LATE MAASTRICHTIAN CALCAREOUS NANNOFOSSIL CLIMATE RECORD AT QUSEIR REGION, RED SEA COAST, EGYPT: IS THAT LINKED TO DECCAN VOLCANISM?

Calcareous nannofossil record of the Late Maastrichtian is analyzed at three sections at the Eastern
Desert, Quseir region, Red Sea coast, Egypt. These sections are Gabal Anz, Gabal Atshan and Gabal
Hamadat. Species richness as well as the relative abundance of sensitive nannofossil indicators throughout
this interval signified remarkable climatic changes. It is indicated that the Late Maastrichtian is marked by
cool climate that intersected by two warming episodes. The lower episode is marked by a drop in species
richness as well as cool-water indicators concomitant with a positive shift of the warm-water species
Micula decussata and M. murus. This event is interpreted as a response to sea-level fluctuations associated
with an extreme oligotrophic condition of local environmental signal. The second episode corresponds to
the latest Maastrichtian warming event. It is nearly has the same characteristics of the lower episode but it
differs in the assemblage diversity. The nannofossil results during this event are correlated globally with
similar observed findings. The main outcome of this correlation is the bloom of M. murus at the terminal-
Maastrichtian is contemporaneous with the observed acme at other localities. The possible drivers for such
warming at the studied area throughout the latest Maastrichtian could be attributed to the double effect of
the main phase of Deccan volcanism (Phase-2) that associated with sea-level fluctuations due to local
tectonic activity. The climatic evolution of the interval preceding directly the Cretaceous/Paleogene
(K/Pg) boundary cannot be traced due to the presence of hiatus.
Keywords: Calcareous nannofossil; Late Maastrichtian; climate change; Deccan volcanism, Quseir region;
Egypt