2013/01/29 by Ioannis Baziotis, Yang Liu, Paul S. DeCarli +4 · 1 citation
Earth and Planetary Sciences · Physics and Astronomy · #Astro and Planetary Science #High-pressure geophysics and materials #Planetary Science and Exploration
paper · pdf · doi:10.1038/ncomms2414
openalex publication_date 2013/01/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
High-pressure minerals in meteorites provide clues for the impact processes that excavated, launched and delivered these samples to Earth. Most Martian meteorites are suggested to have been excavated from 3 to 7 km diameter impact craters. Here we show that the Tissint meteorite, a 2011 meteorite fall, contains virtually all the high-pressure phases (seven minerals and two mineral glasses) that have been reported in isolated occurrences in other Martian meteorites. Particularly, one ringwoodite (75 × 140 μm2) represents the largest grain observed in all Martian samples. Collectively, the ubiquitous high-pressure minerals of unusually large sizes in Tissint indicate that shock metamorphism was widely dispersed in this sample (~25 GPa and ~2,000 °C). Using the size and growth kinetics of the ringwoodite grains, we infer an initial impact crater with ~90 km diameter, with a factor of 2 uncertainty. These energetic conditions imply alteration of any possible low-T minerals in Tissint. High-pressure minerals in meteorites reflect the conditions prevailing when they were excavated and launched from their parent bodies. Tissint—a recent Martian meteorite—contains an unusual number of large high-pressure minerals, suggesting excavation from an impact of larger magnitude than for previous Martian samples.