Geologic units in Saint James Parish, Louisiana

Alluvium (Holocene) at surface, covers 55 % of this area

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

Natural Levees (Holocene) at surface, covers 45 % of this area

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