The Paleocene in North Africa – Sea-level Changes and Paleoproductivity in Tunisa, Libya and Egypt Using Microfossils

Abstract

The Paleocene is a time of warm oceans and generally high sea levels. In North Africa, vast epicontinental seas extended far inside the African continent. In this paper we correlate sea level, primary paleoproductivity and facies distribution of the proximal, carbonate-dominated Paleocene deposits of the northern Sirte Basin with the distal, marl-dominated strata of Tunisia and Egypt. The Paleocene depositional record in North Africa is dominated by microfossil-rich hemipelagic marls that form important seals for petroleum accumulations in Tunisia, Libya and Egypt. In the investigated successions, sea level changes can be discerned through variations in sedimentological and faunal composition and, rarely, in lithological changes. By integrating analysis of quantitative distribution patterns of microfossils and sedimentological patterns, our study aims to reconstruct paleoenvironmental changes with emphasis on sea level and paleoproductivity fluctuations. Our data recognized a third-order cycle during the middle Paleocene, which correspond to a change in the paleobathymetric setting and to increased paleoproducitvity, with locally associated anoxia. This third-order cycle in the middle Paleocene, seems to be a suitable event not only for a regional correlation, but probably also to the global scheme.