摘要
分析了中国大陆东部地区和东海海域地球物理场、大地构造、地球动力学特征.根据分析得出:东海海域的重磁场特征与中国大陆重磁场特征密切相关,分布趋势与走向均与大陆边缘重磁场相同,是大陆地球物理场向海域的延伸.东海陆架盆地地区具有大陆地球物理场特征,东海东部边缘、海槽具有大陆边缘地球物理场特征.根据研究区的重磁资料计算了该区莫霍、居里界面深度与分布.地壳结构特征表明:莫霍界面在中国东部的主要走向为NE—NNE向,与东海莫霍界面的走向基本一致,说明是大陆地壳向海域的延伸.在冲绳海槽以东海域,地壳厚度由十几公里迅速减薄到几公里,表明地壳由过渡壳向洋壳的转变,因此冲绳海槽应该是大陆地壳的自然终结.中国大陆东部居里界面的差异,反映了地壳结构的不同,陆区及陆架区的磁场特征主要反映了上地壳的磁性结构,相应的也形成了不同的磁场特征与居里界面特征.地球动力学特征表明:东海海域地球动力学特征与中国东部大陆地球动力学特征关系密切,这一地区是欧亚板块与菲律宾海板块的结合地带,构造活动十分强烈,是研究中国大陆及其邻域构造运动,进行地球动力学特征分析的极为有利、重要的地区.
This paper analysed characters of geophysical fields, tectonics and geodynamics of eastern of Chinese continent and East China Sea region. Based on analysing we can cognize that characters of gravitational and magnetic fields were quite correlation between East China Sea region and Chinese continent. The distribution and tend towards of gravitational and magnetic fields of East China Sea were similar with that of Chinese continent and they were the extent of Chinese continent geophysical fields. The shelf basins of East China Sea had characters of continental geophysical fields. The east margin of East China Sea and Okinawa Trough had geophysical field characters of continental margin. Using gravitational and magnetic data of the area we calculated Moho and Courier interfaces. The characters of crust showed that main tend towards of eastern of Chinese continent was NE-NNE and it was similar with that of East China Sea region. This fact showed that continental crust was extended to sea region. The thickness of crust decreased rapidly from 13 to 4 kilometers since eastern of Okinawa Trough. It was shown that character of crust changed from transitional to oceanic crust. Based on this fact, Okinawa Trough should be nature end of continental crust. The difference of Courier interface of Chinese eastern showed that differ of crust structure. The characters of magnetic field of continent and continent shelf region mainly reflected magnetism configuration of upper crust. The magnetism configuration formed different characters of magnetic field and Courier interface. The characters of geodynamics showed osculatory relation between East China Sea region and Chinese continent eastern. East China Sea region was combined zone of Eurasian Plate and Philippines Sea Plate. The tectonics activity of the region was quite (intensity. It was important region to study tectonics activity of Chinese continent and adjacent area.)
出处
《地球物理学进展》
CSCD
2004年第1期75-90,共16页
Progress in Geophysics
基金
国家重点基础研究发展规划项目(编号:G20000467 03).
关键词
地质构造
大地构造
地球动力学
莫霍界面
居里界面
geological structure, tectonics, geodynamics, Moho interface, Courier interface
