ABSTRACT: Application of Bathyal Foraminiferal Events to the Neogene through Pleistocene Biostratigraphic Framework of the Gulf Coast Basin
BREARD, SYLVESTER Q., ARDEN D. CALLENDER, and MICHAEL J. NAULT
A preliminary bathyal foraminiferal biozonation for Neogene through Pleistocene strata of the Gulf Coast Basin is introduced. The zonation is composed of fifty foraminiferal events, including nine each in the Pleistocene and Pliocene, eleven in both Upper and Middle Miocene, plus ten in the Lower Miocene. These horizons include subregional and Gulf of Mexico wide extinctions, local events, acmes and reoccurring events. The majority of these datums are limited to the bathyal zone (600-6000 ft/200-2000 m paleowater depths), although several range into the outer shelf.
This bathyal zonation, primarily benthic species, includes both published and previously unpublished markers. Zonation advantages are enhanced correlation between established planktic markers, greater correlation potential in a deep, expanded section, and high correlative potential between Gulf Coast Basin bathyal sediments with other basins, even trans-Atlantic. This zonation may provide an approximate method for relating foreign Neogene through Pleistocene deep water strata to established standard Gulf Coast Basin benthic markers having narrower resolution than planktic horizons alone.
Environmental conditions of the bathyal maim and methods for establishing the zonal scheme are also discussed. The geographic utility of each foraminiferal horizon, both within and beyond the Gulf Coast Basin (if applicable), is considered. The bathyal utility of selected shelf markers and multiple reoccurrences of arenaceous facies are addressed. Although some limitations exist, the proposed zonation is based on extensive well studies from active exploration in deep water sediments of the Gulf Coast Basin, and should enhance correlation there, as well as in Western Hemisphere and other worldwide basins.
AAPG Search and Discovery Article #90941©1997 GCAGS 47th Annual Meeting, New Orleans, Louisiana