气候变化领域集成服务门户(CCPortal): Climatic variation in the Linxia basin, NE Tibetan Plateau, from 13.1 to 4.3 Ma: The stable isotope record

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DOI	10.1016/j.palaeo.2006.11.001
	Climatic variation in the Linxia basin, NE Tibetan Plateau, from 13.1 to 4.3 Ma: The stable isotope record
	Fan, Majie; Dettman, David L.; Song, Chunhui; Fang, Xiaomin; Garzione, Carmala N.
发表日期	2007
ISSN	0031-0182
EISSN	1872-616X
起始页码	313
结束页码	328
卷号	247 期号:3-4
英文摘要	The delta C-13 and delta O-18 values of carbonates and delta C-13(org) values, % C, and C/N ratios of organic matter from lacustrine and fluvial sediments were measured from two stratigraphic sections in the Linxia basin on the northeastern margin of the Tibetan Plateau. Diagenesis, when present, is early, limited to small spatial scales and restricted stratigraphic intervals. A strong correlation exists between dolomite content and the delta O-18 values of micritic carbonate suggesting that carbonates are primary precipitates from lake water and that delta O-18 values reflect changes in the lake environment, with more positive values derived from evaporated and more saline lake water. The first part of this record is characterized by strong oscillations between dry and wet conditions accompanied by changes in the lake system between hydrographically closed and open states (13.1-8.0 Ma). The most severe aridity occurred from 9.6 to 8.5 Ma. After similar to 8.0 Ma, a more stable and less and climate dominated the region and the drainage system was open (8.0-5.3 Ma). After 5.3 Ma, climate became gradually drier and/or cooler (5.3-4.3 Ma). The organic matter preserved in the Linxia basin is most likely a mixture of terrestrial C-3 plant matter and lake algae. A correlation between C/N and delta C-13(org), indicates that a significant percentage of the organic matter is derived from terrestrial sources. The organic matter has undergone selective degradation during which the C/N ratios and organic carbon percentage decreased. The delta C-13(org) values are relatively stable throughout the 13.1 to 4.3 Ma interval ranging from -24 to -29%o VPDB, suggesting that C-4 grasses were either absent or insignificant in the Linxia region prior to 4.3 Ma. (C) 2006 Elsevier B.V. All rights reserved.
关键词	CHINESE LOESS PLATEAU ORGANIC-MATTER ASIAN MONSOON C/N RATIOS SOURCE INDICATORS CARBON-ISOTOPE LATE MIOCENE EVOLUTION NITROGEN DOLOMITE
英文关键词	Linxia basin; oxygen isotope; organic matter; diagenesis; Tibetan Plateau
语种	英语
WOS研究方向	Physical Geography ; Geology ; Paleontology
WOS类目	Geography, Physical ; Geosciences, Multidisciplinary ; Paleontology
WOS记录号	WOS:000246167300008
来源期刊	PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/257512
推荐引用方式 GB/T 7714	Fan, Majie,Dettman, David L.,Song, Chunhui,et al. Climatic variation in the Linxia basin, NE Tibetan Plateau, from 13.1 to 4.3 Ma: The stable isotope record[J]. 中国科学院青藏高原研究所,2007,247(3-4).
APA	Fan, Majie,Dettman, David L.,Song, Chunhui,Fang, Xiaomin,&Garzione, Carmala N..(2007).Climatic variation in the Linxia basin, NE Tibetan Plateau, from 13.1 to 4.3 Ma: The stable isotope record.PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY,247(3-4).
MLA	Fan, Majie,et al."Climatic variation in the Linxia basin, NE Tibetan Plateau, from 13.1 to 4.3 Ma: The stable isotope record".PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY 247.3-4(2007).