中国东北～500Ma泛非期孔兹岩带的确定及其意义  

Confirming of the Heilongjiang ～500Ma Pan-African khondalite belt and its tectonic implications

作　　者：周建波[1] 张兴洲[1] Simon A WILDE 郑常青[1] 

机构地区：[1]吉林大学地球科学学院,长春130061 [2]Department of Applied Geology,Curtin University of Technology

出　　处：《岩石学报》2011年第4期1235-1245,共11页Acta Petrologica Sinica

基　　金：国家自然科学基金项目(40739905;40872121);国家重点基础研究发展规划项目(2009CB825008)联合资助

摘　　要：东北地区的变质基底,如佳木斯地块的麻山群、兴安地块的兴华渡口群等岩石组合是以(含石墨)大理岩、夕线石榴片麻岩、斜长角闪岩等为主要标志的孔兹岩系。在额尔古纳、兴安和佳木斯-兴凯地块的夕线石榴片麻岩分别得到锆石U-Pb年龄,证明这些高级变质岩的原岩年龄以新元古代(600～850Ma)为主,变质年龄为～500Ma,因此东北地区的变质基底记录了从Rodinia到Gondwana大陆的聚合与离散的过程。泛非期高级变质岩及其同期岩浆岩在额尔古纳、兴安、松辽、佳木斯和兴凯地块等断续分布,总体出露范围>1300km,并沿虎头、鸡西、萝北、兴华渡口和漠河一线总体北西向沿黑龙江断续分布,因此我们命名为"中国东北泛非期孔兹岩带"。"中国东北泛非期孔兹岩带"的提出和进一步研究,对深入探讨东北地区各地块基底组成的异同性以及陆块聚合的过程,以及东北地区的构造演化历史及其在Gondwana大陆重建中的位置都具有重要的科学意义。The basement rocks in NE China,including Mushan Group in Jiamusi Block,Xinghuadukou Group in the Xing＇an Block,constitute a khondalitic sequence of sillimanite-and garnet-bearing gneisses,hornblende-plagioclase gneiss and felsic paragneisses.Zircon U-Pb dating of the garnet-sillimanite gneiss samples from Erguna,Xing＇an and Khanka blocks indicates high-grade metamorphism occurred at ~500Ma,where several detrital zircon grains whose ages extend between 600Ma to 850Ma.The Pan-African high-grade metamorphism with magmatism events were obtained from all the blocks in NE China,including the Erguna,Xing＇an,Songliao and Jiamusi-Khanka blocks,establish a over 1300km Pan-African khondalite belt in NE China,named here the ＇Northeast China Khondalite Belt＇.The results from this study provide new idea for researching the tectonic affinity and plate evolution in the NE China.

关 键 词：孔兹岩带 泛非期 原岩年龄 变质年龄 高级变质岩 中国东北 

分 类 号：P588.345[天文地球—岩石学]