Constraining the Timing of the Closure of the Intra-Pontide Ocean by U-Pb Dating of Syntectonic Calcite

The western Black Sea region is a key area for the study of the Neo-Tethys orogenic belt, as it contains records of the evolutionary history of the entire Alpine orogeny from subduction to oceanic closure and collision. The Izmir-Ankara and the Intra-Pontide suture zones represent the final closure of the Neo-Tethys oceans. However, when the final closure took place is still disputed. In this study, we investigate syn-collisional faulting events in the western Black Sea region near Istanbul. We performed kinematic analyses of faulting and U-Pb dating of syntectonic calcite precipitates on the fault planes to constrain the timing of Neo-Tethys Ocean closure and post-collisional contractional tectonics. Syntectonic calcite precipitates associated with regional N-S compressional tectonics provide precise U-Pb ages between 48 and 57 Ma, constraining the early Eocene age of reverse faulting and associated closure of the Intra-Pontide Ocean.