LOCATION CIRCLEBACK TX

Established Series
Rev. DAB-JCW-RM
03/2016

CIRCLEBACK SERIES

The Circleback series consists of deep, excessively drained, rapidly permeable soils that formed in sandy eolian sediments. These soils are on nearly level plains to undulating dunes. Slopes are complex with landscape base slopes from 0 to 5 percent and individual dune side slopes from 5 to 30 percent. The mean annual precipitation is about 483 mm (19 in) and the mean annual air temperature is about 16 degrees C (61 degrees F).

TAXONOMIC CLASS: Siliceous, thermic Lamellic Ustipsamments

TYPICAL PEDON: Circleback fine sand--rangeland. (Colors are for dry soil unless otherwise stated.

A--0 to 15 cm (0 to 6 in); brown (7.5YR 5/4) fine sand, dark brown (7.5 4/4) moist; single grain; loose; nonsticky and nonplastic; common very fine, fine and medium roots; neutral; clear smooth boundary. (Thickness is 8 to 20 cm [3 to 8 in]).

E--15 to 76 cm (6 to 30 in); reddish yellow (7.5YR 6/6) fine sand, strong brown (7.5YR 5/6) moist; single grain; loose; nonsticky and nonplastic; common very fine, fine and medium roots; neutral; clear wavy boundary. (Thickness is 15 to 89 cm [6 to 35 in].)

E and Bt1--76 to 116 cm (30 to 46 in); reddish yellow (7.5YR 6/6) fine sand, strong brown (7.5YR 5/6) moist; single grain; loose; nonsticky and nonplastic; few fine roots; several 1 to 5 mm (0.04 to 0.2 in) thick bands of reddish yellow (5YR 6/8) loamy fine sand; yellowish red (5YR 5/8) moist, bands from 2 to 20 mm (0.08 to 0.8 in) apart; slightly alkaline; clear wavy boundary. (Combined thickness of the E and Bt horizons is 76 to 152 cm [30 to 60 in])

E and Bt2--116 to 203 cm (46 to 80 in); light brown (7.5YR 6/4) fine sand, brown (7.5YR 5/4) moist; single grain; loose; nonsticky and nonplastic; few woody shin oak roots; many wavy horizontal bands of reddish yellow (5YR 6/8) loamy fine sand, yellowish red (5YR 5/8) moist, that are 1 to 10 mm (0.04 to 0.4 in) thick and 5 to 20 mm (0.2 to 0.8 in) apart; slightly alkaline.

TYPE LOCATION: Cochran County, Texas; from the intersection of Texas Highway 125 and Farm Road 595 in Bledsoe, east 1 block, 0.4 mile south on county road; 0.03 mile west on county road; south 0.9 mile south on private ranch trail; then 20 feet west in rangeland. Latitude: 33 degrees, 35 minutes, 55 seconds N; Longitude: 103 degrees, 1 minute, 18 seconds W; Bledsoe, Texas USGS quad; NAD 83.

RANGE IN CHARACTERISTICS: Soil moisture: An ustic moisture regime bordering on aridic. The soil moisture control section is dry in some or all parts for more than 180 but less than 220 days, cumulative, in normal years. April and October through November are the driest months. These soils are intermittently moist in December through March and May through September.
Mean annual soil temperature: 15 to 18 degrees C (59 to 64 degrees F).
Solum thickness: more than 203 cm (80 in)
Particle-size control section: 2 to 10 percent silicate clay.

