活动断裂两盘地块的迁移特征及其形成机制

通过对典型活动断裂两盘重力场特征的对比与分析，发现具有大面积布各重力负异常（或相对我异常）的地块总是向赤道方向运动，而布格重力正异常（或相对正异常）的地块向极点方向运动，布格重力异常图反映了密度情况，正异常带为大密度地块，负异常带为小密度地块，从理论分析得知，地块的密度变化导致了受力条件的改变，致使地块失稳产生运动，岩浆活动是造成地块密度变化的重要因素。

Movement Characteristics and Formation Mechanism of Two Sides of an Active Fracture

By comparing and analysing the characteristics of gravity fields on two sides of a typical active fracture, the author finds that the massifs where Bougucr gravity anomalies are regionally negative (or relatively negative) always move towards the equator, while the massifs where the Bouguer gravity anomalies are positive (or relatively positive) move towards the poles. The map of Bouguer gravity anomaly portrays the density distribution of the massifs. The massif with positive gravity anomaly has a high density and that with negative gravity anomaly has a low density. According to the theoretical analysis, the change in density of the massif will lead to a change in stress conditions, which causes the loss of stability of the massif and put massif in motion. The magmatic activity is an important factor for the density change.