Chen, Y. Y.; Huang, T. C.; McLaughlin, P. P. - Exxon Exploration Co.
Synthesis of multi-fossil-group biostratigraphic studies of the Cretaceous of central and West Africa permit us to establish a preliminary, integrated biostratigraphy for marine and non-marine sediments on the African margin of the south Atlantic Ocean. This zonation is based on studies in Chad, Niger, Central Africa Republic, Angola, Ivory Coast, and Senegal and is tied to a global chronostratigraphic standard. The findings were compared with coeval zonations from South America (Brazil, Venezuela, Colombia, Ecuador, and Peru) to establish preliminary correlations across the Cretaceous south Atlantic Ocean.
Spores and pollen are a valuable tool for regional correlation. They occur relatively continuously through the period and are well represented in various sedimentary environments, both non-marine and marine. We identified over forty morphologically distinctive and stratigraphically restricted palynomorphs that divide the period into twenty-three zones. For the Albian and younger section, the non-marine zonation is calibrated to the chronostratigraphic standard based on coeval dinoflagellate, foraminifera, and nannoplankton data.
Comparison between the palynomorph biostratigraphy of West and central Africa with the published literature for Brazil suggests that the biostratigraphic frameworks of these areas are generally compatible. Most variations are due to endemic species that constitute less than 20% of the total assemblage or due to minor regional variations of the ranges of a few forms.
AAPG Search and Discovery Article #90933©1998 ABGP/AAPG International Conference and Exhibition, Rio de Janeiro, Brazil