Geologic units in De Soto Parish, Louisiana

Wilcox Group (undifferentiated) (Paleocene) at surface, covers 67 % of this area

Gray to brown lignitic sands and silty to sandy lignitic clays, many seams of lignite; some limestone and glauconite.

Alluvium (Holocene) at surface, covers 21 % of this area

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

Prairie Terraces (Pleistocene) at surface, covers 9 % of this area

Light gray to light brown clay, sandy clay, silt, sand, and some gravels.

Natural Levees (Holocene) at surface, covers 3 % of this area

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

Intermediate Terraces (Pleistocene) at surface, covers 0.7 % of this area

Light gray to orange-brown clay, sandy clay, and silt; much sand and gravel locally.

Wilcox Group, undivided (Paleocene to Eocene) at surface, covers < 0.1 % of this area

Wilcox Group, undivided

Alluvium (Holocene) at surface, covers < 0.1 % of this area

Alluvium

Terrace deposits (Pleistocene and Holocene) at surface, covers < 0.1 % of this area

Terrace deposits