Depth of solum is 203 cm (80 in) or more. Combined thickness of the A and E horizon is 25 to 102 cm (10 to 40 in). Mixed texture of all horizons is sand or fine sand with a clay content of about l to about 8 percent. Reaction is slightly acid to moderately alkaline and noncalcareous throughout

A horizon:
Hue: 7.5YR or 10YR
Value: 4 to 6, 3 to 5 moist
Chroma: 3 or 4
Texture: sand, fine sand
Effervescence: none
Reaction: neutral

E horizon:
Hue: 7.5YR or 10YR
Value: 5 to 7, 4 to 6 moist
Chroma 3 to 6
Texture: sand, fine sand
Effervescence: none
Reaction: neutral

E and Bt horizons:
Hue: 5YR
Value: 5 to 6, 4 to 5 moist
Chroma: 4 to 8
Effervescence: none
Reaction: neutral to slightly alkaline

The E and Bt horizons alternate. At least one E and Bt horizon occurs in the solum which contains at least 2 lamellae that are l mm (0.04 in) or more in thickness. The total thickness of lamellae more than l cm (0.4 in) thick to a depth of 152 cm (60 in) is less than l5 cm (6 in). The lamellae are too thin or too few to be an argillic horizon. Lamella are from l to 30 mm (0.04 to 1.2 in) thick and loamy fine sand or fine sandy loam in texture.

COMPETING SERIES: There are no competing series in this family. Similar soils are the Aline, Arenosa, Eufaula, Goltry, Likes, McCaffery, Milsand, Nutivoli, Penwell, Pratt, and Tivoli series.

Aline, Eufaula and Goltry soils: have lamellae that total more than 15 cm (6 in) thick.
Arenosa soils: have more than 95 percent quartz in the sand fraction.
Derby soils: have mixed minerology and are most for longer periods.
Likes and Milsand soils: are calcareous and lack lamellae.
McCaffery soils: are in the frigid temperature zone.
Nutivoli soils: do not contain lamellae
Penwell soils: do not contain lamellae and are dry for longer periods.
Pratt soils: have argillic horizons.
Tivoli soils: do not contain lamellae and are moist for longer periods.

GEOGRAPHIC SETTING:
Parent material: sandy eolian sediments of Pleistocene and Holocene age.
Landform: nearly level plains to steep undulating dunes.
Slopes: 0 to 30 percent.
Mean annual air temperature: 14 to 17 degrees C (57 to 63 degrees F)
Mean annual precipitation: 432 to 533 mm (16 to 21 in).
Frost-free period: 185 to 220 days.
Elevation: 975 to 1,341 m (3,200 to 4,400 ft)
Thornthwaite annual P-E index Values: 25 to 36

GEOGRAPHICALLY ASSOCIATED SOILS: This is the similar Nutivoli soil and the Plains and Yoakran series.
Nutivoli soils: on similar landscape positions
Plains and Yoakran soils: on slightly lower landscape positions and have argillic horizons

DRAINAGE AND PERMEABILITY: Excessively drained and rapid permeability. Runoff is negligible on slopes less than 5 percent and very low on 5 to 20 percent slopes.

USE AND VEGETATION: Mainly used for livestock grazing. Native climax vegetation is dominantly little bluestem, sand bluestem, sand lovegrass, sand dropseed, and sideoats grama. Sand sagebrush and shin oak are woody increasers. Yucca, snakeweed, annuals, and a few small mesquite invade the site when the range condition deteriorates under continued heavy grazing.

DISTRIBUTION AND EXTENT: Southern High Plains and western Rolling Plains of west Texas and New Mexico. The series is of very limited extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas

SERIES ESTABLISHED: Bailey County, Texas; l984.

REMARKS: These soils were formerly included with the Tivoli series.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: 0 to 15 cm (0 to 6 in) (A horizon)
Albic horizon: 15 to 203 cm (6 to 80 in) (E, E and Bt1 and E and Bt2 horizons)
Lamellae; 76 to 203 cm (30 to 80 in) (E and Bt1 and E and Bt2 horizons)

ADDITIONAL DATA: Laboratory data available is NSSL Sample Nos. 76028l-760290. Additional analysis of these samples indicated that the mineralogy is siliceous instead of mixed.

Taxonomic Version: Keys to Soil Taxonomy, Twelfth Edition, 2014.

National Cooperative Soil Survey
U.S.A.