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

Berengere Mougel*, Frederic Moynier, Christian Koeberl, Daniel Wielandt, Martin Bizzarro

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

15 Citations (Scopus)

Abstract

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.

Original languageEnglish
JournalMeteoritics and Planetary Science
Volume54
Issue number10
Pages (from-to)2592-2599
Number of pages8
ISSN1086-9379
DOIs
Publication statusPublished - 1 Oct 2019

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