File:Phyllites (Anakeesta Formation).jpg

English: Phyllites (Anakeesta Formation, Neoproterozoic; Newfound Gap Road roadcut, Great Smoky Mountains, Tennessee, USA) 5

Phyllite in the Precambrian of Tennessee, USA.

This is an outcrop of Anakeesta Formation in the Great Smoky Mountains. It's one of many stratigraphic units in the ~50,000 feet thick Ocoee Supergroup. The Ocoee has considerable deposits of sandstone and shale originally deposited as sands and muds in an ancient ocean trench. Trenches form along subduction zones, where a tectonic plate composed of thin, heavy oceanic lithosphere dives down into the mantle below another tectonic plate of either oceanic lithosphere or thick, lightweight continental lithosphere.

Rocks in the Anakeesta Formation were originally shales, but have been metamorphosed to phyllites. Phyllite is a foliated, low to intermediate grade metamorphic rock dominated by mica. It often has wrinkled and crinkled foliation surfaces. The brownish coloration in this outcrop is iron oxide staining produced by oxidative weathering of pyrite in the phyllite.

Stratigraphy: Anakeesta Formation, Great Smoky Group, Ocoee Supergroup, Neoproterozoic

Locality: roadcut along Newfound Gap Road (= Rt. 441) (= locality at mile markers 11 to 12 of Moore, 1988, p. 93 - A Roadside Guide to the Geology of the Great Smoky Mountains National Park), near Anakeesta Ridge landslide viewing area, ~1-2 road miles north of Newfound Gap, Great Smoky Mountains, far-southern Sevier County, far-eastern Tennessee, USA