中国东部大兴安岭重力梯级带域地球物理场特征及其成因

Geophysical characteristics of Daxinganling gravitational gradient zone in the East China and its geodynamic mechanism

综合利用 7条地学断面 (GGT)资料研究了大兴安岭重力梯级带附近的壳幔地球物理特征模式 .分析了形成上述地球物理特征的 3种因素 :东亚大陆边缘周边三大板块运动、地幔流运动和地幔热柱 .对大兴安岭重力梯级带的重力异常的正演拟合结果表明 ,壳幔物质密度不均匀和莫霍界面起伏造成该带的重力异常 .地应力场的综合作用产生了该重力梯级带系列地球物理特征 .最后 ,探讨了大兴安岭重力梯级带成因机制 ,提出了以“挤”、“涌”为动力的“三结点模型” .

Integrating geophysical data 7 Geoscience transects (GGT), we make the study on the geophysical characteristics model of crust and mantle along the Daxinganling gravitational gradient belt. We analyses 3 kinds of factors to generate the above-mentioned geophysical characteristics, such as the mantle current movement, the mantle thermal plume and the three plates movement surrounding around the continental margin. The forward and fitting results of gravity anomaly along Daxinganling gravitational gradient belt demonstrate the combination of the Earth material density variation in the crust and upper mantle and the Moho interface fluctuation leading to the gravity anomaly of the belt. The stress fields crossed at the continental margin in the East Asia and formed a series along the geophysical characteristics of the gravitational gradient zone. At last, we study the origin of the gravitational gradient zone along Daxinganling Mountain-Taihang Mountain-Wuling Mountain, and present the triple-junction model with dynamic force of compression stress and the upwelling action.