LOCATION RIGOLETTE LAEstablished Series
TAXONOMIC CLASS: Fine-loamy, siliceous, active, thermic Typic Epiaqualfs
TYPICAL PEDON: Rigolette loamy fine sand on a concave 9 percent slope, in pine woodland. (Colors are for moist soil. When described, the soil was dry below 32 inches.)
A--0 to 4 inches; grayish brown (10YR 5/2) loamy fine sand; weak fine granular structure; very friable; many fine and medium roots; few fine distinct yellowish brown iron stains along root channels; strongly acid; clear smooth boundary. (3 to 7 inches thick)
E--4 to 12 inches; light brownish gray (10YR 6/2) loamy fine sand; many fine distinct yellowish brown mottles; weak fine granular structure; very friable; common fine and few coarse roots; common fine discontinuous random tubular pores; ; many fine distinct yellowish brown masses of iron accumulation; strongly acid; clear smooth boundary. (3 to 10 inches thick)
BE--12 to 17 inches; light brownish gray (10YR 6/2) fine sandy loam; weak coarse prismatic structure parting to weak medium subangular blocky; friable; few medium roots; common medium discontinuous random tubular pores; many medium distinct yellowish brown (10YR 5/6) masses of iron accumulation; few medium distinct strong brown (7.5YR 5/6) masses of iron accumulation; very strongly acid; clear smooth boundary. (4 to 10 inches thick)
Btg1--17 to 22 inches; gray (10YR 6/1) sandy clay loam; weak coarse prismatic structure parting to moderate medium subangular blocky; firm; common medium and few fine roots; few light gray (10YR 7/1) silt coats 1 to 3 mm thick on some vertical faces of peds; common medium discontinuous random tubular pores; common discontinuous distinct thick clay films on vertical faces of peds; many coarse distinct strong brown (7.5YR 5/8) masses of iron accumulation; few fine prominent yellowish red masses of iron accumulation; very strongly acid; clear smooth boundary. (4 to 12 inches thick)
Btg2--22 to 32 inches; gray (10YR 6/1) sandy clay loam; weak medium prismatic structure parting to moderate medium subangular blocky; firm; few coarse and few medium roots; few light gray (10YR 7/1) silt coats on vertical faces of some peds; common discontinuous distinct thick clay films on vertical faces of peds; many medium distinct strong brown (7.5YR 5/6) masses of iron accumulation; few fine prominent yellowish red masses of iron accumulation; very strongly acid; clear smooth boundary. (5 to 15 inches thick)
2Btgb--32 to 37 inches; light gray (10YR 7/1) silty clay; moderate coarse prismatic structure; very firm, extremely hard; few fine roots; few shiny surfaces on vertical faces of peds; few thin seams of uncoated fine sand on vertical faces of some peds; few fragments of soft sandstone 2 to 15 cm in thickness and 15 to 30 cm in length; common medium distinct strong brown (7.5YR 5/6) masses of iron accumulation; few coarse faint greenish gray (5GY 5/1) iron depletions; very strongly acid; clear smooth boundary. (0 to 10 inches thick)
2Cg1--37 to 49 inches; light brownish gray (2.5Y 6/2) silty clay; massive; very firm, extremely hard; few fine roots; common medium distinct strong brown (7.5YR 5/6) masses of iron accumulation; few coarse faint greenish gray (5GY 5/1) iron depletions; very strongly acid; gradual wavy boundary. (5 to 20 inches thick)
2Cg2--49 to 61 inches; light gray (10YR 7/1) silty clay; massive; very firm, extremely hard; few medium distinct strong brown (7.5YR 5/6) masses of iron accumulation; few medium prominent red (2.5YR 4/8) masses of iron accumulation; very strongly acid; gradual wavy boundary.
2Cg3--61 to 75 inches; light brownish gray (2.5Y 6/2) clay; massive; very firm, extremely hard; few medium distinct yellowish brown (10YR 5/6) masses of iron accumulation; few medium faint greenish gray (5GY 5/1) iron depletions; very strongly acid.
TYPE LOCATION: Grant Parish, Louisiana; about 3 miles north of Colfax; 275 feet west of Louisiana Highway 158; northeast 1/4 northeast 1/4 sec. 30, T. 7 N., R. 3 W.
RANGE IN CHARACTERISTICS: Depth to clayey discontinuity ranges from 20 to 60 inches, but typically is 20 to 50 inches. Typically, fragments of soft sandstone or siltstone are in some part of the 2Btg or 2Cg horizons. Base saturation ranges from 45 to 70 percent at 50 inches below the top of the argillic horizon.
