LOCATION VAMONT TXEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Oxyaquic Dystruderts
TYPICAL PEDON: Vamont clay-forest
(Colors are for moist soil unless otherwise stated.)
A--0 to 5 inches; grayish brown (10YR 5/2) clay, moderate medium subangular blocky structure; very hard, very firm, very sticky and very plastic; many very fine to medium roots; very few faint dark grayish brown (10YR 4/2) organic coats on surfaces of peds; few bits of charcoal; many fine and medium interstitial and tubular pores; 4 percent fine and medium prominent strong brown (7.5YR 4/6) iron concentrations along roots and pores; extremely acid; clear smooth boundary. (3 to 9 inches thick)
Bw--5 to 19 inches; 50 percent reddish yellow (7.5YR 6/8) and 50 percent light gray (10YR 7/2) clay; moderate fine and medium angular blocky structure; very hard, very firm, very sticky and very plastic; many very fine and fine roots; common fine and medium tubular pores; few distinct pressure faces; 3 percent fine prominent yellowish red (5YR 5/8) iron concentrations along roots, pores, and surfaces of peds; extremely acid; gradual wavy boundary. (0 to 15 inches)
Bssg1--19 to 44 inches; 55 percent light gray (10YR 7/2) and 40 percent reddish yellow (7.5YR 6/8) clay; moderate medium angular blocky structure; extremely hard, extremely firm, very sticky and very plastic; many very fine, fine and few medium roots; common fine tubular pores; common distinct pressure faces; 5 percent fine prominent yellowish red (5YR 5/8) iron concentrations along roots, pores, and surfaces of peds; common distinct slickensides; extremely acid; gradual wavy boundary.
Bssg2--44 to 66 inches; light gray (N 7/0) clay; moderate fine and medium angular blocky structure; extremely hard, extremely firm, very sticky and very plastic; common very fine and fine roots; few fine tubular pores; common distinct pressure faces; many distinct slickensides; 8 percent fine and medium prominent reddish yellow (7.5YR 6/8) iron concentrations with clear boundaries; 5 percent medium and coarse prominent red (2.5YR 4/6) iron concentrations with sharp boundaries; 2 percent fine prominent yellowish red (5YR 5/8) iron concentrations with sharp boundaries along roots, pores and surfaces of peds; very strongly acid; gradual wavy boundary.
Bssg3--66 to 80 inches; 50 percent light gray (N 7/0) and 35 percent strong brown (7.5YR 5/8) clay; moderate fine and medium angular blocky structure; extremely hard, extremely firm, very sticky and very plastic; common very fine and fine roots; few fine tubular pores; common distinct pressure faces; many distinct slickensides; 15 percent fine and medium faint reddish yellow (7.5YR 6/8) iron concentrations with clear boundaries on surfaces of peds; 1 percent fine distinct greenish gray (5BG 6/1) iron depletions with diffuse boundaries along roots; very strongly acid. (combined thickness of the Bssg horizons is 55 to 75 inches)
TYPE LOCATION: Hardin County, Texas; from the intersection of Texas Highway 770 and Texas Highway 787 in Saratoga; 6.7 miles northwest on Texas Highway 787 to forest road; 3.1 miles southwest on forest road; 0.3 mile west on forest road; 100 feet north in pine plantation.(Latitude is 30N, 19, 30; Longitude is 94W, 37, 40.)
RANGE IN CHARACTERISTICS: The range in characteristics includes 50 percent or more of the pedon. Solum thickness is more than 80 inches. This cyclic soil ranges from about 4 to 12 feet from the top of the microhigh to the center of the microlow. Undisturbed areas have gilgai microrelief with microhighs 6 to 18 inches higher than microlow. Texture is clay or silty clay. Slickensides and wedge-shaped peds begin at a depth ranging from 8 to 25 inches below the soil surface. The soil is usually moist, but during the summer in some years cracks 1 to 2 inches wide extend from the surface to depths more than 20 inches. Iron-manganese concretions, 2 to 5 mm across, range from none to common throughout.
Soil Moisture: An udic soil moisture regime. The soil moisture control section is 4 to 12 inches.
Mean annual soil temperature: 69 to 72 degrees F.
