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- Usage in publication:
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- Tunnel Hill Coal Bed
- Modifications:
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- Named
- Dominant lithology:
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- Coal
- AAPG geologic province:
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- Illinois basin
Summary:
Coal that crops out 40 to 70 ft above the Reynoldsburg is "herein named" the Tunnel Hill Coal Bed of the Abbott Formation. [Elsewhere in the report authors state all units within the Abbott, except the Reynoldsburg Coal Bed and the Murray Bluff Sandstone Member are named informally.] Though no type section is designated, unit is described at a surface mine in NW1/4NW1/4, sec. 6, T12S, R4E, once operated by the Holly Mining Co. Coal here is 12 to 14 in. thick where exposed. Measures 28 in. in test hole C-5. Tunnel Hill is classified as latest Morrowan (early Westphalian B stage) and is palynologically equivalent to the Bell (1B) coal bed of western KY. Conodonts from the overlying limestone are indicative of a late Morrowan or early Atokan 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 ([ ]).