Miospore Biostratigraphy of Oligocene ? Lower Miocene Sediments in Well X, Deep Offshore Niger Delta

The miospore biostratigraphy has been carried out on ditch cutting rock samples from Oligocene and Lower Miocene sediments in well X, deep offshore Niger Delta following the standard method of palynological sample processing and analysis. The rock succession is characterised by the alternation of thick black shales and grey shales with thick Medium to coarse grained, fairly well sorted sandstone at the base believed to be turbidite sand of the Upper Akata formation. while the top of the studied interval is more paralic and made of black shales intercalating with medium to coarse grained sandstones and siltstones at intervals characteristically of the paralic Agbada Formation (figure 3). The palynologigal analysis of samples yielded a well preserved and diverse biostratigraphic relevant Miospores among which fifty- nine Miospores were identified. On the basis of the first and last downhole occurrences of these Palynological events, twelve miospore biozones were erected. The zones are from the base to top Zonocostites ramonae, Inaperturopollenites sp, Striatriculpites pimulus, Pachydermites diederixi, Dualidites laevigatus, Retitricolporites irregularis, Retibrevitricolpites obodoensis, Anacolosidites luteoide, Racemonocolpites hians, Monoporites annulatus, Verrutriculporites rotundiporis, and Magnastiatites howardi. These zones were correlated with the standard palynological biozonation schemes in the area and used it to delineate the Oligocene/Lower Miocene boundary.