Chromium isotope evidence in ejecta deposits for the nature of Paleoproterozoic impactors

Autor: Bérengère Mougel, Christa Göpel, Christian Koeberl, Frédéric Moynier
Přispěvatelé: Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), Department of Lithospheric Research [Wien], Universität Wien, Natural History Museum [Vienna] (NHM), IPGP multidisciplinary program PARI, and the Region île-de-France SESAME for Grant no.12015908.IDEX13C445UnivEarthS Labex program ANR-10-LABX-0023ANR-11-IDEX-0005-02IPGP multidisciplinary program PARI Region Ile-de-France12015908, ANR-11-IDEX-0005,USPC,Université Sorbonne Paris Cité(2011), European Project: 637503,H2020,ERC-2014-STG,PRISTINE(2015), Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)
Rok vydání: 2017
Předmět:
Zdroj: Earth and Planetary Science Letters
Earth and Planetary Science Letters, Elsevier, 2017, 460, pp.105-111. ⟨10.1016/j.epsl.2016.12.008⟩
Earth and Planetary Science Letters, 2017, 460, pp.105-111. ⟨10.1016/j.epsl.2016.12.008⟩
ISSN: 0012-821X
DOI: 10.1016/j.epsl.2016.12.008
Popis: 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 (Graenseso) 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 Graenseso 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 Graenseso and Zaonega spherule layers, and could indicate the impact of a heterogeneous chondritic body.
Databáze: OpenAIRE