“三江”哀牢山带蛇绿岩特征研究

哀牢山带蛇绿岩由变质橄榄岩、堆晶杂岩和基性熔岩组成。其中二辉橄榄岩近似原始地幔岩,方辉橄榄岩为残留地幔岩。辉长岩－辉绿岩－辉石玄武岩系列及辉石岩－辉长闪长岩－钠长玄武岩－苦橄玄武岩系列分别为原始二辉橄榄岩经部分熔融产生的拉斑玄武岩浆及苦橄玄武岩浆结晶或结晶分异演化而成;前者具有洋脊玄武岩特征,后者具有准洋脊玄武岩特征,它们形成于大洋中脊环境。其形成时代不晚于早石炭世（Ｃ１）,侵位在晚三叠世一碗水组（Ｔ３ｙ）之前。

Characteristics of Ophiolites in Ailaoshan Belt, "Sanjiang" Region

Ophiolites of Ailaoshan belt are composed of meta peridotite, cumulate complex and basic lava, in which lherzolite is similar to primary pyrolite, and harzburgite is relic pyrolite. The gabbro diabase pyroxene basalt series and the pyroxenite gabbro diorite albite basalt picritic basalt series were formed respectively by crystallization or crystallization differentiation of tholeiitic magma and picritic basaltic magma produced by partial melting of primary tholeiite; the former is characterized by oceanic ridge basalt, whereas the latter by paraoceanic ridge basalt, both formed in an environment of mid oceanic ridge. Their formation time was not later than Early Carboniferous (C 1), and the emplacement took place before the formation of Late Triassic Yiwanshui Formation (T 3 y ).