珠三角鼎湖—高明—金湾深地震测深剖面地壳构造与速度结构特征分析  

Crustal structure and tectonic attribute revealed by a deep seismic sounding profile of Dinghu-Gaoming-Jinwan in the pearl river delta

作　　者：叶秀薇[1,2] 张项[1,2] 吕金水[1,2] 刘宝峰[3] 王小娜[1,2] 王力伟[1,2] 吕作勇[1,2] 谭争光[1,2] 熊成 YE XiuWei;ZHANG Xiang;Lü JinShui;LIU BaoFeng;WANG XiaoNa;WANG LiWei;Lü ZuoYong;TAN ZhengGuang;XIONG Cheng(Guangdong Provincial Key Laboratory of Earthquake Early Warning and Safety Diagnosis of Major Projects,Guangdong Earthquake Agency,Guangzhou 510070,China;CEA Key Laboratory of Earthquake Monitoring and Disaster Mitigation Technology,Guangdong Earthquake Agency,Guangzhou 510070,China;Geophysical Exploration Center,China Earthquake Adminstration,Zhengzhou 45002,China)

机构地区：[1]广东省地震局,广东省地震预警与重大工程安全诊断重点实验室,广州510070 [2]广东省地震局,中国地震局地震监测与减灾技术重点实验室,广州510070 [3]中国地震局地球物理勘探中心,郑州450002

出　　处：《地球物理学报》2020年第5期1959-1969,共11页Chinese Journal of Geophysics

基　　金：国家自然科学基金项目(41676057,41604055);广东省科技计划项目(2017B030314082,2018B020207011)资助.

摘　　要：为研究珠江三角洲及近海区域深部地壳结构,广东省地震局联合多家单位于2015年在珠江口区域实施了大规模三维人工地震测深实验.本文利用珠江口西侧NW向鼎湖—高明—金湾L1测线数据进行处理、解释,采用地震射线走时正演构建了该剖面二维速度模型.结果表明:沿剖面莫霍面深度从NW向SE,从30.0 km逐渐抬升到28.0 km,鼎湖至高明间存在莫霍面隆起;中地壳低速层非均匀连续,NW一侧速度低于SE一侧,且莫霍面隆起区之上为最显著的低速异常区域,中心最低速度为6.05 km·s-1;吴川—四会断裂、广州—恩平断裂可能为深部物质上涌的主要通道之一,两条断裂所围限的从珠江口西侧的鼎湖、高明往北东延伸到珠江口东侧的清远、从化区域为可能的连续莫霍面隆起区.To find out the crustal structure and tectonic attribute of the Pearl river delta and offshore area(PRD),in 2015,the Guangdong Earthquake Agency collaboration with the other unit carried out a three-dimensional joint onshore-offshore seismic detection experiment in the PRD.This paper processed the data of Dinghu-Gaoming-Jinwan line L1 on the west side of PDR.We utilized ray tracing and travel-time simulation method to obtained a P-wave velocity model of the L1 profile.The study showed:Along the profile,The depth of the Moho gradually decreases from the northwestern inland 30.0 km to the southwestern coastal 28.0 km.Upheaval of the Moho is between Dinghu and Gaoming.Inhomogeneous continuity of low velocity layer in the middle crust.The velocity of low velocity layer NW side is lower than the SE side,especially between Dinghu and Gaoming.The minimum velocity is 6.05 km·s-1.The deep Wuchuan-Sihui fault and Guangzhou-Enping fault may be one of the most important channels for deep material upwelling.It is the continuum upheaval of the Moho which from Dinghu,Gaoming on the west side of PDR to Qingyuan,Conghua on the east side of PDR delimited by Wuchuan-Sihui fault and Guangzhou-Enping fault.

关 键 词：珠江口深地震剖面 地壳速度结构 莫霍面隆起 吴川—四会断裂 广州—恩平断裂 

分 类 号：P315[天文地球—地震学]