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蛇绿岩研究进展、存在问题及思考
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引用本文:史仁灯.2005.蛇绿岩研究进展、存在问题及思考[J].地质论评,51(6):681-693
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作者单位
史仁灯 中国科学院壳幔物质和环境重点实验室中国科学技术大学地球与空间科学学院合肥230026 
基金项目:本文为国土资源部十五重点项目(编号20010201)和国家自然科学基金重大国际合作项目(编号49732070)资助的成果
中文摘要:2O世纪7O年代建立的蛇绿岩(Ophiolite)概念认为出露在缝合带中的一套镁铁一超镁铁岩组合是大洋岩石圈的残留,其岩性单元可以与现代大洋岩石圈各个层圈一一对应,所以蛇绿岩是确定古板块边界的重要证据,该认识促进了板块构造学说的发展。近年来完善的MOR 型和SSZ型蛇绿岩理论体系认为MOR 型蛇绿岩形成于洋中脊(MOR),SSZ型蛇绿岩形成于俯冲带上(Supra—Subduction Zone),二者的地幔橄榄岩、堆晶岩组合及上部熔岩在岩石学、矿物学和地球化学方面均有不同的特征,洋陆俯冲和洋内俯冲是形成SSZ型蛇绿岩的两种机制,较为合理地解释了蛇绿岩的多样性及其与大洋岩石圈的差异。由于大洋板块的俯冲作用,在缝合带中MOR型蛇绿岩很少被保存下来,保存较好的大多数为SSZ型蛇绿岩。本文探讨了蛇绿岩研究中经常遇到的问题并提出了解决的思路,同时认为Rodinia超大陆前是否存在蛇绿岩、太古宙绿岩是否为蛇绿岩均为有待深入研究的问题。
中文关键词:MOR型蛇绿岩  SSZ型蛇绿岩,Rodinia超大陆  太古宙绿岩  板块构造学
 
Comment on the Progress in and Probl ems on Ophiol ite Study
NameInstitution
SHI RendengSchool of Earth and Space Sciences,University of Science and Technology of China,Hefei,230026
Abstract:According to the concept of ophiolite in 1 970s,exposure of marie—ultramafic rocks in the orogenic zone hasbeen interpreted to represent the relic of fossil ocean lithosphere based on its lithology units consisting withoceanic crust and upper mantle.So the ophiolite is a key e.vidence of boundary between the fossil plates,and hasbeen played an im portant role on the formulation and advancement of the plate tectonic theory. Recently,ophiolite is divided into M OR—and SSZ—types based on the formation tectonic setting. M OR-type ophioliteformed at Mid—ocean ridges(M oR),and SSZ—type ophiolite formed on the supra—subduction zone caused bythe ocean—continent subduction or intra—ocean subduction.and there are obvious difference in mantle sequence,cumulated assem blage and lavas in petrology, mineralogy and geochemistry between M OR— and SSZ—typeophiolites.This classification explains well the various ophiolites and the difference between the ophiolite andoceanic lithosphere.During the subduction of oceanic lithosphere,the M OR—type ophiolite was subducted,or ispreserved only as dismembered thrust sheets or blocks in ophiolitic m61ange,while SSZ—type ophiolite,asfragments of modified oceanic or rebirth lithosphere caused by fossil oceanic plate subduction,is commonlypreserved in the orogenic zone due to it formed above subduction zone.Therefore,SSZ-type ophiolite is majorone preserved well in the orogenic zone.Also discussed in this paper are the problems in the ophiolite study,such as the difference between the ophiolite and ocean lithosphere in peridotites.and the methods to solve theseproblems. And the pre—Rodinia super—continent ophiolite record is still considered poorly understanding,andwhether Archean greenstone is ophiolite or not.These are all questions to answer.
keywords:MOR—type ophiolite  SSZ—type ophiolite  Rodinia super—continent  Archean greenstone  plate tectonic theory
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