THE MESSINIAN CARBONATE PLATFORMS OF THE ORAN AREA (ALGERIA) - NEW DATA AND CONSEQUENCES

The Messinian carbonate platforms which develop west of Oran are ident ified along 60 km. Their organization strongly depends on the pre-exis ting structures, especially the distribution of the accommodation and the directions of progradation of carbonated units. Aggradational and progradational processes led to important restrictions of the communic ation zones between the different coastal basins. The infilling of the accommodation should be a fundamental phenomenon leading to evaporite s deposition in narrowing areas. Relative sea-level drops, if true, sh ould be of limited amplitude.