Particle-size control section (weighted average)
Clay content: 45 to 60 percent
Silt content: 30 to 45 percent
A Horizon
Hue: 10YR
Value: 3 to 5
Chroma: 1 to 3
Redox concentrations: amount-2 to 4 percent, size-fine to medium, color-shades of brown; contrast-distinct or prominent, boundary-clear or diffuse, location-along roots and pores and on surfaces of peds
Reaction: extremely acid or very strongly acid
Bw Horizon
Hue: 7.5YR or 10YR
Value: 50 to 75 percent is 4 to 6 and 25 to 50 percent is 5 to 7
Chroma: 50 to 75 percent is 4 to 8 and 25 to 75 percent is 1 or 2
Redox concentrations: amount-2 to 25 percent, size-fine to coarse, color-shades of yellow, brown, or red, contrast-faint to prominent, boundary-diffuse to sharp, location-throughout
Redox depletions: amount-2 to 15 percent, size-fine or medium, color-shades of gray, contrast-distinct or prominent, boundary-clear or diffuse, location-throughout
Reaction: extremely acid to strongly acid
Upper Bssg Horizons
Hue: 7.5YR or 10YR
Value: 5 to 8
Chroma: 55 to 70 percent is 1 or 2, and 30 to 45 percent is 4 to 8
Redox concentrations: amount-2 to 25 percent, size-fine to coarse, color-shades of yellow, brown, or red, contrast-faint to prominent, boundary-diffuse to sharp, location-throughout
Redox depletions: amount-2 to 15 percent, size-fine or medium, color-shades of gray, contrast-distinct or prominent, boundary-clear or diffuse, location-throughout
Reaction: extremely acid to strongly acid
Lower Bssg Horizons
Hue: 10YR, 2.5Y, or N/
Value: 5 to 7
Chroma: 0 to 2
Redox concentrations: amount-2 to 25 percent, size-fine to coarse, color-shades of yellow, brown, or red, contrast-faint to prominent, boundary-diffuse to sharp, location-throughout
Redox depletions: amount-2 to 15 percent, size-fine or medium, color-shades of gray, contrast-distinct or prominent, boundary-clear or diffuse, location-throughout
Reaction: extremely acid to slightly acid
COMPETING SERIES: There are no other series in the same family. Similar soils are the
China,
Ichusa,
League, and
Louin series.
China and League soils: hyperthermic temperature regime and have a mollic epipedon
Ichusa and Louin soils: have aquic conditions in some part in most years
GEOGRAPHIC SETTING:
Parent material: Clayey sediments derived from the Beaumont Formation of late Pleistocene age.
Landform: Flats
Slope: 0 to 3 percent
Mean annual air temperature: 67 to 69 degrees F.
Mean annual precipitation: 48 to 60 inches
Precipitation pattern: Uniform throughout the year with slight peaks in spring and fall
Frost-free period: 240 to 270 days
Elevation: 15 to 75 feet
Thornthwaite annual P-E indices: 68 to 80
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Bevil,
Evadale,
Gist, and
Texla series.
Bevil soils: have aquic conditions and are in depressions
Evadale soils: loamy surface layer on similar landscape positions
Gist and Texla soils: loamy surface layer and on mounds
DRAINAGE AND PERMEABILITY: Somewhat poorly drained. Permeability is very slow. Runoff is high on 0 to 1 percent slopes. Runoff is very high on 1 to 3 percent slopes. The soil is ponded for less than two weeks and aquic conditions may occur during the months of January to March in the microlows. Microhighs become saturated during this time but do not have aquic conditions or reduce. The microlows make up less than 50 percent of the pedon.
USE AND VEGETATION: Used mainly for woodland and pasture with some areas in rice cultivation. Woodlands are mainly loblolly pine and red oak. Grasses are mainly species of andropogon, paspalum and panicum.
DISTRIBUTION AND EXTENT: Western Gulf Coast Flatwoods (LRR T; MLRA 152B) of Texas and possibly Louisiana mainly east of the San Jacinto River. The series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Harris County, Texas; 1973.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Particle size control section: 10 to 40 inches. (A, Bw, Bssg horizons)
Ochric epipedon: 0 to 5 inches. (A horizon)
Oxaquic feature - are saturated with water for 30 or more days in most years. In 2 to 4 years out of 10 these soils have aquic soil conditions.
Vertisol feature - Slickensides at a depth of 19 to 80 inches with cracks that extend to a depth of 20 inches or more during dry periods.
Additional Comments: Vamont soils were formerly included with the Vaiden series. These soils were formerly classified as Aquentic Chromuderts and were reclassified to Oxyaquic Hapluderts 10/94 based on amendment 16 to Soil Taxonomy. The series was reclassified in April 2000 from Hapluderts to Dystruderts based on lab data. The series type location was moved to Hardin County, April 2000, to reflect a more central location in the series province with lab data.
ADDITIONAL DATA: Data from the Texas A&M University Soil Characterization Laboratory on sample S98TX199-001; Hardin County, Texas.
TAXONOMIC VERSION: Soil Taxonomy, Second Edition, 1999