在迟家店石榴石二辉橄榄岩的橄榄石中发现自然铁及其意义  

Discovery of native iron in olivine of garnet lherzolite in Chijiadian and its significance.

作　　者：冯有利[1] 郑辙[1] 郭延军[1] 吴军[1] 叶凯[2] 

机构地区：[1]北京大学地球与空间科学学院 [2]中国科学院地质与地球物理研究所,北京100029

出　　处：《岩石学报》2003年第4期701-706,共6页Acta Petrologica Sinica

基　　金：国家自然科学基金(批准号:40072016);国家重点基础研究发展规划(G19990755-01)

摘　　要：通过高分辨电子显微镜研究,发现在山东荣成迟家店石榴石二辉橄榄岩的橄榄石中除钛铁矿和磁铁矿出溶物外。还有一种矩形出溶物,长为20μm、宽为5μm,能量损失X射线分光谱(XEDS)分析矩形物的成分为Fe。选区电子衍射花样计算表明该矿物与和JCPDS中的标准矿物自然铁-α和自然铁-γ衍射数据一致。根据自然铁的化学成份推断橄榄石中自然铁-α和自然铁-γ的形成温度范围为490～900℃,压力不超过8.2GPa,并讨论了自然铁与深源地幔流体作用。Studied by High Resolution Transmission Electron Microscopy ( HRTEM) , there existed exsolution minerals in garnet Iherzolite, Chijiadian of Rongcheng county, Shandong province. The exsolution mineral are parallelly arranged acicular ilmenite and magnetite whose diameter is 0. 2 ~ 2. 0 μm and 5 ~ 20μm long in olivine with rectangle topography whose length is 20μm and 5μm wide. Analysed by X-ray Energy Disperse Spectroscopy (XEDS) attached to HRTEM, the chemical composition of the mineral is Fe. Calculated from diagram of Selected Area Diffraction (SAD) , the crystal structure of the mineral and the diffraction data are consistent with standard mineral native Fe-α and native Fe-γ from JCPDS. At last, the calculated forming conditions such as temperature and pressure of native Fe in olive are ranged from 490℃ to 900℃ and below 8.2GPa and the relation between native Fe and fluid reaction from deep source mantle is discussed.

关 键 词：石榴石二辉橄榄岩 高分辨透射电子显微镜 自然铁-α 自然铁-γ 

分 类 号：P578.12[天文地球—矿物学] P578.942[天文地球—地质学]