Variation in 6-methyl branched glycerol dialkyl glycerol tetraethers in Lantian loess-paleosol sequence and effect on paleotemperature reconstruction

doi:10.1016/j.orggeochem.2016.07.006

	Variation in 6-methyl branched glycerol dialkyl glycerol tetraethers in Lantian loess-paleosol sequence and effect on paleotemperature reconstruction
	Lu, Hongxuan 2; Liu, Weiguo 1,2; Wang, Huanye 2; Wang, Zheng 2
刊名	ORGANIC GEOCHEMISTRY
	2016-10-01
卷号	100 期号:2016 页码:10-17
关键词	Gdgts Loess Lantian Paleotemperature Reconstruction
DOI	10.1016/j.orggeochem.2016.07.006
文献子类	Article
英文摘要	The distribution of branched glycerol dialkyl glycerol tetraethers (brGDGTs) has been increasingly used as a proxy in paleoclimate studies of marine, lacustrine and loess environments. A paleothermometer was subsequently quantified using a combination of the methylation and cyclization index of branched tetraethers (MBT-CBT) on the basis that MBT was related to mean annual air temperature and to a lesser extent soil pH, whereas CBT correlated only with soil pH. As newly described 6-methyl brGDGTs seemed to introduce a dependence on soil pH of this temperature proxy, we investigated the effect of the 6-methyl brGDGTs on an existing paleotemperature reconstruction. We describe the evolution in temperature and pH recorded in the Lantian loess-paleosol sequence for the last 120 kyr, using a new analytical method. The results show that 6-methyl brGDGTs were abundant, comprising on average 26% of the total amount of brGDGTs in the sequence. The fractional abundance of 6-methyl brGDGTs generally tracked the change in soil pH at the same soil section. A considerable delay (up to ca. 7 kyr) in the variation in fractional abundance of 6-methyl brGDGTs vs. that of 5-methyl brGDGTs was observed, possibly resulting from the different environmental factors to which they respond. We also found that variation in the reconstructed MAT values using different calibrations could be up to 7 degrees C, possibly due to soil moisture variation, since soil moisture may have a significant impact on the distribution of brGDGTs. Our results further indicate that early warming occurred on the southern Chinese Loess Plateau relative to a monsoonal precipitation increase, as reported elsewhere. (C) 2016 Elsevier Ltd. All rights reserved.
WOS关键词	CHINESE LOESS ; MEMBRANE-LIPIDS ; MONSOON PRECIPITATION ; TEMPERATURE PROXY ; LAKE-SEDIMENTS ; AFRICAN LAKE ; EAST-ASIA ; SOILS ; PLATEAU ; DISTRIBUTIONS
WOS研究方向	Geochemistry & Geophysics
语种	英语
WOS记录号	WOS:000381909900002
内容类型	期刊论文
源URL	[http://ir.ieecas.cn/handle/361006/5696]
专题	地球环境研究所_加速器质谱中心
作者单位	1.Xi An Jiao Tong Univ, Sch Human Settlement & Civil Engn, Xian 710049, Peoples R China 2.Chinese Acad Sci, Inst Earth Environm, State Key Lab Loess & Quaternary Geol, Xian 710075, Peoples R China
推荐引用方式 GB/T 7714	Lu, Hongxuan,Liu, Weiguo,Wang, Huanye,et al. Variation in 6-methyl branched glycerol dialkyl glycerol tetraethers in Lantian loess-paleosol sequence and effect on paleotemperature reconstruction[J]. ORGANIC GEOCHEMISTRY,2016,100(2016):10-17.
APA	Lu, Hongxuan,Liu, Weiguo,Wang, Huanye,&Wang, Zheng.(2016).Variation in 6-methyl branched glycerol dialkyl glycerol tetraethers in Lantian loess-paleosol sequence and effect on paleotemperature reconstruction.ORGANIC GEOCHEMISTRY,100(2016),10-17.
MLA	Lu, Hongxuan,et al."Variation in 6-methyl branched glycerol dialkyl glycerol tetraethers in Lantian loess-paleosol sequence and effect on paleotemperature reconstruction".ORGANIC GEOCHEMISTRY 100.2016(2016):10-17.