ON THE REGIONAL KONKIAN STAGE (MIDDLE MIOCENE) IN THE EASTERN PARATETHYS

Abstract

The paper summarizes paleontological and stratigraphic data on the regional Konkian Stage in the Northern Black Sea, Crimea-Caucasus, and Transcaspian regions. Based on original and published materials, it is shown that the Mediterranean polyhaline elements occur at different stratigraphic levels indicating that the repeated expansion of the Konkian sea was accompanied by the increasing water exchange with the Mediterranean Sea and prochoresis of the marine fauna. At least three prochoresis events are registered for the Konkian time: at the initial ("Sartagan"), middle, and terminal ("Veselyanka") stages of the age. Owing to misunderstanding in dating these levels, it is proposed to deny the previously accepted subdivisions of this regional stage until the Konkian stratigraphy is clarified. In addition, the term "Sartagan" should be rejected because the Sartagan section lacks the basal Konkian layers with polyhaline fauna. Following E.M. Zhgenti, the Kartvelian is proposed to be considered as a unit of the regional stage rank.