华南东南部地壳厚度、属性及其与成矿的关系：基于地震接收函数的约束  

Crustal thickness, properties and its relations to mineralization in the southeastern part of South China: Constraint from the teleseismic receiver functions

作　　者：张永谦 徐峣[1,2] 严加永[1,2,3] 徐志伍 赵金花[1,2,3] ZHANG Yongqian;XU Yao;YAN Jiayong;XU Zhiwu;ZHAO Jinhua(Chinese Academy of Geological Sciences, Beijing, 100037, China;China Deep Exploration Center-SinoProbe Center, China Geological Survey & Chinese Academy of Geological Sciences, Beijing, 100037, China;MNR Key Laboratory of Metallogenyand Mineral Assessment, Institute of Mineral Resources, CAGS,Beijing, 100037, China)

机构地区：[1]中国地质科学院,北京100037 [2]中国地质调查局-中国地质科学院地球深部探测中心,北京100037 [3]中国地质科学院矿产资源研究所,自然资源部成矿作用与资源评价重点实验室,北京100037

出　　处：《中国地质》2019年第4期723-736,共14页Geology in China

基　　金：中国地质调查局项目“钦杭结合带及邻区深部地质调查”（DD20160082）和“武陵山—江南造山带中段深部地质调查”（DD20190012）;中国地质科学院基本业务费项目“基于宽频地震数据的钦杭—武夷山成矿带2D壳幔结构研究”（K1609）;国家自然科学基金项目“宁芜火山岩快速喷发轨迹的地球物理示踪与成矿启示”（41574082）联合资助~~

摘　　要：华南大陆主要由扬子与华夏两大古陆块拼合而成,复杂的构造演化过程使得该区不仅具有多样的几何结构与变形特征,也发育成为中国南部重要的多金属成矿区域,其中包括长江中下游、钦州-杭州、武夷山、南岭、等多个重要成矿带。针对华南东南部及位于该区内的长江中下游、武夷山和南岭成矿带的深部结构与成矿背景,本文利用国家地震台网在该区固定地震台站的远震事件记录信息,通过对各个台站的远震接收函数开展H-κ扫描研究,获得了各台站下方的地壳厚度和波速比。对地壳厚度和波速比的相关性与地壳流变学构造模式进行了对比分析,研究结果显示,华南东南部的Moho面起伏整体较为平缓,自东向西逐渐增厚,波速比分布与成矿带和构造格局有明显相关性,在扬子与华夏块体之间的华南陆内复合造山区呈现明显的低波速比特征;结合该区已有的地质构造等研究分析,认为华南地区地壳减薄与燕山期的强烈岩浆活动和成矿过程密切相关,太平洋板块俯冲以及岩石圈和下地壳拆沉所造成的上地幔热物质扰动上涌或是该区矿产资源集中爆发的驱动力源;本研究所得地壳厚度与波速比分布特征与重力学多尺度边缘检测所刻画的构造界限一致性较好,支持其对扬子与华夏块体南界的划分方案。South China is tectonically composed of the Yangtze block and Cathysian block, with very complicated architecture and deformation characteristics as well as various mineral deposits. In the past years, various geoscience studies focused on the metallogenic process and geodynamics has been conducted in the fields of petrology, chronology, mineral deposits, geochemistry and geophysics in this area. As the architecture and properties of the deep crust resulted from the tectonic evolution process and geodynamics, they would contain key information for understanding the formation of large metallogenic belt and ore concentration area. With the aim of studying the deep crustal structure and metallogenic background, the authors calculated the crustal thickness and Vp/Vs ratio with the method of H-κ scanning of P-wave teleseismic receiver functions using the seismic data provided by China Earthquake Network Center. The results reveal that the crustal thickness in the study region varies slightly and gets deeper from east to west, and the distribution of Vp/Vs ratio is correlated well with the tectonics and metallogenic belts. Combined with the existent geological studies, the authors hold that the crustal thinning in this region was related to the strong magmatism and metalogenic process in the Yanshanian period, and the upwelling of hot materials from the upper mantle was probably the driving force for the eruption of mineral resources in this region. On the other hand, the distribution of crustal thickness and Vp/Vs ratio is correlated well with the tectonic boundaries estimated from the edge detection of gravity data.

关 键 词：华南 钦杭结合带 接收函数 地壳厚度 成矿作用 深地资源工程 

分 类 号：P631.4[天文地球—地质矿产勘探]