LOCATION STAPP OKEstablished Series
TAXONOMIC CLASS: Fine, mixed, active, thermic Aquic Hapludults
TYPICAL PEDON: Stapp gravelly loam, in forest. (Colors are for moist soil unless otherwise stated.)
A--0 to 2 inches; dark grayish brown (10YR 4/2) stony fine sandy loam; weak and moderate medium granular structure; friable; content of coarse fragments of sandstone make up 35 percent by volume; strongly acid; abrupt smooth boundary. (2 to 5 inches thick)
E--2 to 8 inches; brown (10YR 5/3) stony fine sandy loam; weak fine and medium granular structure; friable; content of coarse fragments of sandstone make up 20 percent by volume; strongly acid; clear smooth boundary. (2 to 7 inches thick)
Bt1--8 to 22 inches; red (2.5YR 5/6) clay; moderate medium blocky structure; firm; clay films on faces of peds; coarse fragments of sandstone make up 10 percent by volume; very strongly acid; gradual smooth boundary. (4 to 16 inches thick)
Bt2--22 to 36 inches; red (2.5YR 5/6) clay; moderate medium blocky structure; firm; clay films on faces of peds; content of coarse fragments of sandstone make up 10 percent by volume; many medium prominent light brownish gray (10YR 6/2) iron depletions; very strongly acid; gradual smooth boundary. (9 to 21 inches thick)
Bt3--36 to 44 inches; coarsely variegated red (2.5YR 5/6) and gray (10YR 6/1) clay; moderate medium blocky structure; firm; clay films on faces of peds; content of coarse fragments of shale and sandstone make up 10 percent by volume; very strongly acid; abrupt irregular boundary. (0 to 13 inches thick)
Cr--44 to 50 inches; gray (10YR 5/1) shale; strongly acid; tilted 20 degrees from horizontal.
TYPE LOCATION: Pushmataha County, Oklahoma; about 1 mile south and 2 miles east of Moyers, Oklahoma; 1,320 feet south and 1,320 feet east of the northwest corner of sec. 10, T. 3 S., R. 16 E.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 40 to 60 inches.
The A horizon has hue of 10YR, value of 2 to 4, and chroma of 2 or 3. Texture is loam, fine sandy loam, gravelly loam, gravelly fine sandy loam, stony loam, and stony fine sandy loam. Content of coarse fragments range from 0 to 40 percent by volume. About 0 to 25 percent by volume are less than 76 mm in diameter and about 0 to 15 percent by volume are more than 76 mm in diameter. Reaction ranges from very strongly acid to moderately acid.
The E horizon has hue of 7.5YR or 10YR, value of 5 or 6, and chroma of 3 or 4. Texture is loam, fine sandy loam, gravelly loam, gravelly fine sandy loam, stony loam, and stony fine sandy loam. Content of coarse fragments range from 0 to 40 percent by volume. About 0 to 25 percent by volume are less than 76 mm in diameter and about 0 to 15 percent by volume are more than 76 mm in diameter. Reaction ranges from very strongly acid to moderately acid.
Some pedons have BE horizons about 4 to 8 inches thick. The BE horizon has hue of 7.5YR or 10YR, value of 4 or 5, and chroma of 6 or 8. Texture is loam, fine sandy loam, gravelly loam, gravelly fine sandy loam, stony loam, and stony fine sandy loam. Content of coarse fragments range from 0 to 40 percent by volume. About 0 to 25 percent by volume are less than 76 mm in diameter and about 0 to 15 percent by volume are more than 76 mm in diameter. Reaction ranges from very strongly acid to moderately acid.
The Bt1 horizon has hue of 2.5YR to 7.5YR, value of 4 or 5, and chroma of 6 to 8. Texture is clay loam, clay, gravelly clay loam, and gravelly clay. Content of coarse fragments of sandstone range from 0 to 30 percent by volume. About 0 to 25 percent by volume are less than 76 mm in diameter and about 0 to 15 percent by volume are more than 76 mm in diameter. Reaction ranges from very strongly acid to moderately acid.
The Bt2 and Bt3 horizons have hue of 2.5YR to 7.5YR, value of 4 or 5, and chroma of 6 to 8. Most pedons have iron accumulations and depletions in shades of brown, red, and gray. Some pedons are coarsely variegated in shades of brown, red, and gray. Content of coarse fragments of sandstone and shale range from 0 to 20 percent by volume. About 0 to 20 percent by volume are less than 76 mm in diameter and about 0 to 5 percent by volume are more than 76 mm in diameter. Reaction is extremely acid or very strongly acid.
Some pedons have a BC horizon up to 16 inches thick. The BC horizon has hue of 2.5YR to 10YR, value of 5 to 7, and chroma of 1 to 8. Iron accumulations and depletions are in shades of brown, red, and gray. Content of coarse fragments of shale ranges from 15 to 30 percent by volume and they are less than 76 mm in diameter.
The Cr horizon commonly is gray shale that is tilted more than 20 degrees from horizontal. Some pedons are underlain with a IIR layer of sandstone at depths below 60 inches.
COMPETING SERIES: These are
Annemaine,
Beason,
Craven, Creedmore,
Dogue,
Eulonia,
Helena,
Lignum,
Nemours,
Newco,
Rosenwall,
Sacul,
Vinita, and
Wolftever series in the same family. Soils in similar families are the
Bengal,
Carnasaw,
Enders, and
Endsaw series. All of these soils except Bengal, Carnasaw, Enders, Endsaw, Helena, Lignum, Rosewall, and Vinita have bedrock at depths greater than
60 inches. Bengal and Vinita soils have solum 20 to 40 inches thick over bedrock. Carnasaw, Enders, and Endsaw soils are not saturated with water in the mottled zone that have moist value of 4 or more and moist chroma of 2 or less. Helena soils have a contact with granitic rock. Lignum soils have a contact with mica schist and contain mica within the solum. Rosewall soils have more than 60 percent clay content in the upper B2t horizon.
GEOGRAPHIC SETTING: Stapp soils occur on nearly level to strongly sloping, slightly concave forested uplands of the Ouachita Mountains, MLRA 119. Slopes range from 0 to 12 percent. Mean annual precipitation ranges from 40 to 56 inches. Mean annual temperature ranges from 60 degrees to 64 degrees F. Thornthwaite annual P-E indices are greater than 64.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Carnasaw series and the Clebit, Nashoba, Pirum, and Tuskahoma series. Carnasaw soils are on slightly more convex areas. Clebit, Nashoba, and Pirum soils have less than 35 percent clay content in the control section. In addition, Clebit soils are less than 20 inches to hard sandstone and Nashoba soils are less than 40 inches to hard sandstone. Clebit soils are usually on ridge crests. Nashoba and Pirum soils are on slightly more convex areas. Tuskahoma soils are less than 20 inches to shale bedrock and are on ridge crest.
DRAINAGE AND PERMEABILITY: Stapp soils are moderately well drained. Runoff is medium to rapid and permeability is slow. A perched water table occurs between 1 foot and 3 feet during the winter and spring months.
USE AND VEGETATION: Used mainly for woodland; some of the less sloping areas are in tame pasture and used for beef cattle. The forest vegetation is principally shortleaf pine, and southern red oak. Bermudagrass and bahiagrass are the principal pasture grasses.
DISTRIBUTION AND EXTENT: Ouachita Mountains of Oklahoma and possibly Arkansas. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Pushmataha County, Oklahoma; 1977.
REMARKS: These soils were formerly included in the Sacul series.