Quantitative study of foraminifera and calcareous nannofossils on the boundary between the Cenomanian - Turonian in the coastal chain /Syria/

Abstract

A quantitative study is prepared for the first time to the sediments of Upper Cenomanian /Lower Turonian boundary period in several sections situated in the Costal chain in the west of Syria. Two groups of micropaleontology have been used (Foraminifera) in several sections and Calcareous Nannofossils in Escebleh section. Two zones of low values of the relative abundance of Foraminifera are observed corresponding two anoxic period in the middle Cenomanian and the top of Cenomanian (Bab Abdullah Formation).

Several criteria were used indicating in global the increase in the sea level in the lower part of Turonian. 1- The increase of the relative abundance of Calcareous Nannofossils and Foraminifera species indicates the favorable conditions for its  abundance like the light and the warm water temperature , as evidenced by The dominance in the assemblage of the species of genus Watznueria of calcareous nannofossils is considered the warm specie. 2- The increase in the abundance of Rotalipora of Foraminifera corresponding with the increase in the thickness of water column. The correlation between the relative abundance curve of Calcareous Nannofossils and Foraminifera in the Cenomanian sediments indicates the decrease in the abundance concide to a shallow marine environment that has chemical and debris sedimentation

system in the coastal chain.