南极月球陨石EET 96008矿物学和岩石学特征  

THE PETROLOGY AND MINERALOGY OF LUNAR METEORITE EET 96008 FROM ANTARCTICA

作　　者：夏志鹏[1,2] 缪秉魁[1,2] 陈宏毅[1,2] 姚杰[1,2] 谢兰芳[1,2] 

机构地区：[1]桂林理工大学广西矿冶与环境科学实验中心,广西桂林541004 [2]广西隐伏金属矿产勘查重点实验室,广西桂林541004

出　　处：《极地研究》2013年第4期352-361,共10页Chinese Journal of Polar Research

基　　金：国家自然科学基金(41173077);广西隐伏金属矿产勘查重点实验室主任基金项目(13-A-01-02);广西研究生教育创新计划资助项目(YCSZ2013074)资助

摘　　要：EET 96008是一块发现于南极Elephant地区的玄武岩质角砾岩月球陨石。本文对该陨石的矿物岩石学特征进行了详细的观察和描述。EET 96008具有典型的碎屑结构,其角砾浑圆度低,角砾大小一般为0.1—2 mm,它主要由角砾(50.2 vol%)和基质(49.8 vol%)组成,该陨石角砾类型多样:(1)晶屑:主要为辉石、橄榄石、长石以及石英;(2)岩屑:主要为变粒岩岩屑、基性岩岩屑、苏长岩质斜长岩岩屑;(3)玻屑:主要为斜长岩质。基质和角砾在颗粒上是连续过渡的,基质主要是由粒度小于0.1 mm的矿物碎屑和玻屑组成。该陨石辉石类型多样,成分变化大(Fs18.0-58.0Wo3.9-45.2En3.5-79.1),出溶现象普遍,出溶条纹达到1μm宽;橄榄石中Fa值主要分为两个区域,Fa50-70以及Fa80-95,铁含量较高,平均Fa71.8;长石成分以钙长石为主(An84.9-97.9),部分斜长石已熔长石化。该陨石与QUE 94281同为月球玄武岩质角砾岩,在结构及矿物组成上具有类似性,但是在岩屑类型及橄榄石矿物成分上存在着明显不同,为非成对陨石,且源区可能不同。EET 96008具有三个典型的冲击暗化区域,有大量的玻璃质以及冲击熔融囊的产生,冲击程度达到S5以上。该陨石在冲击作用下,富铁辉石分解产生钙铁辉石-铁橄榄石-石英,该现象为了解月球表面冲击历史提供了重要的科学依据。Meteorite EET 96008 is a lunar basaltic breccia collected from the Elephant Moraine region of Antarctica .The petrography and mineralogy of EET 96008 is described in detail .The meteorite has a typical breccia texture consis-ting of sub-angular clasts （50.2 vol%） and matrix （49.8 vol%）.The clast size is generally between 0.1 and 2 mm.The meteorite clast types are divided into three main categories： minerals, rocks and glassy clasts.（1） Mineral clasts include pyroxene, olivine, feldspar and quartz.（2） Rock clasts are mainly granulite, basic rock and noritic anorthosite .（3） Glassy clasts are anorthositic .In grain size, the clasts and matrix vary gradually .The matrix consists of mineral and glassy clasts that are 〈0.1 mm in size.The meteorite contains a variety of pyrox-enes that cover most of the pyroxene quadrilateral （Fs17.95-58;Wo3.95-45.17; En3.45-79.07）.They also possesses exten-sive exsolution lamellae that are up to 1μm in width.Fe content in the olivine is relatively high , and can be mainly divided into two areas：Fa50-70 and Fa80-95 .The average Fa is 71.8.The plagioclase component in EET 96008 is en-riched in Ca .Some plagioclases have been converted into maskelynite . EET 96008 consists of the same lunar basaltic breccia as QUE 94281.They share a similar texture and miner-al assemblage .Their clear differences in clast type and the mineral composition of olivine indicate that they are not paired and may came from a different source .EET 96008 has the three typical shock-induced darkened areas , and a great deal of glassy clasts and shock pockets , suggesting that its shock stage should be above S 5 . The study of the phenomenon of ferrosilite decomposings into hedenbergite-fayalite-quartz in the meteorite will provide insight for determining the shock history of the lunar surface .

关 键 词：月球陨石 EET96008 月球角砾岩 岩石学 矿物学 

分 类 号：P185.83[天文地球—天文学]