LOCATION GUEYDAN LA
Established Series
Rev. JPE:KEM
10/2021
GUEYDAN SERIES
The Gueydan series consists of very deep, poorly drained, very slowly permeable soils in fresh water coastal marshes that have been protected from flooding by a system of levees and drained with pumps. They formed in fluid clayey sediments that consolidated as a result of artificial drainage. Slopes range from 0 to 1 percent.
TAXONOMIC CLASS: Fine, smectitic, nonacid, thermic, cracked Typic Fluvaquents
TYPICAL PEDON: Gueydan muck -- drained fresh water marsh. (Colors are for moist soil.)
Op--0 to 6 inches; black (10YR 2/1) muck; moderate fine and medium granular structure; friable; very strongly acid; abrupt smooth boundary. (0 to 8 inches thick)
Bg--6 to 12 inches; grayish brown (10YR 5/2) silty clay; moderate medium subangular blocky structure; firm, plastic; common fine roots; common prominent streaks of strong brown (7.5YR 5/8) along root channels and as patchy coatings on faces of peds; common vertical cracks 2 to 4 millimeters wide filled with black muck; strongly acid; clear wavy boundary. (4 to 12 inches thick)
Byg1--12 to 19 inches; dark gray (10YR 4/1) clay; weak coarse subangular blocky structure; firm, plastic and sticky; common prominent streaks of strong brown (7.5YR 5/8) along root channels and as coatings on faces of peds; common vertical cracks 2 to 4 millimeters wide filled with black muck; few medium pockets of white crystals (gypsum); slightly acid; clear wavy boundary. (6 to 15 inches thick)
Byg2--19 to 36 inches; gray (5Y 5/1) clay; weak coarse subangular blocky structure; firm, plastic and sticky; common prominent streaks of strong brown (7.5YR 5/8) along root channels and as coatings on faces of peds; few vertical cracks 2 to 4 millimeters wide; few medium pockets of white crystals (gypsum); few medium brown concretions; neutral; gradual wavy boundary. (5 to 20 inches thick)
BCg--36 to 46 inches; gray (5Y 5/1) clay; few medium distinct light olive brown (2.5Y 5/4) mottles; massive; firm, sticky and plastic; few prominent streaks of strong brown (7.5YR 5/8) on surfaces of cracks; polygonal network of cracks 0.25 to 0.5 inch wide; common fine and medium brown concretions; moderately alkaline; clear wavy boundary. (0 to 15 inches thick)
2Ab--46 to 60 inches; dark gray (N 4/0) silty clay; common medium prominent light olive brown (2.5Y 5/4) mottles; massive; firm, plastic and sticky; moderately alkaline; clear wavy boundary. (0 to 15 inches thick)
2Bkgb--60 to 80 inches; gray (5Y 5/1) clay; common medium prominent olive (5Y 5/6) mottles; massive; plastic and sticky; common medium white concretions (calcium carbonate); moderately alkaline.
TYPE LOCATION: Vermillion Parish, Louisiana; about 7.0 miles south of Gueydan, 1.5 miles east of Louisiana Highway 91, 500 feet northwest of levee; T. 13 S., R. 1 W.
RANGE IN CHARACTERISTICS: Thickness of the solum to buried soil material ranges from 24 to 80 inches or more. The n-values are less than 0.7 in all mineral horizons to a depth of 40 inches or more. Reaction ranges from extremely acid to medium acid in the Op or Oa horizon, from extremely acid to medium acid in the Bg, Byg and BCg horizons, and from mildly alkaline to moderately alkaline in the 2A and 2B horizons.
The O horizon, where present, has hue of 10YR, value of 2 or 3, and chroma of 1 or 2.
The A horizon, where present, has hue of 10YR, value of 2 to 4, and chroma of 1 or 2. Where value is 2 or 3, the horizon is less than 6 inches thick. Texture is mucky clay, clay, or silty clay.
The Bg, Byg, and BCg horizons have hue of 10YR, 5Y, 5BG, 5GY, or 5G, value of 3 to 5, and chroma of 1 or 2, or have neutral chroma with values of 4 to 6. Texture is clay or silty clay. At least some subhorizon of the B horizon has a polygonal network of cracks 2 to 20 millimeters wide that do not close when the soil is wet.
The 2A and 2B horizons have the same color range as the Bg, Byg, and BCg horizons. Texture is clay, silty clay, or silty clay loam.
COMPETING SERIES: There are no other series in this family. The
Barbary,
Gentilly,
Larose, and
Rita series are in similar families. Barbary, Gentilly, and Larose soils have higher n-values in the 8 to 20 inch portion of the control sections. Rita soils have n-values greater than 0.7 within 36 inches.
GEOGRAPHIC SETTING: Gueydan soils are in drained fresh water marshes at elevations at or below sea level. These soils formed in a thick layer of recent clayey alluvium over subsided Prairie-age terrace deposits. These soils are protected from flooding by a system of levees and pumps. Slope is less than 1 percent. Near the type location the annual rainfall is about 53 inches and the mean annual temperature is about 68 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing
Larose series and the
Allemands and
Ged series. Allemands soils are organic and Ged soils have argillic horizons.
DRAINAGE AND PERMEABILITY: Gueydan soils are poorly drained. Runoff is slow to very slow. Permeability is very slow. Water and air, however, move freely through a lateral network of cracks in the lower part of the B horizon. The water table is generally maintained at 1 to 3 feet below the soil surface. It is controlled by a system of levees, ditches, and pumps.
USE AND VEGETATION: Used mainly as cropland and pastureland. Rice is the principal crop.
DISTRIBUTION AND EXTENT: Along the gulf coast marshes of Louisiana and possibly southeast Texas. The soils of this series are of moderate extent.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: AUBURN, ALABAMA
SERIES ESTABLISHED: Vermillion Parish, Louisiana; 1989.
REMARKS: These soils were formerly mapped as Harris soils, drained.
Diagnostic horizons and features recognized in this pedon are:
Irregular carbon distribution - 6 to 60 inches
Cracks - 6 to 46 inches
ADDITIONAL DATA: Sampled as S85LA113-4
National Cooperative Soil Survey
U.S.A.