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The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract


Volume: 66 (1982)

Issue: 9. (September)

First Page: 1430

Last Page: 1430

Title: Paleocene to Middle Eocene Stratigraphy of Alabama: ABSTRACT

Author(s): Thomas G. Gibson, Ernest A. Mancini, Laurel M. Bybell

Article Type: Meeting abstract

Abstract:

Each of the eight Paleocene to middle Eocene formations that crop out across Alabama contains similar lithofacies. Each of the formations is characterized by east to west thickening, representing one or more transgressive cycles. An integrated biostratigraphic framework of calcareous nannofossils and planktonic foraminifers demonstrates that individual formations are generally the same age throughout Alabama, although the base of some cycles may be older in southwestern Alabama. The lower Eocene strata were deposited in a more open-marine environment in eastern Alabama than the rapidly prograding sequence in western Alabama.

The early Paleocene Clayton Formation contains calcareous nannofossils characteristic of Martini's Zones NP1, NP2, and NP3, and planktonic foraminifers typical of Stainforth's Subbotina pseudobulloides and S. trinidadensis Interval zones. The lower and middle parts of the Porters Creek Formation are of late early Paleocene age (Zone NP3 and S. trinidadensis and Morozovella uncinata Interval zones); the upper Matthews Landing Marl Member of the Porters Creek is of early late Paleocene age (Zone NP4 and M. angulata Interval zone). The Coal Bluff Marl Member of the Naheola Formation is also of early late Paleocene age (Zone NP5). The lower Gravel Creek Sand Member of the Nanafalia Formation is assigned to Zone NP5 and is separated by a significant unconformity from the middle and upper m mbers of the Nanafalia; the middle "Ustrea thirsae beds" and the upper Grampian Hills Member are late Paleocene in age (Zone NP7 and NP8 and Planorotalites pseudomenardii Range Zone). The lowermost marl beds of the Tuscahoma Sand in western Alabama are assignable to Zone NP9 and the P. pseudomenardii Range Zone, and the remainder of the Tuscahoma is assigned to Zone NP9 and the Morozovella velascoensis Interval zone (late Paleocene). The Hatchetigbee and Bashi Formations are of earliest Eocene age (Zone NP10 and lower part of Morozovella subbotinae Interval zone). A major unconformity separates these formations from the overlying Tallahatta Formation, which is assignable to Zones NP12, NP13, and NP14, resulting in a late early Eocene age for the lowermost part of the Claiborne Group.

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