 The Paleozoic and Mesozoic structures are visible in Papuk and other Slavonian mountains.The processes also led to the formation of a stratovolcanic chain in the basin 12–17 Mya; intensified subsidence was observed until 5 Mya as well as flood basalts at about 7.5 Mya.The contemporary tectonic uplift of the Carpathian Mountains severed water flow to the Black Sea and the Pannonian Sea formed in the basin.