Identification of a meteoritic component using chromium isotopic composition of impact rocks from the Lonar impact structure, India

Autor(en)
B. Mougel, Frederic Moynier, Christian Koeberl, Daniel Wielandt, Martin Bizzarro
Abstrakt

The existence of mass-independent chromium isotope variability of nucleosynthetic origin in meteorites and their components provides a means to investigate potential genetic relationship between meteorites and planetary bodies. Moreover, chromium abundances are depleted in most surficial terrestrial rocks relative to chondrites such that Cr isotopes are a powerful tool to detect the contribution of various types of extra-terrestrial material in terrestrial impactites. This approach can thus be used to constrain the nature of the bolide resulting in breccia and melt rocks in terrestrial impact structures. Here, we report the Cr isotope composition of impact rocks from the ~0.57 Ma Lonar crater (India), which is the best-preserved impact structure excavated in basaltic target rocks. Results confirm the presence of a chondritic component in several bulk rock samples of up to 3%. The impactor that created the Lonar crater had a composition that was most likely similar to that of carbonaceous chondrites, possibly a CM-type chondrite.

Organisation(en)
Department für Lithosphärenforschung
Externe Organisation(en)
Université Sorbonne-Paris-Cité, Universidad Nacional Autonoma de Mexico, Institut universitaire de France, Naturhistorisches Museum Wien (NHM), University of Copenhagen
Journal
Meteoritics and Planetary Science
Band
54
Seiten
2592-2599
Anzahl der Seiten
8
ISSN
1086-9379
DOI
https://doi.org/10.1111/maps.13312
Publikationsdatum
06-2019
Peer-reviewed
Ja
ÖFOS 2012
105105 Geochemie
Schlagwörter
ASJC Scopus Sachgebiete
Geophysics, Space and Planetary Science
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/1eddadca-b167-4b04-8647-d56ca099767a