LOCATION FRANEAU TXEstablished Series
TAXONOMIC CLASS: Fine, smectitic, hyperthermic Typic Natraquerts
TYPICAL PEDON: Franeau clay--rangeland.
(Colors are for moist soil unless otherwise stated.
A1--0 to 4 inches; black (10YR 2/1) clay; moderate very fine blocky and subangular blocky structure; very hard, very firm; common fine and medium roots; few fine pores; slightly sodic; very slightly saline; slightly acid; gradual wavy boundary.
A2--4 to 16 inches; black (10YR 2/1) clay; moderate fine blocky and subangular blocky structure; very hard, extremely firm; common fine and medium roots; few fine pores; common pressure faces; slightly sodic; very slightly saline; slightly acid; gradual wavy boundary. (combined thickness of the A horizons is 10 to 20 inches)
Bssg1--16 to 21 inches; very dark gray (10YR 3/1) clay; moderate fine and medium angular blocky structure; extremely hard, extremely firm; common fine and medium roots; few fine pores; common prominent slickensides; common pressure faces; few fine iron-manganese concretions; slightly sodic; very slightly saline; slightly acid; gradual wavy boundary.
Bssg2--21 to 27 inches; very dark gray (10YR 3/1) clay; moderate medium angular blocky structure; extremely hard, extremely firm; few fine and medium roots; few fine pores; common prominent slickensides; few fine distinct yellowish brown (10YR 5/4) iron accumulations; common pressure faces; few fine iron-manganese concretions; moderately sodic; slightly saline; neutral; gradual wavy boundary.
Bssg3--27 to 42 inches; gray (10YR 5/1) clay; moderate medium and coarse angular blocky structure; extremely hard, extremely firm; few fine and medium roots; few fine pores; common prominent slickensides; common pressure faces; common medium prominent brownish yellow (10YR 6/6) iron accumulations; few fine iron-manganese concretions; moderately sodic; slightly saline; neutral; gradual wavy boundary.
Bssg4--42 to 54 inches; gray (2.5Y 6/1) clay; strong medium and coarse angular blocky structure; extremely hard, extremely firm; few fine roots; few fine pores; common prominent slickensides; common pressure faces; common medium prominent brownish yellow (10YR 6/6) iron accumulations; few fine iron-manganese concretions; moderately sodic; slightly saline; neutral; gradual wavy boundary .
Bssg5--54 to 61 inches; gray (2.5Y 6/1) clay; strong medium and coarse angular blocky structure; extremely hard, extremely firm; common prominent slickensides; common pressure faces; common medium prominent brownish yellow (10YR 6/6) iron accumulations; few fine iron-manganese concretions; moderately sodic; slightly saline; neutral; gradual wavy boundary.
Bssg6--61 to 80 inches; gray (2.5Y 6/1) clay; moderate medium and coarse angular blocky structure; extremely hard, extremely firm; few fine roots; common prominent slickensides; common pressure faces; common medium prominent brownish yellow (10YR 6/6) iron accumulations; few fine and medium iron-manganese concretions; moderately sodic; slightly saline; moderately alkaline; gradual wavy boundary. (combined Bssg horizons are 60 to 80 inches thick)
TYPE LOCATION: Jefferson County, Texas; from the intersection of State Highway 124 and State Highway 73 southwest of Hampshire; 2 miles west on State Highway 73; 12.55 miles south on State Highway 124; 1.7 miles east on private shell road; 1.05 miles south-southeast on shell road; 1,700 feet south-southeast to fence; 500 feet southeast in rangeland. (Latitude 29N, 37, 36; Longitude 94W, 20, 19)
RANGE IN CHARACTERISTICS: Solum thickness is greater than 80 inches. The clay content of the particle-size control section ranges from 45 to 60 percent. This is a cyclic soil and undisturbed areas have gilgai microrelief with microknolls 4 to 6 inches higher than microdepressions. Distance from the center of the microknoll to the center of the microdepression ranges from about 8 to 16 feet. The amplitude of waviness between mollic colored materials in the upper part of the solum and the higher value colors in the lower part ranges from about 10 to 30 inches. The chimneys of high value materials on the microknolls make up less than 5 percent of the surface area. They are mainly 5 to 10 feet long and 3 to 5 feet wide. When dry, the soil has cracks 1/2 to 2 inches wide at the surface and commonly 1/2 inch wide cracks extend to a depth of 2 feet during the summer. Slickensides begin at a depth of 12 to 24 inches and extend throughout the solum. Iron-manganese concretions, mainly less than 1/4 inch in diameter, range from none to a few throughout, and are mainly in the lower part of the solum. SAR ranges from 6 to 13 in the A horizon, and 13 to 30 in the Bssg horizon. Salinity increases with depth, and conductivity of the saturation extract ranges from 1 to 4 dS/m in the A horizon, 2 to 8 in the Bssg horizon. These soils have aquic conditions in most years.
The A horizon has color with hue of 10YR, value of 2 or 3 and chroma of 1. Iron accumulations in shades of brown range from none to common. Reaction is slightly acid or neutral.
The Bssg horizon has color in neutral colors with value of 6 or 7, or have hue of 10YR, value of 3 to 7, and chroma of 1 or 2, or hue of 2.5Y, value of 6 or 7, and chroma of 1. Iron accumulations in shades of brown or yellow range from few to common. Reaction is neutral in the upper part to moderately alkaline in the lower part. In some pedons the cycle below 60 inches has 2 to 5 percent calcium carbonate concretions and the reaction is moderately alkaline.
COMPETING SERIES: There are no competing series. Similar soils are the Francitas soils. Francitas soils are on higher landscape positions and are dry in the moisture control section for longer periods of time.
GEOGRAPHIC SETTING: Franeau soils are on broad, nearly level coastal plains less than 5 feet above sea level. Slopes are less than 1 percent. The soil formed in clayey sediments of the Pleistocene age Beaumont Formation. Mean annual precipitation ranges from 50 to 60 inches. Mean annual temperature ranges from 70 to 72 degrees F. Frost free days range from 250 to 270. Elevation ranges from 1 to 5 feet. Thornthwaite annual P-E indices range from 68 to 80.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Beaumont, China, League, Meaton and Harris soils. Beaumont, China and League soils are acid and are on slightly higher landscape positions. Meaton soils have argillic horizons and are on slightly higher landscape positions. Harris soils are on lower landscape positions that are flooded daily by tide.
DRAINAGE AND PERMEABILITY: Franeau soils are poorly drained. Runoff is low. Permeability is very slow. An apparent water table occurs in the A and Bssg horizons for a period of several months in most years. These soils have aquic conditions in most years. Storm surges cover most areas below 5 feet elevation about 5 to 50 times in 100 years.
USE AND VEGETATION: Used for native range and pasture. Native grasses are mainly gulf cordgrass, and species of andropogon and paspalum.
DISTRIBUTION AND EXTENT: Gulf Coast Prairie (MLRA 150A) of Texas east of the Trinity River and possibly in western Louisiana. The series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Jefferson County, Texas; 1996
REMARKS: The Franeau soils were formerly included with the Francitas series. The name Franeau is coined.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - 0 to 27 inches (A1, A2, Bssg1, Bssg2 horizon).
Cambic horizon - 27 to 80 inches (Bssg3, Bssg4, Bssg5, and Bssg5 horizons).
Aquic features - redoximorphic features 10 to 80 inches and aquic conditions in the upper part of the pedon in most years.
Vertisol features - Slickensides at a depth of 10 to 80 inches.
Natric features - SAR of 13 or more within 100 cm of the surface
SOIL INTERPRETATION RECORD NUMBER: TX0911