Magnetic Anomalies And Curie Surface Characteristics In Eastern China Seas

The Eastern China and adjacent seas lie on the western side of the western Pacific island arc.During the formation process,North China block,Yangzi block and South China block were combined,and the edge of different blocks formed orogenic belt and various fault zones.The tectonic activities of the Mesozoic and Cenozoic in the eastern sea area are intense,especially the subduction of the paleo-Pacific plate in the Late Mesozoic caused a large-scale magmatic activity,forming a series of fault basins.The interaction between the blocks forms various geological bodies,and this process is often associated with magmatic activities.The magnetic anomaly data have significant effects on studying the distribution of magmatic rocks,revealing the characteristics of magnetic bodies in the earth's crust and the faults related to magmatic activities.The processing and interpretation of magnetic anomaly datas can provide useful information for the study of deep basement structures and fault,revealing the distribution of subduction zone and orogenic belt.This article is based on the Magnetic anomaly mapping project in the Eastern China and adjacent seas for the basic work of science and technology of the Ministry of Science and Technology.This paper collects measured data of ocean magnetic anomaly,gravity anomaly,heat flow,seismicity,and other physical data.In this paper,the reduction-to-pole of magnetic data,upward continuation,Wavelet Multi-Scale decomposition,Pseudo-gravity,Euler deconvolution,Curie isothermal surface inversion and other calculation methods are used.In this paper,the second-order wavelet approximation of RTP magnetic anomalies in the eastern China sea is calculated,and the power spectrum method is used to invert Curie and the Curie depth map is obtained.The results show that the undulations in the eastern China sea change greatly,and the depth varies from 16.8 to 36.6 km,reflecting the undulating state of the degaussing interface in the lithosphere.The depression in Curie is mainly distributed on a stable block with a depth of more than 26 km.The heat flow value is roughly the same as the global average heat flow,such as the northern Jiangsu-South Yellow Sea Basin and the East China Sea continental shelf basin.The depression in Curie is mainly related to the stable tectonic setting,normal crust thickness,or relatively weak Mesozoic and Cenozoic tectonic activities.Curies of Curies are mainly distributed on the edges of active blocks or Mesozoic and Cenozoic orogenic systems such as the Bohai Basin,the Sulu orogenic belt,and the Okinawa Trough.The results of the two gravity magnetic seismic combination profile inversion in the South Yellow Sea indicate that the eastern magnetic layer in the central uplift region is thick and has strong magnetic intrusions.Therefore,it is considered that this massive magnetic anomaly is caused by the combination of uplift of the magnetic base and intrusion of magmatic rocks.