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Holston Formation
Stratigraphic unit containing Tennessee marble in US / From Wikipedia, the free encyclopedia
For other uses of "Holston", see Holston (disambiguation).
The Holston Formation, alternately known as the Holston Limestone, is a stratigraphic unit of Ordovician age within the Chickamauga Group in the Ridge-and-Valley physiographic province of the southeastern United States. A 120-mile (190 km) long outcrop belt of the Holston in East Tennessee is the source of the decorative building stone known as Tennessee marble.
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Near Knoxville the Holston Formation is about 400 feet (120 m) thick but it thins toward the southwest; near Cleveland, Tennessee it is only 200 feet thick. The rock that is quarried for marble is a highly pure (97% CaCO3) crystalline limestone, pink to cedar-red in color.