A striking illustration of how the evolution of mountain belts can rapidly change river drainage patterns has recently been published in Geology.

Following a series of geological fieldwork campaigns in Moldova, Romania and the Ukraine, the CASP-led research group has found that prior to c. 4 Ma, the significant river draining into the west Black Sea flowed parallel and east of the Carpathian Mountain chain. The authors conclude the delivery of large volumes of sediment to the Black Sea via the Carpathian foreland axial system was a consequence of a combination of diachronous continental collision, the break-off of subducted oceanic lithosphere from the crust and sea-level variations. Only once these tectonic drivers had diminished and a number of internal depocentres had been filled, did the Danube establish itself as the most significant river draining into the western Black Sea.

23 June 2020