Geologic units in Alexander county, North Carolina

Additional scientific data in this geographic area

Biotite Gneiss and Schist (Cambrian/Late Proterozoic) at surface, covers 51 % of this area

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.

Mica Schist (Cambrian/Late Proterozoic) at surface, covers 29 % of this area

Garnet, staurolite, kyanite, or sillimanite occur locally; lenses and layers of quartz schist, micaceous quartzite, calc-silicate rock, biotite gneiss, amphibolite, and phyllite.

Metamorphosed Granitic Rock (Ordovician/Cambrian) at surface, covers 11 % of this area

Equigranular to megacrystic, foliated to massive. Includes Toluca Granite.

Amphibolite and Biotite Gneiss (Cambrian/Late Proterozoic) at surface, covers 7 % of this area

Interlayered; minor layers and lenses of hornblende gneiss, metagabbro, mica schist, and granitic rock.

Megacrystic Biotite Gneiss (Cambrian/Late Proterozoic) at surface, covers 1 % of this area

Poorly layered to massive; megacrysts of microcline and quartz; local mica schist, amphibolite, and biotite gneiss