【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，二辉橄榄岩为部分熔融较弱亏损的地幔更多还原

【Abstract】 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.更多还原