Discovered: the most recent volcanic eruptions in the Iberian Peninsula

The study, in which the Catalan Institute of Human Paleology and Social Evolution (IPHES) has participated, has been carried out on a 14-meter-deep survey in Vall d’en Bas (Girona). This volcanic activity caused several volcanic flows to block the valley of the Fluvià river near Olot and to form a large lake on the plain that is now known as Pla de les Preses.

The sediments that were deposited in this ancient lake surrounded by volcanoes, which include numerous layers of volcanic ash and lapilli, have been studied by different specialists, analyzing sedimentary, paleoclimatic and biological indicators such as chronostratigraphy, sedimentology, pollen, ostracods, lake algae, diatoms etc

All of this has made it possible to reconstruct the paleoclimatic evolution of the last 13,000 years in the northeast of the Iberian Peninsula, the volcanism of La Garrotxa, and the impact of these eruptions on the plant and lake ecosystems and on the Mesolithic human populations of the area.

In the area closest to the zone of volcanic activity (up to 50 km) and during volcanic eruption events, different processes such as lava flows, deposit of volcanic materials, ash rain, gas emanation, aerosols, pyroclastic flows and earthquakes affected flora and fauna (bioresources) as well as air and water quality, and constituted a danger to human populations.

In this sense, and from the study of nearby archaeological sites, it can be seen that the closest hunter-gatherer populations left the area temporarily during periods of high volcanic activity, to later return in quiet times, demonstrating a high capacity for reorganization. and adaptation.