A 20 Ma pollen record of East-Asian summer monsoon evolution from Guyuan, Ningxia, China

doi:10.1016/j.palaeo.2008.04.016

	A 20 Ma pollen record of East-Asian summer monsoon evolution from Guyuan, Ningxia, China
	Jiang, Hanchao; Ding, Zhongli
刊名	PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
	2008-07-31
卷号	265 期号:1-2 页码:30-38
关键词	pollen East-Asian monsoon neogene fluviolacustrine sediments Sikouzi Ningxia
ISSN号	0031-0182
DOI	10.1016/j.palaeo.2008.04.016
文献子类	Article
英文摘要	Pollen analysis was conducted on the fluviolacustrine sediments from the east side of the Liupan Mountains, a relatively monsoon-sensitive region, and provided for the first time a continuous evolutionary history of vegetation and climate in East China during the Neogene. The pollen record spanning the last 20 Ma indicates that the vegetation and thus East-Asian summer monsoon evolution can be divided into three stages: 20.13-14.25 Ma 14.25-135 Ma and 11.35-0.008 Ma, in spite of general dominance of steppe throughout the Neogene. During the period 20.13-14.25 Ma, the pollen assemblage was characterized by high abundance of Artemisia and small amounts of temperate to subtropical deciduous broad-leafed trees such as Juglans, Carya, Quercus and Betula, suggesting that the East-Asian summer monsoon was generally strong. The interval from 14.25 to 11.35 Ma was marked by a significant decline in the East-Asian summer monsoon, as indicated by Artemisia gradually replaced by Humulus and halophytic Chenopodiaceae, Nitraria and Ephedra also reached high values in this period. Since 11.35 Ma ago, percentages of halophytes dominated by Chenopodiaceae and Tamaricacease maintained a high mean value of about 40%, revealing a week intensity of East-Asian summer monsoon. The general weakening of the monsoon circulation during the Neogene and the significant monsoon decline during the late Middle Miocene in particular might link with the global cooling trend probably through two mechanisms. Cooling and ice-sheet expansion over the polar region caused an increase in meridional temperature gradients leading to the southward retreat of the monsoon circulation. The global cooling may have also reduced the amount of water vapor held in the atmosphere, and led to both additional cooling and further weakening of the East-Asian summer monsoon. The cause for a short-lived resumption during the period 1.0-0.8 Ma is under investigation. (C) 2008 Elsevier B.V. All rights reserved.
WOS关键词	BASIN WESTERN TIBET ; CENOZOIC HISTORY ; NORTH-ATLANTIC ; LOESS PLATEAU ; LATE MIOCENE ; MYR AGO ; CLIMATE ; UPLIFT ; VEGETATION ; DEPOSITS
WOS研究方向	Physical Geography ; Geology ; Paleontology
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000258992100003
资助机构	National Natural Science Foundation of China(40502017 ; National Natural Science Foundation of China(40502017 ; 40730208) ; 40730208) ; National Natural Science Foundation of China(40502017 ; National Natural Science Foundation of China(40502017 ; 40730208) ; 40730208) ; National Natural Science Foundation of China(40502017 ; National Natural Science Foundation of China(40502017 ; 40730208) ; 40730208) ; National Natural Science Foundation of China(40502017 ; National Natural Science Foundation of China(40502017 ; 40730208) ; 40730208)
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/70123]
专题	中国科学院地质与地球物理研究所
通讯作者	Jiang, Hanchao
作者单位	Chinese Acad Sci, Inst Geol & Geophys, Key Lab Cenozo Geol & Environm, Beijing 100029, Peoples R China
推荐引用方式 GB/T 7714	Jiang, Hanchao,Ding, Zhongli. A 20 Ma pollen record of East-Asian summer monsoon evolution from Guyuan, Ningxia, China[J]. PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY,2008,265(1-2):30-38.
APA	Jiang, Hanchao,&Ding, Zhongli.(2008).A 20 Ma pollen record of East-Asian summer monsoon evolution from Guyuan, Ningxia, China.PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY,265(1-2),30-38.
MLA	Jiang, Hanchao,et al."A 20 Ma pollen record of East-Asian summer monsoon evolution from Guyuan, Ningxia, China".PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY 265.1-2(2008):30-38.