Precisely dating the Frasnian-Famennian boundary: implications for the cause of the Late Devonian mass extinction.

ABSTRACT: The Frasnian-Famennian boundary records one of the most catastrophic mass extinctions of the Phanerozoic Eon. Several possible causes for this extinction have been suggested, including extra-terrestrial impacts and large-scale volcanism. However, linking the extinction with these potential causes is hindered by the lack of precise dating of either the extinction or volcanic/impact events. In this study, a bentonite layer in uppermost-Frasnian sediments from Steinbruch Schmidt (Germany) is re-analysed using CA-ID-TIMS U-Pb zircon geochronology in order to constrain the date of the Frasnian-Famennian extinction. A new age of 372.36 ± 0.053 Ma is determined for this bentonite, confirming a date no older than 372.4 Ma for the Frasnian-Famennian boundary, which can be further constrained to 371

SUBMITTER: Percival LME 

PROVIDER: S-EPMC6014997 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature