Migmatitic; interlayered and gradational with biotite-garnet gneiss and amphibolite; locally abundant quartz and alumino-silicates. Stratigraphic position uncertain.
Locally sulfidic; interlayered and gradational with mica schist, minor amphibolite, and hornblende gneiss.
Metagraywacke, massive, graded bedding common; includes dark-gray slate, mica schist, and nodular calc-silicate rock.
Unconformity; pinkish gray to light gray, massive to well-foliated, granitic to quartz monzonitic; includes variably mylonitized orthogneiss and paragneiss, interlayered amphibolite, calc-silicate rock, and marble. Includes granites of the Bryson City area, Straight Fork window, and Elk Park Plutonic Suite.
Cross-bedded, feldspathic, locally conglomeratic; includes dark slate and metasiltstone.
Thick metasedimentary sequence of massive to graded beds of metagraywacke and metasiltstone with interbedded graphitic and sulfidic slate and schist.
Greenish gray, fine to medium grained, locally cross-bedded, metamorphosed; interbedded metasiltstone and phyllite.
Sandy slate to coarse-grained pebbly metagraywacke with local graded bedding. Basal quartz-sericite schist or phyllite.
Unconformity; greenish gray to pinkish gray, porphyroclastic to mylonitic; epidote, sericite, and chlorite common.
Feldspathic; interbedded with dark argillaceous layers and laminae. Stratigraphic position uncertain.
Feldspathic metasiltstone, metasandstone, and phyllite. Basal schist contains lenses of quartz-pebble conglomerate.
Mottled pink and light green, coarse grained to porphyritic, massive; contains biotite.
Thin bedded to laminated, commonly cross-bedded, metamorphosed; locally includes argillite and calcareous and arkeritic metasiltstone grading to silty metalimestone.
Interlayered with biotite-garnet gneiss, biotite-muscovite schist, garnet-mica schist, and amphibolite.
Slate to phyllite, dark gray, graphitic, sulfidic; includes metagraywacke with local graded bedding.
Great Smoky Group - Characterized by very massive layers of coarse graywacke and arkose. The formations at right have been mapped only in region of the Great Smoky Mountains. Thickness 14,000 to about 25,000 feet; includes Unnamed Sandstone Unit - Gray, coarse sandstone and fine conglomerate, similar to Thunderhead Sandstone. Thickness about 4,500 feet; Anakeesta Formation - Dark-gray, bluish-gray, and black slate with dark-gray interbeds of fine-grained sandstone. Thickness 3,000 to 4,500 feet; Thunderhead Sandstone - Coarse, gray feldspathic sandstone, graywacke, and conglomerate; occurs in massive ledges; graded bedding and blue quartz characteristic. Thickness 5,500 to 6,300 feet; Elkmont Sandstone - Coarse to fine, gray feldspathic sandstone, graywacke, and fine conglomerate; generally finer grained beds in lower part; graded bedding typical. Thickness 1,000 to 8,000 feet.
Metamorphosed dunite, local peridotite; serpentinite, soapstone, and other altered ultramafic rock. Only larger bodies shown.
Snowbird Group - The formations at right are applicable chiefly in the area of the Great Smoky Mountains. Thickness 13,000 to about 20,000 feet. Includes Pigeon Siltstone - Laminated, greenish quartzose and feldspathic siltstone; minor fine-grained gray sandstone. Thickness as much as 10,000 feet; Roaring Fork Sandstone - Interbedded massive feldspathic sandstone, greenish siltstone, and greenish phyllite. Maximum thickness 7,000 feet; Metcalf Phyllite - Lustrous, pale-green and silvery sericitic and chloritic phyllite; siltstone interbeds abundant. Thickness uncertain; at least 5,000 feet; Longarm Quartzite - Feldspathic quartzite and arkose, conspicuously light-colored, current bedded and crossbedded. Thickness about 5,000 feet; Wading Branch Formation - Medium- to dark-gray sandy slate to coarse, pebbly feldspathic sandstone and graywacke; basal part is quartz-sericite phyllite; graded bedding common. Thickness about 1,500 feet.
Gray, massive beds of feldspathic, fine- to medium-grained sandstone, with interbeds of dark slate and arkosic conglomerate; exact stratigraphic position unknown. Thickness about 1,500 feet.
Granite, porphyritic, light-gray to reddish; coarse potash feldspar crystals and clustered interstitial mafics (chloritized biotite and hornblende) give spotted appearance; includes Max Patch Granite.