9块西北非HED族陨石的岩石矿物学特征及亚型划分  

Petrological and Mineralogical Characteristics and the Subtype Classification of 9 Pieces of the HED Meteorite from Northwestern Africa

作　　者：黄丽霖[1] 缪秉魁[1] 陈宏毅[1] 陈国柱[1] HUANG Li-lin;MIAO Bing-kui;CHEN Hong-yi;CHEN Guo-zhu(Institute of Meteorites and Planetary Materials Research,Key Laboratory of Planetary Geological Evolution at Universities of Guangxi Province,Guangxi Key Laboratory of Hidden Metallic Ore Deposits Exploration,Guilin University of Technology,Guilin Guangxi 541004,China)

机构地区：[1]桂林理工大学陨石与行星物质研究中心,行星地质演化广西高校重点实验室,广西隐伏金属矿产勘查重点实验室,广西桂林541004

出　　处：《矿物岩石地球化学通报》2020年第4期826-835,共10页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：国家自然科学基金资助项目(41776196,41866008);国家科技基础条件平台项目(2005DKA21406);广西科技基地人才专项(桂科AD1850007)。

摘　　要：HED族陨石是太阳系最早的岩浆岩,对其进行亚型划分对认识其成分特征以及了解其母体岩浆演化和后期变质作用有重要意义。对西北非9块HED陨石进行了岩石结构及矿物组成、辉石Mg~#值、全岩Mg元素X射线分布和热变质程度等分析研究。结果表明,NWA 11600可划分为堆晶辉长岩型Eucrite,热变质程度为1型(最低);NWA 11602为玄武质非角砾岩型Eucrite,热变质6型(最高);NWA 11601为玄武质单矿碎屑角砾岩型Eucrite,热变质4型;NWA 11593、NWA 11594、NWA 11596和NWA 11597为玄武质复矿碎屑角砾岩型Eucrite,NWA 11598和NWA 11605为Howardite,不同角砾具有不同的热变质程度,分布在1~6型之间。NWA 11600冲击程度为S1,其余样品为S2。玄武岩的热变质程度远高于堆晶岩,热变质发生在冲击破碎之前,冲击并非导致热变质的原因。The HED meteorite is the earliest magmatic rock in the solar system.The subtype classification and classification basis are of great significance for understanding its composition characteristics,parent magma evolution,and late metamorphism.According to various parameters,including the textures and mineral components,Mg#values of pyroxenes,Xray Mg elemental mapping results of the whole rock,and degrees of thermal metamorphism,of these meteorite samples,the NWA 11600 meteorite is classified into the cumulate gabbro Eucrite with Type 1 thermal metamorphism(the lowest),the NWA 11602 belongs to the basaltic non-breccia Eucrite with Type 6 thermal metamorphism(the highest),the NWA 11601 belongs to the basaltic monomict brecciated Eucrite with Type 4 thermal metamorphism,the NWA 11593,NWA 11594,NWA 11596,and NWA 11597 samples belong to the basaltic polymict brecciated Eucrite,and the NWA 11598 and NWA 11605 samples belong to the Howardites,with different degrees(from Type 1 to Type 6)of thermal metamorphism for those fragments of breccia.The impact metamorphism degrees of samples are S1 for the NWA 11600,but S2 for the others.The thermal metamorphism degree of basaltic rock is much higher than that of cumulated rock.Therefore,the thermal metamorphism could not be caused by the impact as it should have occurred before the impact fracturing of meteorites.

关 键 词：HED族陨石 岩石学 矿物学 亚型划分 热变质 

分 类 号：P584[天文地球—岩石学]