TITLE:
Benin and Western Nigeria Offshore Basins: A Stratigraphic Nomenclature Comparison
AUTHORS:
Gérard Alfred Franck d’Almeida, Christophe Kaki, James Adejimi Adeoye
KEYWORDS:
Benin, Western Nigeria, Offshore Basins, Stratigraphy, Stratigraphic Nomenclature, Comparison
JOURNAL NAME:
International Journal of Geosciences,
Vol.7 No.2,
February
29,
2016
ABSTRACT: The Benin and Western Nigeria Offshore
Basins, which are parts of an extensive basin called the Dahomey (Benin) Embayment,
were formed during the Early Cretaceous under similar tectonic conditions and
continental sedimentary environments. Based mainly on available lithological,
biostratigraphic and paleoenvironmental data, this paper summarizes the
stratigraphic succession of theses basins and attempts a comparison of these
stratigraphic nomenclatures. The bulk of data shows that sedimentation begins
with terrestrial at the base, passes through shallow marine, deep marine (with
restrictive bottom circulation) and ends with open deep marine conditions. The
stratigraphy of the Offshore Benin Basin was established later and considering
lithological and paleontological similarities with formations of various
southern Nigeria basins, the stratigraphic chart adopted for this basin was a
mixed variant of various Southern Nigerian basins nomenclatures. For the first
time, a correlation of stratigraphic charts of each basins and a schematic
cross section showing their lithostratigraphic units, especially the
Cretaceous-Paleocene interval which is petroliferous, are proposed. The study
shows that the nomenclature adopted in Benin Republic must be revised by using
type section/locality names for some particular Formations and widely accepted
Formations names of Nigeria for the others. This will permit to avoid
confusions as it is presently the case for the name “Afowo Formation”
representing a Cretaceous sequence in Nigeria and which is use in Benin
Republic to distinguish some sediments of Miocene age. Moreover, a High
Resolution Biostratigraphy summary (including micropaleontology, nannopaleontology
and palynology distributions) relating to each offshore basin is needed for
sequences correlations and entire harmonization of the stratigraphic
nomenclature of these offshore basins.