LOCATION SLIDELL TXEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Udic Haplusterts
TYPICAL PEDON: Slidell clay--pastureland. (At center of microdepression. Colors are for dry soil unless otherwise stated.)
Ap--0 to 6 inches; dark gray (10YR 4/1) clay, very dark gray (10YR 3/1) moist; moderate fine subangular blocky and granular structure; extremely hard, very firm; many fine roots; common fine and medium concretions of calcium carbonate; slightly effervescent; moderately alkaline; abrupt smooth boundary. (4 to 8 inches thick)
A--6 to 19 inches; very dark gray (10YR 3/1) clay, black (10YR 2/1) moist; few fine dark grayish brown redox concentrations in the lower part; moderate medium angular blocky structure; extremely hard, very firm; common fine roots; few fine pores; common pressure faces; few fine and medium concretions of calcium carbonate; slightly effervescence; moderately alkaline; gradual wavy boundary. (9 to 30 inches thick)
Bss--19 to 32 inches; very dark gray (10YR 3/1) clay, black (10YR 2/1) moist; moderate medium angular blocky structure; extremely hard, very firm; few fine roots; few fine pores; common prominent slickensides; few vertical streaks of grayish brown (10YR 5/2); few fine and medium concretions of calcium carbonate; strongly effervescent; moderately alkaline; gradual wavy boundary. (0 to 25 inches thick)
Bkss1--32 to 49 inches; grayish brown (10YR 5/2) clay, dark grayish brown (10YR 4/2) moist; weak coarse angular blocky structure; extremely hard, very firm; few fine roots; few fine pores; common prominent slickensides; few vertical streaks of very dark gray (10YR 3/1); common fine and medium concretions of calcium carbonate; strongly effervescent; moderately alkaline; diffuse boundary. (6 to 42 inches thick)
Bkss2--49 to 72 inches; grayish brown (2.5Y 5/2) clay, dark grayish brown (2.5Y 4/2) moist; few fine distinct yellowish brown (10YR 5/6) redox concentrations; weak coarse angular blocky structure; extremely hard, very firm; common prominent slickensides; few vertical streaks of very dark gray (10YR 3/1); common coarse concretions of calcium carbonate; violently effervescent; moderately alkaline; diffuse boundary. (0 to 30 inches thick)
Bkss3--72 to 80 inches; light brownish gray (2.5Y 6/2) clay, grayish brown (2.5Y 5/2) moist; common fine distinct olive yellow (2.5Y 6/6) redox concentrations; weak coarse angular blocky structure; very hard, very firm; common prominent slickensides; few vertical streaks of grayish brown (2.5Y 5/2); common coarse concretions and soft masses of calcium carbonate; violently effervescent; moderately alkaline.
TYPE LOCATION: Denton County, Texas; from intersection of Farm Road 1173 and Farm Road 156 in Krum; 7.2 miles west on Farm Road 1173 to county road; 1.4 miles west on county road; 800 feet south in pasture. (Latitude 33N, 18, 01; Longitude 97W, 21, 55)
RANGE IN CHARACTERISTICS: Solum thickness ranges from 60 to more than 80 inches. When dry, cracks up to 1 inch wide extend to a depth of more than 20 inches. Cracks open and close more than once each year and remain open 90 to 150 cumulative days in most years. Large slickensides begin at depths ranging from 16 to 25 inches. In more than half of each pedon the calcium carbonate equivalent ranges from 40 to 60 percent in some part of the particle-size control section. Texture throughout is silty clay or clay. Thickness of the A horizon and depth to any subhorizon, having matrix colors with chroma more than 1.5, ranges from 20 to 50 inches in more than 60 percent of any pedon. In less than 40 percent of the pedon there are chromas of 2 or more within depths ranging from 8 to 20 inches. Cycles of microdepressions and microknolls are repeated each 6 to 20 feet. In undisturbed areas, microknolls range from 3 to 16 inches higher than microdepressions.
