西北地质2024，Vol.57Issue(2)：46-58,13.DOI:10.12401/j.nwg.2023037
松辽盆地东部地区花岗岩地球化学特征及其地质意义
Geochemical Characteristics and Geological Significance of Granites in Eastern Songliao Basin
摘要
Abstract
LA-ICP-MS dating and trace REE geochemical analysis of biotite-bearing granites in the eastern part of Songliao basin and the western part of Zhangguangcai range are carried out to explore their diagenetic age and environment in this paper.The sample zircon oscillatory growth zone is obvious,and the Th/U ratio is big,indicating that it belongs to magmatic origin.The ages of zircon U-Pb dating are(179.3±1.5)Ma;(177.5±1.4)Ma,belonging to the end of Early Jurassic.Light rare earth elements have obvious fractionation,heavy rare earth elements have no obvious fractionation,and Eu and Ce elements have positive anomalies.The sample was formed in the subduction and accumulation environment of the plate.The formation of granites in the two regions is mainly controlled by partial melting.The two dikes have the duality of crust and mantle,may have mantle contamination.Based on the statistics of the ages of the granites in the Greater Khingan Mountains,Songliao basin and Zhangguangcai range,it is found that the granites in Zhangguangcai range were formed earli-er than those in Songliao basin.Validate the previous speculation that the ancient Pacific plate and the Mongo-lia-Okhotsk ocean plate have double subduction and delamination.关键词
地球化学/花岗岩/U-Pb年代学/构造背景/松辽盆地Key words
geochemistry/granite/U-Pb chronology/tectonic setting/Songliao basin分类
天文与地球科学引用本文复制引用
刘昊,崔军平,金玮,成科璋,刘静静..松辽盆地东部地区花岗岩地球化学特征及其地质意义[J].西北地质,2024,57(2):46-58,13.基金项目
国家自然科学基金面上项目"热年代学约束下的松辽盆地石炭-二叠系构造热演化史恢复"(41772121)资助. （41772121）
