长江中下游成矿带深部结构层析成像图像揭示华北板块的东南向俯冲  

Southeastward Subduction of North China Block:Insights from Tomographyic Image of the Middle and Lower Yangtze River Metallogenic Belt

作　　者：郑洪伟[1,2] 李廷栋 贺日政[4] Zheng Hongwei;Li Tingdong;He Rizheng(Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China;Shanghai Sheshan National Geophysical Observatory,Shanghai 200062,China;Chinese Academy of Geological Sciences,Beijing 100037,China;China Deep Exploration Center,Chinese Academy of Geological Sciences,Key Laboratory of Earth Probe and Geodynamics,Ministry of Natural Resources,Beijing 100037,China)

机构地区：[1]中国地质科学院地质研究所,北京100037 [2]上海佘山地球物理国家野外科学观测研究站,上海200062 [3]中国地质科学院,北京100037 [4]中国地质科学院深部探测中心自然资源部深部探测与地球动力学重点实验室,北京100037

出　　处：《地球科学》2020年第11期4187-4197,共11页Earth Science

基　　金：上海佘山地球物理国家野外科学观测研究站开放基金项目(No.2020K07);国家重点研发计划项目(No.2016YFC0600301);中国地质调查项目(Nos.DD20190448,DD20190370);国家自然科学基金项目(No.41374101)。

摘　　要：远震层析成像结果所揭示的华北板块东南向俯冲到扬子板块之下对于重新认识长江中下游地区成矿机制具有重要意义.利用来自中国地震台网中心,包括湖北、河南、安徽、江西、浙江、江苏等省级地震台网记录的波形数据对长江中下游地区深部结构进行了远震P波层析成像反演.综合研究结果显示,三叠纪华北与扬子板块俯冲碰撞,华北板块越过郯庐断裂带,向东南俯冲到扬子板块之下.推断板块碰撞的深部缝合线在郯庐断裂带以西位于大别造山带以南,在郯庐断裂带以东位于长江一线.经历后期的中生代构造转换过程,该带发生活化,成为中生代含矿岩浆和流体上升的通道,并形成著名的大型成矿带.What the North China block southeastward subducted under the Yangtze plate revealed by the tomography images is important for reunderstanding the metallogenic mechanism in the Middle and Lower reaches of the Yangtze River.In this paper,It determines the 3-D P-wave velocity structure beneath the Middle and Lower Reaches of Yangtze River metallogenic belt by using waveform data recorded by the China Seismic Network Center including Hubei,Henan,Anhui,Jiangxi,Zhejiang and Jiangsu seismic networks.The results show that North China block subducted southeastward under the Yangtze plate in the Triassic period.It is concluded that the deep suture between North China block and Yangtze block is located in the south of Dabie orogenic belt to the west of Tanlu fault and in the Yangtze River to the east of Tanlu fault.After the Late Mesozoic tectonic transformation,the deep suture belt was reactivated and became a channel for the uplift of ore-bearing magma and fluid in Mesozoic,and formed a famous large metallogenic belt.

关 键 词：长江中下游地区 壳幔速度结构 P波层析成像 华北板块东南向俯冲 地球物理 

分 类 号：P3[天文地球—地球物理学]