LOCATION THURBER TX

Established Series
Rev. ACT:WJG
11/2013

THURBER SERIES

The Thurber series consists of very deep, moderately well drained, very slowly permeable soils that formed in clayey slope alluvium derived from claystone of Pennsylvanian age. These soils occur on nearly level and very gently sloping toe slopes of ridges. Slope ranges from 0 to 3 percent. Mean annual precipitation is about 813 mm (32 in) and the mean annual air temperature is about 18.3 degrees C (65 degrees F).

TAXONOMIC CLASS: Fine, smectitic, thermic Typic Haplustalfs

TYPICAL PEDON: Thurber clay loam--rangeland. (Colors are for dry soil unless otherwise stated.)

A--0 to 20 cm (0 to 8 in); dark grayish brown (10YR 4/2) clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium and coarse platy structure in upper 2 inches and massive below; very hard, very firm; few fine roots; slightly alkaline; clear smooth boundary. Thickness is 10 to 30 cm (4 to 12 in)

Bt1--20 to 51 cm (8 to 20 in); brown (10YR 4/3) clay, dark brown (10YR 3/3) moist; strong fine angular blocky structure; very hard, very firm; few fine roots; continuous clay films on surfaces of peds; slightly alkaline; clear wavy boundary. Thickness is 20 to 51 cm (8 to 20 in)

Bt2--51 to 97 cm (20 to 38 in); brown (10YR 4/3) clay, dark brown (10YR 3/3) moist; strong fine angular blocky structure; very hard, very firm; few fine and medium roots; common clay films on surfaces of peds; few very fine masses and few fine concretions of calcium carbonate; slightly effervescent; moderately alkaline; gradual wavy boundary. Thickness is 20 to 61 cm (8 to 24 in)

Btk--97 to 122 cm (38 to 48 in); brown (10YR 5/3) clay, brown (10YR 4/3) moist; weak medium angular blocky structure; very hard, very firm; few fine and medium roots; common clay films on surfaces of some peds; 5 percent films, threads, and masses of calcium carbonate; strongly effervescent; moderately alkaline; gradual wavy boundary. Thickness is 0 to 36 cm (0 to 14 in)

B't1--122 to 145 cm (48 to 57 in); yellowish brown (10YR 5/4) clay loam dark yellowish brown (10YR 4/4) moist; weak fine and medium angular blocky structure; hard, firm; few fine and medium roots; common clay films on surfaces of some peds; few threads and films of calcium carbonate; strongly effervescent; moderately alkaline; gradual boundary. Thickness is 0 to 38 cm (0 to 15 in)

B't2--145 to 180 cm (57 to 71 in); dark yellowish brown (10YR 4/4) clay loam, dark yellowish brown (10YR 3/4) moist; weak fine and medium angular blocky structure; very hard, firm; few fine roots; common clay films on surfaces of some peds; few films, threads and concretions of calcium carbonate; weakly effervescent; moderately alkaline; gradual boundary. Thickness is 0 to 51 cm (0 to 20 in)

BC--180 to 203 cm (71 to 80 in); yellowish brown (10YR 5/8) clay loam, dark yellowish brown (10YR 4/6) moist; weak fine and medium subangular blocky structure; very hard, friable; few fine roots; few fine faint strong brown masses of iron accumulation; few concretions of calcium carbonate; noncalcareous; moderately alkaline.

TYPE LOCATION: Erath County, Texas; about 19 miles northwest of Stephenville, and about 1 mile north of the X-Ray Gas Plant; north-northwest 18.5 miles from County Courthouse on Texas Highway 108, then 100 feet west of highway in rangeland. USGS topographic quadrangle: Turkey Creek, TX; Latitude: 32 degrees, 26 minutes, 9.77 seconds, N; Longitude: 98 degrees, 21 minutes, 31.49 seconds, W. WGS84; UTM Easting 560281.97 m, UTM Northing 3588950.81; UTM Zone 14.

