The youngest volcanic eruptions in East-Central Europe—new findings from the Ciomadul lava dome complex, East Carpathians, Romania

Violent explosive eruptions occurred between c. 51 and 29 thousand years ago—during the Last Glacial Maximum in East-Central Europe—at the picturesque volcano of Ciomadul, located at the southernmost tip of the Inner Carpathian Volcanic Range in Romania. Field volcanology, glass geochemistry of tephra, radiocarbon and optically stimulated luminescene dating, along with coring the lacustrine infill of the two explosive craters of Ciomadul (St Ana and Mohos), constrain the last volcanic activity to three subsequent eruptive stages. The explosivity was due to the silicic composition of the magma producing Plinian-style eruptions, and the interaction of magma with the underlying, water-rich rocks resulting in violent phreatomagmatic outbursts. Tephra (volcanic ash) from these eruptions are interbedded with contemporaneous loess deposits, which form thick sequences in the vicinity of the volcano. Moreover, tephra layers are also preserved in the older Mohos crater infill, providing an important archive for palaeoclimate studies. Identifying the final phreatomagmatic eruption of Ciomadul at c. 29.6 ka, which shaped the present-day landform of the 1600-m-wide St Ana explosion crater, we were able to correlate related tephra deposits as far as 350 km from the source within a thick loess-palaeosol sequence at the Dniester Delta in Roxolany, Ukraine. A refined tephrostratigraphy, based on a number of newly found exposures in the Ciomadul surrounding region as well as correlation with the distal terrestrial and marine (e.g. Black Sea) volcano-sedimentary record, is expected from ongoing studies.