Use of palynofossils in sequence stratigraphic interpretation of Oku 1 well sediments, Niger Delta, Nigeria

Author:Odedede, O.

published date:2019-Jun-19

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Abstract

Palynofossils recovered from 1730 – 3730 m interval of the Oku -1 well in combination with lithological data provide information for the establishment of sequence stratigraphic framework. Marine incursion, paleo - salinity and sequence stratigraphic setting were determined using Palynological Marine Index (PMI = (Rm/Rt +1) 100 and Salinity Index (SI = In [(F+0.1) / (M+0.1)]/e. Quantitative results from twenty palynological samples combined with lithological data aided the sequence analysis. Terrestrial palynomorphs are common and abundant in the shale especially Botryococcus braunii, recorded fluctuating values of PMI (100.00) and indicate highstand system tracts. Palynofossils and lithological data indicate brackish water to fresh water paleo-depositional environment for the lower section and the overlying sandstone unit respectively. Constant values of PMI (100), lithological characteristics and significant amount of terrestrial alga B. braunii indicate lowstand system tracts

Keywords: Brackish water, lowstand, palynofossils, sequence, stratigraphic

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