
第28卷第1期 2014年2月
现代地质 GEOSCIENCE
Vol. 28No. 1
Feb.2014
内蒙古狼山山前台地成因及其新构造运动意义
何泽新,张绪教,贾丽云,武法东,周轶群
鲍淑燕,,包智强,殷志刚,郭斌(1.中国地质大学(北京)地球科学与资源学院,北京100083: 2.内蒙古巴彦漳尔市地质公园管理局,内蒙古巴彦淳尔015000)
摘要:内蒙古狼山地处阴山造山带西段、河套断陷带的西北缘,晚新生代以来狼山山前断裂广泛发育、构造抬升强烈。研究晚更新世以来狼山的构造隆升对深人了解河套断陷带的形成演化机制及其隆升过程对河套盆地古地理格局的影响具有重要的意义。狼山山前翁格勒其格和乌兰敖包台地的沉积学、地貌学和年代学研究表明,T1台地形成于47.4 kaB.P.,其沉积物为晚更新世河套古大湖沉积;T2台地形成于69kaB.P.,
,其沉积物可能为黄河流经狼山山前的冲积
物。台地特征的分析显示,狼山山前台地主要由构造抬升形成,两级台地记录了狼山晚更新世晚期(Qp"-2)以来的构造隆升过程。69kaB.P.到47.4kaB.P.翁格勒其格和乌兰包地区的隆升速率分别为1.34m/ka和1.25m/ka,47.4 kaB.P.以来分别为0.81m/ka和1.18m/ka,狼山南段(翁格勒其格地区)构造抬升有减小的趋势。晚更新世晚期(Qp3-2)以来由于狼山的快速隆升,导致黄河河道不断东迁,河套平原的古河道是其迁移的证据。狼山山前湖岸阶地的研究进一步证实晚更新世晚期河套地区发育统一古大湖。
关键词:内蒙古狼山;山前台地;构造隆升;黄河迁移:河套古大湖;晚更新世(Qp")
中图分类号:P546
文献标志码:A
文章编号:10008527(2014)01009811
Genesis of Piedmont Terraces and Its Neotectonic Movement Significance
inLangshanMountainArea,InnerMongolia
HE Ze-xin', ZHANG Xu-jiao', JIA Li-yun', WU Fa-dong', ZHOU Yi-qun',
BAO Shu-yan', BAO Zhi-qiang, YIN Zhi-gang, GUO Bin?
(1. School of Earth Sciences and Resources, China Unirersity of Geosciences, Bejing 100083, China 2. Inner Mongolia Bayannur Bureau of Geopark Administration, Bayannur, Inner Mongolia015000, Chine)
Abstract: Langshan Mountain is located in the western segment of Yinshan orogenic belt and the northwester margin of the Hetao rift zone in Inner Mongolia. Piedmont faults and tectonic uplifts in this region developed widely since the Late Cenozoic. The research on the tectonic uplift process of Langshan Mountain since the Late Pleistocene has significance in having a good knowledge of the formation and evolution mechanism of Hetao rift zone and the influence of the uplift process to the paleogeographic framework of Hetao basin. The sedimentologi cal, geomorphological and geochronological study of the piedmont terraces in Wenggeleqige and Ulaan Ovoo, in-dicates that T1 terrace formed at 47. 4 kaB. P. is characterized by lacustrine deposits from Hetao megalake, and T2 terrace developed at 69 kaB. P. is characterized by fluvial deposits which may be the products of the Yellow River when it flows through the pediment of Langshan Mountain. The analysis on characteristics of terraces
收稿日期:2013-03-16;改回日期:2013-11-07;责任编辑:潘令枝。
(8060060600
套平原形成演化关系初步研究”;中国地质调查局“青藏高原与贝加尔裂谷动力学背景与古地磁响应"项目(1212011120182)。
作者简介:何泽新,男,博士研究生,1989年出生,第四纪地质学专业,主要从事地貌与新构造运动研究。
Email:zexinhe@ sina.com。
通信作者:张绪教,男,博士,副教授,1964年出生,第四纪地质学专业,主要从事地貌与第四纪地质、新构造运动的教学及
科研工作。Email:zhangxj@ cugh. edu.cn。