
Mats Eriksson
Professor

Refined Ordovician timescale reveals no link between asteroid breakup and biodiversification
Författare
Summary, in English
The catastrophic disruption of the L chondrite parent body in the asteroid belt c. 470 Ma initiated a prolonged meteorite bombardment of Earth that started in the Ordovician and continues today. Abundant L chondrite meteorites in Middle Ordovician strata have been interpreted to be the consequence of the asteroid breakup event. Here we report a zircon U-Pb date of 467.50±0.28 Ma from a distinct bed within the meteorite-bearing interval of southern Sweden that, combined with published cosmic-ray exposure ages of co-occurring meteoritic material, provides a precise age for the L chondrite breakup at 468.0±0.3 Ma. The new zircon date requires significant revision of the Ordovician timescale that has implications for the understanding of the astrogeobiologic development during this period. It has been suggested that the Middle Ordovician meteorite bombardment played a crucial role in the Great Ordovician Biodiversification Event, but this study shows that the two phenomena were unrelated.
Avdelning/ar
- Berggrundsgeologi
Publiceringsår
2017-01-24
Språk
Engelska
Publikation/Tidskrift/Serie
Nature Communications
Volym
8
Dokumenttyp
Artikel i tidskrift
Förlag
Nature Publishing Group
Ämne
- Geology
Aktiv
Published
Projekt
- Early–Middle Ordovician biotic and sedimentary dynamics in the Baltoscandian paleobasin
ISBN/ISSN/Övrigt
- ISSN: 2041-1723