Holocene climatic and environmental changes recorded in Baahar Nuur Lake core in the Ordos Plateau, Inner Mongolia of China  

作　　者：GUO LanLan FENG ZaoDong LI XinQing LIU LianYou WANG LiXia 

机构地区：[1]MOE Key Laboratory of Environment Change and Natural Disaster, Beijing Normal University, Beijing 100875, China [2]MOE Key Laboratory of Western China's Environmental Systems, Lanzhou University, Lanzhou 730000, China [3]Department of Geology, Baylor University, Waco, Texas 76798, USA [4]Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China [5]Provincial Environmental Quality Monitoring Administration, Shenyang 110031, China

出　　处：《Chinese Science Bulletin》2007年第7期959-966,共8页

基　　金：Supported by the National Natural Science Foundation of China (Grant Nos. 40025105, 40331102, 40421101 and 40671184);US National Science Foundation (Grant No. NSF-ESH04-02509);Ministry of Science and Technology of China (Grant No. G2000048701);National Geographic Ministry of Society (Grant No. NGS-6938-00)

摘　　要：A 5.3 m lake core was drilled in Baahar Nuur Lake in the Ordos Plateau, and measurements of meangrain size, organic δ 13C (δ 13Corg), organic carbon content (TOC), C/N, carbonate content, carbonate δ 13C(δ 13Ccar) and δ 18O (δ 18Ocar) were conducted for retrieving the Holocene chronosequence of climaticchanges based on 15 AMS 14C dates. The record documented four major stages of climate change inthe Ordos Plateau: (IV) a cold and dry condition before ～7.65 14C ka BP; (III) a warm and humid stagebetween ～7.65 and ～5.40 ka BP; (II) a generally drier and cooler climate since ～5.40 ka BP with twohumid events occurring from ～4.70 to ～4.60 ka BP and from ～4.20 to ～3.70 ka BP, and (I) a dry climatecharacterized by complete desiccation of the lake after 3.70 ka BP. Stage III can be further divided intothree sub-stages: (IIIa) a warm and humid episode from ～7.65 to ～6.70 ka BP, (IIIb) a warm and relativelydry episode from ～6.70 to ～6.20 ka BP, and (IIIc) the magthermal and maghumid episode of the Holo-cene from ～6.20 to ～5.40 ka BP.A 5.3 m lake core was drilled in Baahar Nuur Lake in the Ordos Plateau, and measurements of mean grain size, organic δ^13C （δ^13Corg）, organic carbon content （TOC）, C/N, carbonate content, carbonate δ^13C （δ^13Ccar） and δ^13O （δ^13Ocar） were conducted for retrieving the Holocene chronosequence of climatic changes based on 15 AMS 14C dates. The record documented four major stages of climate change in the Ordos Plateau： （Ⅳ） a cold and dry condition before -7.65 ^14C ka BP; （Ⅲ） a warm and humid stage between -7.65 and -5.40 ka BP; （Ⅱ） a generally drier and cooler climate since -5.40 ka BP with two humid events occurring from -4.70 to -4.60 ka BP and from -4.20 to -3.70 ka BP, and （Ⅰ） a dry climate characterized by complete desiccation of the lake after 3.70 ka BP. Stage Ⅲ can be further divided into three sub-stages： （Ⅲa） a warm and humid episode from -7.65 to -6.70 ka BP, （Ⅲb） a warm and relatively dry episode from -6.70 to -6.20 ka BP, and （Ⅲc） the magthermal and maghumid episode of the Holocene from -6.20 to -5.40 ka BR

关 键 词：内蒙古 鄂尔多斯高原 巴汗淖尔 湖泊沉积 岩芯记录 全新世 气候变化 环境变化 

分 类 号：P532[天文地球—古生物学与地层学] P343.3[天文地球—地质学]