LOCATION TARPLEY                 TX

Established Series
Rev. MLG-WJG-RM
02/2018

TARPLEY SERIES

The Tarpley series consists of shallow, well drained, slowly permeable soils that formed in calcareous clayey residuum over limestone bedrock of the Cretaceous period. These soils occur on nearly level to strongly sloping upland plateaus and ridges. Slopes range from 0 to 10 percent. Mean annual temperature is about 18.3 degrees C (65 degrees F), and mean annual precipitation is about 762 mm (30 in).

TAXONOMIC CLASS: Clayey, smectitic, thermic Lithic Argiustolls

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

A--0 to 18 cm (0 to 7 in); very dark grayish brown (10YR 3/2) clay loam, very dark brown (10YR 2/2) moist; moderate medium and fine subangular blocky structure; very hard, firm; common very fine and fine roots; few very fine pores; vertical cracks 1.5 to 3 cm (1/2 to 1 in) wide extend through the horizon; neutral; clear smooth boundary. (Thickness is 8 to 20 cm [3 to 8 in])

Bt--18 to 46 cm (7 to 18 in); reddish brown (5YR 4/4) clay, dark reddish brown (5YR 3/4) moist; strong, medium subangular blocky and angular blocky structure; extremely hard, very firm; common very fine and fine roots; few very fine pores; thin continuous clay films on surfaces of peds; few fragments of chert mostly less than 0.75 cm (1/4 in); vertical cracks 1.5 to 3 cm (1/2 to 1 in) wide extend to the bedrock; neutral; abrupt smooth boundary. (Thickness is 15 to 42 cm [6 to 16 in])

R--46 to 56 cm (18 to 22 in); pale yellow, coarsely fractured, indurated limestone bedrock.

TYPE LOCATION: Mills County, Texas; from the Mills County Courthouse in Goldthwaite, Texas, 14.5 miles southeast on Farm Road 572; north 1.4 miles on an unpaved road to a private pasture road; east on pasture road 200 yards to the top of a flat mountain and 400 yards southeast on the plateau in rangeland.

USGS topographic quad: Star, Texas
Latitude: 31 degrees, 25 minutes, 46.95 seconds N
Longitude: 98 degrees, 33 minutes, 35.9 seconds W

Decimal Degrees
Latitude: 31.4297085
Longitude: -98.5599747
Datum: WGS84

UTM Easting: _ 541818.37_ m
UTM Northing: _ 3477309.74_ m
UTM Zone: 14

RANGE IN CHARACTERISTICS:
The surface is covered by about 15 percent limestone fragments 4 to 380 mm (1/8 to 15 in) in diameter and few chert fragments 130 to 380 mm (5 to 15 in) in diameter.
Depth of lithic contact: 20 to 51 cm (8 to 20 in)
Depth to argillic horizon: 8 to 20 cm (3 to 8 in)
Thickness of the mollic epipedon: 18 to 51 cm (7 to 20 in)

Particle-size control section (weighted average)
Clay content: 44 to 70 percent
Rock fragments: 0 to 30 percent

A horizon:
Hue: 5YR, 7.5YR or 10YR
Value: 2 to 4
Chroma: 2 or 3
Texture: clay loam or clay with gravelly or cobbly modifier when needed
Clay content: 30 to 55 percent
Rock fragments: 0 to 30 percent; 0 to 20 percent gravels, 0 to 10 percent cobbles, 0 to 5 cobbles and stones; limestone or chert
Electrical conductivity (decisiemens per meter): 0 to 2
Effervescence: none
Reaction (pH): moderately acid to slightly alkaline (5.6 to 7.8)

Bt horizon:
Hue: 2.5YR, 5YR, or 7.5YR
Value: 3 or 4
Chroma: 2 to 4
Texture: clay with gravelly or cobbly modifier when needed
Clay content: 44 to 80 percent
Rock fragments: 0 to 30 percent; 0 to 20 percent gravels, 0 to 10 percent cobbles, 0 to 5 cobbles and stones; limestone or chert
Electrical conductivity (decisiemens per meter): 0 to 2
Effervescence: none
Reaction (pH): slightly acid to slightly alkaline (6.1 to 7.8)

The R layer is strongly cemented to indurated limestone bedrock.

COMPETING SERIES: There are no other soils in this family. Similar soils are Bexar, Caradan, Lenapah, Hensley, Purves, Rumple, Speck, and Tarrant series.
Bexar, Caradan, and Rumple soils: have sola more than 51 cm (20 in) thick
Hensley soils: lack mollic epipedons and have less than 60 percent clay in the Bt horizon
Lenapah soils: have Bt horizons in hue of 10YR and 2.5Y section.
Purves and Tarrant soils: lack Bt horizons and have calcic horizons
Speck soils: have mixed mineralogy

GEOGRAPHIC SETTING:
Parent material: clayey residuum over limestone bedrock of Lower Cretaceous age
Landscape: dissected plateaus
Landform: summit, shoulder, and backslopes of interfluves and side slopes
Slope: 0 to 10 percent but are mostly less than 4 percent
Mean annual precipitation: 711 to 889 mm (28 to 35 in)
Thornthwaite P-E Index: 35 to 54
Mean annual air temperature: 17.8 to 21.1 degrees C (64 to 70 degrees F)
Frost-free period: 220 to 250 days
Elevation: 304.8 to 739.1 m (1000 to 2425 ft)

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Caradan, Denton, Eckrant, Evant Oglesby, Real, and Tarrant series.
Cardan soils: are very deep and are slightly convex stream terraces.
Denton soils: have sola thicker than 51 cm (20 in) and lack Bt horizons
Eckrant soils: lack Bt horizons
Evant soils: are on similar positions and are underlain by petrocalcic horizons
Oglesby soils: are on similar positions and do not have argillic horizons
Real soils: are loamy-skeletal, carbonatic, lack argillic horizon, and are on backslopes of ridges.
Tarrant soils: are clayey-skeletal, lack argillic horizon, and are on summits, shoulders, and backslopes of ridges.

DRAINAGE AND PERMEABILITY:
Drainage class; Well.
Permeability class: slow.
Runoff: medium on slopes less than 1 percent, high on 1 to 5 percent slopes, and very high on 5 to 10 percent slopes.

USE AND VEGETATION: A few small areas are cultivated for crop production of small grains. Mostly used for livestock grazing and wildlife habitat. Native vegetation consists mostly of Texas wintergrass, sideoats grama, little bluestem, and Indiangrass. Woody vegetation is white shin oak, live oak, post oak, mesquite, catclaw, and pricklypear.

DISTRIBUTION AND EXTENT: Central Texas, mainly in the southern part of the Grand Prairie and the eastern part of the Edwards Plateau. The series is of large extent.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Temple, Texas.

SERIES ESTABLISHED: Mills County, Texas; 1975.

REMARKS: Tarpley series was formerly included as a shallow phase of the Crawford series.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: 0 to 18 cm (0 to 7 in) (A horizon)
Argillic horizon: 18 to 46 cm (7 to 18 in) (Bt horizon)
Lithic contact: soil/limestone interface at 46 cm (18 in)

ADDITIONAL DATA: None

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

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National Cooperative Soil Survey
U.S.A.