山西地堑系甸子梁期低起伏高海拔地貌面成因及新构造演化  

Diagnosing the formation mechanisms of the Dianziliang low-relief, high-elevation surface in Shanxi graben system and its implication of neotectonic evolution

作　　者：苏鹏[1] 何宏林[1] 石峰[1] 谭锡斌[1] 邹俊杰[1] 孙稳 Su Peng;He Honglin;Shi Feng;Tan Xibin;Zou Junjie;Sun Wen(Key Laboratory of Active Tectonics and Volcano,Institute of Geology,China Earthquake Administration,Beijing 100029)

机构地区：[1]中国地震局地质研究所活动构造与火山重点实验室,北京100029

出　　处：《第四纪研究》2018年第6期1348-1357,共10页Quaternary Sciences

基　　金：中国地震局地质研究所基本科研业务专项项目（批准号：IGCEA1416）资助

摘　　要：在山西地堑系的山地顶部广泛发育着一级低起伏高海拔地貌面，即甸子梁面。认识甸子梁面的形成模式，是能否以其作为地貌标志进行区域地貌演化和构造变形研究的关键。文章在阐述低起伏高海拔地貌面形成模式的基础上，以蔚县-广灵盆地南缘山地上发育的甸子梁面为例，探索该级低起伏高海拔地貌面的成因机制。结果表明，甸子梁面是残留的准平原，其被准平原化后分别经历了新近纪早期构造抬升、新近纪晚期断裂形成、唐县期山麓剥蚀以及第四纪断陷等4个时期。蔚县-广灵盆地南缘断裂自开始正断运动以来，该断裂总的水平断错量约902±71 m，总的垂直断错量约1567±5 m，其中在唐县期之前（〉3 Ma）的垂直断错量约276±16 m，在唐县期之后（〈3 Ma）的垂直断错量约1291±15 m。蔚县-广灵盆地南缘断裂在距今3 Ma以来的活动性稳定，不同时间尺度的垂直断错速率均约0.4~0.5 mm/a。Planation surfaces are an old-fashioned but important topic in geomorphology because they make up much of the landscape. Peneplanation of mountain ranges has been regard as the result of long-term erosion, smoothing relief and lowering elevation near sea level. Therefore, peneplain remnants preserved in mountain ranges have been used to infer posttectonic surface uplift. However, recent studies proposed that divide migration and drainage capture could produce similar low-relief upland topography, which might be falsely interpreted as recording surface uplift.The Shanxi graben system in Northern China, separating the great Northern China Great Plain to the east from the Ordos block to the west, is one of the most outstanding continental graben systems in China. On the upland of the Shanxi graben system, low-relief, high elevation patches are widely preserved, which are called the Dianziliang surface. Whether the patches of Dianziliang surface are preserved remnants of a preexisting peneplain or a product of stream piracy determines whether the Dianziliang surface can be used as a regional geomorphic marker to constrain tectonic activity or not.In this paper, we focus our research on the south mountain of the Yuxian-Guangling basin and its surrounding area in the northern part of the Shanxi graben system, where the climate is relatively dry and the Dianziliang surface is well preserved. Here, interpretation of low-relief, high elevation patches are based on Google Earth images, ALOS World 3D-5 m DEM and ALOS World 3D-30 m DEM data. We use diagnostic criteria that developed by Whipple et al. （2017）to distinguish these alternative mechanisms of low-relief upland formation.This work demonstrates that the low-relief, high elevation patches of the Dianziliang surface are remnants of a formerly continuous low-relief regional-scale peneplain. Using the Dianziliang surface as a regional geomorphic marker, we further discussed the tectonic geomorphic evolution and tectonic activity in the study area. Near the Yuxian-Gua

关 键 词：夷平面 甸子梁面 山西地堑系 地貌演化 构造活动性 

分 类 号：P546[天文地球—构造地质学] P512.31[天文地球—地质学]