New insights into the formation and emplacement of impact melt rocks within the Chicxulub impact structure, following the 2016 IODP-ICDP Expedition 364

Abstract This study presents petrographic and geochemical characterization of 46 pre-impact rocks 32 impactites containing and/or representing impact melt rock from the peak ring Chicxulub structure (Yucatán, Mexico). The aims were both to investigate components that potentially contributed (i.e., lithologies) better elucidate emplacement at Chicxulub. presented here are subdivided into two sample groups: lower rock–bearing unit, which intrudes different intervals, upper overlies ring. five identified lithologies granitoid, dolerite, dacite, felsite, limestone) was able constrain bulk composition impactite units. These thus likely represent main constituent involved in formation rock. In general, units can be explained by mixing primarily felsic mafic lithologies, but with varying degrees carbonate dilution. It is assumed initially part same impact-produced melt, discrete processes separated them during crater formation. unit interpreted injected crystalline basement compression/excavation stage cratering. layers acted as delamination surfaces within basement, accommodating its displacement movement strongly comminuted present structure. contingent on entrainment have stayed surface development. Its not finalized until modification stage, when material would reentered crater.