Similarities in lithology and age suggest that the Moesian and Moldavian platforms were united until late Precambrian tine when an independent geological evolution began in parts of Romania and lasted through Paleozoic time. In Middle Triassic time, mafic rocks appeared in the East Carpathians and Dobrogea as part of a wide belt, caused by crustal distension, from the West Carpathians to the Caucasus. Plate separation led to the development of the Siret Ocean between Pannonia and Moldavia.
Jurassic sedimentation started as a shallow-water, transgressive facies except in spreading centers, such as the Siret Ocean and the proto-Apuseni area, which was then part of the Dinarides and where ophiolites with interlayered chert and radiolarite formed. By Early Cretaceous time, movement sense changed and the microplates were translated toward the stable craton. The Apuseni ophiolites were obducted onto continental crust. Convergent plate boundaries, with flysch, nappe structures, and silicic volcanism, developed between Moesia-Pannonia and the Tethys-Dinaric Oceans and between Pannonia and the Siret Ocean.
In Paleocene time, a belt of calc-alkalic rocks (banatites) developed in western Romania and the Balkan Mountains as a result of plate convergence of Rhodope and Moesia as the last of Tethys was subducted. This was followed by a continental collision of Moesia and Pannonia and the uplift of the South Carpathians. Neogene volcanism and molasse developed as end stages of plate subduction and collision. Modern earthquake activity of the Vrancea Mountains and high heat flow in Transylvania suggest that subduction is still going on around the great Carpathian arch.