LOCATION SPILLER TXEstablished Series
TAXONOMIC CLASS: Fine, mixed, semiactive, thermic Ultic Paleustalfs
TYPICAL PEDON: Spiller loamy fine sand, on a 2 percent convex and linear west-facing slope--improved pasture. (Colors are for dry soil unless otherwise stated).
Ap--O to 15 inches; brown (10YR 5/3) loamy fine sand, brown (10YR 4/3) moist; weak fine and medium subangular blocky structure; loose, very friable, slightly sticky and nonplastic; common fine and medium roots; slightly acid; clear smooth boundary. (10 to 20 inches thick)
E--15 to 18 inches; light yellowish brown (10YR 6/4) loamy fine sand, yellowish brown (10YR 5/4) moist; weak fine and medium subangular blocky structure; loose, very friable, nonsticky and nonplastic; common fine and medium roots; slightly acid; clear smooth boundary. (0 to 10 inches thick)
Bt1--18 to 24 inches; brownish yellow (10YR 6/6) sandy clay, yellowish brown (10YR 5/6) moist; strong fine subangular blocky structure; hard, friable, sticky and plastic; common fine roots; many thick continuous dark yellowish brown (10YR 4/4) clay films along both vertical and horizontal surfaces of peds; few fine prominent red (2.5YR 5/6) masses of iron accumulation with sharp boundaries; slightly acid; clear smooth boundary. (5 to 20 inches thick)
Bt2--24 to 33 inches; light yellowish brown (10YR 6/4) sandy clay, yellowish brown (10YR 5/4) moist; strong fine and medium subangular blocky structure; hard, friable, sticky and plastic; common fine roots; many thick continuous light brownish yellow (10YR 6/4) clay films along both vertical and horizontal surfaces of peds; many medium distinct brownish yellow (10YR 6/8), and common medium prominent red (2.5YR 5/8) masses of iron accumulation with sharp boundaries; moderately acid; clear smooth boundary. (5 to 20 inches thick)
Bt3--33 to 43 inches; pale brown (10YR 6/3) sandy clay, brown (10YR 5/3) moist; common distinct light brownish gray (2.5Y 6/2) mottles; moderate fine and medium subangular blocky structure; very hard, firm, sticky and plastic; common fine roots along ped faces; many thick continuous pale brown (10YR 6/3) clay films along both vertical and horizontal surfaces of peds; many medium distinct brownish yellow (10YR 6/6) masses of iron accumulation with fine and medium red (2.5YR 5/8) centers; and moderately acid; clear smooth boundary. (0 to 12 inches thick)
BCt--43 to 54 inches; brownish yellow (10YR 6/8) sandy clay loam, yellowish brown (10YR 5/8) moist; common distinct light brownish gray (2.5Y 6/2) mottles; weak fine and medium angular blocky structure; very hard, very firm, sticky and plastic; few fine roots and root traces along surfaces of peds; many coarse prominent red (2.5YR 5/8) masses of iron accumulation with sharp boundaries; moderately acid; clear smooth boundary. (0 to 12 inches thick)
C--54 to 85 inches; weakly consolidated brownish yellow (10YR 6/8) loamy strata with common light brownish gray (2.5Y 6/2) shale strata 1 to 2 inches thick; moderately alkaline.
TYPE LOCATION: Brazos County, Texas; from the intersection of Texas Highway 6 and FM 974 in Bryan, 0.9 mile northeast on FM 974 to intersection with FM 2223, 5.2 miles northwest on FM 2223 to Broach road, 1,000 feet northwest on FM 2223 to an oil field road, 1,000 feet northeast and 600 feet northwest on oil field road, 100 feet southwest in pasture.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 40 to about 60 inches. Clay content of the 10- to 40- inch particle size control section ranges from 35 to 45 percent. Base saturation throughout the argillic horizon ranges from 35 to 75 percent. Ironstone pebbles less than 15 mm across range from 0 to 15 percent by volume.
The combined A and E horizons range from 10 to 20 inches thick. The A horizon has hue of 7.5YR or 10YR, value of 3 to 5, and chroma of 3 or 4. The E horizon has hue of 7.5YR or 10YR, value of 4 to 6, and chroma of 3 to 6. Texture is loamy fine sand or fine sandy loam. Reaction ranges from moderately acid to neutral.
