R5: Extraterrestrial materials

[R5-16] Microstructural observations of quartz from the basement rocks of the Chicxulub impact structure and shock pressure estimation

Riho Tani^2,1, *Naotaka Tomioka¹, Masahiro Kayama³, Chang Yu ³, Hirotsugu Nishido⁴, Kaushik Das², Auriol Rae^5,6, Ludovic Ferrière⁷, Sean Gulick⁸, Joanna Morgan⁵, IODP-ICDP Expedition 364 Scientists (1. Japan Agency for Marine-Earth Science and Technology, 2. Hiroshima University, 3. University of Tokyo, 4. Okayama University of Science, 5. Imperial College London, 6. Albert-Ludwigs-Universität Freiburg, 7. Natural History Museum Vienna, 8. University of Texas at Austin)

Keywords:Chicxulub impact crater, drilling core samples, cathodoluminescence, quartz, TEM

Our study aims at evaluating a newly developed shock barometry method and to characterize shock effects in quartz from the basement granitic rocks recovered by the IODP-ICDP Expedition 364. Shock pressures estimated using the CL spectroscopy method are almost constant throughout the drilling depth in the range of 15–25 GPa. Orientations of planar deformation features and a superstructure in the shocked quartz obsearved by TEM also indicate pressure generation of ~20 GPa.