Cenomanian to Coniacian sea-level changes in the Lower Benue Trough (Nkalagu area, Nigeria) and the eastern Dahomey Basin: palaeontological and sedimentological evidence for eustasy and tectonism (original) (raw)

Geological Society, London, Special Publications

Abstract

The Benue Trough formed in close relation to the opening of the South Atlantic and experienced sea-level fluctuations of different magnitudes during the Cenomanian to Coniacian interval. We identify depositional environments from outcrop sections and a drilling as control record. Lines of evidence for the interpretation include facies analyses, foraminiferal assemblage composition (P/B-ratio) and the presence of planktonic deep-water indicators. While the analysis of the well data from the Dahomey Basin indicates a continuous deep-water (bathyal) environment, the succession in the Nkalagu area of the Lower Benue Trough evolved in a different and more complex way. Beginning with latest Cenomanian shoreface to shelf deposits, a long period of subsidence lasted until the middle Turonian when pelagic shales and calcareous turbidites were deposited at upper to middle bathyal depths. These conditions continued during late Turonian and Coniacian times. The general deepening trend of the Lo...

samuel akande hasn't uploaded this paper.

Let samuel know you want this paper to be uploaded.

Ask for this paper to be uploaded.