论文部分内容阅读
具有较高分辨率的日本海沟-长白山-东乌珠穆沁旗的地震层析成像剖面,显示了太平洋板块俯冲板片的形貌特征和长白山、大兴安岭下方的岩石圈结构特征,表明太平洋板块以26°倾角俯冲到660km之后明显下插,在其西侧伴有一显著低速的热上涌体,不存在俯冲板块继续向西深入的迹象。根据太平洋板块俯冲时间及俯冲作用引起岩浆活动的时间差,可认为中国东部中生代岩浆活动与太平洋板块俯冲无直接的成因联系。同时还强调地震层析剖面反映的是现存的深部结构,它可以保留某些中生代的岩石圈结构特征,据此可推测华北中生代岩浆的演化与大陆板块内软流圈上涌体的活动有关。
Seismic tomography profiles of the Japan trench-Changbai Mountain-Dongwuzhuqin Banner with higher resolution show the morphological characteristics of the subducted plate of the Pacific Plate and the lithospheric structure beneath the Changbai Mountains and the Greater Hinggan Mountains, indicating that the The subduction of 26 ° dip to 660km obviously plunges, accompanied by a remarkably low rate of thermal upwelling on the west side, with no sign that the subduction plate continues to go west. According to the time difference of magmatic activity caused by the subduction time and subduction of the Pacific plate, there is no direct genetic association between the Mesozoic magmatism and the subduction of the Pacific plate in eastern China. At the same time, it is stressed that the seismic tomographic profile reflects the existing deep structure, which can retain some Mesozoic lithospheric structural features. Therefore, it can be inferred that the Mesozoic magmatic evolution in North China is related to the upwelling of asthenosphere within the asthenosphere in the continental plate.