RANGE IN CHARACTERISTICS:
Soil Moisture: Typic-ustic soil moisture regime
Solum Thickness: greater than 152 cm (60 in)
Depth to secondary carbonates: 38 to 76 cm (15 to 30 in)

Particle-size control section (weighted average)
Clay content: 35 to 55 percent
Sand content: 15 to 45 percent

A horizon:
Hue: 7.5YR to 2.5Y
Value: 3 to 5
Chroma: 2 to 4
Texture: clay loam, silty clay loam
Clay content: 27 to 40 percent
Structure: is both hard and massive when dry.
Reaction: slightly acid to slightly alkaline

Bt horizon:
Hue: 7.5YR to 2.5Y
Value: 3 to 5
Chroma: 2 to 4
Texture: clay loam or clay
Clay Content: 35 to 55 percent
Concentrations: few to common; concretions, masses, and threads of calcium carbonate in the lower Bt
Reaction: neutral or slightly alkaline in the upper Bt; slightly alkaline or moderately alkaline and calcareous in the lower Bt

Btk, B't, BC and BCk horizons (where present):
Color: shades of brown and gray
Textures: loam, sandy clay loam, clay loam, or clay
Concentrations: none to many; concretions and masses of calcium carbonate
Reaction: slightly alkaline or moderately alkaline

COMPETING SERIES: There are no other series in the same family. Similar soils are the Callahan, Kirkland, Payne, and Tillman series.
Callahan soils: have mixed mineralogy
Kirkland and Tillman soils: have mollic epipedons that are not both hard and massive when dry
Payne soils: depth to secondary carbonates is more than 76 cm (30 in)

GEOGRAPHIC SETTING:
Parent material: calcareous, clayey slope alluvium derived from claystone of Pennsylvanian age
Landscape: hills
Landform: head slopes and toe slopes on base slopes of ridges
Slope: dominantly 0.5 to 2 percent, but ranges from 0 to 3 percent
Mean annual precipitation: 660 to 889 mm (26 to 35 in)
Thornthwaite annual PE index: 40 to 50
Mean annual air temperature: 17.2 to 18.9 degrees C (63 to 66 degrees F)
Frost free period: 210 to 240 days
Elevation: 213.4 to 640.1 m (700 to 2100 ft)

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Blanket, Bluegrove, Bonti, Bosque, Hassee, Leeray, Set, and Truce series.
Blanket soils: have a mollic epipedon greater than 20 inches thick and occur on similar positions
Bluegrove soils: are less than 102 cm (40 in) deep to weakly cemented sandstone and occur on higher positions
Bonti and Truce soils: have reddish, clayey argillic horizons and occur on higher positions in the landscape
Bosque soils: have mollic epipedons and occur on lower positions on flood plains
Hassee soils: have aquic properties and occur in slight depressions
Leeray soils: have slickensides with vertic properties and occur on similar positions
Set soils: have a mollic epipedon and occur on higher escarpments and knolls

DRAINAGE AND PERMEABILITY: Moderately well drained. Permeability is very slow. Runoff is high on slopes less than 1 percent and very high on 1 to 3 percent slopes.

USE AND VEGETATION: Used mainly for rangeland with a few areas farmed to small grain and sorghums. Native vegetation includes buffalograss, curlymesquite, vine-mesquite grass, and Texas wintergrass. Invader plants are mesquite, condalia, tasajillo, pricklypear, and ragweed.

DISTRIBUTION AND EXTENT: Texas North Central Prairie (MLRA 80B), and West Cross Timbers (MLRA 84B) of Texas. The series is extensive.

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

SERIES ESTABLISHED: Eastland County, Texas; 1972.

REMARKS: Thurber soils previously have been included in the Kirkland series.

Changed to tabular format and included metric values (RFG-11/2013)

Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 20cm (0 to 8 in). (A horizon). Both hard and massive when dry.
Argillic horizon - 20 to 180 cm (8 to 71 in). (Bt and Btk horizons).

ADDITIONAL DATA: Lincoln Lab. Sample number 72L075, 79P908-916, 82P1535-1536, and 82P1544.

Taxonomic version: Keys to Soil Taxonomy, Eleventh Edition, 2010

National Cooperative Soil Survey
U.S.A.