Contribution to the sedimentology of the Messinian carbonates of the Chelif Basin (Boukadir, Algeria)

The Messinian (Upper Miocene) is characterized at the level of its marginal basins by development numerous carbonate platforms. This study concerns platform Boukadir region in south Chelif Basin Algeria. It composed a lower prograding rimmed and an upper aggradational homoclinal ramp resting upon Tortonian–Lower Blue Marl Formation, thickness reaches ~280 m Basin. red-algae unit uniform subhorizontal with minimum 90 m. Petrographic analysis reveals three different microfacies, Lithothamnium, foraminifera, high porosity, microsparitic matrix. MF1 packstone, MF2 packstone/bindstone deposited above fair-weather wave base MF3 wackestone to packstone below this level. made up entirely autochthonous biogenic elements without significant external fluvial contribution. was formed shallow marine environment, very productivity export sediments produced. aggradation followed rapid exhumation (regression) transforming all aragonite into calcite. platforms correspond T2 complex reef formation (6.7–5.95 Ma) documented on other South Alboran Sea that just before Salinity Crisis.