Upper Cretaceous to Paleogene Palynosequence Stratigraphy of H-1 Well Offshore Eastern Dahomey Basin, Southwestern Nigeria

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Research areas:
Year:
2015
Type of Publication:
Article
Keywords:
Palynosequence Stratigraphy, Palynology, Palynofacies, Offshore Dahomey Basin
Authors:
Oluwatosin Adebiyi Adeniran
Journal:
IJRIES
Volume:
2
Number:
3
Pages:
81-88
Month:
May
BibTex:
Abstract:
The detailed palynosequence stratigraphy and reconstruction of depositional successions of H-1 well was done from studies of its palynology, palynofacies and sedimentology. Palynological evidences indicated a Late Cenomanian to Early Eocene age. The observed absence of the upper and middle Maastrichtian, lower Santonian, Coniacian and the Turonian sections led to the recognition of three major unconformities, with two in the late Cretaceous and one in the early Tertiary. There are two minor boundaries recognized as well. The sequence stratigraphic analysis of the well led to the recognition of six sequences beginning in the late Cretaceous with a Highstand systems tract (HST) and ending in the Tertiary with a Transgressive systems tract (TST). Each of this systems tract were delineated based on the distribution, abundance and diversity of humic gel-like palynomasceral (Phytoclasts), the Palynological marine index (PMI) and the Amorphous organic matter (AOM). Sequence boundaries were picked at the lowest values of amorphous organic matter and the Palynological marine index (PMI) as well as the highest values of the Palynomasceral -1. A significant observation is the round shape of the debris at virtually all the maximum flooding surfaces (MFS). The recognized sequence stratigraphic sequences with their candidate maximum flooding surfaces and sequence boundaries as well as the equivalent ages were based on the stratigraphic positions of each event with respect to the 86.0 Ma MFS and its sequence boundary at 87.5Ma being the only marine events in the recognized Santonian interval. An ongoing nannofossil and foraminiferal study will confirm the assigned ages.