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

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. 

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

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.