Late Maastrichtian And Paleocene Calcareous Nannofossils From Ain Dabadib Section, Nw Kharga Oasis, Egypt

Abstract

On terms of calcareous nannofossils, the late Maastrichtian and Paleocene sediments were subdivided into several biozones. The Cretaceous-Tertiary boundary is marked by a hiatus concerning the latest Maastrichtian and the early Danian. To predict the surface water paleotemperature during the late Maastrichtian-Paleocene interval, the warm-water/cool-water; the Micula staurophora/Watz-naueria barnesae, and Discoaster/Chiasmolithus ratios were calculated for each studied samples. There is some nannofossil evidence to suggest that the paleotemperature was already declining in the late Maastrichtian. A slight cooling in the surface-water temperature has occurred at the end of Danian. However, the late Paleocene (Thanetian) is characterized by the predominance of warm-water forms and also by an increased value of the Discoaster/Chiasmolithus ratio. This suggested an increase of the surface-water paleotemperature during this time interval.