中国东部及近海磁异常特征及大地构造意义  

Magnetic anomaly in eastern China and adjacent sea,and its tectonic significance

作　　者：吴招才[1] 高金耀[1] 沈中延[1] 杨春国[1] 张涛[1] 

机构地区：[1]国家海洋局第二海洋研究所国家海洋局海底科学重点实验室,浙江杭州310012

出　　处：《地学前缘》2018年第1期210-217,共8页Earth Science Frontiers

基　　金：国家海洋局"全球变化与海气相互作用"专项(GASI-02-SCS-DWZP1;GASI-GEOGE-01-05);科学技术部科技基础性工作专项(2013FY112900);国家重点研发计划项目(2016YF0600402)

摘　　要：根据全球磁异常数据和中国近海高精度、高分辨率的海洋船磁资料,通过频率域的迭代下延方法,将两种不同分辨率的数据进行融合,得到了覆盖我国东部及近海的大面积地磁异常数据。对磁异常进行大范围变倾角化极,并进行了小波分解和频谱分析,计算、分析磁源重力异常、磁异常解析信号及倾斜角等转换场。结果显示中国东部及近海主要地质构造单元的磁异常特征,揭示了华北地块古陆块分布和扬子地块的南北边界走向,并指出浙闽火山岩带向西南可能和东沙隆起相连,都是中生代古俯冲的火山弧,南海北部NW向断裂可能是古特提斯构造域向太平洋构造域转换边界断裂,对中生代古俯冲及由主动陆缘向被动陆缘转化过程都有控制作用。On the basis of the latest shipboard magnetic data merging with the world digital magnetic anomaly, we have calculated the reduction to the pole （RTP） anomaly, pseudogravity anomaly, analytic signal and tilt angle, and used the wavelet decomposition and frequency spectrum analysis for the RTP anomaly. The results revealed the magnetic signature of the main tectonics in eastern China and adjacent sea. The distributions of paleocontinental nucleus in the North China block were indicated as well as the boundaries of Yangzi block. It was pointed out that the volcanic belt in the coastal area of Zhejiang and Fujian provinces connects to the Dongsha Uplift, and both of them are Mesozoic subduction volcanic arc. The NWoriented fault may be the boundary fault in which PaleoTethys tectonic domain converted to the Pacific tectonic domain, and controlled the subduction process during the Late Mesozoic and the conversion from the active continental margin to the passive continental margin since the Mesozoic at the Northern South China Sea continental margin.

关 键 词：中国东部及近海 磁异常 数据融合 构造特征 

分 类 号：P318.43[天文地球—固体地球物理学] P54[天文地球—地球物理学]