High-pressure minerals in NWA2727 lunar meteorite and understanding of its impact history

Abstract

Asteroid and meteorite collisions contribute to revolution of the Moon and Earth. Recently, Ohtani et al. (2011) and Miyahara et al. (2013) discovered high-pressure silica polymorphs (coesite, stishovite and seifertite) in lunar meteorites, Asuka-881757 and NWA4734 and their existences give us valuable information on impact history on the Moon. In this study, we newly found moganite coexisted with coesite in lunar meteorite NWA2727 and provide constraints on the shock pressure and temperature during impact event, based on transition processes clarified by high-pressure experiments using diamond anvil cell for terrestrial moganite.