Del Rio Mining District, Cocke County, Tennessee, USAi

Regional Level Types
Del Rio Mining District	Mining District
Cocke County	County
Tennessee	State
USA	Country

A baryte mining area in southeastern Cocke County, Tennessee, that is about 19 miles long and has a maximum width of 7 miles. It trends NE. The district contains about 12 mines and prospects.

The rocks of the area are the Snowbird formation and the Sandsuck shale of Precambrian (?) age, and the clastic rocks of the Unicoi, Hampton, and Erwin formations, the Shady dolomite, and the Rome formation - all of Early Cambrian age. These rocks occur in two overthrust sheets that have been pushed from the southeast into their present positions: the Brushy Mountain sheet overrode the Del Rio sheet.

Two principal deposits of barite occur along or near fault planes. Small but comparatively high-grade deposits (Moccasin Gap type of Ferguson and Jewell) are localized along a bedding-plane fault at the base of a quartzite bed 50 feet thick that dips 50º SE. The quartzite has been named the Moccasin Gap member of the Unicoi formation. The zone of extensive shearing and brecciation, which is as much as 7 feet thick, served as a channel for the ascending hydrothermal solutions. This fault zone is well exposed at the Moccasin Gap, Darky Tom, and East Meyer mines.

The mineral assemblage generally consists of ankerite, dolomite, barite, quartz, and pyrite. White, glassy, coarsely crystalline barite occurs in pods and veinlets in the ankerite-rich parts of the fault zone, and to a lesser extent in the lower part of the quartzite hanging wall.

Large, low-grade deposits of the Williams type (of Ferguson and Jewell) occur in a shear zone at the base of the upper thrust sheet in the pink arkosic to quartzitic Snowbird formation. The shear zone is as much as 9 feet thick and contains quartz, hematite, barite, fluorite, pyrite and traces of several copper minerals, all of which have a platy appearance inherited from the previously mylonitized host rocks. The most abundant mineral is quartz discolored by blue-black hematite.

The mineral composition of the deposits in the eastern and western parts of the Del Rio District differs so markedly as to suggest a mineral zoning regardless of whether the deposits are of the Williams or Moccasin Gap type.

Sericite, specularite, fluorite, and traces of copper are characteristic of the barite deposits in the eastern part of the district; abundant ankerite, little sericite and fluorite, and no specularite are characteristic of the deposits in the western part of the district.

Localities in this Region

Other Regions, Features and Areas containing this locality

References