An air-fall ash layer in the Grotta dei Baffoni cave in the Frasassi Gorge (Marche Apennine, Italy)

Autor(en)

Alessandro Montanari, Christian Koeberl, Toni Schulz, Victoria C. Smith, Mihály Molnár, Katalin Tóth-Hubay

Abstrakt

A thin tephra layer was discovered in a section of cave sediments in the Grotta dei Baffoni Cave (GDB), in the Marche Apennine of central Italy, immediately underlying a clayey layer containing charcoal fragments dated at 12,843 ± 122 years before present. This date indicated that humans were occupying the cave at the very beginning of the Younger Dryas cooling event. Petrographic and geochemical analysis of the volcanic glass contained in the tephra layer suggests that this deposit represents a distal air-fall ash erupted from a volcano in the Campi Flegrei caldera, which produced the Neapolitan Yellow Tuff (NYT). Radiocarbon AMS dating of charcoal particles from this GDB tephra layer yielded an age around 14.4 ± 0.4 ka, which is consistent with the chronology of the NYT eruption, which occurred some 14.1 ± 1.4 thousand years ago. Nevertheless, the sediment succession in this cave deposit actually covers a time interval across the sudden and drastic Younger Dryas cooling event, which occurred around 12.9 ka. There is an ongoing debate about the causes of the Younger Dryas event, which divides the scientific community into a faction sustaining that the Younger Dryas cooling event was triggered by an elusive meteorite impact, and an opposing one that advocates volcanic eruptions, such as the eruption of the Laacher See volcano in central Germany, which was precisely dated at 13 ka. A detailed trace element and ¹⁸⁷Os/¹⁸⁸Os analysis of the sedimentary succession in the Grotta dei Baffoni Cave did not reveal evidence of any platinum-group element anomalies or an osmium isotope signature that would support an extraterrestrial impact event around the time of the Younger Dryas event. The Grotta dei Baffoni tephra layer turned out to be derived from a large eruption in the Campi Flegrei of southern Italy, which produced the huge Neapolitan Yellow Tuff around 14.1 thousand years ago. This catastrophic event appears to be synchronous with the minor Older Dryas cooling event, which preceded the Younger Dryas by some 1300 years.

Organisation(en)

Department für Lithosphärenforschung

Externe Organisation(en)

Osservatorio Geologico di Coldigioco, University of Oxford, Magyar Tudományos Akadémia

Journal

Journal of Volcanology and Geothermal Research

Band

450

ISSN

0377-0273

DOI

https://doi.org/10.1016/j.jvolgeores.2024.108067

Publikationsdatum

06-2024

Peer-reviewed

Ja

ÖFOS 2012

105120 Petrologie, 105105 Geochemie

Schlagwörter

ASJC Scopus Sachgebiete

Geophysics, Geochemistry and Petrology

Sustainable Development Goals

SDG 13 – Maßnahmen zum Klimaschutz

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/8d513126-a957-4da2-bb13-e9f5cacefa1d