南阳盆地北缘更新世以来的构造演化特征

南阳盆地是白垩纪晚期以来持续发育的断陷盆地，通过对南阳盆地钻孔及河流阶地的研究，并结合ESR测年方法，对南阳盆地北缘更新世以来的构造演化特征进行了分析。结果表明：研究区冲洪积层主要由全新统、上更新统、中更新统组成，分别构成了湍河的Ⅰ级、Ⅱ级、Ⅲ级阶地；中更新统以来，研究区垂直升降运动较为明显，湍河下蚀作用十分强烈，多级阶地的结构体现了更新世中晚期以来的总体持续下蚀过程，且时间和空间上表现出不均衡性，其下蚀速率由慢至快又逐渐减缓。

Tectonic Evolution Characteristics Since the Pleistocene in the Northern Margin of Nanyang Basin

Nanyang Basin is a fault basin that has been continuously developed since the late Cretaceous.Through the study of boreholes and river terraces in Nanyang Basin,combined with the ESR dating method,the tectonic evolution of the northern margin of Nanyang Basin since the Pleistocene has been analyzed.The results show that the alluvial deposits in the study area are mainly composed of Holocene,Upper Pleistocene and Middle Pleistocene,which constitute the Grade I,II and III terraces of Tuanhe River;since Middle Pleistocene,the vertical movement of the study area is more obvious,and the depression of the Tuanhe River is very strong,the structure of the multi level terrace reflects the overall continuous erosion process since Middle and Late Pleistocene,and it shows unevenness in time and space,tts undercut rate slows down from slow to fast and then to slow again.