Bio-Sequence Stratigraphy of Shagamu Quarry Outcrop, Benin Basin, Southwestern Nigeria

The Paleocene/Eocene boundary has been a significant subject globally for sometimes now. This work focuses on the application of sequence stratigraphy where diagnostic microfossils trends of abundances and qualitative parameters can be integrated with sedimentology in the recognition of stratigraphic surfaces. Such surfaces / boundaries are highstand systems tract (HST), transgressive systems tract (TST), lowstand systems tract (LST), maximum flooding surface (MFS) / condensed section (CD) and sequence boundary (SB). These will no doubt provide an excellent opportunity for the identification of a functional boundary in a fairly assemblage-rich basin. 14 outcrop samples from the Shagamu Quarry were studied for their palynomorphs and foraminifera. Correlation with previous works on nannofossils and palynomorphs was also carried out to aid interpretations. Systems tracts and surfaces recognized and proposed for the study area are: HST (4.2-7.1 m, 9.5-11.5 m and 26.8-28.0 m), TST (7.7-9.5 m, 11.5-19.0 m, 19.0-20.2 m {TST/CD)}), LST (1.3-4.2 m and 20.2-26.8 m), MFS (56.8, 58.1 and 59.7 Ma) and SB (56.5, 57.0, 57.5 and 60.4 Ma. Depositional environments varied from inner to outer neritic settings. This study will aid exploration efforts not only in the onshore but also in offshore settings where sizeable sections have been reported missing.