- Usage in publication:
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- Mahan formation
- Modifications:
-
- Named
- Dominant lithology:
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- Limestone
- Chert
- AAPG geologic province:
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- Appalachian basin
Summary:
Named the Mahan formation for Mahan Road, Snow Hill quad., Hamilton Co., southeastern TN. Consists of ribbon-banded to thick-bedded, dove-gray calcilutite, lower half of which is characteristically studded with plates and nodules of black chert. Upper part is even-bedded calcilutite with numerous shaly interbeds. Thickness is 200 feet. Overlies Long Savannah formation. Top of unit is defined at type locality by a red mudstone, one of several intercalations in a thick succession of ribbon-banded limestones. The Mahan is of Middle Ordovician (Mohawkian) age.
Source: GNU records (USGS DDS-6; Reston GNULEX).
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
Asterisk (*) indicates published by U.S. Geological Survey authors.
"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).
Slash (/) indicates name conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).