橄辉无球粒陨石的矿物-岩石学特征及其分类  

MINERALOGIC-PETROLOGIC CHARACTERISTICS OF UREILITES AND THEIR HISTORY OF COSMIC-RAY EXPOSURE AGES

作　　者：王道德[1] 缪秉魁[2] 

机构地区：[1]中国科学院广州地球化学研究所同位素年代学和地球化学重点实验室,广州510640 [2]桂林工学院资源环境工程系

出　　处：《极地研究》2007年第2期139-150,共12页Chinese Journal of Polar Research

基　　金：国家自然科学基金项目(40473037)资助

摘　　要：本文主要综述单矿和复矿碎屑橄辉无球粒陨石的矿物-岩石学特征及冲击变质效应,并依据Δ17O,δ13C,mg#[MgO/(MgO+FeO)mol%],稀有气体,辉石丰度及辉石类型讨论橄辉无球粒陨石的分类和成因模式。橄辉无球粒陨石为超基性的岩浆岩,既显示原始无球粒陨石,又显示分异无球粒陨石的一些特征,并认为是来自球粒陨石质母体的部分熔融,大多数典型的橄辉无球粒陨石具单矿碎屑岩的结构,复矿碎屑岩质橄辉无球粒陨石较少,其角砾岩碎片含单矿碎屑岩橄辉无球粒陨石的石屑碎屑及其它物质。橄辉无球粒陨石为原始和分异特征的混合物,其成因模式主要是超基性火成堆积岩或部分熔融的残余。The mineral-petrological characteristics and shocked effects of the monomict and polymict ureilites are studied in this paper. On the basis of△^17O,δ^13C, MgO/（MgO ＋ FeO）mol% , noble gases, abundances and types of pyroxenes in ureilites, we discussed the classification and origin model. Ureilites are ultramafic magmatic rooks and they exhibit some characteristics of both primitive and differentiated achondrites. Ureilites generally originate from a once partially molten, originally chondritic parent body. Most typical ureilites have monomict textures. The Polymiet ureilites are a few, their fragmental breccias contain lithic clasts of monomict ureilite material and other materials. The origin model is mainly ultramafic igneous cumulates or partially melted residues.

关 键 词：陨石 无球粒陨石 橄辉无球粒陨石 

分 类 号：P185.83[天文地球—天文学] P583