Miospores and Geological Boundaries in Maastrichtian to Lutetian Succession of Ajire -1 Well, Anambra Basin, Nigeria
Lucas, F. A.
Department of Geology,
University of Benin, Benin-City, Nigeria
E-mail: drfalucas@gmail.com
ABSTRACT
Evaluation and appraisal of biostratigraphically significant miospores in Ajire-1 well, Anambra Basin allow the delineation of five geological stage boundaries from Maastrichtian to the Lutetian succession of the well. The delineated boundaries are Maastrichtian/Danian, Danian/Selandian, Selandian/Thanetian, Thanetian/ Ypresian and Ypresian/Lutetian respectively. Estimate of the numerical ages have been possible by the comparison of the miospore events with those of dinocysts recognized in the well. Five Eocene diagnostic miospores- Mauriitidites crassiexinus, Grimsdalea pol ygonallis, Forma ‘C’, Psilatriclpites okeziei and Proteacidites otamirinensis, originally described from the upper Eocene Ogwashi –Asaba Formation, south-east Nigeria have their first stratigraphic occurrences in the Early Eocene. This is the first attempt in which miospores are being used in Nigeria to delineate the Paleocene epoch into three internationally recognized stages. It is envisaged that the information documented in this study would further refine the Nigeria Chronostratigraphy and bring it in-line with new standard global stratigraphy scale.
Keywords: Miospore; Geological Boundaries; Maastrichtian; Lutetian; Ajire-1 Well; Anambra Basin; Nigeria.
