Mineral Resources On-Line Spatial Data
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Geologic units in Harnett county, North Carolina
- Castle Hayne Formation; Comfort Member and New Hanover Member, undivided (Tertiary) at surface, covers 0.3 % of this area
Comfort Member and New Hanover Member, undivided - Comfort Member: bryozoan-echinoid skeletal limestone, locally dolomitized, solution cavities common. New Hanover Member: phosphate-pebble conglomerate, micritic, thin; restricted to basal part of Castle Hayne Formation in southeastern counties.
- Phyllite and Schist (Cambrian/Late Proterozoic) at surface, covers 5 % of this area
Phyllite and Schist - minor biotite and pyrite; includes phyllonite, sheared fine-grained metasediment and metavolcanic rock.
- Terrace Deposits and Upland Sediment (Tertiary) at surface, covers 5 % of this area
Terrace Deposits and Upland Sediment - gravel, clayey sand, and sand, minor iron-oxide cemented sandstone.
- Granitic Rock (Permian/Pennsylvanian) at surface, covers 0.2 % of this area
Granitic Rock (265-325 my) - megacrystic to equigranular. Castalia, Lillington, Medoc Mountain, Sims, Contentnea Creek (?), and Elm City (?) intrusives.
- Metamorphosed Granitic Rock (Cambrian/Late Proterozoic) at surface, covers < 0.1 % of this area
Metamorphosed Granitic Rock (520-650 my) - megacrystic, well foliated, locally contains hornblende; Fountain intrusive.
- Black Creek Formation (Cretaceous) at surface, covers < 0.1 % of this area
Black Creek Formation - clay, gray to black, lignitic; contains thin beds and laminae of fine-grained micaceous sand and thick lenses of cross-bedded sand. Glauconitic, fossiliferous clayey sand lenses in upper part.
- Cape Fear Formation (Cretaceous) at surface, covers 12 % 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.
- Middendorf Formation (Cretaceous) at surface, covers 67 % 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.
- Biotite Gneiss and Schist (Cambrian/Late Proterozoic) at surface, covers 5 % 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.
- Felsic Mica Gneiss (Cambrian/Late Proterozoic) at surface, covers 6 % of this area
Felsic Mica Gneiss - interlayered with biotite and hornblende gneiss and schist.
- Metavolcanic-Epiclastic Rock (Cambrian/Late Proterozoic) at surface, covers 0.4 % of this area
Metavolcanic-Epiclastic Rock - metamorphosed argillite, mudstone, volcanic sandstone, and conglomerate, and volcanic rock.