LOCATION KEMAH TXEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Typic Albaqualfs
TYPICAL PEDON: Kemah silt loam-pasture.
(Colors are for moist soil unless otherwise stated.)
A--0 to 10 inches; dark grayish brown (10YR 4/2) silt loam, grayish brown (10YR 5/2) dry; weak medium subangular blocky structure; hard, friable, nonsticky and nonplastic; many fine and medium roots; common fine pores; few yellowish brown organic stains; medium acid; abrupt smooth boundary. (4 to 22 inches)
E--10 to 15inches; grayish brown (10YR 5/2) loam, light brownish gray (10YR 6/2) dry; few fine distinct dark red (2.5YR 3/6) mottles; weak medium subangular blocky structure; hard, friable, nonsticky and nonplastic; few fine roots; common fine pores; few dark grayish brown krotovina; strongly acid; abrupt wavy boundary. (0 to 18 inches)
Btg1--15 to 24 inches; mottled dark gray (10YR 4/1) and grayish brown (10YR 5/2) clay; many fine prominent dark red (2.5YR 3/6) and yellowish brown (10YR 5/6) mottles; moderately fine subangular blocky structure, very hard, very firm, sticky and plastic; few fine roots; common shiny pressure faces; few patchy clay films on faces of peds; few dark krotovina; few dark concretions 2 to 4 mm across; medium acid; gradual wavy boundary. (5 to 38 inches)
Btg2--24 to 38 inches; grayish brown (10YR 5/2) clay, light brownish gray (10YR 6/2) dry; common fine distinct yellowish brown (10YR 5/6) and few fine distinct dark red (2.5YR 3/6) mottles; moderate fine subangular blocky structure; very hard, very firm, sticky and plastic; common shiny pressure faces; few f1ne roots; streaks of dark grayish brown krotovina; few shiny ped surfaces; few patchy clay films on faces of peds; few dark concretions 2 to 4 mm across; medium acid; gradual wavy boundary. (6 to 30 inches)
Btg3--38 to 60 inches; grayish brown (2.5YR 5/2) sandy clay loam, light brownish gray (10YR 6/2) dry; moderate medium subangular blocky structure; few fine roots; few shiny ped surfaces few patchy clay films on faces of peds; few medium dark concretions 2 to 5 mm across; neutral.
TYPE LOCATION: Galveston County, Texas; from the intersection of Texas Highway 146 and Farm Road 517 about 7 miles east of Dickinson, 1.1 miles south on Texas Highway 146, 100 feet east on a paved road going under Dickinson Bayou bridge, and 50 feet east in a pasture.
RANGE IN CHARACTERISTICS: Combined thickness of the A and E horizons ranges from 10 to 22 inches in over 60 percent of the pedon. The solum thickness is greater than 50 inches. Typically, the boundary between the A or E and B horizon is abrupt but ranges to clear. COLE ranges from 0.07 to 0.10 in the B horizons and PLE ranges from 4 to 6 cm in the upper 1 meter of the soil.
The A and Ap horizons have a hue of 10YR, value of 3 through 5, and chroma of 1 through 3. When the value is 3, the thickness is less than 7 inches. The texture is silt loam, loam, or fine sandy loam. Reaction is strongly acid through neutral.
The E horizon, where it exists, has a hue of 10YR, value of 5 through 7, and chroma of 1 or 2. Mottles in shades of red, yellow or brown range from none to common. The texture is silt loam, loam, or fine sandy loam. Reaction is strongly acid through neutral.
The Btg horizons have hues of 10YR or 2.5Y, value of 4 through 7, and chroma of 1 or 2. Mottles in shades of yellow, brown, or red range from few to many. The texture is clay, clay loam, or sandy clay loam. Pitted concretions of calcium carbonate range from none to few within the control section and range to common below the control section. Reaction is strongly acid through mildly alkaline in the control section and ranges to moderately alkaline in some pedons below the control section and may have a calcareous matrix.
The C and 2C horizon, where it occurs, has hues of 10YR or 2.5Y, value of 4 to 7, and chroma of 1 to 6. Mottles in shades of yellow and brown range from none to many. Texture is clay loam, sandy clay loam, clay, or silty clay loam. Some pedons have few to common pitted concretions of calcium carbonate. The reaction is neutral through moderately alkaline and noncalcareous.
COMPETING SERIES: These are the Alusa, Arol, Corrigan, Crowley, Falba, Leaksville, and Meikle series in the same family and the similar Cherokee, Edna, Forestdale, Inez, Meggett, Telferner, and Wrightsville series. Alusa, Edna, and Meikle soils have A horizons that averages less than 10 inches thick. Arol, Corrigan, Falba, and Leaksville soils have solums less than 40 inches thick. Cherokee soils have mixed mineralogy. Crowley soils have more than 50 percent silt in the control section. Forestdale soils lack an abrupt textural change from the A or E to the B. Inez and Telferner soils have temperatures above 72 degrees F. Meggett soils have mixed mineralogy. Wrightsville soils have tongues of glossic materials into a B horizon.
GEOGRAPHIC SETTING: The Kemah soils occur on nearly level to gently sloping uplands on slightly convex positions. Slope gradients range from 0 to 3 percent. Few circular mounds about 10 to 30 feet in diameter and 6 to 12 inches high occur in some places. The parent material is fluvial sediments of the Beaumont Formation which was deposited during the Pleistocene age. At the type location, the mean annual temperature is about 68 degrees F. and the average annual rainfall is about 45 inches. The Thornthwaite P-E index is 56 to 76.
GEOGRAPHICALLY ASSOCIATED SOILS: They include the Aris, Leton, and Verland and the competing Edna series. The Verland soils have finer textured A horizons and do not have an abrupt texture change. The Aris and Leton soils have tongues of E extending into the B horizon.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; slow runoff and internal drainage; very slow permeability. Seasonal high water table perches above the clayey subsoil at 0.5 to 1.5 feet below the surface, primarily during the winter months.
USE AND VEGETATION: Native vegetation was tall prairie grasses that included primarily Andropogons, Paspalums, switchgrass, and Indiangrass. Most of the soils are now cultivated and used for rice, soybeans, cotton, corn, and grain sorghum. Trees have encroached on some areas.
DISTRIBUTION AND EXTENT: Upper and middle Gulf Coast Prairies of Texas. The series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Gavleston County, Texas, 1983. The name is from a town in Galveston County.
REMARKS: These soils were formerly included in the Crowley series. High silt content in the surface is common in the eastern part of the series extent and rare in the western part where fine sandy loam textures are typical.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon
Abrupt textural increase
Argillic horizon
Aquic moisture regime
Low chroma colors and mottles