LOCATION THENAS TXEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, active, thermic Fluvaquentic Eutrudepts
TYPICAL PEDON: Thenas fine sandy loam--pastureland.
(Colors are for moist soil unless otherwise stated.)
A--0 to 9 inches; dark brown (10YR 4/3) fine sandy loam, pale brown (10YR 6/3) dry; weak medium granular and subangular blocky structure; hard, friable; slightly acid; gradual smooth boundary. (4 to 16 inches thick)
Bw1--9 to 23 inches; dark brown (10YR 4/3) fine sandy loam, pale brown (10YR 6/3) dry; weak medium subangular blocky structure; hard, friable; common fine and medium pores; few medium faint grayish brown (10YR 5/2) iron depletions; slightly acid; clear smooth boundary. (5 to 16 inches thick)
Bw2--23 to 32 inches; variegated in a coarse pattern, brown (10YR 5/3) and dark brown (10YR 3/3) fine sandy loam; weak medium subangular blocky structure; hard, very friable; common medium and fine pores, few ferromanganese concretions 3 to 10 mm in diameter; common medium faint pale brown (10YR 6/3) and light brownish gray (10YR 6/2) iron depletions; moderately acid; gradual wavy boundary. (5 to 26 inches thick)
Bw3--32 to 44 inches; light yellowish brown (10YR 6/4) sandy clay loam; weak medium subangular blocky structure; very hard, friable; few ferromanganese concretions; many medium and coarse distinct dark brown (7.5YR 4/2)iron depletions; common medium faint light brownish gray (10YR 6/2) iron depletions; moderately acid; gradual wavy boundary. (0 to 15 inches thick)
Bw4--44 to 50 inches; yellowish brown (10YR 5/4) sandy clay loam; weak fine and medium subangular blocky structure; very hard, firm; few fine ferromanganese concretions; many medium distinct yellowish red (5YR 5/6) masses of iron accumulation; common medium distinct light brownish gray (10YR 6/2) iron depletions; slightly acid; diffuse wavy boundary. (0 to 10 inches thick)
Bw5--50 to 62 inches; dark brown (10YR 4/3) clay loam; moderate medium subangular blocky structure; very hard, firm; few fine ferromanganese concretions; many distinct brown (7.5YR 4/4) masses of iron accumulation; many distinct light gray (10YR 7/1) iron depletions; slightly acid; diffuse wavy boundary. (0 to 14 inches thick)
C--62 to 84 inches; variegated, yellowish brown (10YR 5/4), strong brown (7.5YR 5/6) and light gray (10YR 7/1) sandy clay loam; thin strata of sandy loam and loamy sand; massive; very hard, friable; slightly acid.
TYPE LOCATION: Anderson County, Texas; 6 miles northwest of county courthouse in Palestine, 100 feet east of State Highway 19, in the flood plain of Six Mile Creek.
RANGE IN CHARACTERISTICS: Thickness of the solum ranges from 50 to more than 80 inches. Reaction ranges from strongly acid through neutral throughout.
The A horizon has hue of 10YR, value of 5 or 6, and chroma of 3 or 4, or value of 4, and chroma of 2 or 3. Texture is fine sandy loam, loam, or clay loam.
The Bw horizon has matrix hue of 10YR, value of 4 to 6, and chroma of 3 or 4. Gray (10YR 7/1) or light brownish gray (10YR 6/2) iron depletions, and yellowish red (5YR 5/6)or brown (10YR 3/3 or 7.5YR 4/4) iron accumulations are common. Iron depletions in shades of gray are few or common in the upper 24 inches of the solum. Texture is fine sandy loam in the upper part of the Bw horizon, and fine sandy loam, sandy clay loam, or clay loam in the lower part. Thin strata of loamy fine sand through clay loam are in the Bw horizon in many pedons. The average clay content in the 10 to 40 inch control section is 7 to 18 percent.
The C horizon has color similar to the Bw horizon, or it is variegated in shades of brown and gray. Texture ranges from fine sand to clay.
COMPETING SERIES: This is the Fontaine series in the same family, and the Bibb, Bruin, Coushatta, Hamblen, Iuka, Keo, Mantachie, Marietta, Ochlockonee, and Wehadkee series in closely related families. Fontaine soils are on terraces and formed in alluvial sediments eroded from loess and underlying Tertiary materials. Bibb soils have dominantly gray matrix colors throughout the subsoil and have aquic conditions within a depth of 20 inches. Bruin and Keo soils have less than 15 percent sand coarser than very fine sand in the 10 to 40 inch control section. In addition, Keo soils do not have iron depletions in shades of gray or aquic conditions within a depth of 24 inches. Coushatta soils have more than 18 percent clay in the 10 to 40 inch control section and do not have iron depletions in shades of gray or aquic conditions within a depth of 24 inches. Iuka and Ochlockonee soils do not have a cambic horizon and are more acid. In addition, Ochlockonee soils are well drained. Hamblen, Marietta, Mantachie, and Wehadkee soils have more than 18 percent clay in the 10 to 40 inch control section.
GEOGRAPHIC SETTING: These soils are on flood plains of streams mainly on the Western Coastal Plain. Slopes range from 0 to 2 percent. These soils formed in loamy alluvial sediments. Average annual temperature near the type location is 66 degrees F. The average annual rainfall is 42 inches and the Thornthwaite annual P-E indices are about 68.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the closely related Bibb, Iuka, Mantachie, Marietta, and Ochlockonee series, and the Nahatchie and Robinsonville series. Nahatchie soils have aquic conditions within a depth of 20 inches and have a fine-loamy control section. Robinsonville soils do not have a cambic horizon.
DRAINAGE AND PERMEABILITY: Moderately well drained; negligible rate of runoff on slopes up to 1 percent, and low rate of runoff on slopes more than 1 percent; moderate permeability. Most areas of these soils are subject to frequent stream flooding. The soil is saturated in the layers below 2 to 3 feet during October through May in normal years.
USE AND VEGETATION: Many areas were cleared and cultivated, but are now in pasture. Native vegetation is mixed hardwood with some loblolly pine in the eastern parts of the series extent.
DISTRIBUTION AND EXTENT: Western Coastal Plain (MLRA 133B) of Texas and possibly Arkansas, Louisiana, and Oklahoma. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Anderson County, Texas; 1970.
REMARKS: These soils were formerly classified in the Alluvial great soil group. Diagnostic horizons and features recognized in the type location pedon include:
Ochric epipedon ---- 0 to 9 inches (A horizon)
Cambic horizon ----- 9 to 62 inches (Bw horizons)
Aquic conditions --- 23 to 32 inches (Bw2 horizon)