LOCATION EDDY TX
Established Series
Rev. GLL-RM-JAW
02/2018
EDDY SERIES
The Eddy series consists of soils that are shallow to very shallow, well drained, moderately permeable soils that formed in residuum from chalky limestone. These soils are on gently sloping to moderately steep uplands. Slopes range from 1 to 20 percent.
TAXONOMIC CLASS: Loamy-skeletal, carbonatic, thermic, shallow Typic Ustorthents
TYPICAL PEDON: Eddy gravelly clay loam--native pasture. (Colors are for dry soil unless otherwise stated.)
A1--0 to 15 cm (0 to 6 in); light brownish gray (10YR 6/2) very gravelly clay loam, dark grayish brown (10YR 4/2) moist; strong fine granular structure; hard, firm; many fine roots; common fine pores; about 35 percent by volume of platy fragments of chalk, mostly 2.5 to 76 mm (0.1 to 3 in) in diameter; calcareous; moderately alkaline; abrupt irregular boundary. (5 to 25 cm [2 to 10 in] thick)
A2--15 to 25 cm (6 to 10 in); light brownish gray (10YR 6/2) extremely gravelly clay loam, dark grayish brown (10YR 4/2) moist; strong fine granular structure; chalk fragments range from 60 percent at top of horizon to 85 percent at bottom; many roots in upper part and few roots in the lower part; calcareous; moderately alkaline; abrupt wavy boundary. (0 to 23 cm [0 to 9 in] thick)
Cr--25 to 152 cm (10 to 60 in); very pale brown (10YR 8/2) level-bedded partially cemented marine chalky limestone; moderately alkaline; about 2 on Mohs scale in the upper part grading to 3 or more on Mohs scale in the lower part.
TYPE LOCATION: Collin County, Texas; 14 miles southwest of McKinney on Texas Highway 121, and 1.3 miles by road west of its junction with Texas Highway 289, 400 ft north in pasture.
USGS topographic quadrangle: Hebron, TX;
Latitude: 33 degrees, 5 minutes, 30.52 seconds N;
Longitude: 96 degrees, 49 minutes, 35.02 seconds W.
Datum: WGS84.
RANGE IN CHARACTERISTICS:
Depth of solum: 8 to 36 cm (3 to 14 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 Paralithic Contact: 8 to 36 cm (3 to 14 in)
Additional features: The whole soil contains 35 to 60 percent by volume of chalky limestone fragments. The fragments range from very weakly cemented to strongly cemented. They are mostly 2.5 to 76 mm (0.1 to 3 in) in the long axis, but some are as much as 25 cm (10 in). Some of the coarse fragments slake in water upon repeated tumbling.
A or Ap horizon(s):
Hue: 7.5YR to 2.5Y dry or moist
Value: 3 to 6 dry or moist
Chroma: 2 to 6 dry or moist
Where moist color values and chromas are less than 3.5, the A horizon is less than 10 cm (4 in) thick.
Texture: extremely gravelly clay loam, extremely gravelly loam, very gravelly loam, very gravelly clay loam, gravelly loam, gravelly clay loam, and in some horizons thinner than 13 cm (5 in), loam and clay loam. The A2 horizon is extremely gravelly loam or extremely gravelly clay loam.
Reaction: moderately alkaline
Fragments: amount-30 to 85 percent, kind-Chalk, shape-non-flat and flat, cementation-weakly to indurated, size-gravel to stones
Cr horizon:
Hue: 10YR to 2.5Y
Value: 8
Chroma: 2
Texture: clay loam or loam when present between beds, and in cracks of the chalk parent material
Fragments: kind-Chalk, cementation-weakly to strongly cemented
Additional: The chalky limestone ranges in hardness from about 1 to slightly less than 3 on Mohs scale, but in some pedons, it increases in hardness with depth to more than 3 on Mohs scale.
COMPETING SERIES: These are the
Harmon soils in the same family. Similar soils are the
Brackett,
Cottonwood,
Maloterre,
Potter,
Stephen,
Talpa, and
Tarrant series.
Brackett soils: have sola containing less than 35 percent coarse fragments and B horizons having evident soil structure, segregated calcium carbonate, and mixing by earthworms.
Cottonwood and
Potter soils: are are in drier climates. In addition, Cottonwood soils developed in gypsum beds.
Harmon soils: are drier and formed in thin layers of fractured dolomite limestone.
Maloterre,
Talpa, and
Tarrant soils: are all underlain by limestone having hardness exceeding 3 on Mohs scale. In addition, Talpa and Tarrant soils have mollic epipedons.
Stephen soils: have mollic epipedons, are clayey, and formed in residuum weathered from chalk.
GEOGRAPHIC SETTING:
Parent material: residuum derived from weathered chalk predominantly of the Austin chalk geologic formation
Landscape: summit, shoulder, or backslopes on interfluves or side slopes of ridges on dissected plains
Slope: 1 to 20 percent, but are dominantly 3 to 5 percent
Mean annual precipitation: 787 to 991 mm (31 to 39 in)
Mean annual air temperature: 17.6 to 20.7 degrees C (64 to 69.3 degrees F)
Frost-free period: 234 to 270 days
Elevation: 118 to 347 m (387 to 1139 ft)
Thornthwaite P-E Index: 48 to 76
GEOGRAPHICALLY ASSOCIATED SOILS: These are mainly the competing
Brackett and
Stephen series and the
Austin series.
Austin and
Stephen soils: occur at lower elevations. In addition, Austin soils have mollic epipedons, and sola 51 to 102 (20 to 40 in) thick.
Brackett soils: occur on similar surfaces.
DRAINAGE AND PERMEABILITY:
Drainage class: Well;
Permeability class: Moderately slow
Runoff: medium on slopes of 1 to 5 percent and high on slopes of 5 to 20 percent.
USE AND VEGETATION: Small areas are cultivated, mainly to small grains. Most of the soil is in native pastures of buffalograss, Texas grama, and annuals. Shrubs and trees, especially juniper, are common in many places.
DISTRIBUTION AND EXTENT: The known areas are in a narrow band along the western edge of the Blackland Prairie of Texas and in small areas on outcrops of marine chalks other than those of the Austin Formation. The soil is of large extent.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: McLennan County, Texas; 1944.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: 0 to 25 cm (0 to 10 in)
Free carbonates: 0 to 25 cm (0 to 10 in)
Paralithic contact: 25 to 152 cm (10 to 60 in), interface of soil and chalky limestone.
ADDITIONAL DATA: None
Taxonomic Version: Keys to Soil Taxonomy, Twelfth Edition, 2014.
National Cooperative Soil Survey
U.S.A.