Improving stratigraphic control within the Paratethys: overview of a decade of integrated magnetostratigraphic, geochronologic and biostratigraphic research

The restricted nature of the large land-locked Paratethys Sea, its largely endemic fauna and the distinctive evolution of its individual basins pose a challenge to rigorous stratigraphic control. The contemporary biostratigraphic framework relies heavily on the occurrence of species that are environmentally sensitive such as molluscs, benthic foraminifera and ostracods, which are on top of that restricted to shallow-water habitats. Time-indicative biostratigraphic markers that can be straightforwardly correlated, for instance, to the Mediterranean stratigraphic framework are generally absent. The silled nature of the basins that constituted Paratethys furthermore made them particularly sensitive to eustatic changes and tectonism leading to frequent isolation and a disparate evolution.

Events recognizable in the stratigraphic record can, as a result, rarely be confidently correlated from one location to another. This lack of stratigraphic control is problematic for hydrocarbon exploration and precludes a thorough scientific understanding of the dynamics of Paratethys. There is thus a strong need for a stratigraphic toolset enabling Paratethys-wide correlations.

Magnetostratigraphy and radio-isotopic dating can provide the required long-range, environment-independent stratigraphic tie-points. Considerable progress has been made over the past decade and a range of constraints is now available for the Miocene and Pliocene Paratethys stages. Sampling efforts encompassed the Southern Pannonian Basin, Transylvanian Basin, Carpathian Foredeep, Dacian Basin, Black Sea, Caspian Sea and Tarim Basin. The results are integrated with high resolution biostratigraphic analyses and provide a state-of-the-art framework for the solution of both scientific and hydrocarbon-exploration-related issues.