LOCATION DEMOPOLIS AL+AR MSEstablished Series
TAXONOMIC CLASS: Loamy, carbonatic, thermic, shallow Typic Udorthents
TYPICAL PEDON: Demopolis silty clay loam, on a convex 2 percent slope, in a pasture. (Colors are for moist soil.)
Ap--0 to 6 inches; dark grayish brown (2.5Y 4/2) silty clay loam; moderate medium granular structure; friable; few medium and many fine roots; common fine and medium nodules of calcium carbonate; about 5 percent fragments of soft chalk; strongly effervescent; moderately alkaline; abrupt smooth boundary. (2 to 8 inches thick)
C--6 to 13 inches; dark grayish brown (2.5Y 4/2) silty clay loam; weak fine and medium granular structure; friable; common fine roots; many fragments of soft chalk; common fine and medium nodules and soft masses of calcium carbonate; many fine and medium distinct olive yellow (2.5Y 6/8) masses of iron accumulation; violently effervescent; moderately alkaline; abrupt wavy boundary. (4 to 12 inches thick)
Cr--13 to 65 inches; light gray (5Y 7/2) and gray (5Y 6/1) chalk; moderate medium and thick platy rock structure; level-bedded; very firm; violently effervescent; moderately alkaline; gradual wavy boundary.
TYPE LOCATION: Marengo County, Alabama; 2.1 miles south of junction of U.S. Highways 80 and 43 on U. S. Highway 43; site is 300 feet west of road; 1000 feet north and 1000 feet east of southwest corner of sec. 4, T. 17 N., R. 3 E.
RANGE IN CHARACTERISTICS: Thickness of the soil over level-bedded, chalk bedrock ranges from 10 to 20 inches. Reaction is slightly alkaline or moderately alkaline throughout the profile and the soil is strongly or violently effervescent. The fine-earth fraction of the soil contains from 18 to 35 percent clay. Chalk fragments are considered pararock fragments and are not used in determining the particle-size family.
The A or Ap horizon has hue of 10YR or 2.5Y, value of 4 to 6, and chroma of 2 to 4. Texture is loam, silt loam, clay loam, or silty clay loam; or their channery or cobbly analogues. Percent by volume of chalk fragments ranges from 5 to 35 percent. Content of nodules, concretions, and/or soft masses of calcium carbonate ranges from few to many.
The C horizon has hue of 10YR to 5Y, value of 4 to 7, and chroma of 1 or 2. Redox accumulations in shades of brown and yellow range from none to common and are considered to be relic features. Texture is loam, silt loam, clay loam, or silty clay loam; or their channery or cobbly analogues. Percent by volume of soft chalk fragments ranges from 5 to 35 percent. Content of nodules, concretions, and/or soft masses of calcium carbonate ranges from common to many.
The Cr horizon is level-bedded chalk or soft limestone with platy rock structure. It can be excavated with difficulty with hand tools, and is rippable by mechanized equipment.
COMPETING SERIES: There are no other known series in the same family. Competing series in similar families include the Prim series. Prim soils have a mollic epipedon.
GEOGRAPHIC SETTING: Demopolis soils are on dissected uplands of the Blackland Prairie. Slopes range from 1 to 35 percent. It formed in materials weathered from thick beds of chalk, primarily the Demopolis and Mooreville Chalks of the Selma Group. The average annual air temperature ranges from 60 to 65 degrees F., and the average annual precipitation ranges from 48 to 56 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Binnsville, Eutaw, Griffith, Houston, Kipling, Leeper, Okolona, Oktibbeha, Sucarnoochee, Sumter, Vaiden, and Watsonia soils. Binnsville soils are on similar positions and have a mollic epipedon and are clayey. Eutaw, Houston, Kipling, Okolona, Oktibbeha, and Vaiden soils are generally at slightly higher elevations on smoother positions and are very deep to chalk bedrock. Griffith, Leeper, Sucarnoochee, and Trinity soils are in flood plains and are very deep to bedrock. Sumter and Watsonia soils are in similar positions as Demopolis soils. Sumter soils are moderately deep to chalk. Watsonia soils have vertic properties and are acid in the upper part.
DRAINAGE AND PERMEABILITY: Well drained; very slowly permeable.
USE AND VEGETATION: Most of the acreage is used for pasture and hay. A small acreage is used for oilseed and grain crops. Many idle areas have scattered cedar, osage orange, and ash.
DISTRIBUTION AND EXTENT: Uplands of the Blackland Prairie in Alabama, Arkansas, and Mississippi. The series is of large extent.
MLRA OFFICE RESPONSIBLE: Auburn, Alabama
SERIES ESTABLISHED: Chickasaw County, Mississippi; 1969.
REMARKS: The series classification was changed from loamy-skeletal to loamy in 1996. The chalk fragments are considered to be pararock, since they are mostly pulverized during sample processing.
Diagnostic horizons and significant features recognized in this pedon are:
Ochric epipedon......0 to 6 inches (Ap horizon)