Shock-deformed zircon from the Chicxulub impact crater and implications for cratering process

Large impact structures with peak rings are common landforms across the solar system, and their formation has implications for both interior structure thermal evolution of planetary bodies. Numerical modeling structural studies have been used to simulate ground truth peak-ring formative mechanisms, but shock metamorphic record minerals within these remains be ascertained. We investigated impact-related microstructures high-pressure phases in zircon from melt-bearing breccias, melt rock, granitoid basement Chicxulub ring (Yucatán Peninsula, Mexico), sampled by International Ocean Discovery Program (IODP)/International Continental Drilling Project (IODP-ICDP) Expedition 364 Hole M0077A. Zircon grains exhibit features such as reidite, twins, granular including “former reidite neoblastic” (FRIGN) zircon. These an initial wave (>30 GPa), subsequent relaxation during passage rarefaction wave, a final heating annealing stage. Our observed grain-scale deformation history agrees well stress fields predicted dynamic collapse model, central uplift collapsed downward-then-outward form ring. The occurrence large basin on Earth represents first discovery, preserved due its separation rapid cooling resurging ocean. coexistence FRIGN melt–bearing breccias indicates that seawater was heterogeneous. results provide valuable information when different how they modified according position structure, this study further improves use barometry diagnostic tool understanding cratering process.