LOCATION LEERCO TXEstablished Series
TAXONOMIC CLASS: Fine, smectitic, nonacid, hyperthermic Typic Hydraquents
TYPICAL PEDON: Leerco muck--marsh rangeland.
(Colors are for moist soil unless otherwise stated.)
Oe--0 to 5 inches; black (10YR 2/1) muck, about 30 percent fiber, about 20 percent rubbed; about 20 percent mineral matter; massive; fluid; many fine to coarse roots; very slightly saline; moderately acid; clear smooth boundary. (3 to 10 inches thick)
Ag--5 to 14 inches; very dark gray (2.5Y 3/1) mucky clay; massive; slightly fluid, flows with difficulty between fingers when squeezed leaving small residue (n-value 0.7 to 1); common fine roots; slightly saline; moderately acid; gradual smooth boundary. (5 to 15 inches thick)
Cg1--14 to 26 inches; gray (2.5Y 5/1) clay; massive; slightly fluid, flows with difficulty between fingers when squeezed leaving small residue (n-value 0.7 to 1.0); common strata of dark gray (10YR 4/1) mucky clay 1 to 2 cm thick; common medium dark gray (2.5Y 4/1) masses with diffuse boundaries; few fine iron-manganese concretions; slightly saline; moderately acid; gradual smooth boundary.
Cg2--26 to 34 inches; gray (2.5Y 5/1) clay; massive; slightly fluid, flows with difficulty between fingers when squeezed leaving small residue (n-value 0.7 to 1.0); common strata of very dark gray (2.5Y 3/1) mucky clay 1 to 2 cm thick; common medium faint dark gray (2.5Y 4/1) masses with diffuse boundaries; common medium prominent yellowish brown (10YR 5/4) iron accumulations; few fine iron-manganese concretions; moderately saline; strongly acid; gradual smooth boundary.
Cg3--34 to 80 inches; gray (2.5Y 6/1) clay; massive; very fluid, flows easily between fingers when squeezed leaving small residue (n-value 1.0 to 1.5); few strata of very dark gray (2.5Y 3/1) mucky clay 1 cm thick; common medium faint dark gray (2.5Y 4/1) and gray (2.5Y 5/1) masses with diffuse boundaries; common fine distinct black (2.5Y 2.5/1) iron-manganese concentrations; moderately saline; moderately acid. (combined thickness of the Cg horizons is 55 to 70 inches)
TYPE LOCATION: Jefferson County, Texas; from the intersection of Texas Highway 87 and Farm Road 3322 in Sabine Pass; 12 miles west on Texas Highway 87 to McFaddin Marsh National Wildlife Refuge; 5.0 miles northwest on refuge road to Intracoastal Waterway; 3.0 miles southwest on road along Intracoastal Waterway; 0.35 mile south on levee; 100 feet east in marsh. (Latitude 29N, 41, 03; Longitude 94W, 09, 18)
RANGE IN CHARACTERISTICS: The soils are saturated with slightly brackish water most of the year. N-value ranges from 0.7 to 1.0 within 8 inches of the surface. Depth to n-value that ranges from 1.0 to 2.0 is from 20 to 40 inches and extends to more than 80 inches. Electrical conductivity of the upper 10 inches is less than 4 dS/m and ranges from 4 to 12 dS/m in the lower part of the pedon. The particle-size control section contains 40 to 60 percent clay.
The Oe horizon has color with hue of 10YR to 5Y, or N, value of 2 to 5, and chroma of 1 or less. Texture is muck, peat, or mucky peat. Reaction ranges from moderately acid to neutral.
The A horizon has color with hue of 10YR to 5Y, or N, value of 2 to 4, and chroma of 1 or less. Texture is silty clay, clay, or mucky clay. Reaction ranges from moderately acid to slightly alkaline.
The Cg horizons have color with hue of 10YR to 5BG, or N, value of 3 to 6, and chroma of 1 or less. Most pedons have few to common strata of muck or mucky clay, 5 mm to 3 cm thick, with hue 10YR to 5Y, value 2 or 3, and chroma 1. Redox features, mainly iron-manganese and iron accumulations, are in shades of black, brown, and gray. Texture is silty clay or clay. Reaction ranges from moderately acid to slightly alkaline.
COMPETING SERIES: These are the Caplen, Creole, and Gentilly series in the same family and Bancker, Barnett, Barbary, Larose, and Scatlake series in similar families. Caplen, Bancker, Larose, and Scatlake series have n-values more than 1.0 throughout. Creole soils have EC of more than 4 dS/m in the surface layers. Gentilly series have n-values in the lower horizons of less than 0.7. Barnett series have n-values in the upper part that are less than 0.7. Barbary and Larose series are less saline.
GEOGRAPHIC SETTING: Leerco soils are in intermediate Gulf Coast marshes mainly adjacent to upland soils. The soil formed in clayey sediments of Holocene age. Slopes are less than 1 percent. Mean annual precipitation ranges from 50 to 62 inches. Mean annual temperature ranges from 70 to 72 degrees F. Frost free days range from 250 to 270. Elevation ranges from 0 to 2 feet. The Thornthwaite P-E index is 68 to 80.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Caplen and Creole soils, and the similar Barnett and Bancker soils. Also associated are the Allemands and Zummo soils. Allemands soils are Histosols. Zummo soils have n-value of less than 0.7 within 15 inches of the surface. All of these soils are on similar landscape positions.
DRAINAGE AND PERMEABILITY: Leerco soils are very poorly drained. Runoff is negligible. Permeability is very slow. The water table ranges from the surface to a depth of 0.5 foot below the soil surface. Leerco soils are frequently flooded with slightly brackish water to a depth of 1 to 2 feet during high tides. Flooding to a depth of several feet occurs during major storms. These soils also flood with fresh runoff water from adjacent uplands after heavy rains.
USE AND VEGETATION: Used mainly for wildlife land and rangeland. The vegetation consists of seashore paspalum, marshhay cordgrass, commom reed, knotroot bristlegrass, longtom, cockspur, sprangletop, bulrush, cattails, arrowhead, and smartweed.
DISTRIBUTION AND EXTENT: The Gulf Coast Marsh (MLRA 151) of Texas and possibly Louisiana. The series is of minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Jefferson County, Texas; 1996. The name is coined.
REMARKS: Leerco soils were formally included in the Harris and Creole series.
Diagnostic horizons and features recognized in this pedon are:
Hemic soil materials - 0 to 5 inches (Oe horizon).
Mollic epipedon - 5 to 14 inches (Ag horizon).
n-value - more than 0.7 from 0 to 80 inches.
Aquic features - Redoximorphic features, reduction, and saturation throughout the pedon all year.
SOIL INTERPRETATION RECORD NUMBER: TX1305