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

Geologic units in Anson county, North Carolina

Chatham Group, undivided (Triassic) at surface, covers < 0.1 % of this area

Chatham Group, undivided: conglomerate, sandstone and mudstone

Lithology: conglomerate; sandstone; mudstone

Terrace Deposits and Upland Sediment (Tertiary) at surface, covers 2 % 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

Granitic Rock (Permian/Pennsylvanian) at surface, covers 11 % of this area

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

Lithology: granite

Newark Supergroup, Chatham Group; Chatham Group, Undivided (Triassic) at surface, covers 40 % of this area

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

Lithology: conglomerate; sandstone; mudstone

Phyllite and Schist (Cambrian/Late Proterozoic) at surface, covers 2 % 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

Tillery Formation; Metamudstone and Meta-Argillite (Cambrian/Late Proterozoic) at surface, covers 0.1 % 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

Persimmon Fork Formation (Cambrian to Neoproterozoic) at surface, covers < 0.1 % of this area

Persimmon Fork Formation: predominately metatuff

Lithology: metavolcanic rock

Cid Formation, Mudstone Member (Ordovician to Late Cambrian) at surface, covers < 0.1 % of this area

Cid Formation, Mudstone Member: thin bedded tuffaceous metasiltstone

Lithology: metasedimentary rock

Middendorf Formation (Cretaceous) at surface, covers 9 % 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

Floyd Church Formation; Metamudstone and Meta-Argillite (Cambrian/Late Proterozoic) at surface, covers 10 % 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

Metamudstone and Meta-Argillite (Cambrian/Late Proterozoic) at surface, covers 9 % 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

Cid Formation; Felsic Metavolcanic Rock (Cambrian/Late Proterozoic) at surface, covers 0.6 % of this area

(southwest of Asheboro); Felsic Metavolcanic Rock - metamorphosed dacitic to rhyolitic flows and tuffs, light gray to greenish gray; interbedded with mafic and intermediate metavolcanic rock, meta-argillite, and metamudstone.

Lithology: felsic metavolcanic rock; mafic metavolcanic rock; intermediate metavolcanic rock; meta-argillite; metasedimentary rock

Biotite Gneiss and Schist (Cambrian/Late Proterozoic) at surface, covers 3 % 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

Cid Formation; Metamudstone and Meta-Argillite (Cambrian/Late Proterozoic) at surface, covers 12 % 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

Pee Dee Gabbro (Pennsylvanian) at surface, covers < 0.1 % of this area

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

Lithology: gabbro