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.
Bedding plane and axial-planar cleavage common; interbedded with metasandstone, meta-conglomerate, and metavolcanic rock.
Gravel, clayey sand, and sand, minor iron-oxide cemented sandstone.
Megacrystic to equigranular. Castalia, Lillington, Medoc Mountain, Sims, Contentnea Creek (?), and Elm City (?) intrusives.
Metamorphosed dacitic to rhyolitic flows and tuffs, light gray to greenish gray; interbedded with mafic and intermediate metavolcanic rock, meta-argillite, and metamudstone.
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.