MEOTIAN-PONTIAN GEOCHRONOLOGY OF THE EASTERN PARATETHYS

Abstract

This article sums up the second stage of work on devising a Late Cenozoic radiometric time scale for the eastern Paratethys, in which we initially dated Sarmatian deposits of Moldavia and the Kerch'-Taman' region. Radiometric dating of rocks was done by the U238 fission-track method on volcanic glass, sampled mainly from ash layers in Meotian-Pontian sections of Azerbaidzhan. Our data confirm the earlier view that the Pontian Stage is entirely Miocene, and that the Miocene-Pliocene boundary (5.4 m.y.) lies above the top of this stage in the Black Sea region, i.e., within the Kimmerian Stage. Accordingly, the Meotian in this region must correspond to the upper half of the Tortonian in the Mediterranean region, and the Pontian to the larger part of the Messianian there, probably without the Lago Mare beds.