浙西江山新元古代上墅组火山碎屑岩锆石U-Pb年龄及其地质意义  

Zircon U-Pb Age of the Neoproterozoic Shangshu Formation inJiangshan of West Zhejiang and Its Geological Implications

作　　者：张雪 张炜强 黎广荣[3] 倪凤娟 郭福生[1] 王哲 刘鑫 赵月 ZHANG Xue;ZHANG Weiqiang;LI Guangrong;NI Fengjuan;GUO Fusheng;WANG Zhe;LIU Xin;ZHAO Yue(School of Earth Sciences,East China University of Technology,Nanchang 330013,China;Gandong College,Fuzhou 344000,China;State Key Laboratory of Nuclear Resource and Environment,East China University of Technology,Nanchang 330013,China;Jiangxi Modern Polytechnic College,Nanchang 330095,China)

机构地区：[1]东华理工大学地球科学学院,江西南昌330013 [2]赣东学院,江西抚州344000 [3]东华理工大学核资源与环境国家重点实验室,江西南昌330013 [4]江西现代职业技术学院,江西南昌330095

出　　处：《东华理工大学学报（自然科学版）》2024年第4期324-337,共14页Journal of East China University of Technology(Natural Science)

基　　金：国家自然科学基金项目(41402028,41572185);东华理工大学实践教学基地项目(DHJD-202203)。

摘　　要：为进一步确定浙西江山上墅组火山碎屑岩年龄及沉积物来源,采用LA-ICP-MS技术对该碎屑岩中的锆石开展U-Pb同位素测年并与邻区锆石年龄对比。结果表明,上墅组火山碎屑岩中锆石U-Pb年龄为717~902 Ma,主要集中分布于902~883 Ma、875~812 Ma、794~775 Ma三个区间,峰值分别为(892±7) Ma、(846±7) Ma、(784±9) Ma,记录了华南新元古代裂谷盆地扩张、构造-岩浆-热事件,其中(846±7) Ma峰值可能反映了超级地幔柱的上涌,(784±9) Ma峰值指示了裂谷盆地的扩展。上墅组火山碎屑岩物质主要可能来自浙江中部地区。本研究成果可为江山地区沉积物来源分析、构造演化研究和陆块亲缘关系判别提供依据。To further determine the age and sediment provenance of the Shangshu Formation volcanic clastic rock in the Jiangshan of west Zhejiang,U-Pb isotope dating of zircon in these clastic rocks was conducted using LA-ICP-MS and compared with zircon ages from adjacent areas.The results show that the U-Pb ages of zircons in the Shangshu Formation volcanic clastic rocks range from 717~902 Ma,primarily distributed in three intervals:902~883 Ma,875~812 Ma,and 794~775 Ma,with age peaks at(892±7)Ma,(846±7)Ma,and(784±9)Ma.These age peaks record the expansion of the Neoproterozoic rift basin,tectonic-magmatic-thermal events in South China,with the(846±7)Ma peak potentially reflecting the upwelling of a super mantle plume,and the(784±9)Ma peak indicating the expansion of the rift basin.The materials of the Shangshu Formation volcanic clastic rocks likely originated mainly from the central Zhejiang region.The findings of this study can provide a basis for sediment provenance analysis,tectonic evolution research,and the determination of the affinity of continental blocks.

关 键 词：新元古代 火山碎屑岩 锆石U-PB年龄 上墅组 浙西江山 

分 类 号：P581[天文地球—岩石学]