A Tiny Piece of Basalt Probably from Asteroid 4 Vesta  

作　　者：LINYangting WANGDaode WANGGuiqing 

机构地区：[1]InstituteofGeologyandGeophysics,ChineseAcademyofSciences,Beijing100090 [2]GuangzhouInstituteofGeochemistry,ChineseAcademyofSciences,Guangzhou,Guangdong510640

出　　处：《Acta Geologica Sinica(English Edition)》2004年第5期1025-1033,共9页地质学报（英文版）

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 (1-3μm in width of the lamellae), recrystallization of the shpck-induced melt pockets and veins (5-20μm 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.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 (1-3μm in width of the lamellae), recrystallization of the shpck-induced melt pockets and veins (5-20μm 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：METEORITE BASALT eucrite ASTEROID MAGMATISM shock metamorphism thermal history 

分 类 号：P185.83[天文地球—天文学] P588.145