Chapter 17 - Sedimentology and Cu-U mineralisation of the Upper Cretaceous Bin Affin Member, Dur Waddan, Southwestern El Haruj, Murzuq Basin, Libya

Abstract

This chapter discusses the preliminary sedimentological investigations that reveal that the upper Cretaceous bin affin member consists of four lithofacies. Firstly, cross-bedded sandstone consisting of calcareous pebbly sandstone rich in tree logs and roots, and believed to be deposited on the point bars of fluvial channels. Secondly, sand sheet facies composed of structureless poorly sorted sandstone beds rich in root-like bodies where Cu-U mineralization is restricted. The depositional environment of this facies seems to be fluvial channels of low sinuosity. Thirdly, sandstone and siltstone rich in the trace fossil ophiomorpha characteristic of shallow subtidal environments and, finally, pebbly sand facies uppermost in the bin affin member is composed of friable sandstone rich in poorly preserved vertebrate bones and deposited in tidal channels.