2012年3月，第18卷，第1期，52-61页 March2012，Vol.18，No.1，p.5261
高校地质学报
Geological Journal of China Universities
熔体再富集作用对大陆岩石圈地慢的影响
孙晶12，刘传周，吴福元
1.中国科学院地质与地球物理研究所岩石图演化国家重点实验室，北京100029；
2.中国科学院研究生院，北京100049
用通常是指软流圈来源的玄武质熔体加人到难熔的方辉橄榄者或纯橄岩形成更为饱满的二辉橄榄岩的过程。除了使主量元损特征。对于熔体再富集作用是否改变橄榄岩的Os同位素组成还存在较大的争议，它主要取决于加人熔体的比例，熔体中硫的饱和程度以及熔体再富集作用发生的时间等因素。对于以低熔/岩比例为主的大陆岩石圈地来说，熔体再富集作用对橄榄岩的Os同位索组成的影响可能较为有限。除了化学成分上的影响之外，熔体的加入也会改变大陆岩石圈地峻的物理特征。这一过程使得岩石圈地慢的渗透率增大和黏滞度降低，从而会破坏大陆岩石圈地慢的稳定性。虽然熔体再富集作用可
以影响和改变岩石圈地的性质，但它是否导致克拉通地慢的减薄以及克拉通破坏尚有疑问。关键词：熔体再富集作用；大陆岩石圈地慢；Sr-Nd-Os同位索
中图分类号：P584
文献标识码：A
文章编号：1006-7493（2012)0052-10
EffectsofMeltRefertilizationontheSubcontinentalLithosphericMantle
SUN Jing2,LIU Chuanzhou",wU Fuyuan'
1.State Key Laboratory of Lithospherie Evolution, Institute of Geology and Geophysics, Chinese
Academy of Sciences, Beijing 100029, China; 2. Graduate University of the Chinese Academy of Sciences, Beijing 100049, China Abstract: The herzolites have been commonly regarded as mantle residues after low degrees of partial melting. However, melt refertilization, which refers to transform the refractory harzburgites to fertile lherzolites through adding asthenosphere-derived basaltic melts, provides a new explanation for the fertile Iherzolites. Besides the enrichment in major elements, this process also transforms the enriched characteristics in trace elements and Sr-Nd isotopes of the harzburgites to the depleted characteristics of Iherzolites. It is still highly debated as to whether melt refertilization can change the Os isotopic compositions of mantle peridotites, which depend on the ratios of the refertilizing melts, the sulfur saturation of the melt, and the time of refertilization, etc. The melt/rock ratios in the sub-continental lithospheric mantle are commonly low. Therefore, effects of melt refertilization on the Os isotopic compositions of the peridotites are probably limited. In addition to chemical compositions, addition of refertilizing melts changes the physical properties. Melt refertilization would destabilize the lithospheric mantle through increasing the permeability and decreasing the viscosity. Although it can change the chemical-physical properties of the lithospheric mantle, it is
unclear whether the melt refertilization process is responsible for lithospheric thinning and craton destruction. Key words: Melt refertilization; Subcontinental lithospheric mantle (SCLM); SrNdOs isotope
Corresponding author: Liu Chuanzhou, Ph.D; E-mail: chzliu@mailLiggcas.ac.cn 收稿日期：2011-1114；修回日期：2011-12-14
基金项目：中国科学院知识创新工程重要方向项目（KZCX2-EW-109）
作者简介：孙品，博士研究生，地慢地球化学专业；E-mailsunjing@mail.iggcas.ac.er
+通讯作者：刘传周，副研究员；E-mail:chzliu@mail.iggcas.ac.en