用不同层次方法分析南海及其北部沿岸的地壳稳定性

论述了地壳稳定性的层次，一般从高到低，从大到小可分为3个层次。高层次着重从岩石圈块体运动和大区域的大地构造因素分析岩石圈块体的活动性；中层次着重从地壳块体运动和区域构造因素分析地壳块体的稳定性；低层次着重从地壳浅层的新构造运动和地震活动对工程建设的影响程度进行分析。从这个意义来说，地壳稳定性分析从大到小可分大区域、中区域和小区域3个层次，大区域地壳稳定性评价是概略评价，而小区域地壳稳定性评价则是详细评价，在此基础上对南海及北部沿岸不同层次的地壳稳定性进行了分析。

AN ANALYSIS ON GRADATION OF CRUSTAL STABILITY IN SOUTH CHINA SEA AND ITS NORTHERN COAST

Three levels of crustal stability are discussed, i. e. high-level,medium-level and low-level. The high-level of crustal stability relates to lithospheric block movement and large-ranged tectonic factors which affect the activity of lithospheric block, the medium-level involves crustal block movement and regional geological factors which affect the stability of crustal block; and the low-level deals with neotectonic movement and seismic activities which influence engineering construction. In this significance, the evaluation on crustal stability may be divided correspondingly into three spatial levels of large, medium and small ranges. Large-range evaluation is sketchy and small-range one is detailed. The crustal stability in South China Sea and its northern coast are analyzed on this basis.