An Abrupt Climatic Event around 4.2 Cal Ka BP Documented by Fossil Pollen of Tuolekule Lake in the Eastern Xinjiang Uyghur Autonomous Region
详细信息
- 责任者：Tao Shichen (Key Laboratory of Western China’s Environmental Systems ; Ministry of Education ; Lanzhou University ; Lanzhou 730000 ; China) ; An Chengbang
- 刊名：Acta Palaeontologica Sinica
- 出版年：2013
- 卷期：52(2)
- 关键词：全新世 ; Holocene ; 孢粉组合 ; palynological assemblage ; 气候 ; climate ; 新疆 ; Xinjiang
- 页码：p.234-242
- 图表：illus., 53 refs.
- 分类号：1400
- issnNo：ISSN0001-6616
- isbnNo：CN32-1188/Q
摘要
A prolonged cold and dry event that occurred about 4 200 years ago might play a significant role in the collapse of pre-historical cultures around the World.However,evidence of this event is rare in Northwest China.Pollen data of Tuolekule Lake indicate that this event is also found in Xinjiang region.During 4.5-3.8 cal ka BP,the oscillation of pollen assemblages in Tuolekule Lake shows rapid environmental and climatic changes.Gramineae pollen dramatically decreased,while Chenopodia-ceae pollen increased remarkably,and the AC ratio also reduce.This shift in vegetation components implies that climate rapidly became extremely cold and dry during this period(4.5-3.8 cal ka BP).During this episode the steppedesert-steppe was displaced by desert vegetation.While this 4.2 ka BP event is recorded by many sites around the world,the onset and termination of this event differs from place to place,possibly from alterations in resolution and dating methods.The climatic disruptions during the 4.2 ka BP event are variable due to different geographic settings and resolution.Unfortunately,the mechanism of this event is still unclear and more paleoclimatic records are needed to address it in detail.