俯冲带壳-幔相互作用的高温高压实验：对地幔不均一性成因的启示  

An Experimental of Crust-Mantle Interaction in Subduction Zones:Implications for Genesis of Mantle Heterogeneity

作　　者：王春光[1] 许文良[1] Wang Chunguang;Xu Wenliang(College of Earth Sciences,Jilin University,Changchun 130061,China)

机构地区：[1]吉林大学地球科学学院

出　　处：《地球科学》2019年第12期4112-4118,共7页Earth Science

基　　金：科技部国家重点基础研究项目(No.2015CB856101)

摘　　要：使用活塞-圆筒式高温高压装置进行一系列榴辉岩部分熔融熔体与橄榄岩反应实验,可以为深入了解俯冲带壳-幔相互作用的影响因素及地幔不均一性的成因提供重要信息.实验使用反应偶的方法,并在0.8~3.0 GPa和1200~1425℃条件下进行.实验结果表明,榴辉岩部分熔融熔体-橄榄岩反应的动力学和结果受控于熔体主量元素成分、熔体中的H2O、温度、压力和橄榄岩的物理状态等因素.大陆俯冲带地幔岩石中斜方辉石的富集是再循环陆壳熔体与上覆地幔反应的结果,地幔岩石中斜方辉石岩脉的形成与含水熔体交代有关,地幔岩石中的石榴辉石岩和石榴石岩可能形成于高压、低温条件下的熔体-橄榄岩反应.A series of experiments reacting peridotite with melts derived from partial melting of eclogites was accomplished in order to better understand factors that control crust-mantle interaction in subduction zones.The experiments were conducted using the reaction couple method at 0.8-3.0 GPa and 1200-1425℃.The experimental results show that kinetics and consequence of melt-rock reaction are controlled by factors including major element composition and H2O in reacting melt,temperature,pressure,and physical state of reacting peridotite.Orthopyroxene enrichment in mantle beneath subduction zones is a result of interaction between melt derived from recycling continental crust and overlaying mantle.Formation of orthopyroxenite veins in mantle rocks is related to hydrous mantle metasomatism.Garnet-bearing and garnet-rich lithologies in mantle rocks were likely formed by meltrock reaction in the low-temperature regime.

关 键 词：俯冲带 壳一幔相互作用 地幔不均一性 熔体一橄榄岩反应实验 岩石学 

分 类 号：P611[天文地球—矿床学]