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

Geologic units in Montgomery county, North Carolina

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

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

Middendorf Formation (Cretaceous) at surface, covers 8 % 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

Mafic Metavolcanic Rock (Cambrian/Late Proterozoic) at surface, covers 0.4 % of this area

Mafic Metavolcanic Rock - metamorphosed basaltic flows and tuffs, dark green to black; interbedded with felsic and intermediate metavolcanic rock and metamudstone.

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

Tillery Formation; Metamudstone and Meta-Argillite (Cambrian/Late Proterozoic) at surface, covers 19 % 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

Yadkin Formation (Cambrian/Late Proterozoic) at surface, covers 0.7 % of this area

Yadkin Formation - metamorphosed graywacke, volcanic sandstone, and siltstone; interbedded with mafic and intermediate metavolcanic flows and tuffs.

Lithology: metasedimentary rock; mafic metavolcanic rock; intermediate metavolcanic rock

Pinehurst Formation (Tertiary) at surface, covers 2 % 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

Newark Supergroup, Chatham Group; Chatham Group, Undivided (Triassic) at surface, covers 11 % of this area

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

Lithology: conglomerate; sandstone; mudstone

Uwharrie Formation; Felsic Metavolcanic Rock (Cambrian/Late Proterozoic) at surface, covers 30 % of this area

(at Asheboro and to south); 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

Metavolcanic-Epiclastic Rock (Cambrian/Late Proterozoic) at surface, covers 18 % of this area

Metavolcanic-Epiclastic Rock - metamorphosed argillite, mudstone, volcanic sandstone, and conglomerate, and volcanic rock.

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

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

Cid Formation; Mafic Metavolcanic Rock (Cambrian/Late Proterozoic) at surface, covers 3 % of this area

(Southwest of Asheboro); Mafic Metavolcanic Rock - metamorphosed basaltic flows and tuffs, dark green to black; interbedded with felsic and intermediate metavolcanic rock and metamudstone.

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

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

Metamudstone and Meta-Argillite (Cambrian/Late Proterozoic) at surface, covers 3 % 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 0.8 % 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

Intermediate Metavolcanic Rock (Cambrian/Late Proterozoic) at surface, covers 2 % 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