Evidence of a humid mid- Holocene in the western part of Chinese Loess Plateau  

作　　者：ANChengbang FENGZhaodong TANGLingyu 

机构地区：[1]NationalLaboratoryofWesternChina'sEnvironmentalSystems,MinistryofEducation,LanzhouUniversity,Lanzhou730000,China [2]NanjingInstituteofGeologyandPaleontology,ChineseAcademyofSciences,Nanjing210008,China

出　　处：《Chinese Science Bulletin》2003年第22期2472-2479,共8页

基　　金：supported by the NSFC"Outstanding Young Scholar Program"(Grant No.40025105);by the National Key Basic Research Project(Grant No.G2000048701);the Knowledge Innovation Project of CAS(Grant No.KZCX1-10-01)

摘　　要：Field works show that the wetland/swamp layers were distributed ubiquitously in the western part of the Chinese Loess Plateau. Universality of the wetland/swampy layer and the consistency of the age reveal that the layer was developed under the humid climatic condition. Dated between 9 and 3.8 kaBP, the wetland/swampy layer is full of aquatic mollusks and has the highest tree and shrub pollen, indicating a humid mid-Holocene. Variations of grain size suggest that winter monsoon weakened during 9—3.8 kaBP while climate change to humid and vegetation cover increased from 9 kaBP onward. After 5.9 kaBP, the humidity declined gradually. In 3.8 kaBP, summer monsoon sharply retreated, and the climate changed to dry.Field works show that the wetland/swamp layers were distributed ubiquitously in the western part of the Chinese Loess Plateau. Universality of the wetland/swampy layer and the consistency of the age reveal that the layer was developed under the humid climatic condition. Dated between 9 and 3.8 kaBP, the wetland/swampy layer is full of aquatic mollusks and has the highest tree and shrub pollen, indicating a humid mid-Holocene. Variations of grain size suggest that winter monsoon weakened during 9—3.8 kaBP while climate change to humid and vegetation cover increased from 9 kaBP onward. After 5.9 kaBP, the humidity declined gradually. In 3.8 kaBP, summer monsoon sharply retreated, and the climate changed to dry.

关 键 词：中国 西部地区 黄土高原 湿地 全新统 

分 类 号：P534.632[天文地球—第四纪地质学]