The Bt1 and Bt2 horizons have hue of 10YR, value of 4 to 6, and chroma of 3 to 8. Masses of iron accumulation range from few to many in shades of red, yellow or brown. Texture is clay loam, sandy clay, or clay. Reaction ranges from strongly acid to slightly acid.
The Bt3 horizon has hue of 7.5YR or 10YR, value of 4 to 6, and chroma of 3 to 8. Masses of iron accumulation in shades of red and yellow range from few to many. Mottles in shades of gray, where present, are inherited from parent materials. Texture is clay loam, sandy clay or clay. Pressure faces range from none to common. Reaction ranges from strongly acid to moderately acid.
The BCt horizon has hue of 2.5Y to 10R, value of 4 to 6, and chroma of 1 to 8. Redox features in shades of red, yellow and gray range from few to many. Texture is loam, clay loam, sandy clay loam, or sandy clay. Reaction ranges from strongly acid to slightly acid.
The C horizon has colors in shades of red, brown or yellow. These materials are weakly consolidated fine sandy loam, loam or sandy clay loam with strata of gray shale 1 to 5 inches thick. Reaction ranges from strongly acid to moderately alkaline.
COMPETING SERIES: These soils include the Birome, Bonti, Darst, Gause, Jedd, Rosanky, and Travis series. Similar soils are the Chazos, Gasil, and Tabor series. Birome, Bonti, Darst, and Jedd soils have sola 20 to 40 inches thick to a paralithic contact. In addition, these series have epipedons that averages less than 12 inches thick and have dominant hue redder than 7.5YR in the upper part of the argillic horizon. Gause and Travis soils have sola from 60 to greater than 80 inches thick. In addition, Travis soils formed in alluvium and have redder hue in the argillic horizon. Rosanky soils have sola 40 to 60 inches thick to a paralithic contact. In addition, Rosanky soils have redder upper Bt horizons. Chazos soils have zones of iron depletion due to wetness within 30 inches of the surface. Gasil soils have fine-loamy control sections. Tabor soils have montmorillonitic mineralogy and have vertic properties.
GEOGRAPHIC SETTING: Spiller soils are on gently sloping erosional uplands. Slopes range from 1 to 5 percent. These soils generally have drainage basin relief of no more than 25 feet. They are on narrow summits, shoulder, and backslope positions. Slopes are commonly convex in the vertical slope direction and linear in the horizontal slope direction. Spiller soils formed in thinly stratified loamy and clayey sediments of the Tertiary Age, mainly of the Cook Mountain Formation. Mean annual temperature ranges from 66 to 69 degrees F., and mean annual precipitation ranges from 36 to 42 inches. Frost free days range from 250 to 280 days, and elevation ranges from 275 to 650 feet. The Thornthwaite P-E index ranges from 52 to 64.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Crockett, Rader and the competing Tabor soils. Crockett soils are on broad linear and convex slopes in lower positions and have thin A horizons and vertic properties. Rader and Tabor soils occur on lower linear and concave positions and have gray iron depletions due to wetness.
DRAINAGE AND PERMEABILITY: Moderately well drained. Permeability is slow. Runoff is medium.
USE AND VEGETATION: Native areas of Spiller soils produce a post oak savannah with medium and tall native grasses. Present vegetation consists of a post oak-yaupon thicket with American beautyberry and longleaf uniola as common understory species. Cleared areas are mainly in bermudagrass and bahiagrass pasture.
DISTRIBUTION AND EXTENT: Mainly in east central Texas. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Madison County, Texas; 1989.
REMARKS: The soil has gray colors that appear to be inherited from the parent material in the argillic horizon. Semiactive cation exchange activity class. Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 18 inches (Ap and E horizons).
Argillic horizon - 18 to 54 inches (Bt and BCt horizons).
Pale feature - abrupt textural change from E to Bt horizon.
Ultic feature - base saturation is 35 to 75 percent throughout the argillic horizon.
Soil Interpretation Record: TX0835