ABSTRACT: Gulf of Mexico Cenozoic Bio-, Litho-, and Sequence Stratigraphic Event Chronology

FILLON, RICHARD H., PAUL N. LAWLESS, and ROME G. LYTTON

A set of Gulf of Mexico biostratigraphic and cycle charts has recently been completed for the Paleocene and Eocene, the Oligocene and Miocene, and the Pliocene and Pleistocene. The chart set includes: onlap curves of second, third and fourth order cycles; key flooding surfaces; sequence boundaries; sequence stratigraphic and lithostratigraphic units; important planktonic foraminiferal and nannofossil first and last appearance data; traditional benthic foraminiferal "tops" and recently compiled last appearance data; foraminiferal and nannofossil biochronozones; industry biochronozones; magneto- and stable isotope chronozones; and WHCS and other codes. While much of the information presented in this chart series is available from other published sources, many of the charted third and fourth order sequences are newly defined and are based on the recent integration of numerous offshore and onshore well and seismic record studies. For example, within the Discoaster prepentaradiatus third order sequence, we have identified an additional third order sequence and four fourth order sequences. The inclusion of planktonic foraminiferal and nannofossil first appearance, i.e., "evolution point" data in this chart series reflects the newly recognized utility of fossil "first occurrences" as stratigraphic markers in wells with high resolution digital micropaleo reports. Of particular importance are the first appearance data (FADs) of Globorotalia truncatulinoides, a marker event discernable in the great majority of Pliocene-Pleistocene wells; the FAD of Orbulina spp., discernable in most Lower to Middle Miocene wells; and the FAD of Hantkenina spp., a useful marker in Lower to Middle Eocene wells.

AAPG Search and Discovery Article #90941©1997 GCAGS 47th Annual Meeting, New Orleans, Louisiana