地震工程学报Issue(2)：338-346,352,10.DOI:10.3969/j.issn.1000-0844.2014.02.0338
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
摘要
Abstract
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 pat-tern 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 throughout the province,indicating a fairly arid climate.During this time,large-scale ba-salt flooding and eruptions occurred in the Datong Basin,caused by Himalayan orogenic move-ments.In the middle Pleistocene the climate was temperate humid and semi-arid forest steppe, warm and humid in the early part of this interval,cold and drought-prone later,and in general col-der and drier than the early Pleistocene.Middle Pleistocene hominid cultural sites have been found at the He River in Ruicheng,containing mainly stone and also burned bones.In the Middle Pleis-tocene,loess was deposited almost throughout the province which formed the thickest deposits are still preserved today.The most prominent event in the late Pleistocene was the demise of the lakes,and the geography became much closer to its current form.During this time,the mountains were being uplifted and undergoing erosion and sedimentation occurred in the rift basin,with ac-cumulation of thick lacustrine,fluvial-lacustrine and fluvial-alluvial deposits,which formed the present-day plain and became the main sites of ancient and modern human activity.During this in-terval,the humid,semi-arid forest steppe climate gradually became a steppe climate.Finally,we predict that the Shanxi basin will continuously subside,and,ultimately,the rivers in the basin will not drain,forming a great-lake landscape,similar to modern Lake Baikal.关键词
晚新生代/古地理/沉积环境/新构造运动Key words
Late Cenozoic/paleogeographic/sedimentary environment/Neotectonics分类
天文与地球科学引用本文复制引用
闫小兵,李自红,郭瑾,赵晋泉,陈文,扈桂让,苏宗正..山西晚新生代古地理环境变迁与新构造运动响应[J].地震工程学报,2014,(2):338-346,352,10.基金项目
地震行业科研专项（200908001）；地震行业科研专项 （）
