Ar‐Ar and U‐Pb ages of Chelyabinsk and a re‐evaluation of its impact chronology

• DOI: 10.1111/maps.13927
• Publication Date: 2022-12-01T19:11:34Z
• Authors: Sky P. Beard; Timothy D. Swindle; Thomas J. Lapen; David A. Kring
• Keywords: 13. Climate action; 01 natural sciences; 0105 earth and related environmental sciences

Abstract The LL5 chondrite Chelyabinsk has had numerous isotopic studies since its fall in 2013. These data have been used to suggest ~8 impact events recorded from multiple systems (e.g., Ar‐Ar, U–Pb, Sm‐Nd, Rb‐Sr, among others). We report details of Ar‐Ar and U‐Pb results re‐evaluate the geochronology Chelyabinsk. Argon youngest age meteorites, 25 ± 11 Ma, an older resetting event at ~2550 Ma. analysis upper concordia 4456 23 Ma a lower 184 200 intercept represents later thermal impact), most recent time that lead loss occurred, could represent by Ar‐Ar. Combining our with literature results, we find strong evidence least four (~4450, 2550, 1700, Ma), some for two additional impacts (~3700, 1000 Ma).