Geologic units in Madison Parish, Louisiana

Additional scientific data in this geographic area

Natural Levees (Holocene) at surface, covers 60 % of this area

Gray and brown silt, silty clay, some very fine sand, reddish brown along the Red River.

Alluvium (Holocene) at surface, covers 40 % of this area

Gray to brownish gray clay and silty clay, reddish brown in the Red River Valley, some sand and gravel locally.

Alluvium (Holocene) at surface, covers 0.6 % of this area

Loam, sand, gravel, and clay; mapped only in Mississippi River Alluvial Plain.

Braided Stream Terraces (Pleistocene) at surface, covers < 0.1 % of this area

Light gray, tan and brown fine to coarse sand; some clay silt and gravel. Overlain by 1-9 meters of loess.

Vicksburg group and Chickasawhay limestone (Oligocene) at surface, covers < 0.1 % of this area

Chickasawhay limestone, sandy limestone, and sand, present only in eastern MS (mapped with it is the overlying Paynes Hammock sand of Miocene age); Vicksburg group, predominantly limestone and marl, but contains some bentonite and near the top, chocolate-colored clay and some sand.