山西晚新生代古地理环境变迁与新构造运动响应  

Evolution of Late Cenozoic Geography and Environment in Shanxi Province and the Neotectonic Response

作　　者：闫小兵[1] 李自红[1,2] 郭瑾[3] 赵晋泉[1] 陈文[1] 扈桂让[1] 苏宗正[1] 

机构地区：[1]山西省地震局,山西太原030021 [2]太原理工大学,山西太原030024 [3]成都理工大学,四川成都610059

出　　处：《地震工程学报》2014年第2期338-346,352,共10页China Earthquake Engineering Journal

基　　金：地震行业科研专项(200908001);地震行业科研专项(201208009-14)

摘　　要：系统解读了山西晚新生代古地理古环境特征,结合近年来笔者的研究给出了各时代古地理分布图。上新世的构造运动和地理环境演化奠定了现今地理环境的基础,尤其是奠定了现今地貌、水系的轮廓。早更新世地理环境最突出的事件是各断陷盆地中的湖泊广泛发育,出现淹没整个盆地的大湖景观;黄土广泛发育,但主要堆积于吕梁山分水岭以西;黄河在早更新世已经发育,并形成5级阶地。中更新世古地理的主要事件是湖泊的衰退,黄土堆积范围几乎遍布全省,厚可达200m左右,表明气候较早更新世进一步明显变干。晚更新世古地理的主要特征是湖泊消亡,其地理环境更加接近现代。最后,笔者预测未来山西断陷盆地将持续断陷,各盆地内水系不再外流,形成贯通的大湖景观,类似现今的贝加尔湖。The Late Cenozoic paleogeography of Shanxi was affected by geomorphology, rivers, sedimentary environment, animals, plants, climate, loess, and ancient human activities during the Pliocene and Pleistocene epochs,from about 5.5 million to 12 thousand years ago. The evolution of the paleogeography formed the basis of the modern geography and environment, particularly the modern landscape and water systems. Understanding the ancient environment is also of great importance for effective environmental protection and for predicting future climate. Using infor- mation from our recent field investigations conducted throughout Shanxi Province, this paper sys- tematically gives explanatory notes on the paleogeographical and paleoenvironmental characteris- tics for all epochs of the late Cenozoic in Shanxi Province. During tectonic movements in the early Pliocene, the Shanxi rift zone began to subside. In the Datong, Xinding, Taiyuan, and Linfen areas a rift basin began to form,with the corresponding emergence of small lakes. In the middle and late Pliocene,these basins formed large-scale rift lake because of the intense tectonic movement. The neighboring mountains were uplifted significantly. From then on,the basic geomorphological pattern was consistent with that of the current basin. In the late Pliocene,the rift basin subsided sig- nificantly,the climate became cooler, and large lakes began to appear in the rift basin. The early Pleistocene is characterized by wide-spread lakes in rift basins. In general, the climate at this time was a temperate forest and grassland monsoon climate alternating between wet and dry. It was moister and cooler than the Pliocene period, warm and humid in the earlier part, and cool and hu- mid later. Loess deposition began,but mainly in the west of the Luliang Mountain watershed;the Yellow River developed in the early Pleistocene, during which five terraces formed. In the middle Pleistocene the lakes in the first basins began to recede,and loess deposits up to 200 m thick were deposited throu

关 键 词：晚新生代 古地理 沉积环境 新构造运动 

分 类 号：P531[天文地球—古生物学与地层学] P546[天文地球—地质学]