Chromium isotope evidence in ejecta deposits for the nature of Paleoproterozoic impactors
- Author(s)
- Bérengère Mougel, Frédéric Moynier, Christa Göpel, Christian Koeberl
- Abstract
Non-mass dependent chromium isotopic signatures have been successfully used to determine the presence and identification of extra-terrestrial materials in terrestrial impact rocks. Paleoproterozoic spherule layers from Greenland (Grænsesø) and Russia (Zaonega), as well as some distal ejecta deposits (Lake Superior region) from the Sudbury impact (1849±0.3 Ma) event, have been analyzed for their Cr isotope compositions. Our results suggest that 1) these distal ejecta deposits are all of impact origin, 2) the Grænsesø and Zaonega spherule layers contain a distinct carbonaceous chondrite component, and are possibly related to the same impact event, which could be Vredefort (2023±4 Ma) or another not yet identified large impact event from that of similar age, and 3) the Sudbury ejecta record a complex meteoritic signature, which is different from the Grænsesø and Zaonega spherule layers, and could indicate the impact of a heterogeneous chondritic body.
- Organisation(s)
- Department of Lithospheric Research
- External organisation(s)
- Université Sorbonne-Paris-Cité, Université Paris VII - Paris-Diderot
- Journal
- Earth and Planetary Science Letters
- Volume
- 460
- Pages
- 105-111
- No. of pages
- 7
- ISSN
- 0012-821X
- DOI
- https://doi.org/10.1016/j.epsl.2016.12.008
- Publication date
- 02-2017
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 105105 Geochemistry
- Keywords
- ASJC Scopus subject areas
- Geochemistry and Petrology, Geophysics, Earth and Planetary Sciences (miscellaneous), Space and Planetary Science
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/6e554ec0-0b6c-44d5-a74a-2d588d4d5dc4