极地研究Issue(4)：394-402,9.DOI:10.3724/SP.J.1084.2013.00394
西宁陨石的岩石学特征及其类型划分
PETROLOGIC CHARACTERISTICS AND CLASSIFICATION OF THE XINING METEORITE
摘要
Abstract
The Xining meteorite has a typically chondritic texture .The matrix displays a moderate to high degree of re-crystallization .Most plagioclase grains have a diameter of around 5-40μm with a few grains greater than 50μm. The chemical compositions of olivine and low-Ca pyroxene in the Xining meteorite are homogeneous:e.g., olivine (Fa24.7-25.2, avg.Fa24.9, PMD 0.64%);low-Ca pyroxene (Fs21.3-21.9, avg.Fs21.5, PMD 0.84%;En77.6-78.2, avg. En78.6;Wo0.46-0.57, avg.Wo0.46).This feature indicates that the olivine and low-Ca pyroxene in the Xining meteor-ite are in thermodynamic equilibrium and the Xining meteorite should be classified as an equilibrated ordinary chon -drite.Based on the textural characteristics , metal abundance , chemical composition of silicate minerals and thermal metamorphic characteristics (the equilibrium temperature is 778℃), the Xining meteorite is classed as an L5 ordi-nary chondrite that is beginning to change to an L 6.The degrees of shock metamorphism and terrestrial weathering are S3 and W0, respectively.The parent body of the Xining meteorite suffered impact and thermal metamorphism , which resulted in fragmentation of chondrules , devitrification of glass , and recrystallization of the matrix .关键词
西宁陨石/普通球粒陨石/平衡型/L5/降落陨石Key words
Xining meteorite/ordinary chondrite/equilibrated type/L5/meteorite fall引用本文复制引用
陈宏毅,缪秉魁,刘希军,谢兰芳,夏志鹏,陈丽菲..西宁陨石的岩石学特征及其类型划分[J].极地研究,2013,(4):394-402,9.基金项目
国家自然科学基金“行星冲击产生的高温高压相变反应月球火星陨石中后成合晶的研究”（41173077）和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）资助 （）
