Palynostratigraphy Of Miocene Through Pleistocene Sediments From Part Of The Western Niger Delta, Nigeria.

ABSTRACT

Palynological analyses were carried out on four wells, Bentu-DX, Eze-DX, Meren-66 and Meren-67 from the

Western Niger Delta. The palynomorphs recovered were abundant and diverse in the horizons studied. The

Bentu-DX and Eze-DX wells are of Late Miocene (P860) – Late Pleistocene (P900) age (ca. 5.8Ma -1.3Ma).

The assemblages are dominated by land derived palynomorphs particularly Monoporites annulatus, the

mangrove pollen Zonocostites ramonae, Podocarpus milanjianus, Stereisporites spp., Cyperaceaepollis spp.,

Sapotaceoidaepollenites spp., Nympheaepollis clarus, Psilatricolporites crassus, Retitricolporites irregularis

and pteridophyte spores, in association with abundant records of dinoflagellate cysts especially in the Bentu-

DX well. The commonest species were Polysphaeridium zoharyi, Operculodinium centrocarpum, Spiniferites

ramosus, Achomosphaera ramulifera, Hystrichokolpoma rigaudiae, Lingulodinium macahaerophorum,

Spiniferites mirabilis, Spiniferites membranaceus, Spiniferites delicatus, Spiniferites bulloideus, Spiniferites

elongatus, Achomosphaera ramulifera, Achomosphaera spp., Selenopemphix nephroides, Selenopemphix spp.,

Achomosphaera andalousiensis and the acritarch Leiosphaeridia spp. Fewer dinocysts were recovered in the

Eze-DX well. A predominantly dry climate is inferred for these sediments due to the abundance of savanna

species, and the preponderance of the dinoflagellate cysts Polysphaeridium zoharyi and Operculodinium

centrocarpum, species adapted to very saline and warm waters. These dinoflagellate cysts clustered between the

2.0Ma -3.4Ma denoting the glacial maxima events during these periods. On the other hand, the Meren-66 and

Meren-67 wells were of Middle Miocene (P720) – Earliest Pliocene (P870) age (ca. 15.0Ma -