Stratigraphic record of the asteroidal Veritas breakup in the Tortonian Monte dei Corvi section (Ancona, Italy)

Autor(en)

Alessandro Montanari, Ken Farley, Philippe Claeys, David De Vleeschouwer, Niels de Winter, Stef Vansteenberge, Matthias Sinnesael, Christian Koeberl

Abstrakt

The discovery of elevated concentrations of the cosmogenic radionuclide

³He in deepsea sediments from Ocean Drilling Program (ODP) Site 926 (Atlantic Ocean) and ODP Site 757 (Indian Ocean) points toward accretion of extraterrestrial matter, probably as a result of the catastrophic disruption of a large asteroid that produced the Veritas family of asteroids at ca. 8.3 ± 0.5 Ma, and which may have had important effects on the global climatic and ecologic systems. Here, we investigated the signatures possibly related to the Veritas event by performing a highresolution multiproxy stratigraphic analysis through the late Tortonian-early Messinian Monte dei Corvi section near Ancona, Italy. Closely spaced bulk-rock samples through a 36-m-thick section, approximately spanning from ca. 9.9 Ma to ca. 6.4 Ma, show an ~5- fold

³He anomaly starting at ca. 8.5 Ma and returning to background values at ca. 6.9 Ma, confirming the global nature of the event. We then analyzed, at 5 cm intervals, bulk-rock samples for sedimentary and environmental proxies such as magnetic susceptibility, calcium carbonate content, total organic carbon, and bulk carbonate δ

¹⁸O and δ

³C, through a 21-m-thick section encompassing the

³He anomaly. Available high-resolution sea-surface temperature data (via alkenone analyses) for this site show a temperature decrease starting exactly at the inception of the

³He anomaly. Cyclostratigraphic fast- Fourier-transform spectral analyses of the proxies indicate an age of 8.47 ± 0.05 Ma for the inception of the

³He anomaly. A search for impact ejecta (analogous to what is present in the late Eocene, where both a

³He anomaly and large-scale impact events are recorded) was not successful. Detailed cyclostratigraphic analyses of our data suggest that the changes in the stable isotope series and environmental proxy series through this late Tortonian time interval had a common forcing agent, and that perturbations of orbitally forced climate cycles are present exactly through the interval with the enhanced influx of extraterrestrial

³He. Thus, the chemostratigraphic evidence for a collisional event that created the Veritas family of asteroids, coinciding with climate perturbations on Earth, suggests yet another form of interaction between Earth and the solar system.

Organisation(en)

Department für Lithosphärenforschung

Externe Organisation(en)

Osservatorio Geologico di Coldigioco, California Institute of Technology (Caltech), Vrije Universiteit Brussel, Universität Bremen, Naturhistorisches Museum Wien (NHM)

Journal

Geological Society of America. Bulletin

Band

129

Seiten

1357-1376

Anzahl der Seiten

20

ISSN

0016-7606

DOI

https://doi.org/10.1130/B31476.1

Publikationsdatum

09-2017

Peer-reviewed

Ja

ÖFOS 2012

105105 Geochemie, 105123 Stratigraphie

Schlagwörter

ASJC Scopus Sachgebiete

Geology

Sustainable Development Goals

SDG 13 – Maßnahmen zum Klimaschutz

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/a5ac8d5b-d25a-43e8-a8e7-15bddb1e6eaa