LOCATION WILBURTON OK+AREstablished Series
The Wilburton series consists of very deep, well drained, moderately permeable soils that formed in loamy colluvium and alluvium. These soils are on very gently sloping to moderately steep uplands in the valleys of the Ouachita Mountains and the Arkansas Valley and Ridges. Slope ranges from 1 to 20 percent. Mean annual temperature is 63 degrees F., and mean annual precipitation is 46 inches.
TAXONOMIC CLASS: Loamy-skeletal, siliceous, active, thermic Ultic Hapludalfs
TYPICAL PEDON: Wilburton cobbly loam, in forest. (Colors are for moist soil unless otherwise stated.)
A--0 to 7 inches; brown (10YR 4/3) cobbly loam; moderate medium granular structure; very friable; many roots of all sizes; sandstone fragments make up 20 percent by volume; slightly acid; clear wavy boundary. (5 to 12 inches thick)
BA--7 to 13 inches; brown (7.5YR 4/4) cobbly loam; weak medium granular structure; friable; common roots; sandstone fragments make up 30 percent by volume; moderately acid; gradual wavy boundary. (0 to 9 inches thick)
Bt--13 to 36 inches; reddish brown (5YR 4/4) very cobbly sandy clay loam; weak medium subangular blocky structure; firm; common roots; patchy clay films on faces of peds and fragments of sandstone; sandstone fragments make up 60 percent by volume; moderately acid; diffuse wavy boundary. (12 to 30 inches thick)
BC--36 to 52 inches; yellowish red (5YR 4/6) very cobbly sandy clay loam; many medium distinct strong brown (7.5YR 5/6), brown (7.5YR 5/4), and yellowish brown (10YR 5/6) mottles; weak medium subangular blocky structure; firm; few roots; patchy clay films on faces of peds and fragments of sandstone; sandstone fragments make up 70 percent by volume; moderately acid; diffuse wavy boundary. (12 to 30 inches thick)
C--52 to 80 inches; coarsely mottled brownish yellow (10YR 6/6), pale brown (10YR 6/3), gray (10YR 6/1) and reddish yellow (5YR 6/6) very cobbly loam; massive; firm; common black or dark brown bodies, streaks, and concretions; sandstone fragments make up 80 percent by volume; strongly acid.
TYPE LOCATION: Latimer County, Oklahoma; about 5 miles west and 2 miles north of Wilburton; 1,500 feet east and 150 feet north of the southwest corner of sec. 33, T. 6 N., R. 18 E.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 40 to 60 inches. Depth to bedrock is more than 60 inches.
The A horizon has hue of 7.5YR or 10YR, value of 4 or 5, and
chroma 2 to 4. Texture is loam, fine sandy loam, cobbly loam,
cobbly fine sandy loam, stony loam, or stony fine sandy loam.
Content of coarse fragments of sandstone range from 5 to 60
percent by volume. About 0 to 25 percent by volume is less than 76 mm in diameter and 5 to 35 percent by volume is more than 76 mm in diameter. Reaction is slightly acid to strongly acid.
The BA horizon has hue of 5YR or 7.5YR, value of 4 to 6, and
chroma 3 to 8. Texture is cobbly fine sandy loam, cobbly loam, cobbly clay loam, and cobbly sandy clay loam. Content of coarse fragment of sandstone range from 20 to 60 percent by volume. About 5 to 25 percent by volume is less than 76 mm in diameter and 15 to 35 percent by volume is more than 76 mm in diameter. Reaction is slightly acid to strongly acid.
The Bt horizon has hue of 5YR or 7.5YR, value of 4 to 6, and
chroma of 4 to 8. Texture is gravelly or very gravelly clay loam, gravelly or very gravelly sandy clay loam, gravelly or very gravelly loam, cobbly clay loam, cobbly sandy clay loam, or cobbly loam. Content of coarse fragments of sandstone range from 35 to 75 percent by volume. About 20 to 45 percent by volume is less than 76 mm in diameter and 15 to 30 percent by volume is more than 76 mm in diameter. Reaction is medium acid to very strongly acid.
The BC horizon has hue 5YR or 7.5YR, value 4 to 6, and chroma 4 to 6. Some pedons have mottles in shades of red or brown. Texture is similar to the B2t horizon, but includes very cobbly loam, very cobbly clay loam, or very cobbly sandy clay loam. Content of coarse fragments of sandstone range from 55 to 85 percent by volume. About 30 to 45 percent by volume is less than 76 mm in diameter and 25 to 40 percent by volume is more than 76 mm in diameter. Reaction is medium acid to very strongly acid.
The C horizon has hue of 5YR, 7.5YR, or 10YR, value of 4 to 6, and chroma of 4 to 6. Some pedons have C horizons that are coarsely mottled in shades of brown, yellow, and gray. Texture is similar to the Bt horizon, but includes gravelly or very gravelly fine sandy loam, very cobbly loam, very cobbly clay loam, very cobbly sandy clay loam, and cobbly or very cobbly fine sandy loam. Content of coarse fragments of sandstone range from 55 to 90 percent by volume. About 30 to 40 percent by volume is less than 76 mm in diameter and 25 to 50 percent by volume is more than 76 mm in diameter. Reaction is slightly acid to strongly acid.
COMPETING SERIES: There are no other series in this family. Soils in closely related families include the Tilk and Waben series in a mesic temperature regime, and the Kenefick, Kenn, Speer, and Wiville series in a fine-loamy textural family.
GEOGRAPHIC SETTING: Wilburton soils are on very gently sloping to moderately steep uplands in the valleys of the Ouachita Mountains and the Arkansas Valley and Ridges. They formed in loamy colluvium and alluvium. Slopes are 1 to 20 percent. Mean annual precipitation ranges from 40 to 56 inches. Mean annual temperature ranges from 61 degrees to 64 degrees F. Thornthwaite annual P-E indices are greater than 64.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Avilla, Caston, Ceda, Dela, Kenn, Mena, Octavia, and Sallisaw series. Avilla soils formed in loamy alluvium and have less than 35 percent rock fragments in the control section. Caston soils formed in loamy colluvium on benches and footslopes, and have less than 35 percent base saturation. Ceda and Dela soils do not have argillic horizons and are on flood plains. In addition, Dela soils have a coarse-loamy control section. Kenn soils are on flood plains and have a gravelly discontinuity. Mena soils formed in pedisediments and old alluvium. Octavia soils formed in loamy colluvium over clay on colluvial benches and footslopes, and have less than 35 percent base saturation in the control section. Sallisaw soils are on similar areas.
DRAINAGE AND PERMEABILITY: Wilburton soils are well drained.
Runoff is medium to rapid and permeability is moderate.
USE AND VEGETATION: Used mainly as bermudagrass and bahiagrass pasture for beef cattle. Most steep or stony phases are used for woodland. The vegetation is mainly post oak, blackjack oak, hickory, eastern redcedar, and some shortleaf pine.
DISTRIBUTION AND EXTENT: Ouachita Mountains and the Arkansas Valley and Ridges of Oklahoma and Arkansas. The series is of minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Latimer County, Oklahoma; 1980.
REMARKS: These soils were formerly included in the Sallisaw
series.
ADDITIONAL DATA: