LOCATION CROCKETT                TX+OK

Established Series
Rev. GLL-RMR
04/2015

CROCKETT SERIES


The Crockett series consists of soils that are deep to weathered shale of Cretaceous age. They are moderately well drained, and very slowly permeable. These soils are on broad ridges on the dissected plains. These nearly level to moderately sloping soils formed in alkaline residuum derived from interbedded shale and clay. Slopes are dominantly 1 to 5 percent, but range from 0 to 10 percent.

TAXONOMIC CLASS: Fine, smectitic, thermic Udertic Paleustalfs

TYPICAL PEDON: Crockett fine sandy loam--cropland. (Colors are for dry soil unless otherwise stated).

Ap--0 to 20 cm (0 to 8 in); brown (10YR 4/3) fine sandy loam, dark brown (10YR 3/3) moist; massive; very hard, friable; few wormcasts; moderately acid; abrupt wavy boundary. (10 to 38 cm [4 to 15 in] thick)

Bt1--20 to 41 cm (8 to 16 in); distinctly and coarsely mottled reddish brown (5YR 4/4) and brown (10YR 4/3) clay, moderate fine and medium angular blocky structure; extremely hard, very firm; few fine pores; distinct clay films and dark grayish brown stains on surfaces of peds, few fine pressure faces; vertical cracks partially filled with darker soil; few fine black iron-manganese concretions; few fine and medium prominent dark red (10R 3/6) masses of iron accumulation; moderately acid; diffuse wavy boundary.

Bt2--41 to 76 cm (16 to 30 in); olive (5Y 5/4) clay, moderate medium and coarse angular blocky structure; extremely hard, very firm; few fine pores; thin clay films on surfaces of peds, few fine pressure faces; few small slickensides; few vertical streaks of dark brown soil that is less clayey; few fine black iron-manganese concretions; common medium and coarse distinct reddish brown (5YR 4/4), and yellow (10YR 7/6) masses of iron accumulation, common medium and coarse distinct grayish brown (10YR 5/2) iron depletions; slightly acid; gradual wavy boundary.

Bt3--76 to 107 cm (30 to 42 in); pale olive (5Y 6/4) clay, olive (5Y 5/4) moist; weak coarse angular blocky structure; extremely hard, very firm; thin patchy clay films; few fine pressure faces; few small slickensides; few fine black concretions; few black streaks or stains on faces of peds; common medium distinct pale yellow (5Y 7/4) masses of iron accumulation, and common medium distinct light brownish gray (2.5Y 6/2) iron depletions; neutral; gradual wavy boundary. (Combined thickness of Bt horizons is 36 to 114 cm [14 to 45 in])

BCtk--107 to 145 cm (42 to 57 in); distinctly and coarsely mottled light brownish gray (2.5Y 6/2) and pale olive (5Y 6/4) clay; weak coarse angular blocky structure; extremely hard, very firm; few thin clay films on surfaces of peds; few pressure faces and cleavage planes; few calcium carbonate concretions; few masses of calcium carbonate to 1.3 cm (1/2-in) in diameter; few fine black iron-manganese concretions; few black streaks along pressure faces and cleavage planes; slightly alkaline; abrupt smooth boundary. (25 to 76 cm [10 to 30 in] thick)

Cdk1--145 to 185 cm (57 to 73 in); pale yellow (2.5Y 7/4) stratified clay loam, light yellowish brown (2.5Y 6/4) moist; massive; extremely hard and very firm in place, friable when broken; 25 percent of weakly cemented, brittle weathered shale fragments; 20 percent white calcium carbonate masses and concretions; common medium distinct dark yellowish brown (10YR 4/4) masses of iron accumulations, mainly along fractures of weathered shale; violently effervescent; moderately alkaline; diffuse smooth boundary. (0 to 76 cm [0 to 30 in] thick)

Cdk2--185 to 203 cm (73 to 80 in); pale yellow (2.5Y 7/4) clay loam containing about 40 percent interbedded weakly consolidated shale in layers of 1.3 to about 5 cm (1/2 to about 2 in), shale is light olive brown (2.5Y 5/4) in lower part; massive; extremely hard, very firm in place, friable when broken; 10 percent masses of calcium carbonate in the upper part grading to none in the lower part; soil matrix is violently effervescent in spots and shale is noncalcareous; moderately alkaline.

TYPE LOCATION: Kaufman County, Texas; From the intersection of Farm Road 986 and State Highway 80 in Terrell, approximately 1.5 miles north on Farm Road 986 and 250 ft east of Farm Road 986 in pastureland. USGS Terrell North topographic quadrangle; Latitude: 32 degrees, 45 minutes, 42.01 seconds N; Longitude: 96 degrees 16 minutes, 55.70 seconds W. Datum: WGS84.

RANGE IN CHARACTERISTICS:
Depth of solum: 102 to 150 cm (40 to 60 in)
Soil moisture: Dry in some or all parts of the soil moisture control section for more than 90 or more cumulative days and moist in some parts either for more than 180 cumulative days per year or for 90 or more consecutive days in normal years. Ustic soil moisture regime
Depth to abrupt texture change: 18 to 25 cm (7 to 10 in)
Depth to secondary carbonates: 76 to 150 cm (30 to 60 in)
Depth to densic materials: 145 to 203 cm (57 to 80 in)
Clay content: 40 to 50 percent
Coefficient of linear extensibility: 0.07 to 0.10 in upper 102 cm (40 in) of the Bt horizon(s)
Additional features: Some pedons do not have visible carbonates. When dry, cracks 1.3 to about 5 cm (1/2 to about 2 in) wide extend from the top of the Bt horizon to depths of 61 to 152 cm (24 to 60 in). If the A horizon is eroded or thin, the soil cracks to the surface. Pressure faces and slickensides range from few to common throughout the Bt horizon and in the BC and C horizon of some pedons.

A or Ap horizon(s):
Hue: 7.5YR or 10YR, dry or moist
Value: 3 to 6 dry or moist
Chroma: 2 to 4 dry or moist
Texture: fine sandy loam, very fine sandy loam, loam, silt loam, or their gravelly counterparts
Fragments: amount-0 to 35 percent, kind-quartzite, shape-flat and non-flat, cementation-non-cemented to indurated; size-gravel to cobble
Reaction: moderately acid to slightly alkaline
Boundary: The boundary between the A and Bt horizon is commonly wavy. It is abrupt over subsoil crests and clear in subsoil troughs with an abrupt textural change between the A and Bt horizons

Upper Bt or Btss horizon(s):
Hue: 2.5YR to 10YR dry or moist
Value: 3 to 5 dry or moist
Chroma: 1 to 6 dry or moist
Texture: clay loam, clay, sandy clay
Reaction: moderately acid to neutral
Base saturation: 75 to 100 percent
Fragments: amount-0 to 15 percent, kind- quartzite, shape-flat and non-flat, cementation-non-cemented to indurated; size-gravel to cobble

Lower Bt, Btk, Btkss, or Btss horizon(s) (where present):
Hue: 7.5YR to 2.5Y dry or moist
Value: 3 to 5 dry or moist
Chroma: 1 to 6 dry or moist
Texture: clay loam, clay, sandy clay
Reaction: slightly acid to moderately alkaline
Fragments: amount-0 to 15 percent, kind-quartzite, shape-flat and non-flat, cementation-non-cemented to indurated; size-gravel to cobble
Identifiable secondary carbonates: amount-0 to 2, size-fine or medium, kind-masses, threads, or concretions, location-throughout

BCtk, BCt, CBd, or CBdy horizon(s):
Hue: 7.5YR to 5Y dry or moist
Value: 3 to 7 dry or moist
Chroma: 1 to 8 dry or moist
Texture: clay loam, clay, sandy clay
Reaction: slightly acid to moderately alkaline
Fragments: amount-0 to 15 percent, kind-shale, shape-flat and non-flat, cementation-non-cemented to indurated; size-gravel to cobble
Identifiable secondary carbonates: amount-0 to 4, size-fine or medium, kind-masses, threads, or concretions, location-throughout

Cdk or Cy horizon(s):
Hue: 7.5YR to 5Y dry or moist
Value: 4 to 7 dry or moist
Chroma: 1 to 8 dry or moist
Texture: clay, clay loam, loam, stratified loam and clay
Reaction: slightly acid to moderately alkaline
Fragments: amount-0 to 5 percent, kind-shale, shape-flat and non-flat, cementation-non-cemented to indurated; size-gravel to cobble
Identifiable secondary carbonates: amount-0 to 20, size-fine or medium, kind-masses, threads, or concretions, location-throughout
Gypsum: amount-0 to 2, size-fine or medium, kind-masses or crystals, shape-threadlike or spherical, location-throughout

COMPETING SERIES: These are the Axtell, Bremond, Crosstell, Kurten, Navo, Zack, and Zulch series. Similar soils are the Normangee and Ponder series.
Axtell, Kurten and Tabor soils: are strongly acid in the Bt1 horizon and have base saturation of less 75 percent.
Bremond soils: have sola more than 152 cm (60 in) thick.
Crosstell and Kurten soils: have hue of 7.5YR or redder in the upper part of the Bt horizon.
Navo soils: do not have an abrupt textural change between the A and B horizons. In addition, Axtell, Navo, and Tabor soils: also have sola from 152 to greater than 203 cm (60 to greater than 80 in).
Zulch soils: have sola 51 to 102 cm (20 to 40 in) thick.
Normangee soils: do not have an abrupt textural change between the A and Bt horizons.
Ponder soils: do not have redoximorphic features in the upper part of the Bt horizon.

GEOGRAPHIC SETTING:
Parent material: residuum derived from weathered alkaline shale of Cretaceous age interbedded with sandier materials, mainly of Cretaceous age
Landscape: broad nearly level to moderately sloping ridges and plains on dissected plains
Slope: 0 to 10 percent, but are mostly between 1 and 5 percent
Mean annual precipitation: 635 to 1,143 mm (25 to 45 in)
Mean annual air temperature: 16.7 to 21.1 degrees C (62 to 70 degrees F)
Frost-free period: 230 to 276 days
Elevation: 61 to 263 m (200 to 863 ft)
Thornthwaite P-E Index: 50 to 75

GEOGRAPHICALLY ASSOCIATED SOILS: These include the Axtell, Bonham, Burleson, Mabank, Normangee, Payne and Wilson series.
Bonham soils: have mollic epipedons and have sola greater than 152 cm (60 in).
Burleson soils: are clays throughout with slickensides.
Mabank and Wilson soils: are dominated by chromas or 2 or less.
Axtell, Bonham, Normangee, and Payne soils: are on similar landscapes with Crockett soils.
Burleson, Mabank, and Wilson soils: are on lower positions.

DRAINAGE AND PERMEABILITY: Moderately well drained. Permeability is very slow. Runoff is low on slopes less than 1 percent, medium on 1 to 3 percent slopes, high on 3 to 5 percent slopes, and very high on 5 to 10 percent slopes.

USE AND VEGETATION: Mainly used for growing cotton, grain sorghums, and small grain, but more than half the acreage is now in pastures. Native vegetation is prairie grasses such as bluestems, indiangrass, switchgrass, and gramas, with scattered elm, hackberry, and mesquite trees.

Note: Crockett and Axtell soils are close competitors. Native vegetation of Crockett was dominantly prairie grasses whereas that of Axtell was trees with an understory of grasses. Morphologically, Crockett soils are less acid and leached in the upper part of the Bt horizon than Axtell soils. At present, this difference is attributed primarily to vegetation.

DISTRIBUTION AND EXTENT: Mainly in the Blackland Prairies of Texas (MLRA 86A, 86B, 87A) but minor areas are in Oklahoma. The series is extensive.

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

SERIES ESTABLISHED: Houston County, Texas; 1905.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon: 0 to 20 cm (0 to 8 in), (Ap horizon). Layer is hard and massive when dry.

Pale feature: Abrupt textural change at 20 cm (8 in).

Argillic horizon: 20 to 145 cm (8 to 57 in). (Bt1, Bt2, Bt3 and BCtk horizons)
Slickensides: 41 to 107 cm (16 to 42 in)
Densic materials: 145 to 203 cm (57 to 80 in)

Vertic properties: COLE is 0.07 to 0.10

ADDITIONAL DATA: LSL17760-17767, Kaufman County, Texas.

Soil Interpretation Record: TX0318

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


National Cooperative Soil Survey
U.S.A.