Eustatic and tectonic effects in sequences stratigraphy of the paralic-shelfal marine section, upper cretaceous, Alabama

Conference · Wed Sep 01 00:00:00 EDT 1993 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:6965658

King, Jr, D T ^[1]

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1. Auburn Univ., Auburn, AL (United States)

In Alabama, sequence stratigraphic facies relations within the late Santonian to latest Maastrichtian (85-67 Ma) marine section have been strongly influenced by second-, third-, and fourth-order sea level changes related both to global eustasy and regional tectonics. Through detailed lithostratigraphic and biochronostratigraphic correlations, one can delineate the dictating mechanism (eustasy versus tectonics). In the outcrop region, the marine section is 450 m thick and is comprised to paralic and shelfal facies turn, make up the 13 genetic packages (i.e., stratigraphic sequences) of the total marine section. Second-order eustatic oscillations of 3.5-5.0-m.y. duration dictated the paleogeographic (depositional) strike and the characteristics of lateral and vertical facies relations along paleogeographic strike. Third-order sea level oscillations (0.5-3.5 m.y.) are related to either eustasy or regional tectonics. Oscillations driven by eustasy produced stratigraphic breaks with appreciable relief, significant regional paleogeographic reorganizations, increased lateral and vertical facies entropy, and notable faunal changes. Stratigraphy of tectonically induced third-order oscillations generally lacks most or all of these features. Fourth-order sea level oscillations (less than 0.5 m.y.) are related most closely to minor regional tectonic adjustments coeval with the onset of episodic, Farallon-North American plate interactions. the episodic (rather than periodic) nature of fourth-order shelfal parasequences in the area, their fining-upward textural signature, characteristic transitional benthic-to-pelagic fossil record, and stratigraphic correlations with thin, prograding clastic tongues (paralic facies) collectively demonstrate a non-Milankovitch origin of the shelfal parasequences.

• OSTI ID: 6965658
• Report Number(s): CONF-9310237-; CODEN: AABUD2
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Vol. 77:9; Conference: American Association of Petroleum Geologists (AAPG) mid-continent section meeting, Amarillo, TX (United States), 10-12 Oct 1993; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
03 NATURAL GAS
GEOLOGIC STRATA
ORIGIN
SEA LEVEL
VARIATIONS
STRATA MOVEMENT
CORRELATIONS
ALABAMA
CRETACEOUS PERIOD
FOSSILS
STRATIGRAPHY
TECTONICS
DEVELOPED COUNTRIES
GEOLOGIC AGES
GEOLOGIC STRUCTURES
GEOLOGY
LEVELS
MESOZOIC ERA
NORTH AMERICA
USA
020200* - Petroleum- Reserves
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030200 - Natural Gas- Reserves
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