北京煤岭弧形断裂现今应力状态

本文从地应力测量、岩石组构分析和模拟实验砰究等资料,确定北京煤岭弧形断裂附近地区的局部地应力场为旋扭应力场,自燕山运动晚期以来直至现今长期活动,外旋均作顺时针方向的旋扭运动。它与新华夏系现今区域地应力场的特征不同,前者最大主压应力迹线呈弧形弯曲,往东南收敛,向西北撒开;后者最大主压应力迹线作近北西西方向延伸。     

PRESENT STRESS STATE NEAR MEILING ARCUATE FAULTS

In this paper an analysis of the present stress field near the Meiling arcuate faults in Beijing area is made. Based on the in situ stress measurements, petrofabric analysis and model experiments, it has been found that this local stress field is a rotational shear stress field. It has been active from the late Yenshanian up to the present with the outer side rotating clockwise. The features of the local stress field are different from those of the present regional stress field characteristic of the Neocathaysian system. The trajectories of the maximum principal compressive stresses of the former show an arcuate pattern converging towards SE and diverging towards NW. However, those of the latter extend approximately in the NWW direction.