Stratigraphy and paleobathymetry of upper cretaceous-lower tertiary exposures in beris-doush area, kharga oasis, western desert, Egypt.

Abstract

The detailed study of the Upper Cretaceous-Lower Tertiary succession exposed in Beris-Doush area enabled the subdivision of this succession into a number of rock units well known in the Nile Valley facies area in Egypt. Also present a thin part of the Kurkur Formation of the Garra-Arabian facies. 96 foraminiferal species were identified and used to classify the studied succession into a number of benthonic and planktonic foraminiferal biostratigraphic zones. This foraminiferal assemblage is composed mainly of arenaceous foraminifera with simple wall structure in addition to rare calcareous benthonic and planktonic elements. Thus, a littoral to inner shallow shelf environment with fresh water supply is suggested for the Late Cretaceous part of the succession and a littoral to shallow middle shelf environment for the early Tertiary part. During Late Cretaceous-Early Tertiary times, over Berish-Doush area, three transgressive phases were detected: during the Middle Maestrichtian (G. gansseri Zone), at the early Middle Paleocene (M. uncinata. Zone), and in the early Late Paleocene (P. pseudomennardii Zone). The Nummofallotia, Barrier & Neumann, 1959is recorded for the first time