华北地区重力场变化与构造运动的关系

PRIMARY STUDY ON THE VARIATION OF GRAVITY FIELD OF NORTHERN CHINA AND ITS RELATIONSHIP WITH TECTONIC MOVEMENTS

根据重力场和形变场观测结果及其年变化率，结合均衡异常（经典和现代的补偿模型）和地质构造及其演化历史，探索了该区的重力场和构造运动特征。研究结果表明：华北地区处于再活动阶段；岩石圈弹性厚度薄，以致地壳破裂严重；有一大的正均衡异常区（北京以南），说明此处质量运移多，也正是地震发生多的地带。

The characters of gravity field and tectonic movements are investigated based on the observations of gravity and deformation field and their annual variation rate,combing with the isostatic field (classical and modern compensation models),geological tectonics and evolution history.The results show that Northen China is in the re-active stage.The elastic thickness of lithosphere is relatively thin so that the crust ruptures greatly in the area. The existance of large possitive isostatic anomaly zone,located in the southern part to Beijing, suggests that much more mass removal esists in this area where earthquake occurs frequently.