摘要
佳木斯地块东南缘的兴凯湖花岗杂岩体主要由花岗闪长岩、二长花岗岩和正长花岗岩组成,其锆石的LA-ICP-MS U-Pb测年结果显示,杨田寨南山岩体形成于257±2 Ma,双子山岩体形成于215～212 Ma;花岗岩的时空展布表明,两期花岗质岩浆的就位可能分别与古亚洲洋板块的俯冲作用和后造山伸展进程密切相关。结合本区和黑龙江东部其他花岗质岩石的年龄,揭示了佳木斯地块和兴凯地块在早古生代、二叠纪及三叠纪共同经历了三期大规模岩浆活动,暗示两者具有相同的构造属性,共同组成了同一陆块。
Khanka Lake granitic complex is located in the southeastern margin of Jiamusi Massif,mainly composed of granodiorite,monzogranite and syenogranite.Zircon U-Pb dating by LA-ICP-MS technique indicates that the Yangtianzhainanshan and Shuangzishan plutons were emplaced with ages of 257±2 Ma and 215~212 Ma,respectively.The spatial and temporal distribution of granitoids reveals that they were related to the subduction of the Paleo-Asian oceanic plate and the post-collisional extensional environment of northeastern China.Considering other previously dating of granitic rocks,we proposed that the Jiamusi Massif and Khanka Massif commonly experienced three stages of magmatism in large scale（the Early Paleozoic,Permian and Triassic）.The two massifs should be considered to constitute a single crustal entity.
出处
《世界地质》
CAS
CSCD
2012年第4期621-630,共10页
World Geology
基金
中国地质调查局项目(1212011085480和2012000100350001)
