新生代构造运动对黄土高原地貌分异与黄河形成的控制作用  

CONTROL ACTION ON THE GEOMORPHIC DIFFERENTIATION IN LOESS PLATEAU AND THE FORMATION OF YELLOW RIVER BY CENOZOIC TECTOGENESIS

作　　者：袁宝印[1] 汤国安[2] 周力平[3] 郝青振[1] 李发源[2] 陆中臣[4] 

机构地区：[1]中国科学院地质与地球物理研究所,北京100029 [2]南京师范大学地理科学学院,南京210046 [3]北京大学城市与环境学院地表过程分析与模拟教育部重点实验室,地理系,北京100871 [4]中国科学院生态环境研究中心,北京100085

出　　处：《第四纪研究》2012年第5期829-838,共10页Quaternary Sciences

基　　金：国家自然科学基金重点项目(批准号:40930531)资助

摘　　要：黄土高原面积广大,不同区域的新生代构造演化有很大差别,根据新生代构造运动特征与沉积过程的差异,将黄土高原划分为鄂尔多斯稳定地块、陇西地区和汾渭新生代裂谷3个新生代构造运动分区。新生代构造运动控制黄土高原新生代沉积与侵蚀过程,从而产生明显地貌分异,并可划为3个一级地貌分区:1)鄂尔多斯黄土地貌区。第四纪黄土覆盖在新近纪红土梁、峁及红土盆地等古地形之上,后被侵蚀,形成复杂多变的黄土地貌景观;2)陇西黄土地貌区。主体为新近纪红土地貌,上覆少许第四纪黄土,实际为红土地貌区;3)汾渭裂谷黄土地貌区。裂谷盆地的地貌主体为河流两侧的阶地和台地,其上堆积第四纪黄土,形成不同时期的黄土台塬。鄂尔多斯周边新生代裂谷的出现控制了黄河的发育。新近纪末银呼裂谷与汾渭裂谷进入快速发展期,吕梁山相应隆起;鄂尔多斯地块西北部也轻微抬升,使古黄河初步形成并流经晋陕峡谷一带,进入三门湖并东流入海。第四纪时期早期,黄河曾长期处于河湖并存期,中更新世末,黄河溯源侵蚀使湖泊消失,并呈现目前的黄河地貌景观。There is tremendous difference in structural characteristics among the different parts of the vast Loess Plateau of China. In this study,three neotectonic regions are defined according to their association with the varying stages of Cenozoic structural evolution in the Loess Plateau： Ordos stable block, Longxi region and Fen-Wei rift valley. The tectonic history and the ancient landform created by the Cenozoic depositional processes have determined the types of loess landform and the sequences of the regional stratigraphy. Geomorphologically, Loess Plateau can be divided into three major geomorphological regions. First, Ordos loess landscape. Here Quaternary loess was mantled on the ancient landform consisting of Neogene red clay Liang, Mao and basin and then eroded, creating the highly diversified and complex landforms. Second, Longxi loess landscape. Its main body consists of red clay landform of Neogene age,covered with thin Quaternary loess. The characteristics of the resent-day landforms are dominated by those of the red clay. Third,loess landscape in the Fen-Wei rift valley. Here Quaternary loess is found to cover the river terraces or lacustrine sediments, forming the so-called Loess Table Yuan. The formation of Cenozoic rift valley around the Ordos block determined the evolution of Yellow River. The rapid development of the Yinhu rift valley and Fen-Wei rift valley during the Neogene caused an abrupt uplift of the Lfiliang Mountain and a moderate uplift of the northwestern part of Ordos block. This led to the initial formation of the ancient Yellow River which flowed through Jinshaan Gorge region into ancient Sanmen Lake and finally emptied into Yellow Sea. During the Quaternary period, Yellow River co-existed with lakes for a long time. At the end of Middle Pleistocene,the erosion of Yellow River cut through Sanmen Gorge, leading to the disappearance of the ancient Sanmen Lake and the formation of modern landscape.

关 键 词：黄土高原 新构造运动分区 黄土地貌分区 黄河发育史 

分 类 号：P542[天文地球—构造地质学] P931.6[天文地球—地质学]