基于重、磁异常的西太平洋中段构造特征研究  

Structural features in the mid-latitude Western Pacific based on gravity and magnetic anomalies

作　　者：朱莹洁 王万银[1,2] J.Kim Welford Colin G.Farquharson 杨永 罗新刚 王丁丁[1,2] 马涛 马杰 ZHU YingJie;WANG WanYin;J.Kim Welford;Colin G.Farquharson;YANG Yong;LUO XinGang;WANG DingDing;MA Tao;MA Jie(Institute of Gravity and Magnetic Technology,School of Geological Engineering and Geomatics,Key Laboratory of Western China′s Mineral Resources and Geological Engineering,Ministry of Education,Chang′an University,Xi′an 710054,China;National Engineering Research Center for Offshore Oil and Gas Exploration,Beijing 100028,China;Department of Earth Sciences,Memorial University of Newfoundland,St.John′s A1B3X5,Canada;Southern Marine Science and Engineering Guangdong Laboratory,Guangzhou 511458,China;Key Laboratory of Marine Mineral Resources,Ministry of Natural Resources,Guangzhou Marine Geological Survey,Guangzhou 510075,China)

机构地区：[1]长安大学重磁方法技术研究所,长安大学地质工程与测绘学院,长安大学西部矿产资源与地质工程教育部重点实验室,西安710054 [2]海洋油气勘探国家工程研究中心,北京100028 [3]纽芬兰纪念大学地球科学系,加拿大圣约翰斯A1B3X5 [4]南方海洋科学与工程广东省实验室(广州),广州511458 [5]自然资源部海底矿产资源重点实验室,广州海洋地质调查局,广州510075

出　　处：《地球物理学报》2022年第5期1712-1731,共20页Chinese Journal of Geophysics

基　　金：自然资源部中国地质调查局地质调查项目(DD20190629);国家留学基金委、国家自然科学基金面上项目(42072324);中国大洋“十三五”资源环境类课题“合同区海山地形单元识别与底质类型研究”(DY135-C1-1-03)联合资助.

摘　　要：西太平洋中段包含发育众多独立海山、海山链及海岭的西太平洋海山省(WPSP)、马里亚纳海沟和马里亚纳岛弧,其形成与演化与构造运动密切相关.研究区金属矿产、尤其是WPSP区域的富钴结壳资源较丰富,具有重要的研究意义.本文采用重、磁异常数据研究了西太平洋中段的构造特征.其中,采用归一化总水平导数垂向导数(NVDR-THDR)方法技术划分区域内的断裂,并采用欧拉反褶积深度反演方法得到断裂的视深度;采用深度约束下的双界面模型快速反演方法得到研究区莫霍面的起伏形态;同样采用NVDR-THDR方法技术识别NE向和NW向磁条带;采用重磁对应分析方法圈定研究区的火成岩,包括独立海山、海山链、海岭、马里亚纳岛弧型火成岩及大洋盆地溢流型玄武岩省.通过对研究区断裂分布、莫霍面深度、磁条带分布及火成岩分布的研究,得到了西太平洋中段的构造单元分布特征.马里亚纳海沟东侧,即WPSP区域内识别的断裂走向主要为NW(WNW)向和NE(ENE)向,而西侧,即马里亚纳岛弧区域识别的断裂与马里亚纳岛弧近N-S向的走向特征一致.研究区的大洋盆地溢流型玄武岩省呈NW向条带状展布、NE向块状分布的特征,并与独立海山、海山链和海岭相间分布.综合对西太平洋中段构造特征的研究,认为断裂对研究区的构造演化起到了重要作用.莫霍面深度在一级深大断裂两侧普遍存在突变;一些磁条带被断裂错断;火成岩的形成与分布也受控于断裂:独立海山、海山链、海岭及马里亚纳岛弧型火成岩位于莫霍面凹陷区,大洋盆地溢流型玄武岩省位于莫霍面隆起区.综合以上研究,划分了西太平洋中段的构造单元.在WPSP的构造单元呈NW向条带状展布、NE向块状分布的特征,而马里亚纳弧沟体系的构造单元呈近N-S向带状展布的特征.The formation and evolution of the mid-latitude Western Pacific,including the West Pacific Seamount Province(WPSP),where isolated seamounts,seamount trails and submarine ridges widely developed,the Mariana trench and Mariana island arc,are closely related to tectonic movements.It has important research significance for rich metallic mineral resources,especially cobalt-rich crustal resources specifically contained in the WPSP.Here,gravity and magnetic anomalies are used to study the structural features in the mid-latitude Western Pacific.Faults are delineated by using the normalized vertical derivative of the total horizontal derivative(NVDR-THDR)method.The apparent depth of the faults is inverted by using the Euler deconvolution depth inversion method.The Moho depth is inverted by using the rapid inversion method for a double-interface model with depth constraints.Magnetic lineations with NE-and NW-trends are identified also by using the NVDR-THDR method.The igneous rocks,including the isolated seamounts,seamount trails,submarine ridges and the ocean basin flood basalt provinces,are delineated using the correspondence analysis method on gravity and magnetic data.The structural features of the mid-latitude Western Pacific have been interpreted by studying the distribution of faults,the Moho depth,the distribution of magnetic lineations and igneous rocks.The strikes of the recognized faults in the WPSP,on the east side of Mariana trench,are mainly NW-(or WNW-)and NE-(or ENE-)trends.The strikes of the recognized faults in the Mariana island arc,on the west side of the Mariana trench,are approximately N-S trends,corresponding well with the approximately N-S trend of the Mariana island arc.The ocean basin flood basalt provinces form NW-trending belts,and cut northeastward into blocks,alternating with isolated seamounts,seamount trails and submarine ridges.Based on the study of the structural features in the mid-latitude Western Pacific,it is indicated that the faults played an important role in the tectonic evolution

关 键 词：西太平洋海山省 马里亚纳 重、磁异常 断裂 莫霍面深度 磁条带 火成岩 

分 类 号：P631[天文地球—地质矿产勘探] P541[天文地球—地质学]