1 cenomanian ramp ( galala formation ) , north eastern desert , egypt : facies architecture and depositional history

The Cenomanian Galala Formation is composed of a thick mixed siliciclastic-carbonate facies outcropping in the north Eastern Desert, Egypt. It was deposited on a passive continental margin of southern Tethys. It displays a lateral facies changes in the form of a homoclinal ramp that is divided into two environmental settings; proximal and middle ramp. The proximal ramp is characterized by the silicclastic-dominanted coastal marine shoreface to peritidal facies and the mixed siliciclastic-carbonate intertidal-supratidal facies. The middle ramp includes three facies types; the peritidal, shallow subtidal and deep subtidal facies. The facies distribution on the middle ramp points out to that the ramp was drowned under the effect of local tectonic subsidence due to the east-west Tethyan tectonic movements during the Jurassic rifting forming an intra-ramp basin at the Southern Galala. The dominance of the carbonate facies in the northern part of the study area reflects that it was subjected to structural uplifting under the effect of the Syrian Arc System to form a carbonate buildup at Gebel Ataqa.