Facies and fauna proxies to reconstruct the MIS 5 and MIS 7 coastal environments in Eastern Tunisia

Abstract

This study is based on the analysis of the sedimentology and the fossil assemblages of the Pleistocene deposits in Eastern Tunisia. It aims to establish the different fauna assemblages in order to highlight their paleoenvironments and discuss the importance of the Persististrombus latus distribution especially in the MIS 5e deposits around the Mediterranean Basin.

The stratigraphic succession has been divided into two main units. The lower unit is quartz-rich sediment. Its lower marine term revealed well preserved species (Bivalves, Gastropods, Echinoids and Scirripedia) dominated by Acanthocardia, Cerastoderma, Parvicardium, Arca, Donax, Glycymeris, Loripes, Tellina and Cerithium. This fauna is representative of a typical association/biocenosis which may be developed in a sheltered bay, where the hydrodynamism is regularly moderate to low and/or quickly post-mortem buried.

The upper unit is carbonated. Its basal term is also rich marine fauna which contains the extant tropical West African species Persististrombus latus.

The occurrence of Persististrombus latus in this unit compared to its presence in the whole Mediterranean basin in the Upper Pleistocene leads to question its importance in the interpretation of the climate warming during the Upper Pleistocene, confirming its Atlantic origin.