Lithostratigraphic study of the phosphate bearing sedimentary sequence of some occurrences in Dakhla Oasis, Western Desert, Egypt

Abstract

The south of the Western Desert of Egypt exhibits well exposures of Late Cretaceous successions, represented by the fluvio-marine (Nubian sandstone group) and shallow marine deposits. The phosphate bearing horizons of Abu-Tartur plateau and Dakhala Oasis are concentrated in the base of Duwi Formation, Campanian age. Duwi Formation uncomfortably overlies Quseir variegated shale and conformably and partially uncomfortably overlain by Maastrichtian Dakhla shale. The phosphate layer of Duwi Formation at Abu-Tartur and Dakhla Oasis regarded as the main sources of the phosphorites of Egypt. This research aims to provide a comprehensive understanding of the geological framework and lithostratigraphic characteristics of the phosphate bearing sedimentary sequences of Dakhla Oasis, which extends from west Abu-Tartur to Gabal-Edmonston in the Dakhla Oasis, with a special focus on phosphorite deposits and the associated non-phosphate interlayers. The study combines regional stratigraphic and lithological investigations to elucidate the vertical and lateral distribution patterns of phosphorite layers. The results will contribute to knowledge of phosphorite formation processes and evaluation of potential resources in the study area.