Middle Devonian (Eifelian) carbonates, Appalachian Basin: A new stratigraphic synthesis
- Univ. of Rochester, NY (United States). Dept. of Geological Sciences
Carbonate-dominated strata equivalent to the Onondaga Formation of New York are widely known across eastern North America, from the James Bay Region of Ontario to southeastern Quebec to Georgia to Illinois. Relationships between Onondaga-equivalent strata within the Appalachian Basin itself, however, have been poorly understood. Detailed stratigraphic study of interbedded limestones and calcareous shales of the Selinsgrove Member (Needmore Formation) in central Pennsylvania reveals a number of distinctive marker units that are widely traceable throughout the region. Marker units include: a massive limestone; shale-dominated intervals; several thin black shales; the widely recognized Tioga Ash Beds; distinctive yellow to gray clays that represent additional apparent K-bentonite beds; and pyrite nodule-rich intervals. Combined, these form a very distinctive microstratigraphic framework that is widely correlatable across central Pennsylvania. This microstratigraphic framework is directly correlatable into the Onondaga Limestone of central New York, Direct comparison of the New York and Pennsylvania sections permit recognition of four subunits of the Selinsgrove Member that are equivalent to the four members of the Onondaga Formation (Edgecliff, Nedrow, Moorehouse, and Seneca Members). Therefore, it is shown that the Selinsgrove Member of the Needmore Formation is the direct equivalent of the Onondaga Formation of New York.
- OSTI ID:
- 6906342
- Report Number(s):
- CONF-9404217--
- Journal Information:
- Geological Society of America, Abstracts with Programs; (United States), Journal Name: Geological Society of America, Abstracts with Programs; (United States) Vol. 26:5; ISSN GAAPBC; ISSN 0016-7592
- Country of Publication:
- United States
- Language:
- English
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