秭归龙会观5.1级震区及其邻区新生代以来的地壳应力场特征

为了研究三峡坝库区的地壳稳定性，根据奥陶－侏罗纪地层中构造变形的实际观测资料，计算了秭归龙会观５．１级震区及其邻区新生代以来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，该区构造应力场相对稳定和统一。

FEATURES OF CRUSTAL STRESS FIELD IN EPICENTRAL AREA AND ITS VICINITY OF THE ZIGUI LONGHUIGUAN EARTHQUAKE(Ms5.1)

On the basis of observations of tectonic deformation in strata of the Ordovician- Jurassic period,the orientations of maximum principal stress since the cenozoic Era in the epicentral area and its vicinity of Zigui Longhuiguan earthquake(Ms=5. 1) are calculated. The results show that the orientations of principal compressive stress and principal tensile stress are NEE and NNW respectively. The modern tectonic stress field is in keeping with that since cenozoic Era. Thus,it is considered that crustal stress field in the area investigated are relatively stable and uniform since Neogene.