Greener Journal of Physical Sciences Vol. 3 (7), pp. 255-272, November 2013.
ISSN: 2276-7851 © 2011 Greener Journals
Manuscript Number: 052713640
Palynostratigraphy, Age Determination and Depositional Environments of the Imo Shale Exposures at the Okigwe/Port Harcourt Express Road Junction Okigwe, Southeastern Nigeria
Durugbo Ernest Uzodimma
Department of Biological Sciences, Redeemer’s University Mowe, Ogun State, Nigeria.
Email: ernestduru @ yahoo.com; durugboe @ run.edu.ng
study of the shale exposures at the Okigwe-Port Harcourt
Express Road Junction Okigwe, Southeastern Nigeria yielded
moderate records of palynomorphs dominated by palm pollen
Longapertites marginatus, L. vanendeenburgi, Mauritidites
crassiexinus, Spinizonocolpites echinatus, Echitriporites
trianguliformis, with abundant fern spores
Deltoidospora adriennis, Cyathidites minor, common
and sparse records of the dinoflagellate cysts
Ifecysta fusiforma, Ifecysta heterospinosa, Phelodinium
magnificum, P. africanum, Fibrocysta lappacea, Homotryblium
tenuispinosum, Diphyes colligerum, Cerodinium spp.,
Ceratiopsis spp., Apectodinium spp.,
Kallosphaeridium spp., Cordosphaeridium spp.,
Exochosphaeridium spp., Spiniferites spp.,
Cleistosphaeridium spp., and Lejeunecysta
spp. The sequences composed of alternating successions of
brown to grey, soft to moderately hard ,
and fissile mudstones, with sand intercalations.
Carbonaceous matter and ferrugineous materials were the
accessory minerals. The recovered microfloral assemblages with abundant plant debris,
sparse cuticles, common fungal spores suggests nearshore
to marginal marine depositional environments. Published
ranges of the palynostratigraphically important taxa enabled
the delineation of the age as
Middle Paleocene – Early Eocene thereby indicating that the
exposure belongs to the Imo Formation. Again, the
preponderance of palm pollen supports the Cretaceous – Early
Tertiary palm province which traversed the southern
hemisphere. The kerogen analysis revealed that the samples
were immature for oil and gas generation.
Keywords: Okigwe, Imo Formation, palynomorphs, kerogen, phytoclasts.