Geologic units in Wilson county, North Carolina

Yorktown Formation and Duplin Formation, Undivided (Tertiary) at surface, covers 69 % of this area

Yorktown Formation: fossiliferous clay with varying amounts of fine-grained sand, bluish gray, shell material commonly concentrated in lenses; mainly in area north of Neuse River. Duplin Formation: shelly, medium- to coarse-grained sand, sandy marl, and limestone, bluish gray; mainly in area south of Neuse River.

Metamudstone and Meta-Argillite (Cambrian/Late Proterozoic) at surface, covers 14 % of this area

Bedding plane and axial-planar cleavage common; interbedded with metasandstone, meta-conglomerate, and metavolcanic rock.

Terrace Deposits and Upland Sediment (Tertiary) at surface, covers 11 % of this area

Gravel, clayey sand, and sand, minor iron-oxide cemented sandstone.

Granitic Rock (Permian/Pennsylvanian) at surface, covers 4 % of this area

Megacrystic to equigranular. Castalia, Lillington, Medoc Mountain, Sims, Contentnea Creek (?), and Elm City (?) intrusives.

Felsic Metavolcanic Rock (Cambrian/Late Proterozoic) at surface, covers 1 % of this area

Metamorphosed dacitic to rhyolitic flows and tuffs, light gray to greenish gray; interbedded with mafic and intermediate metavolcanic rock, meta-argillite, and metamudstone.

Cape Fear Formation (Cretaceous) at surface, covers 1 % of this area

Sandstone and sandy mudstone, yellowish gray to bluish gray, mottled red to yellowish orange, indurated, graded and laterally continuos bedding, blocky clay, faint cross-bedding, feldspar and mica common.