The evolution process of planets explored from the texture of minerals and rocks

Abstract

Study of rock texture will surely make a breakthrough in the elucidation of the evolution process of planets. This report presents two examples showing methodologies for the study of rock texture in planetary materials. The first example is the study of pallasites. Rounded texture of olivine grains was reproduced through annealing experiments and rounding kinetics was characterized. The result shows that small scale rounding of olivine in pallasites such as Eagle Station requires a rapid cooling after olivine-metal mixing. The second example is the study of polymict eucrites. The results from detailed observation of their texture show the individual origin of pyroxene fragments and suggest that the polymict breccias were generated by gathering locally ordinary eucrites and cumulate eucrites. In future planetary exploration, observation of rock texture will serve as indispensable technology. © 2005, Japan Association of Mineralogical Sciences. All rights reserved.