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Mineral Resources > Online Spatial Data > Geology > by state > North Carolina Geology

Geologic units in Richmond county, North Carolina

Phyllite and Schist (Cambrian/Late Proterozoic) at surface, covers 4 % of this area

Phyllite and Schist - minor biotite and pyrite; includes phyllonite, sheared fine-grained metasediment and metavolcanic rock.

Lithology: phyllite; schist; phyllonite; metasedimentary rock; metavolcanic rock

Newark Supergroup, Chatham Group; Chatham Group, Undivided (Triassic) at surface, covers 13 % of this area

Chatham Group, Undivided - conglomerate, fanglomerate, sandstone, and mudstone. Conglomerate and fanglomerate shown by pattern.

Lithology: conglomerate; sandstone; mudstone

Granitic Rock (Permian/Pennsylvanian) at surface, covers 3 % of this area

Granitic Rock (265-325 my) - megacrystic to equigranular. Castalia, Lillington, Medoc Mountain, Sims, Contentnea Creek (?), and Elm City (?) intrusives.

Lithology: granite

Terrace Deposits and Upland Sediment (Tertiary) at surface, covers 1.0 % of this area

Terrace Deposits and Upland Sediment - gravel, clayey sand, and sand, minor iron-oxide cemented sandstone.

Lithology: terrace; gravel; sand; clay or mud; sandstone

Pinehurst Formation (Tertiary) at surface, covers 12 % of this area

Pinehurst Formation - sand, medium- to coarse-grained, cross-bedding and rhythmic bands of clayey sand common, unconsolidated.

Lithology: sand; clay or mud

Middendorf Formation (Cretaceous) at surface, covers 55 % of this area

Middendorf Formation - sand, sandstone, and mudstone, gray to pale gray with an orange cast, mottled; clay balls and iron-cemented concretions common, beds laterally discontinuous, cross-bedding common.

Lithology: sand; sandstone; mudstone; clay or mud

Cape Fear Formation (Cretaceous) at surface, covers 0.3 % of this area

Cape Fear Formation - 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.

Lithology: sandstone; mudstone; sand; clay or mud

Peedee Formation /Black Creek Group, undivided (Cretaceous) at surface, covers < 0.1 % of this area

Peedee Formation /Black Creek Group, undivided

Lithology: clay or mud; sand; limestone

Intermediate Metavolcanic Rock (Cambrian/Late Proterozoic) at surface, covers 1.0 % of this area

Intermediate Metavolcanic Rock - metamorphosed andesitic tuffs and flows, medium to dark grayish green; minor felsic and mafic metavolcanic rock.

Lithology: intermediate metavolcanic rock; felsic metavolcanic rock; mafic metavolcanic rock

Metamudstone and Meta-Argillite (Cambrian/Late Proterozoic) at surface, covers 10 % of this area

Metamudstone and Meta-Argillite - bedding plane and axial-planar cleavage common; interbedded with metasandstone, meta-conglomerate, and metavolcanic rock.

Lithology: metasedimentary rock; meta-argillite; meta-conglomerate; metavolcanic rock

Pee Dee Gabbro (Pennsylvanian) at surface, covers 0.7 % of this area

Pee Dee Gabbro (314 my) - dark gray to black, medium to fine grained, massive.

Lithology: gabbro

Cid Formation; Metamudstone and Meta-Argillite (Cambrian/Late Proterozoic) at surface, covers 0.2 % of this area

(Southwest of Asheboro); Metamudstone and Meta-Argillite - thin to thick bedded; bedding plane and axial-planar cleavage common; interbedded with metasandstone, metaconglomerate, and metavolcanic rock.

Lithology: meta-argillite; meta-conglomerate; metasedimentary rock; metavolcanic rock

Biotite Gneiss and Schist (Cambrian/Late Proterozoic) at surface, covers < 0.1 % of this area

Biotite Gneiss and Schist - inequigranular, locally abundant potassic feldspar and garnet; interlayered and gradational with calc-silicate rock, sillimanite-mica schist, mica schist, and amphibolite. Contains small masses of granitic rock.

Lithology: biotite gneiss; mica schist; amphibolite; calc-silicate rock; granite