Chemical composition of some Senonian bivalvian shells and its significance in paleoecological studies, in the area of Abu Roash, Egypt

Chemical analyses of the shells of three bivalvian families of Senonian age from the Abu Roash area indicate that Sr, Mn and Mg increase from Lower to Upper Senonian while Al, Si and Fe decrease. Such results point to a paleoecology of a low temperature, saline, shallow basin during the Lower Senonian changing to a higher temperature, less saline and deeper basin during the Upper Senonian. Silicification and ferrugination were stronger during the Lower Senonian.