The A and Bss horizons have hue of 10YR, value of 3 to 5, and chroma of 1. They are dominantly effervescent but are noneffervescent in the center of microdepressions in some pedons.
The Bkss1 horizon has hue of 10YR or 2.5Y, value of 3 to 6, and chroma of 1 to 4. Redox concentrations in shades of brown or yellow range from none to common.
The Bkss2 horizon has hue of 10YR or 2.5Y, value of 5 to 7, and chroma of 2 to 4. Redox concentrations in shades of brown or yellow range from few to common. Calcium carbonate masses and concretions range from 2 to 15 percent throughout the Bkss horizons and is more common in microknolls.
The Bkss3 horizon has matrix colors in shades of brown or gray. Redoximorphic features in shades of brown, gray, olive or yellow range from few to many. Calcium carbonate masses and concretions range from 2 to 25 percent.
Some pedons have C horizons of fractured limestone interbedded with marly silty clay or silty clay loam below a depth of 70 inches.
COMPETING SERIES: These are Bleiblerville, Branyon, Burleson, Clarita, Dimebox, Fairlie, Heiden, Houston Black, Leson, Luling, Ovan, Sanger,and Watonga series. Bleiblerville and Houston Black soils contain less calcium carbonate in the control section. Branyon soils are on terraces, have less amplitude of waviness between the A and B horizons and lack colors with chroma of more than 1.5 within 20 inches of the surface in some part of the pedon. Burleson, Dimebox, and Leson soils are noncalcareous to a depth of more than 12 inches. Clarita soils have hue of 7.5YR or redder in the B horizon. Fairlie soils have paralithic contact with chalk at a depth between 40 and 60 inches. Watonga soils have thinner sola and are on flood plains. Heiden, Luling, Ovan, and Sanger soils have chroma of more than 1.5 within 12 inches of the soil surface in more than half the pedon.
GEOGRAPHIC SETTING: Slidell soils are on nearly level to gently sloping uplands. Slopes range from 0 to 5 percent but are mainly less than 3 percent. The soil formed in calcareous marine sediments of lower Cretaceous formations. Mean annual precipitation is 26 to 34 inches. Mean annual air temperature is 64 to 69 degrees F. Frost free days range from 230 to 250 and elevation ranges from 700 to 1300 feet above sea level. The Thornthwaite P-E indices are 44 to 56.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the competing Sanger series and the Bolar, Crawford, Denton, San Saba, and Somervell series. Bolar, Crawford, San Saba, and Somervell soils have a solum thickness of 20 to 40 inches. Denton soils have a fine-silty particle-size control section. Sanger, Denton, and Somervell soils are on slightly higher positions in the landscape. Bolar, Crawford, and San Saba soils are on similar or slightly higher positions.
DRAINAGE AND PERMEABILITY: Moderately well drained. Runoff is low on slopes less than 1 percent, medium on 1 to 3 percent slopes, and high on 3 to 5 percent slopes. Permeability is very slow. Water enters rapidly when the soil is dry and cracked, and very slowly when the soil is moist.
USE AND VEGETATION: Used for cropland, pasture, and range. Main crops are cotton, small grain, corn and grain sorghum. Pastures are mainly common and coastal bermudagrass. Native vegetation is bluestems, sideoats grama, buffalograss, and Texas wintergrass. Scattered mesquite, elm, and hackberry trees are in some areas.
DISTRIBUTION AND EXTENT: Mainly in the Grand Prairie of north-central Texas. The series is extensive with about 295,000 acres correlated.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Denton County, Texas; 1975.
REMARKS: These soils were formerly included in the San Saba and Houston Black series. Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - 0 to 32 inches.
Moist chroma of less than 1.5 in the upper 12 inches in more than half of each pedon.
Cambic horizon - 32 to 80 inches.
Vertisol feature - Slickensides at a depth of 19 to 80 inches.
SIR Number: TX0485