Goals and objectives: the objective of the proposed work is to provide additional experimental constraints for the further development of a comprehensive barometry and thermometry of impact structures…

This federal contract award, with ID number 80NSSC17K0765, was granted by the Shared Services Center, a civilian agency, to The Research Foundation for the State University of New York (RF SUNY), doing business as Stony Brook University. The $268,442.31 grant is for research to provide additional experimental constraints for the development of a comprehensive barometry and thermometry of impact structures and shocked meteorites. This work aims to better understand the mineralogical record preserved in impact craters and shocked meteorites, which provides insights into solar system formation and planetary evolution. The research will help reconcile discrepancies between experimental data from static and dynamic compression studies and the natural shock conditions observed in meteorites. This grant does not have a set-aside designation.

Goals and objectives: the objective of the proposed work is to provide additional experimental constraints for the further development of a comprehensive barometry and thermometry of impact structures and shocked meteorites. The mineralogical record preserved in impact craters and shocked meteorites provide a unique window into solar system formation and planetary evolution. The impact and ejection processes cause dramatic changes in the microstructure, crystal structure and potentially the isotope composition of the mineral assemblage. Hence, the commonly used shock classification models assigns shock levels from unshocked (S1) to very strongly shocked (S6) based on microstructure and mineral phases. These classification models are mainly derived from characterization of meteorites and rocks from known impact sites and further constrained by experimental data from static and dynamic compression experiments. However, the experimental characteristics in static and dynamic compression experiments, such as investigated timescales and pressure-temperature coupling, are not a direct replication of the natural shock conditions. Therefore, the results from static and dynamic compression experiments provide upper and lower boundaries for the barometry and thermometry of impact structures. For example, the existence of high pressure polymorphs such as ringwoodite, majorite and bridgmanite in shocked meteorites cannot be explained following the established shock barometer and thermometer, since high shock pressure resulting in high bulk rock temperatures would favor a back transformation to the respective low pressure polymorphs.