气候变化领域集成服务门户(CCPortal): Interplay between redox conditions and hydrological changes in sediments from Lake Nam Co (Tibetan Plateau) during the past 4000 cal BP inferred from geochemical and micropaleontological analyses

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DOI	10.1016/j.palaeo.2013.09.027
	Interplay between redox conditions and hydrological changes in sediments from Lake Nam Co (Tibetan Plateau) during the past 4000 cal BP inferred from geochemical and micropaleontological analyses
	Kasper, Thomas; Frenzel, Peter; Haberzettl, Torsten; Schwarz, Anja; Daut, Gerhard; Meschner, Stephanie; Wang, Junbo; Zhu, Liping; Maeusbacher, Roland
通讯作者	Kasper, T (通讯作者)
发表日期	2013
ISSN	0031-0182
EISSN	1872-616X
起始页码	261
结束页码	271
卷号	392
英文摘要	This study focuses on the analysis of lake sediments retrieved from the deepest part of Lake Nam Co (Tibetan Plateau). One gravity core of 115 cm length, covering the last similar to 4000 cal BP, was analyzed for geochemical and biological parameters. High organic content at similar to 4000 cal BP and the coinciding presence of pyrite framboids until similar to 2000 cal BP point to hampered decomposition of organic material due to anoxic conditions within the lake sediments. At the same time sedimentological and biological proxies suggest a rather high lake level, but still similar to 5 m below the recent one, with less saline lake water due to enhanced monsoonal activity. During this time a change in the source of organic matter to lowered input of terrestrial components is observed. A rather quick shift to a dry environment with less monsoonal influence and a lake level similar to 15 m lower than today at similar to 2000 cal BP lead to the oxygenation of sediment the degradation of organic matter and the absence of pyrite. Oscillations of the lake level thereafter were of minor amplitude and not able to establish anoxia at the lake bottom again. A wet spell between similar to 1500 cal BP and similar to 1150 cal BP is visible in proxies referring to catchment hydrology and the ostracod-based water depth transfer function gives only a slightly elevated lake level. The last similar to 300 years are characterized by low TOC and rising TN values reflecting enhanced nutrient supply and hence an advancing influence of human activity in the catchment. Decreasing TOC/TN values point to a complete shift to almost solely aquatic biomass production. These results show that hydrological variations in terms of lake level change based on monsoonal strength can be linked to redox conditions at the lake bottom of Nam Co. Comparison with other archives over larger parts of the Tibetan Plateau and beyond exhibits a rather homogeneous climatic pattern throughout the late Holocene. (C) 2013 Elsevier B.V. All rights reserved.
关键词	BASIN WESTERN TIBET ORGANIC-MATTER ENVIRONMENTAL-CHANGES LACUSTRINE SEDIMENTS FLUCTUATIONS SUMMER PYRITE WATER VARIABILITY INDICATORS
英文关键词	Tibetan Plateau; Monsoon; Redox; Framboidal pyrite; Ostracoda; Diatoms (Bacillariophyta)
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:000330488400018
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/258155
推荐引用方式 GB/T 7714	Kasper, Thomas,Frenzel, Peter,Haberzettl, Torsten,et al. Interplay between redox conditions and hydrological changes in sediments from Lake Nam Co (Tibetan Plateau) during the past 4000 cal BP inferred from geochemical and micropaleontological analyses[J]. 中国科学院青藏高原研究所,2013,392.
APA	Kasper, Thomas.,Frenzel, Peter.,Haberzettl, Torsten.,Schwarz, Anja.,Daut, Gerhard.,...&Maeusbacher, Roland.(2013).Interplay between redox conditions and hydrological changes in sediments from Lake Nam Co (Tibetan Plateau) during the past 4000 cal BP inferred from geochemical and micropaleontological analyses.PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY,392.
MLA	Kasper, Thomas,et al."Interplay between redox conditions and hydrological changes in sediments from Lake Nam Co (Tibetan Plateau) during the past 4000 cal BP inferred from geochemical and micropaleontological analyses".PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY 392(2013).