P-wave Velocity Structure of Crustal and Upper Mantle beneath South China and its Tectonic Implications

作     者：ZHENG Hongwei LI Tingdong HE Rizheng YU Haiying YANG Hui WEN Yanlin WANG Peng LIU Fang SUN Dongjun ZHENG Hongwei;LI Tingdong;HE Rizheng;YU Haiying;YANG Hui;WEN Yanlin;WANG Peng;LIU Fang;SUN Dongjun

作者机构：Institute of GeologyChinese Academy of Geological SciencesBeijing 100037China Shanghai Sheshan National Geophysical ObservatoryShanghai 200062China Chinese Academy of Geological SciencesBeijing 100037China Institute of GeophysicsChina Earthquake AdministrationBeijing 100081China 

出 版 物：《Acta Geologica Sinica(English Edition)》 (地质学报（英文版）)

年 卷 期：2022年第96卷第2期

页      面：621-630页

核心收录：

学科分类：070904[理学-构造地质学] 0709[理学-地质学] 07[理学] 

基　　金：supported by Shanghai Sheshan National Geophysical Observatory(Grant No.2020k07) the Chinese Geological Survey(Grant Nos.DD20190448,DD20190370) the National Natural Science Foundation of China(Grant Nos.41374101,42174172) the National Key Research and Development Program of China(Grant No.2019YFA0708601) 

主　　题：mineralization tomographic images lithosphere structure Youjiang Basin South China 

摘      要：The 3D P-wave velocity structure beneath the South China Block was determined by applying arrival times from 269 teleseismic events recorded by 240 seismic stations within the study region. Our tomographic results reveal the deep structural characteristics of major tectonic units and ore concentration areas. There are distinct high velocity anomalies beneath the ancient Yangtze and Cathaysia blocks, with the lithosphere of the Cathaysia Block being thinner than the Yangtze Block;the Jiangnan orogenic belt, located in the combined zone of two blocks, is a high and low velocity anomaly conversion zone;the famous metallogenic belts of Edongnan, the Youjiang Basin and the Cathaysia Block are obviously low velocity areas with different metallogenic mechanisms. The deep ore-forming material source in the Edongnan metallogenic belt is different from that of the Cathaysia Block. The low velocity anomaly under the Cathaysia Block related to mineralization results from the upwelling of mantle material, caused by the joint action of the Paleo-Tethys tectonic domain, the Paleo-Pacific tectonic domain and the Hainan mantle plume migration and erosion, which has been occurring from northeast to southwest since 80 Ma. The low-temperature mineralization mechanism of Youjiang Basin should be considered not only in terms of the influence of the Emeishan mantle plume in the west and the Paleo-Tethys tectonic domain in the south, but also in the context of the influence of the upwelling of asthenospheric material from the PaleoPacific tectonic domain in the east.