Tectonic Forcing of Diachronous Salt Deposition During the Badenian Salinity Crisis Revealed by U–Pb Dating of Tephra Overlying Tuzla Basin Evaporites

During the Middle Miocene Badenian Salinity Crisis (BSC), extensive evaporites formed across different tectonic settings in the Central Paratethys. Limited age constraints hamper evaporite correlation and identification of driving mechanisms. Here, we use U–Pb dating of zircon by LA-ICP-MS from tephra overlying the Tuzla Basin evaporites. The results indicate cessation of evaporitic conditions at 13.88 ± 0.11 Ma, coeval with the Mi3b event-related global sea-level fall. In Tuzla, a backarc-extension-related sill controlled both evaporite formation and subsequent reflooding, significantly shortening the evaporitic phase. Conversely, flexural subsidence in the Carpathian Foredeep postponed restriction by ~0.5 Myr and prolonged evaporite deposition in deeper settings. We hypothesise that during the BSC, tectonically induced sills governed the timing and distribution of evaporites, as in the well-studied Mediterranean Messinian Salinity Crisis (MSC). Unlike the Gibraltar arc-dominated MSC, multiple, rapidly evolving sills of comparable influence controlled the BSC, producing diachronous and spatially heterogeneous evaporites across the Central Paratethys.