LOCATION GENEVA TX+LA
Established Series
SJR-DJS-ACP
12/2022
GENEVA SERIES
The Geneva series consists of deep, well drained, very slowly permeable soils. They formed in weakly consolidated fluvial marine deposits of loamy and clayey sediments of the Wilcox group of the Tertiary system. These moderately steep to steep soils occur on side slopes of hills and interfluves on Western Coastal Plains (MLRA 133B). Slope ranges from 15 to 40 percent. Mean annual precipitation is about 1,346 mm (53 in) and the mean annual air temperature is about 18 degrees C (64 degrees F).
TAXONOMIC CLASS: Fine, smectitic, thermic Vertic Hapludalfs
TYPICAL PEDON: Geneva silt loam, 35 percent slope in loblolly pine forest at an elevation of 67 m (220 ft). (Colors are for moist soil unless otherwise stated.)
A--0 to 7 cm (0 to 3 in); very dark grayish brown (10YR 3/2) fine sandy loam; weak fine granular structure; friable, soft, nonsticky, nonplastic; common very fine, fine, and medium roots throughout; common medium irregular pores; very strongly acid; clear smooth boundary. (Thickness of the A horizon is 5 to 18 cm [2 to 7 in].)
E--7 to 18 cm (3 to 7 in); brown (10YR 4/3) fine sandy loam; weak fine subangular blocky; friable, soft, nonsticky, nonplastic; common very fine and fine roots throughout; few medium irregular pores; very strongly acid; clear wavy boundary. (Thickness of the E horizon is 3 to 13 cm [1 to 5 in].)
Bt1--18 to 38 cm (7 to 15 in); yellowish red (5YR 5/6) clay; strong medium subangular blocky structure; firm, moderately hard, very sticky, very plastic; common very fine roots throughout and few fine roots throughout; few fine tubular pores; 30 percent faint reddish brown (5YR 4/4), moist, clay films on all faces of peds; linear extensibility percent (LEP) is 10; extremely acid; gradual wavy boundary.
Bt2--38 to 56 cm (15 to 22 in); yellowish red (5YR 5/6) silty clay; strong medium subangular blocky structure; firm, moderately hard, moderately sticky, moderately plastic; common very fine roots throughout; few fine tubular pores; 30 percent faint yellowish red (5YR 5/6), moist, clay films on all faces of peds; 10 percent medium distinct pinkish gray (7.5YR 6/2), moist, masses of reduced iron with sharp boundaries in the matrix; linear extensibility percent (LEP) is 11; extremely acid; gradual wavy boundary. (Combined thickness of the Bt horizons is 35 to 75 cm [14 to 30 in].)
BCt--56 to 72 cm (22 to 28 in); yellowish red (5YR 5/6) silty clay; moderate medium platy structure parts to moderate medium prismatic structure; firm, moderately hard, moderately sticky, moderately plastic; few very fine roots throughout; few very fine tubular pores; 25 percent faint yellowish red (5YR 5/6), moist, clay films on all faces of peds; 10 percent medium distinct light red (2.5YR 6/8), moist, masses of oxidized iron with clear boundaries in matrix and 10 percent medium prominent pinkish gray (7.5YR 6/2), moist, masses of reduced iron with clear boundaries in matrix; extremely acid; gradual wavy boundary. (Combined thickness of the BCt horizon is 0 to 25 cm [0 to 10 in].)
CBt1--72 to 84 cm (28 to 33 in); strong brown (7.5YR 5/6) silty clay loam; moderate thick platy structure; firm, slightly hard, slightly sticky, slightly plastic; few very fine roots throughout; few fine interstitial pores; 25 percent faint strong brown (7.5YR 5/6), moist, clay films on all faces of peds; 10 percent medium prominent light red (2.5YR 6/8), moist, mottles with clear boundaries in matrix and 10 percent medium faint pinkish gray (7.5YR 6/2), moist, extremely acid; gradual wavy boundary.
CBt2--84 to 106 cm (33 to 42 in); reddish yellow (7.5YR 6/6) silty clay; moderate thick platy structure; firm, moderately hard, slightly sticky, slightly plastic; few very fine roots throughout; few fine interstitial pores; 5 percent faint reddish yellow (7.5YR 6/6), moist, clay films on all faces of peds; 10 percent medium prominent light red (2.5YR 6/8), moist, mottles with clear boundaries in matrix and 10 percent medium faint pinkish gray (7.5YR 6/2), moist, mottles with clear boundaries in matrix; extremely acid; gradual wavy boundary. (Combined thickness of the BtC horizons is 0 to 40 cm [0 to 16 in].)
C--106 to 203 cm (42 to 80 in); very dark grayish brown (10YR 3/2) silty clay loam; massive structure; friable, slightly hard, nonsticky, nonplastic; extremely acid. (Thickness of the C horizon is 0 to 100 cm [0 to 39 in].)
