Depositional processes in outer arc marginal sib-basins during the Messinian time; Messinian crisis: An example from western Crete Island, Greece

Abstract

The ratio of sea-level falling rate to subsidence/uplift rate was the master factor controlling the evolution of three adjacent marginal sub-basins, the Platanos, Kastelli and Maleme Sub-Basins. During the Messinian, the Platanos Sub-Basin was characterized by a constant shelf environment with a water depth of deposition not more than 50 m; a sabkha environment which changed during the latest Messinian to a shelf environment characterized the Kastelli Basin, representing a water depth of deposition changing from 0 m to less than 50 m; fmally, a terrestrial environment which changed during the latest Messinian to a shallow marine environment, characterized the Maleme Basin, representing a sea-level rise of no more than 50 m. The evolution of the depositional environments in the three adjacent basins suggests: a. A total sea-level fall of >250 m from latest Tortonian to latest Messinian time in the western Crete (>200 m during latest Tortonian and 50 m during Early Messinian). b. When the ratio of sea-level falling rate to subsidence/uplift rate is > 1, lake or shallow marine environments (shelf) changed to terrestrial, and outer slope environments changed to shelf environment. When the ratio is slightly > 1 a shelf environment changes to a sabkha; and when it equals 1, the depositional environment changes from a sabkha or terrestrial to shelf environment. c. Depositional environments characterized by lowstand conditions during the Messinian time.