Ten-Million-Year-Old Volcanic Eruption Identified in Northern Hungary

2025.07.08.

An international research team has identified a massive explosive volcanic eruption that occurred in the Miocene epoch of Earth’s history, in the northern part of the Carpathian Basin. Their findings were published in early July in the journal Nature Scientific Reports. The research was led by Dávid Karátson, professor and head of the Department of Physical Geography at Eötvös Loránd University (ELTE), with scientists from five countries participating.

According to their results, the colossal, four-phase eruption, which took place 13.06 million years ago, can be traced across more than 3,000 square kilometers — from the eastern edge of the Mátra Mountains, through the Bükk Mountains, all the way to the Tokaj Hills. Named after its type locality at Tarnaszentmária Dobi-oldal, the “Dobi eruption” erupted from the shallow, nearshore waters of the long-lasting inland sea known as the Paratethys. This is supported, among other evidence, by the presence of foraminifera (shell remains of marine single-celled organisms) in the tuffaceous deposits.

The researchers estimate the volume of ejected material at a minimum of 200 cubic kilometers, suggesting an extraordinarily large eruption — corresponding to VEI 7 on the scale of explosive eruptions. The interaction of seawater with magma effectively “powdered” the magma (a so-called phreatomagmatic eruption), producing, alongside centimeter- or decimeter-sized pumice clasts, mostly fine-grained ash tuff. Its chemical composition indicates that the vast amount of magma was tapped from multiple magma sources.

Despite erupting from beneath the sea, the massive tuff deposits were laid down mainly on land, as indicated by the basal layers of the deposits, where plant remains — stems, leaves, even charred tree trunks — have been found, reflecting the ancient terrestrial ecosystem.

Like its famous counterpart at Ipolytarnóc, the Dobi eruption instantly preserved the prehistoric environment of the time. Ongoing research suggests that the long-lasting volcanism of Northern Hungary — never before studied in such detail — may reveal several more sites akin to Ipolytarnóc in the future.

The Nature article: https://www.nature.com/articles/s41598-025-07002-9.epdf

Karátson, D., Lahitte, P., Portnyagin, M. et al. A 13.06 Ma widespread ignimbrite in the Pannonian Basin captured a snapshot of shallow marine to coastal environment in Central Paratethys. Scientific Reports 15, 23528 (2025). https://doi.org/10.1038/s41598-025-07002-9

(Source: Institute of Geography and Earth Sciences)