Sedimentary succession and evolution of the Mediterranean Ridge western sector as derived from lithology of mud breccia clasts

Abstract

Rock fragments from mud breccia extruded by mud volcanoes, discovered during the TTR-4 cruise of the R/V Gelendzhik on the western Mediterranean Ridge, are represented by a number of different lithologies. They provide important information on the composition, genesis, and age of the deep-seated sedimentary series of the basin. Lithological description and age determination of the main rock types obtained as clasts from mud breccia were made on the basis of a study of ninety-seven samples. Depositional processes and environments of their accumulation were determined using sedimentological criteria. The sedimentary section through which mud volcanoes erupted on the western Mediterranean Ridge includes Aptian–Albian claystones, Late Cretaceous limestones, Paleogene siliciclastic rocks, and a variety of Miocene limestones and mudstones. The rock clasts studied throw insight into the evolution of the western sector of the Eastern Mediterranean Basin from, at least, Aptian time. The Aptian–Albian clayey series have been deposited in the marine conditions of a relatively narrow basin with a high input of terrigenous clayey material. During the Late Cretaceous the basin enlarged, terrigenous input into deep parts of the basin decreased, and carbonate pelagic sedimentation became prevalent. Regression in Paleogene time led to the deposition of thick terrigenous siliciclastic series of deltaic–prodeltaic sediments. Extensive turbidite systems were emplaced in the western sector of the Eastern Mediterranean during the Miocene, along with predominantly carbonate pelagic sedimentation.