Shock Metamorphism of Lunar Minerals

Abstract

Impact events have played a crucial role in the formation and evolution of the Moon, as evidenced by the numerous of impact craters on its surface, indicating a long history spanning over 4 billion years characterized by numerous such occurrences. As the moon evolved, it is likely that the early impact craters formed by the bombardment event have subsequently been overlaid by later impacts. However, limited samples and research methods have hindered the discovery of evidence of impacts on the lunar surface. Therefore, this article gives an overview of the study of shock metamorphism in lunar minerals, some new progress in the past 2 decades is reviewed, and the implications of these new discoveries for the composition of the Moon’s crust, history of impact, and the Moon’s evolution are discussed. In addition, some of the issues and limitations that have arisen in the study of lunar shock metamorphism are also summarized. Given the difficulties in the studying of lunar high-pressure minerals and shock metamorphic microstructure using traditional optical microscope, we suggest that the latest nanomineralogical research methods, such as focused ion beam, electron backscatter diffraction, atom probe tomography, Raman spectroscopy, and 3-dimensional electron diffraction, are rational and essential to address the challenges associated with the research on lunar shock metamorphism.