| 大陆地幔研究现状 |
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| 引用本文： | 路凤香.大陆地幔研究现状[J].地学前缘,1994(Z1). |
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| 作者姓名： | 路凤香 |
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| 作者单位： | 中国地质大学 |
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| 摘 要： | 本文主要介绍大陆地幔岩石圈的年龄、大陆地幔演化和地幔流体等三个近年来引人注目的问题。地幔捕虏体的年龄范围２００～３４００Ｍａ，一般认为它可以代表地幔的年龄。澳大利亚二辉橄榄岩捕虏体的Ｐｂ－ｐｂ年龄为２０００～２５００Ｍａ，南非Ｖｉｃｔｏｒ岩管的捕虏体为１７００～２４００Ｍａ。橄榄岩型金刚石的石榴石包裹体Ｓｍ－Ｎｄ年龄为３２００～３３００Ｍａ，榴辉岩型金刚石的年龄为１２００～１５００Ｍａ。这些数值可与橄榄岩及榴辉岩捕虏体的全岩年龄数据相对应。太古代岩石圈地幔以南非为代表，经历了从地壳物质提取的亏损过程到与软流圈反应和与深部热点物质作用的富集过程。以美国西部为代表的元古代岩石圈地幔则经历了元古－显生宙的俯冲作用、地体增生过程以及与热点反应的作用。以澳大利亚东部为代表的显生宙岩石圈地幔经历了元古代的部分熔融、显生宙的俯冲或与ＤＵＰＡＬ的反应以及具ＤＭＭ特征的软流圈的上隆。钾质熔体、碳酸盐熔体、Ｈ＿２、ＣＨ＿４、Ｎ＿２Ｏ、Ｎ、ＣＯ、ＣＯ＿２、Ｓ、Ｆ、Ｃｌ等都是地幔流体的主要组分，它们的类型与所处的深度和氧逸度有关。
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| 关 键 词： | 岩石圈地幔的演化，金刚石中的包裹体，地幔流体 |
PROGRESS IN CONTINENTALL MANTLE STUDIES |
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| Lu Fengxiang.PROGRESS IN CONTINENTALL MANTLE STUDIES[J].Earth Science Frontiers,1994(Z1). |
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| Authors: | Lu Fengxiang |
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| Abstract: | This paper discusses the ages and evolution of the continental mantle and thedistribution of fluids in it,all subjects of much recent study。The ages of mantle xenolithshave been used to determine mantle ages ranging from Phanerozoic to Archaean,0.2～3.4Ga,Pb- pb data for lherzolite xenoliths from Australia indicate an age of 2.0～2.5 Ga,and the Roberts Victor pipe in South Africa containes xenoliths with ages of 1.7～2.4 Ga。Other dating information is forthcoming from mantle megacrysts,much of it providing im-portant constraints on the age and origin of the lithosphere,Sm- Nd data from diamond in-clusions show ages of 3. 2～3.3 Ga for minerals of the peridotite paragenesis and 1.2～1.5Ga for minerals of the eclogite paragenesis.These data correspond to the Archaean to Pro-terozoic ages reported for whole- rock eclogites and peridotites.During Archaean asthenosphere-lithosphere interaction and post-Archaean interactionwith the deep mantle and other hot spots The Archaean lithospheric mantle beneath SouthAfrica experienced processes of crustal extraction.These processes appear to record achange from a predominantly depleted to enriched state,The Proterozoic lithospheric man-tle beneath the western USA is believed to have resulted from Proterozoic-Phanerozoicsupra-subduction processes associated with terrain accretion,and from Phanerozoic plume-lithosphere interaction,The Phanerozoic lithospheric mantle beneath eastern Australia hasproduced a domain consistent with Proterozoic partial melting,Phanerozoic subduction orDUPAL-lithosphere interaction and upwelling of DMM asthenosphere.K-enriched melts,carbonate melts,H_2,CH_4,H_2O, N, CO,CO_2,S.F.Cl.etc,are proba-bly mantle fluid components, The composition and molecular speciation of subsolidus man-tle fluids are controlled both by oxygen fugacity and by depth of the mantle. |
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| Keywords: | evolution of the lithospheric mantle diamond inclusions fluids in the mantle |
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