Delayed onset of regional aridification during global climate cooling: insights from the Miocene Valjevo-Mionica Basin, southeastern Europe

Abstract

The Middle Miocene Climatic Transition (MMCT) was a period of increased global aridity marked by reinforced evaporation and suppressed precipitation, respectively. While this aligns with general terrestrial paleoclimatic trends in Europe, the influence of land-vs-sea distribution and mountain building on regional climatic variability remains understudied. In particular, existing research suggests that southeastern Europe experienced pronounced aridity in the Miocene, linked to a rain shadow caused by the uplift of the Dinarides. However, poor age constraints hamper the establishment of clear causal relationships. In this work, we investigate how regional tectonic processes modulated global climatic trends in southeastern Europe. We conducted a sedimentologicl analysis of the basin fill and U-Pb zircon dating of intercalated volcaniclastic deposits in the Valjevo-Mionica Basin in western Serbia, allowing us to correlate the basin evolution with global and regional climatic forcing mechanisms. Our results reveal significant lake expansion between 14.1 and 13.5 Ma, which suggests a rise in precipitation coeval with the tectonically driven expansion of the Central Paratethys. A subsequent phase of progressive aridification occurred between 13.5 and 12.1 Ma. We correlate this with continued global cooling following the Middle Miocene Climatic Transition, consistent with an intensification of the rain-shadow effect in the Dinarides driven by changes in atmospheric circulation patterns.