哀牢山南段蛇绿岩变质橄榄岩的矿物化学及其成因意义  

THE MINERAL CHEMISTRY AND ITS GENESIS SIGNIFICANCE OF THE METAMORPHIC PERIDOTITE IM OPHIOLITE OF THE SOUTH SECTION OF AILAO MTS

作　　者：凌其聪[1] 程惠兰[1] 沈上越 

机构地区：[1]中国地质大学

出　　处：《云南地质》1999年第1期47-52,共6页Yunnan Geology

基　　金：国家自然科学基金

摘　　要：哀牢山南段蛇绿岩中变质橄榄岩单元，由方辉橄榄岩和二辉橄榄岩组成，前者已强烈蚀变，后者的矿物组成有橄榄石、斜方辉石、单斜辉石及少量尖晶石等。对这些矿物进行了较详细的化学成分分析，橄榄石、斜方辉石的化学成分显示，二辉橄榄岩为较弱亏损的地幔岩；橄榄石、尖晶石的矿物化学反应，变质橄榄岩的原始岩石具有深海橄榄岩的特征；单斜辉石、尖晶石的化学特征显示，二辉橄榄岩经历过部分熔融作用。因此。Abstract The metamorphic peridotite unit in the ophiolite of the south section of Ailao Mountains is composed of harzburgite and lherzolite. The former has been altered intensively whereas the composition of the latter is olivine, enstenite, clino-augite and a few spinell, etc. We have the chemical composition analyses in detail of these minerals. The chemical compositions of olivine and enstentite show that the lherzolite is a weak loss mantle-derived rock. The chemistry of olivine and spinell reflects the abysmal peridotite characteristics of the original rock of the metamorphic peridotite. And the chemical characteristics of clino-augite and spinell indicate that the lherzolite has an experience of partial melting. Therefore, the lherzolite is a weak loss mantle-derived rock of partial melting.

关 键 词：蛇绿岩 变质橄榄岩 二辉橄榄岩 矿物化学 

分 类 号：P588.1[天文地球—岩石学] P588.125[天文地球—地质学]