北京西山东麓与平原地区新构造活动  

A STUDY OF NEOTECTONIC MOVEMENT AT THE EASTERN PIEDMONT OF THE WEST-MOUNTAIN AND THE BEIJING PLAIN

作　　者：李容全[1] 谭利华[1] 

机构地区：[1]华北京师范大学地理学与遥感科学学院,北京100875

出　　处：《第四纪研究》2012年第5期949-956,共8页Quaternary Sciences

摘　　要：根据北京西山东麓的周口店、北安河两地区附近的上新世唐县期山麓侵蚀剥蚀面的变形,和中更新世周口店期洪积扇扇顶及山麓线在两地的高度差,以及晚更新世清水期永定河、大石河的侵蚀谷在毗邻山麓的山前平原埋藏深度的差别,加上永定河古河道位置的移动顺序和永定河冲积扇位置的迁移等多项标志,证明除了山地与山前平原之间存在差异性升降运动之外,山地内南部周口店地区与北部北安河地区在抬升幅度和速度上也存在差别,后者大于前者,而且自中更新世以来这种差别日益显著。山前平原永定河冲积扇形成于末次冰期的主要寒冷阶段。古河道和新老洪积扇都证明,山前平原北部存在向南翘起的趋势。从北京西山出现的这种新构造活动的差异特征,推测存在来自太行山南部向北推挤的新构造应力场。There are many evidences that have been testified the up- and down- movement between the West-Mountain and the Beijing Plain. This study will focus on the otherness up- and down- movements between northern and southern parts in the eastern Piedmont and in the Beijing Plain. Some geomorphologic and deposit evidences have proved this otherness movement between Bei＇ anhe area （north part of the piedmont）and Zhoukoudian area（south part of the piedmont）. 1. The altitude of the Tangxian Piedmont in north part is 154m higher than that in south part. The top altitude of the pluvial fan at Zhoukoudian Stage（from 0. 70MaB. P. to 0.23MaB. P. ）in north part is 130m higher than that in south part. This indicates that the uplift rates in north part（42.31mm/ka）is higher than that in south part （29.47mm/ka） from 2. 6MaB. P. to 0.7MaB. P. 2. The uplift rate in north part （562. 22mm/ka）is higher than that in south part （86.96mm/ka）since 0.23MaB. P. and the uplift of the western Mountain was speeding. The otherness neotectonic movement between the north part and south part in the Beijing Plain is also obvious. The embedding depths inside and outside the Mountain of the Dashi River are 12m and 25 - 30m,while that of the Yongding River are 42. 9m and 89.0m. Relative up- and down- rates are 166. 67 - 230. 77mm/ka and 589.74mm/ka. Paleochannels of the Yongding River can be divided into four stages since 30 - 35kaB. P. According to geomorphologic and deposit evidences and aging data,the Yongding River migrated from NE to SE. All these evidences estimate the upward uplift to north of the eastern Piedmont of the western Mountain, and that to south of the Beijing Plain. The uplift rates and the otherness rates increased since the Early Pleistocene.

关 键 词：北京西山东麓 山前平原 新构造差异活动 

分 类 号：P56[天文地球—构造地质学] P931.6[天文地球—地质学]