Clingmans Dome sill, Great Smoky Mountains, Sevier County, Tennessee, USAi

Regional Level Types
Clingmans Dome sill	Sill
Great Smoky Mountains	Mountain Range
Sevier County	County
Tennessee	State
USA	Country

Sill on north slope of Clingmans Dome.

"A small outcrop of metadiorite occurs at the southeast edge of the report area, in a valley on the north slope of Clingmans Dome at an altitude of 4,350 feet (Silers Bald quadrangle). The metadiorite forms a sill in the Thunderhead sandstone about a thousand feet below the tongue of Anakeesta formation exposed higher on the mountain.

This is the westernmost observed exposure of a metadiorite which forms a group of sills in the Thunderhead sandstone between Mount Collins and Clingmans Dome, best developed beyond the report area (Clingmans Dome quadrangle; Hadley and Goldsmith, 1963). The sills are on line of strike with metadiorite sills in the copper district between Hazel and Eagle Creeks 12 miles to the southwest (Fontana and Proctor quadrangles) (Espenshade, 1946), raising a question as to whether they might be continuous, or nearly so, in the intervening report area. West of the observed outcrop, within the report area, the belt,in which the sills should occur was traversed on three trails without yielding traces of igneous rock and it seems unlikely that any thick sills exist. Thinner ones might, however, be concealed by weathering or be exposed in the unvisited intervening areas.

The age of the metadiorite is undetermined, but is probably Paleozoic. Its sills follow southeast-dipping foliation and bedding, but the smaller bodies are themselves considerably altered and foliated, suggesting that they were introduced during an intermediate stage in the deformation of the region (Hadley and Goldsmith, 1913)."

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