INTERLABORATORY FISSION-TRACK DATING OF VOLCANIC ASH LEVELS FROM EASTERN PARATETHYS - A MEDITERRANEAN PARATETHYS CORRELATION

The age of glass shard levels, interlayered in Sarmatian deposits from the southwestern Russia are measured with the fission track method. The results obtained from different laboratories (Moscow, Pisa, Campinas) using their specific techniques are in good agreement so proving a good interlaboratory agreement. The results suggest a new correlation between Paratethys and the Mediterranean area, in better agreement with the global climatic trend of this period. According to the proposed scheme the Chersonian/Maeotian boundary (9-9.5 Ma) is correlatable with the Vallesian/Turolian boundary (continental Mediterranean stratigraphy) and with the Middle Tortonian (marine Mediterranean stratigraphy); the Bessarabian (time span between 12.5 and 11 Ma) is correlatable with the Lower Vallesian and with the Upper Serravallian; the beginning of the Volhynian, that is the beginning of the Sarmatian (14-13.5 Ma), is correlatable with the Upper Astaracian and with the lower boundary of the Serravallian. Due to the large experimental errors of the ages and possible systematic errors the proposed stratigraphic sequence may be regarded as a working hypothesis to be confirmed by further data.