宁夏沙坡头地区黄河弯曲的成因

在宁夏沙坡头地区,黄河出黑山峡进入中卫盆地处形成一个异常的“Ω”型的弯曲。这不是一般的蛇曲,而是一个穿过两组不同方向与不同性质的活动走滑断裂的河流位错现象。它的出现与此处近东西向的中卫－同心断裂系的左旋走滑和北北西向的常乐－兴仁断裂系的右旋走滑活动的双重作用有关

FORMATION AND ITS SIGNIFICANCE OF HUANGHE RIVER CURVED REACH IN SHAPOTOU AREA,NINGXIA

In the Shapotou,Ningxia,there is a abnomal curved reach,similar to "Ω" of Huanghe River just at the site where runs into the Zhongwei basin from the Heishan gorge.It is found that it is not a general snaking river but a river dislocation with two groups of listric faults of different directions and active behaviours across it.It is associated with the movement of both left-lateral strike-slip faults-nearly E～W striking Zhongwei-Tongxin fault system and right-lateral strkingslip faults-NNW striking Changle-Xingren fault system