The shock response of apatite and its effect on volatiles in eucrites

The abundance and isotopic composition of volatile elements in meteorites are critical for understanding planetary evolution given their importance in a variety of geochemical processes (e.g. [1]). As such, there has been significant interest in the mineral apatite, which is known to contain appreciable amounts of volatile elements. Because shock-induced deformation is pervasive in meteorite samples, it is important to determine if the process has affected their volatile abundance and isotopic composition. Electron Backscatter Diffraction (EBSD) analyses provide crystallographic information at the µm and sub-µm length scales. Recently, greater complexity in microscale deformation features with increasing shock pressure has been observed in phosphate minerals [2–4] and its effect on the abundance and isotopic composition of H has been explored [5]. In this study we investigate the potential linkage between µm-scale shock structures of apatite grains from six eucrites across a broad range of shock stages (S1–S5) using EBSD combined with NanoSIMS volatile abundance and isotopic composition of hydrogen and chlorine.