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Mineral Resources > Online Spatial Data > Geology > by state > Louisiana Geology

Geologic units in Grant Parish, Louisiana

Lena Member (Phanerozoic | Cenozoic | Tertiary | Miocene) at surface, covers 0.3 % of this area

gray calcareous clays which may weather to black soil; siltstone, taffaceous clays and some volcanic ash beds

Lithology: clay or mud; siltstone; volcanic ash

Catahoula Formation (Phanerozoic | Cenozoic | Tertiary | Oligocene) at surface, covers 4 % of this area

gray to white sandstones; loose quartz sand, tuffaceous sandstone, volcanic ash, and brown sandy clays; petrified wood locally.

Lithology: sandstone; sand; volcanic ash

Jackson Group (undifferentiated) (Phanerozoic | Cenozoic | Tertiary | Eocene) at surface, covers 4 % of this area

light gray to brown liginitic clays with thin interbeds of limonitic sands or lignite; near base,calcareous, glauconitic, and fossiliferous beds may weather to black soil.

Lithology: clay or mud; sand; coal

Vicksburg Group (undifferentiated) (Phanerozoic | Cenozoic | Tertiary | Oligocene) at surface, covers 4 % of this area

brown to gray liginitic clays with thin interbeds of lignite or micaceous sands; calcareous shale, petrified wood, and bluish fossilferous clay locally.

Lithology: clay or mud; coal; sand; shale

Prairie Terraces (Phanerozoic | Cenozoic | Quaternary | Pleistocene) at surface, covers 12 % of this area

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

Lithology: clay or mud; silt; sand; gravel

Carnahan Bayou Member (Phanerozoic | Cenozoic | Tertiary | Miocene) at surface, covers 0.8 % of this area

yellow to gray siltstones, sandstones, and clays with thin tuffaceous beds; some lenses of black chert gravel; petrified wood locally.

Lithology: siltstone; sandstone; clay or mud; tuff; gravel

Cockfield Formation (Phanerozoic | Cenozoic | Tertiary | Eocene) at surface, covers < 0.1 % of this area

brown lignitic clays, silts and sands; some sideritic glauconite may weather to brown ironstone in lower part.

Lithology: clay or mud; silt; sand

Intermediate Terraces (Phanerozoic | Cenozoic | Quaternary | Pleistocene) at surface, covers 10 % of this area

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

Lithology: clay or mud; silt; sand; gravel

Alluvium (Phanerozoic | Cenozoic | Quaternary | Holocene) at surface, covers 19 % of this area

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

Lithology: clay or mud; sand; gravel

Natural Levees (Phanerozoic | Cenozoic | Quaternary | Holocene) at surface, covers 8 % of this area

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

Lithology: silt; clay or mud; sand

High Terraces (Phanerozoic | Cenozoic | Quaternary | Pleistocene) at surface, covers 35 % of this area

tan to orange clay, silt, and sand with a large amount of basal gravels.

Lithology: clay or mud; silt; sand; gravel