TYPE LOCATION: Harrison County, Texas; from the intersection of FM 134 and FM 2606 in Karnack, TX; 0.7 miles north on FM 2606; 0.8 miles northeast on FM 2198; 1,480 feet northwest in woods.
USGS Topographic Quadrangle: Karnack, TX
Latitude: 32 degrees, 41 minutes, 21.24 seconds N
Longitude: 94 degrees, 10 minutes, 22.37 seconds W
Decimal Degrees:
Latitude: 32.6892333 degrees
Longitude: -94.1728806 degrees
Datum: WGS 84
RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 19 to 21 degrees C (66 to 70 degrees F)
Abrupt textural change: 7 to 35 cm (3 to 14 in)
Depth to argillic horizon: 7 to 35 cm (3 to 14 in)
Depth to redox concentrations: 7 to 35 cm (3 to 14 in)
Depth to redox depletions: 20 to 40 cm (8 to 16 in)
Vertic features: 7 to 35 cm (3 to 14 in) with a linear extensibility percent (LEP) greater than 9
Particle-size control section (weighted average):
Clay content: 45 to 65 percent; the clay content in the upper part of the Bt horizon is higher than the clay content in the lower part of the epipedon. Typically, the lower solum decreases about 20 to 30 percent in clay content, or a C horizon is encountered within 152 cm (60 in) of the surface.
Linear extensibility percent (LEP): 9 to 14 in the upper 51 cm (20 in) of the Bt horizon
Potential linear extensibility (PLE): 6 to 10 cm (2.5 to about 4 in) in the upper 127 cm (50 in). The soil cracks when dry, typically between June and September. The cracks are 1.5 cm (0.5 in) or wider at a depth of 51 cm (20 in) and are at least 31 cm (12 in) long.
Base saturation: 35 to 60 percent at 127 cm (50 in) below the top of the argillic horizon or at the base of a CB horizon, whichever is shallower.
Fragments: amount-few; size-mainly less than 15 cm (6 in) across; kind-petrified wood, fossilized shells, or ironstone pebbles
A horizon:
Hue: 7.5YR or 10YR
Value: 2 to 5
Chroma: 2 to 4
Other features: where value is 3 and chroma is 3 or less, the horizon thickness is less than 18 cm (7 in)
Texture: fine sandy loam, very fine sandy loam, loam, or silt loam
Reaction: very strongly acid to moderately acid, unless limed (4.5 to 6.0)
E or E/B horizon (where present):
Hue: 7.5YR or 10YR
Value: 4 to 6
Chroma: 3 to 6
Texture: fine sandy loam, very fine sandy loam, loam, or silt loam
Reaction: very strongly acid to moderately acid, unless limed (4.5 to 6.0)
Bt horizon (upper part):
Hue: 2.5R to 10YR
Value: 3 to 6
Chroma: 4 to 8
Texture: silty clay or clay
Clay content: 40 to 65 percent
Other features: a few pedons have an upper Bt with a texture of clay loam
Clay loam textures: 35 to 40 percent, thickness is 18 cm (7 in) or less
Slickensides and/or pressure faces: amount-none to common in the Bt1 horizon
Redox depletions: 0 to 22 percent; contrast-distinct or prominent; boundary-sharp; location-in matrix; color-gray
Reaction: extremely acid to strongly acid (3.5 to 5.5)
Bt horizon (lower part):
Red colors
Hue: 10R to 5YR
Value: 4 or 5
Chroma: 4 to 8
Brown colors
Hue: 7.5YR to 2.5Y
Value: 5 or 6
Chroma: 4 to 8
Gray colors
Hue: 10YR or 2.5Y
Value: 4 to 7
Chroma: 1 or 2
Texture: clay loam, silty clay loam, silty clay, or clay
Clay content: 35 to 60 percent
Slickensides and/or pressure faces: amount-few to common; slickensides are less than 10 cm (4 in) across
Redox concentrations: amount-2 to 20 percent; contrast-distinct or prominent; color-red, yellow, brown, or gray; boundary-sharp; location-in matrix
Reaction: extremely acid to moderately acid (3.5 to 6.0)
BCt horizon:
Hue: 2.5YR to 10YR
Value: 4 to 7
Chroma: 4 to 8
Texture: sandy clay loam, clay loam, silty clay loam, silty clay, or clay
Mottles: amount-2 to 20 percent; contrast-distinct or prominent; color-red, yellow, brown, or gray; boundary-sharp; location-in matrix
Barite: amount-none to common; kind-masses; location-in matrix
Reaction: extremely acid to slightly acid (3.5 to 6.5)
CB horizon:
Red colors
Hue: 10R or 5YR
Value: 3 to 5
Chroma: 2 to 8
Brown colors
Hue: 7.5YR to 2.5Y
Value: 4 or 6
Chroma: 4 to 8
Texture: sandy clay loam, clay loam, silty clay loam, silty clay, or clay
Mottles and/or strata: amount-2 to 20 percent; contrast-distinct or prominent; color-shades of red, yellow, brown, or gray, or variegated matrix with these colors; boundary-sharp; location-in matrix;
Reaction: extremely acid to moderately acid (3.5 to 6.5)
C horizon:
Hue: 2.5YR to 2.5Y
Value: 3 to 7
Chroma: 1 to 8
Texture: fine sandy loam, silty clay loam, or clay
Barite: amount-none to common; kind-masses; location-in matrix
Reaction: extremely acid to moderately acid (3.5 to 6.5)
COMPETING SERIES: These are the
Atasco,
Chickasaw,
Colbert,
Etoile,
Iota,
Kellison,
Oakhurst,
Oula,
Rayburn,
Telogia, and
Woodtell series.
