蛇绿岩研究的进展

近几年蛇绿岩的研究已取得显著的进展，主要反映在下述几个方面：１．对于蛇绿岩的概念已有了新的认识，蛇绿岩代表古代的大洋岩石圈碎片，但并非正常的大洋岩石圈；２．关于蛇绿岩的多样性已经提出了许多不同的见解，最近有关特提斯与环太平洋蛇绿岩的对比研究使许多作者得出结论，它们具有不同的特征；３．蛇绿岩源区的研究表明，蛇绿岩并非唯一地来自亏损的软流圈地幔，不同地幔端元之间的混合以及来自陆壳物质的混染作用也是常见的现象；４．早元古代蛇绿岩的发现。预期９０年代，在蛇绿岩的多样性、地幔岩部分熔融、岩浆来源、蛇绿岩的侵位机制以及蛇绿岩与高压变质作用等方面将取得长足的进展．

RECENT ADVANCES IN THE STUDY OF OPHIOLITES

In recent years, study of ophiolites has made great progress.It is now believedthat ophiolites represent fragments of ancient oceanic lithosphere not of the normal type.Recent work on Tethyan versus Circum-pacific ophiolites have led some researchers toconclude that these ophiolites have divergent characteristics.Tethyan ophiolites in turncan be divided into two types:one is related to SSZ settings the other to rift.Study ofophiolite sources show that not all ophiolites are derived from depleted lithospheric man-tle. Recent research indicates that the mixing between different mantle units and contami-nation from continental crust are common. Finally,some Early Proterozoic ophiolites havebeen identified.It is to be predicted that research on ophiolites in the 1990s will shed new lighon thediversity of ophiolites and magmatic sources of ophiolites, the partial melting of the man-tle,the emplacement mechanism of ophiolites,and the relation between high-pressuremetamorphism and ophiolites.