Geologic units in Transylvania county, North Carolina

Henderson Gneiss (Cambrian) at surface, covers 28 % of this area

Monzonitic to granodioritic; inequigranular.

Ashe Metamorphic Suite and Tallulah Falls Formation; Biotite gneiss (Late Proterozoic) at surface, covers 21 % of this area

Interlayered with biotite-garnet gneiss, biotite-muscovite schist, garnet-mica schist, and amphibolite.

Ashe Metamorphic Suite and Tallulah Falls Formation; Muscovite-biotite gneiss (Late Proterozoic) at surface, covers 16 % of this area

Locally sulfidic; interlayered and gradational with mica schist, minor amphibolite, and hornblende gneiss.

Quartz Diorite to Granodiorite (Devonian) at surface, covers 9 % of this area

Contains biotite, muscovite, and xenocrysts. Includes Whiteside Mountain, Stone Mountain, Mount Airy, Spruce Pine, and other smaller plutons.

Toxaway Gneiss (Middle Proterozoic) at surface, covers 8 % of this area

Unconformity; poorly foliated to well-foliated; equigranular to inequigranular, granitic.

Rocks of Brevard Fault Zone (Uncertain, possibly Permian or Devonian) at surface, covers 5 % of this area

"Fish scale" schist and phyllonite, graphitic; interlayered with feldspathic metasandstone, marble lenses.

Granite Gneiss (Silurian/Ordovician) at surface, covers 4 % of this area

Poorly foliated; interlayered with biotite augen gneiss.

Garnet-Mica Schist (Cambrian/Late Proterozoic) at surface, covers 3 % of this area

Interlayered with amphibolite.

Ashe Metamorphic Suite and Tallulah Falls Formation; Amphibolite (Late Proterozoic) at surface, covers 3 % of this area

Equigranular, massive to well foliated, interlayered, rarely discordant, metamorphosed intrusive to extrusive mafic rock; may include metasedimentary rock.

Caesars Head Granite Gneiss (Devonian/Silurian) at surface, covers 2 % of this area

Equigranular to porphyritic, massive to well foliated; contains biotite and muscovite.

Meta-ultramafic Rock (Paleozoic/Late Proterozoic) at surface, covers < 0.1 % of this area

Metamorphosed dunite, local peridotite; serpentinite, soapstone, and other altered ultramafic rock. Only larger bodies shown.

Granite gneiss (Silurian to Ordovician) at surface, covers < 0.1 % of this area

Equigranular to inequigranular granite gneiss and augen gneiss, undivided

Caesars Head Granite (Ordovician to Silurian) at surface, covers < 0.1 % of this area

Well foliated, banded to non-banded biotite granitoid gneiss or gneissic granitoid; cuts Seneca thrust fault

Garnetiferous mica schist (Cambrian or Neoproterozoic) at surface, covers < 0.1 % of this area

Aluminous muscovite-biotite schist, locally having subordinate amphibolite layers

Henderson Gneiss (Cambrian) at surface, covers < 0.1 % of this area

Biotite granitoid augen gneiss having distinctive microcline augen; monzonite to granodiorite composition