长江三峡地区新生代以来地壳应力场的基本特征

GENERAL FEATUREA OF THE CRUSTAL STRESS FIELD SINCE CENOZOIC IN THE AREA OF YANGTZE GORGES

根据白垩－第三纪红层中构造变形的实际观测及水系统计资料，计算了三峡地区新生代和新构造期分区（幅）及区域应力场的主应力方向。结果表明：主压应力为北东东向、主张应力为北北西向，现代构造应力场与新生代以来应力场基本一致。晚第三纪以来，该区地壳应力场趋于相对稳定和统一。

Based on the data of practical observation of tectonic deformation in the redbeds of Cretaceous-Terhary period and the drainage system statistics, the orientahons of maximum principal stress of zoned and regional stress field during the Cenozoic era and neotectonic movement in the area of Yangtze Goreds are calculated. The result shows that the orientation of compressive principal stress is NEE and that of tensile principal stress is NNW. The modern tectonic stress field is in keeping with that since Cenozoic era. Thus it is considered that the crustal stress field in the area investigated has always been relatively stable and uniform since Neogrne.