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Mineral Resources > Online Spatial Data > Geology > by state > Georgia Geology

Geologic units in Baldwin county, Georgia

Hornblende Gneiss/ Granite Gneiss/ Biotite Gneiss (Precambrian-Paleozoic) at surface, covers 31 % of this area

Hornblende Gneiss/ Granite Gneiss/ Biotite Gneiss

Lithology: gneiss; granitic gneiss; biotite gneiss

Lower Tertiary-Cretaceous undifferentiated (Lower Tertiary-Cretaceous) at surface, covers 21 % of this area

Lower Tertiary-Cretaceous undifferentiated, as mapped includes Middendorf Formation (Sloan, 1904); "Channel Sands" (LaMoreaux, 1946); Tuscaloosa Formation (Cooke, 1939); and "Huber beds" (Buie, informal terminology)

Lithology: sand; clay or mud

Stream alluvium (Quaternary) at surface, covers 5 % of this area

Stream alluvium and undifferentiated terrace deposits

Lithology: alluvium; alluvial terrace

Biotite Granite Gneiss/ Feldspathic Biotite Gneiss/ Amphibolite Hornblende Gneiss (Precambrian-Paleozoic) at surface, covers 3 % of this area

Biotite Granite Gneiss/ Feldspathic Biotite Gneiss/ Amphibolite Hornblende Gneiss

Lithology: granitic gneiss; biotite gneiss; amphibolite

Granite/ gneissic biotite granite (Precambrian-Paleozoic) at surface, covers 5 % of this area

Granite/ gneissic biotite granite

Lithology: granite

Twiggs Clay (Eocene) at surface, covers 0.7 % of this area

Twiggs Clay

Lithology: clay or mud

Irwinton Sand (Eocene) at surface, covers 5 % of this area

Irwinton Sand (Ei), up-dip equivalent of Twiggs Clay, Sandersville Limestone, and Cooper Marl. As mapped, also includes younger clastics of indefinite Late Tertiary age.

Lithology: sand

Biotite Gneiss/ Feldspathic Biotite Gneiss (Precambrian-Paleozoic) at surface, covers 1 % of this area

Biotite Gneiss/ Feldspathic Biotite Gneiss

Lithology: biotite gneiss; felsic gneiss

Undifferentiated Metavolcanics/ Sericite phyllite/ Meta-argillite/ Quartz mica schist (Precambrian-Paleozoic) at surface, covers 14 % of this area

Undifferentiated Metavolcanics/ Sericite phyllite/ Meta-argillite/ Quartz mica schist

Lithology: metavolcanic rock; phyllite; schist

Quartzite/ Mica Schist (Precambrian-Paleozoic) at surface, covers 10 % of this area

Quartzite/ Mica Schist

Lithology: quartzite; mica schist

Ultramafic rocks undifferentiated (Precambrian-Paleozoic) at surface, covers < 0.1 % of this area

Ultramafic rocks undifferentiated

Lithology: ultramafic intrusive rock

Granitic Gneiss undifferentiated (Precambrian-Paleozoic) at surface, covers < 0.1 % of this area

Granitic Gneiss undifferentiated

Lithology: granitic gneiss