a high sodium content in the subsoil.
DRAINAGE AND PERMEABILITY: Cowton soils are well drained. Runoff
is medium to rapid and permeability is slow.
USE AND VEGETATION: Used for native grass hay meadows,
rangeland, and tame pasture. Native vegetation is mainly mid and tall grasses with a few scattered hardwood trees. The dominant
trees are blackjack oak, post oak, sassafras, and winged elm.
DISTRIBUTION AND EXTENT: Ouachita Mountains and the Arkansas
Valley and Ridges of Oklahoma and possibly Arkansas. The series
is of minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: LeFlore County, Oklahoma; 1981.
REMARKS: These soils were formerly classified in the Red-Yellow Podzolic great soil group and included in the Liberal series.