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

TY - JOUR

T1 - Identification of a meteoritic component using chromium isotopic composition of impact rocks from the Lonar impact structure, India

AU - Mougel, Berengere

AU - Moynier, Frederic

AU - Koeberl, Christian

AU - Wielandt, Daniel

AU - Bizzarro, Martin

PY - 2019/10/1

Y1 - 2019/10/1

N2 - 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.

AB - 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.

U2 - 10.1111/maps.13312

DO - 10.1111/maps.13312

M3 - Journal article

AN - SCOPUS:85067388735

SN - 1086-9379

VL - 54

SP - 2592

EP - 2599

JO - Meteoritics and Planetary Science

JF - Meteoritics and Planetary Science

IS - 10

ER -