A Tiny Piece of Basalt Probably from Asteroid 4 Vesta

查看全文 作　　者：[1]LINYangting;[2]WANGDaode;[2]WANGGuiqing 机构地区：[1]InstituteofGeologyandGeophysics,ChineseAcademyofSciences,Beijing100090;[2]GuangzhouInstituteofGeochemistry,ChineseAcademyofSciences,Guangzhou,Guangdong510640 出　　处：《Acta Geologica Sinica(English Edition)》索引2004年第78卷第5期,共9页 基　　金：We are grateful to Drs Guan Yunbin and Xu Ping for their assistance in laboratories This study is supported by the National Natural Science Foundation of China(Grant No.40232026);the pilot project of knowledge-innovation program of the Chinese Academy of Sciences(Grant No.KZCX3-SW-l23). 摘　　要：Grove Mountains (GRV) 99018 is a new eucrite (0.23 g), consisting mainly of pyroxene (50.5 vol%) and plagioclase (37.2 vol%) with minor silica minerals (7.0 vol%) and opaque minerals (5.2 vol%). It was intensely shocked,leading to partial melting, formation of abundant tiny inclusions in pyroxenes and plagioclase, and heavy brecciation.Exsolution of most pyroxenes (1-3 μm in width of the lamellae), recrystallization of the shock-induced melt pockets and veins (5-20 μm in size), and homogeneous compositions of pyroxenes of various occurrences suggest the intense thermal metamorphism of GRV 99018 in the asteroidal body Vesta. This new eucrite will bring additional constraints on the chemical composition and multi-stage thermal and shock history of Vesta. 关 键 词：陨星 玄武岩 钙长辉长岩 小行星 冲击变质作用