邙山东侧地貌陡坎与老鸦陈断层活动性关系讨论

Relationship Between Mangshan Geomorphic Scarp and Laoyachen Fault Activity

地貌陡坎的成因有许多种,其中之一是由断层在新构造时期的活动造成。因此,地貌陡坎的存在可能指示了断层在新生代的活动性,然而在运用地貌线性方法判定新生代以来断层活动的时候还需要有其他资料的相互验证,否则可能得到相反的结论。该文以邙山东侧陡坎与老鸦陈断层为例,通过遥感影像解释、中浅层地震探测、联合钻孔对比、地貌测量等方法,得到了老鸦陈断层是一条倾向NE向的前第四纪正断层,同时将陡坎分为三段,陡坎总体走向NW—NWW向,由北而南,高差逐渐降低,出郑州东南后消失。分析两者之间的关系,认为古黄河改道或其支流侵蚀切割形成邙山东侧陡坎,与老鸦陈断层没有直接关系,陡坎的形成时间不应早于晚更新世。

There are many origins of the geomorphic scarp.One of them is the fault activity in the neotectonic time.So the geomorphic scarp could indicate the activity of the fault.However it still should make sure by the mutual verification with other data.Without doing it,the conclusion may be wrong.Based on the research on relationship between Mangshan scarp and Laoyachen fault,and according to interpretation of remote sensing images,middle-shallow layer seismic detecting and comparison of joint drillings,measurement of landforms etc.,this paper propose that the Laoyachen fault is a NE-dipping pre-Quarternary normal fault.The geomorphic scarp was divided into three parts,general strike is NW—NWW.The elevation differences gradually decrease form north to south.The relationship between them shows geomorphic scrap was formed by erosional cutting of the Yellow River and its age should not be later Pleistocene.