苏鲁超高压带内石桥浅变质岩的地质成因及其研究意义  

THE GEOLOGICAL GENESIS AND SIGNIFICANCE OF THELOW-GRADE METAMORPHIC ROCKS AT SHIQIAO IN THE SULU ULTRAHIGH PRESSURE ZONE

作　　者：刘建辉[1] 周建波[1] 郑常青[1] 

机构地区：[1]吉林大学地球科学学院,吉林长春130061

出　　处：《矿物岩石》2005年第2期40-46,共7页Mineralogy and Petrology

基　　金：国家自然科学基金(编号:40272100)

摘　　要：　苏鲁造山带超高压变质带内部出露仅经过绿片岩相变质作用的浅变质岩系,地质调查显示,石桥浅变质岩与周边超高压变质岩呈构造接触(构造片岩);地球化学研究证实,该浅变质岩形成于扬子板块北缘大陆边缘厚地壳上裂陷或沉积盆地的构造背景;单矿物电子探针分析结果显示,其部分浅变质岩发育多硅白云母,形成于中-高压相变质环境,说明这些浅变质岩曾经历大陆板块俯冲的动力变质作用过程。在此基础上,进一步讨论浅变质岩的成因机制及其与超高压变质岩和扬子板块俯冲之间的关系。Low-grade metamorphic rocks of greenschist facies occurred in the ultrahigh pressure (UHP) metamorphic zone in the Sulu orogen.Investigation showed that the low-grade metamorphic rocks at Shiqiao contact structurally (as structural schists) with UHP metamorphic rocks.Geochemical study demonstrated that the low-grade metamorphic rocks formed in the tectonic setting of rifts or sedimentary basins on the continental margin of thick crust in the north margin of Yangtze plate.The single mineral electron probe analysis revealed that the phengites developed in part of the low-grade metamorphic rocks and formed in the medium-high metamorphism environment,indicating that the low-grade metamorphic rocks once underwent the dynamical metamorphic process due to the subduction of continental plate.The genesis of low-grade metamorphic rocks and the relationship among the low-grade metamorphic rocks,the UHP metamorphic rocks and the subduction of Yangtze plate were discissed and explained in the paper.

关 键 词：苏鲁造山带 浅变质岩 板块府冲 超高压变质岩 加积杂岩 

分 类 号：P588.3[天文地球—岩石学]