Atasco soils: are very deep
Chickasaw soils: have a paralithic contact
Colbert series: formed in limestone bedrock
Etoile soils: are more alkaline, formed in marl, and have lower woodland productivity potential
Iota soils: formed in red alluvium presumed to be derived originally from Permian age redbeds and associated sediments
Kellison soils: have a brown argillic horizon (10YR or 2.5Y) in the upper part
Oakhurst soils: have a brown argillic horizon (10YR or 2.5Y) in the upper part and are formed in tuffaceous materials that overlie siltstone and sandstone strata
Oula soils: typically have a more grayish subsoil
Rayburn soils: formed in tuffaceous sandstone
Telogia soils: formed in limestone
Woodtell soils: have slightly higher reaction in the lower part of the argillic horizon, less annual rainfall, and lower woodland productivity potential
GEOGRAPHIC SETTING:
Parent material: weakly consolidated fluvial marine deposits of loamy and clayey sediments of the Wilcox group of the Tertiary system
Landscape: Coastal Plain
Landform: interfluves
Slope: 15 to 40 percent, typically 20 to 35 percent
Mean annual precipitation: 1,270 to 1,346 mm (50 to 53 in)
Mean annual air temperature: 17 to 18 degrees C (63 to 64 degrees F)
Frost-free period: 226 to 238 days
Elevation: 45 to 190 m (147 to 623 ft)
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Dreka,
Eastwood,
Laneville,
Metcalf,
Hallsummit, and
Sawtown series.
Dreka soils: are lower on flood plains and are nearly level
Eastwood soils: have a sola greater than 100 cm (40 in) thick
Laneville soils: are lower on flood plains and are nearly level
Metcalf soils: have a fine-silty family and are on slightly lower and nearly level positions
Hallsummit soils: do not have vertic properties, do not have shale strata within a depth of 152 cm (60 in), have mixed clay mineralogy and are on slightly higher positions
Sawtown soils: are on mounded lower stream terraces with a fine-loamy control section
DRAINAGE AND PERMEABILITY:
Drainage: well
Permeability: very slow
Runoff: very high
USE AND VEGETATION:
Major uses: woodland but some areas are used for improved pasture
Native vegetation: includes loblolly pine, shortleaf pine, southern red oak, sweetgum, and hickory; mid and tallgrasses include pinehill bluestem, longleaf uniola, and panicums. American beautyberry, sumac, greenbriar and hawthorn species are part of the shrub and vine understory. Improved pastures consist mainly of bermudagrass and bahiagrass with crimson and arrowleaf clovers.
Ecological sites assigned to phases and components of this series are listed below. Current ecological site assignments are in Web Soil Survey. Components of this series include the following ecological sites: Loamy over Clayey Uplands
DISTRIBUTION AND EXTENT:
General area: East Texas and western Louisiana
Land Resource Region: Land Resource Region: P-South Atlantic and Gulf Slope Cash Crops, Forest, and Livestock Region
MLRA 133B-Western Coastal Plain
Extent: small
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Temple, Texas.
SERIES ESTABLISHED: Shelby County, Texas, 2018. The name comes from a nearby community.
REMARKS:
The Geneva soils were formerly included in the Maben and Eastwood series. Geneva soils are in higher sloping areas on the Wilcox geology and in MLRA 133B Western Coastal Plains. The Maben soils are mapped in MLRA 133A on similar geologies.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: 0 to 18 cm (0 to 7 in) (A and E horizon)
Abrupt textural change: at 18 cm (7 in) (top of Bt1 horizon)
Argillic horizon: 18 cm to 106 cm (7 to 42 in) (Bt, BtC, and CBt horizons)
Vertic properties: COLE of 0.23 to 0.36 cm (0.09 to 0.14 in) and PLE greater than 6 cm (2.5 in)
ADDITIONAL DATA: None
TAXONOMIC VERSION: Keys to Soil Taxonomy, 12th Edition, 2014
National Cooperative Soil Survey
U.S.A.