摘要
通过对15块南极格罗夫山普通球粒陨石(中国第19次和第22次南极科考回收)进行岩石学、矿物学分析,为其进一步研究提供重要基础数据。研究表明这些陨石均为平衡型陨石,其中有5块为H群,其余为L群。除GRV 051869和GRV 021491经历较强冲击变质作用、具有S4型的冲击变质程度外,其他陨石的冲击变质作用轻微,主要集中在S1和S2型。这些陨石的风化程度普遍较轻,仅GRV052076达到了W3型,其他为W1和W2型。主要矿物成分分析表明,组成H群和L群的最初始星云物质可能是相同的,陨石的主要差别是由于两个群陨石各自所处环境的不同所造成。L群平均球粒半径大于H群球粒半径,可能为球粒形成过程中星云温度变化不均一或者不同类型球粒分不同时期形成。另外,研究表明橄榄石中的Ca含量可以作为一个反映陨石热历史的有用指标。
The mineralogy and chemical composition of meteorites reflect the history of early solar nebular formation and evolution.Fifteen of ordinary chondrites,recovered from the Grove Mountains in Antarctica by the 19 th and 22 nd CHINARE are studied here to provide significant basic data for further study.All meteorites are equilibrated ordinary chondrites with 5 belonging to H group and 10 belonging to L group.Their petrographic types vary from 4 to 6 in the L group meteorites,with most being type 6,while all H group are classified as type 4 and 5.The shock metamorphism stages of the most chondrites are relatively low,being S1 and S2 stages,only GRV 051869 and GRV 021491 do have some features of S4 stage.The weathering of these Antartic chondrites is mostly limited,only GRV 052076 can reach the stage of W3.By analysing trace elements of the main minerals,H and L group may be formed by the same initial nebular materials,the difference between the two groups is caused by the environment where they stay.The average L group chondrule diameter is larger than that of H group.The temperature to form chondrules in solar nebular might not be homogeneous or different types of chondrules were formed by different periods.Besides,based on our analysis,calcium in olivine can be an indicator of thermal history.
作者
薛永丽
缪秉魁
孙云龙
夏志鹏
朱佳玲
XUE Yongli;MIAO Bingkui;SUN Yunlong;XIA Zhipeng;ZHU Jialing(Guangxi Key University＇s Laboratory of Planetary Geological Evolution,Guilin University of Technology,Guilin 541006,Guangxi china;Guangxi Key Laboratory of Hidden Metallic Ore Deposit Exploration,Guilin University of Technology,Guilin 541006,Guangxi china)
出处
《矿产与地质》
2018年第3期481-492,共12页
Mineral Resources and Geology
基金
国家自然科学基金项目(41173077)
国家科技集成平台建设项目(2005DKA21406-9)共同资助
关键词
平衡型普通球粒陨石
矿物
岩石学特征
分类
南极
equilibrated ordinary chondrites
mineral
petrologic features
classification
Antarctica