The A horizon has hue of 10YR, value of 4 or 5, and chroma of 1 to 3. Texture is loamy fine sand or fine sandy loam. Reaction is very strongly acid or strongly acid.
The E horizon has hue of 10YR, value of 4 to 6, and chroma of 2. Iron accumulations in shades of brown are typical, but are absent in some pedons. Texture is fine sandy loam or loamy fine sand. Reaction is very strongly acid or strongly acid.
The BE horizon has hue of 10YR, value of 4 or 5, and chroma of 1, or value of 6 and chroma of 1 or 2. Texture is fine sandy loam, loam, or sandy clay loam. Reaction is very strongly acid or strongly acid. Fine to coarse iron accumulations in shades of red or brown range from few to many.
The Btg horizon has hue of 10YR or 2.5Y, value of 5, and chroma of 1, or value of 6 and chroma of 1 or 2. Texture is loam or sandy loam. Reaction is very strongly acid or strongly acid. Content of clay ranges from 20 to 35 percent. Fine to coarse iron accumulations in shades of red or brown range from few to many.
The 2Btgb and 2Cg horizons have hue of 10YR, 2.5Y, or 5Y, value of 5 to 7, and chroma of 1 or 2. Texture is silty clay or clay. Reaction ranges from extremely acid to slightly alkaline. Significant amounts of weathered volcanic glass make up the very fine sand fraction. Fine to coarse fragments of soft sandstone or siltstone range from few to common in all or part of the 2Btg and 2Cg horizons. Fragments are channers that range from 6 to 30 cm in length. They make up from less than 1 percent to as much as 15 percent of the soil mass by volume. Fine to coarse iron accumulations in shades of brown and iron depletions in shades of gray range from few to many.
COMPETING SERIES: These include the Vaughan series in the same family, and the Anacoco, Corrigan, Goreen, Grifton, Kisatchie, Moten, Tuckerman, and Younges series in closely related families. Anacoco, Corrigan, Goreen, and Kisatchie soils have a clayey control section. Grifton and Steens soils do not have a clayey discontinuity and have endosaturation. Moten soils are coarse-loamy and have a glossic horizon. Tuckerman and Younges soils do not have a clayey discontinuity and have mixed mineralogy. Vaughan soils do not have a clayey discontinuity.
GEOGRAPHIC SETTING: Rigolette soils are on moderately sloping to moderately steep side slopes on uplands of the Western Coastal Plain. Surfaces are mainly plain and concave. These soils are typically on mid-slope positions. Slope gradients range from 5 to 15 percent. The soil formed in sandy and loamy sediments of Pleistocene Age over clayey, Tertiary Age sediments of the Catahoula Formation. The climate is warm and humid. Mean annual temperature is 65 degrees F, and mean annual precipitation is 56 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the closely related Anacoco and Kisatchie series, and the Cadeville, Lucy, Ruston, and Smithdale series. Anacoco soils are on lower slopes and have a clayey control section. Cadeville soils are on similar landscape positions, have a clayey control section, and do not have rock fragments in the profile. Kisatchie soils are on convex slopes, are well drained, and are shallow to soft sandstone or siltstone. Lucy soils are on ridgetops and have a sandy epipedon 20 to 40 inches thick. The Ruston and Smithdale soils are on narrow ridgetops and upper side slopes, respectively, are well drained, and do not have a clayey discontinuity.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; medium rate of runoff. Permeability is moderately rapid in the surface layer, moderate in the subsoil, and very slow in the underlying material. A water table is perched above the clayey discontinuity during the winter, and excess water moves laterally out of the profile in the spring and early summer. The 2Btg and 2Cg horizons remain dry most of the time. The soil is droughty to most plants during the growing season in normal years.
USE AND VEGETATION: Pine and mixed hardwoods.
DISTRIBUTION AND EXTENT: Western Coastal Plain (MLRA 133B) in Central Louisiana and possibly East Texas. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Grant Parish, Louisiana, 1981.
REMARKS: Diagnostic horizons and features recognized in this pedon include:
Ochric epipedon----------0 to 17 inches (A, E, and BE)
Argillic horizon---------17 to 37 inches (Btg and 2Btg)
Lithologic discontinuity-37 inches (top of 2Cg1 horizon)
Aquic conditions---------17 to 32 inches (Btg1 and Btg2 horizons)
Episaturation------------17 to 32 inches (Btg1 and Btg2 horizons)
ADDITIONAL DATA: Laboratory analyses were run on samples from the type location pedon bt the Louisiana Agricultural Experiment Station and chemical test data are published in the Soil Survey of Grant Parish, Louisiana (S80LA-043-001).