鲁东南岚山头超高压变质岩流体包裹体特征与板片折返史  

Fluid inclusions and exhumation history of ultra-high-pressure metamorphic rocks at Lanshantou in the Sulu terrane,southeastern Shandong province.

作　　者：范宏瑞[1] 郭敬辉[1] 胡芳芳[1] 储雪蕾[1] 金成伟[1] 

机构地区：[1]中国科学院地质与地球物理研究所岩石圈演化国家重点实验室和矿产资源研究重点实验室,北京100029

出　　处：《岩石学报》2005年第4期1125-1132,共8页Acta Petrologica Sinica

基　　金：国家重点基础研究发展规划项目(G1999075502)资助

摘　　要：鲁东南岚山头含柯石英榴辉岩主要产于花岗质片麻岩内,是苏鲁超高压变质带主要榴辉岩体密集分布区之一。流体包裹体研究表明,榴辉岩矿物及细脉石英中捕获有四种类型包裹体:在超高压-高压榴辉岩相条件下捕获的 N_2±CO_2包裹体;在高压榴辉宕重结晶阶段被捕获的 CO_2-H_2O 包裹体和含子矿物高盐度 H_2O 溶液包裹体:在超高压岩石折返过程中的最晚(角闪岩相退变质甚至更晚)阶段捕获的低盐度 H_2O 溶液包裹体。利用榴辉岩矿物及脉体石英中捕获的流体包裹体相互期次关系,可以对本区超高压变质作用板片折返过程中的流体演化史进行重建。Lanshantou eclogites in the southeastern Shandong province are located in the middle part of the Sulu ultra-high-pressure metamorphic terrane, Eastern China. The area is dominated by foliated granitic gneisses. Eclogites occur as blocks in granitic gneisses. Fluid inclusions in coesite-bearing eclogites and eclogite-facies quartz veins at Lanshantou in the Sulu terrane have preserved remnants of peak metamorphic and exhumation fluids. Four types of fluid inclusions have been distinguished ： （ 1 ） N2 ± CO2 inclusion, （2） H2 O-CO2 inclusions, （3） hypersaline H2O inclusion, and （4） low salinity H2O inclusions. N2-rich fluids were introduced during or just after peak metamorphism. CO2-H2O and hypersaline fluids were trapped in high pressure eclogite-facies re-crystallization stage. Low salinity H2O fluids were related with the latest evolutionary stage of ultrahigh pressure exhumation （amphibolite-facies retrogression）. The possibility of deciphering the relative chronology of the fluid pulses can provide fluid evolution history during exhumation of ultra-high-pressure metamorphic rocks.

关 键 词：流体包裹体 超高压变质岩 折返 岚山头 苏鲁 

分 类 号：P588.348[天文地球—岩石学]