气候变化领域集成服务门户(CCPortal): Branched GDGTs in the Tagus River drainage basin and its outflow into the Atlantic Ocean

CCPortal

DOI	https://doi.org/10.1594/PANGAEA.881561
	Branched GDGTs in the Tagus River drainage basin and its outflow into the Atlantic Ocean
	Warden; Lisa; Kim; Jung-Hyun; Zell; Claudia; Vis; Geert-Jan; de Stigter; Henko; Bonnin; Jerome; Sinninghe Damsté; Jaap S
发布日期	2016-10-08
数据集类型	dataset
英文简介	The distributions of branched glycerol dialkyl glycerol tetraethers (brGDGTs), which are transported from the soils where they are predominantly produced to marine sediments via rivers, have been applied in reconstructing mean annual air temperature (MAT) and pH of soils. However, paleoclimate reconstructions using sedimentary brGDGTs have proven difficult in arid regions, including the Iberian Peninsula. Recently, six novel 6-methyl brGDGTs have been described using new analytical methods (in addition to the nine 5-methyl brGDGTs previously used for climate reconstructions), and so new pH and MAT calibrations have been developed that were shown to improve the accuracy of reconstructions in a set of global soil samples, especially in arid regions. Because of this we decided to apply the new method to separate the 5- and 6-methyl isomers along with the novel calibrations to a sample set from the Iberian Peninsula to determine whether it improves paleoclimate reconstructions in this area. This set includes samples that run in a transect from source to sink along the Tagus River and out to the deep ocean off the Portuguese margin spanning the last 6000 years. We found that although pH reconstructions in the soils were improved using the new calibration, MAT reconstructions were not much better even with the separation of the 5- and 6-methyl brGDGTs. This confirmed the conclusion of previous studies that the amount of aquatically produced brGDGTs is overwhelming the soil-derived ones in marine sediments and complicating MAT reconstructions in the region. Additionally, the newseparation revealed a strong and until now unseen relationship between the new degree of cyclization (DC') of the brGDGTs and MAT that could be making temperature reconstructions in this and other arid regions difficult
空间范围	Median Latitude: 39.270424 * Median Longitude: -7.275635 * South-bound Latitude: 38.220000 * West-bound Longitude: -10.166670 * North-bound Latitude: 40.800000 * East-bound Longitude: -2.160000
时间范围	2011-03-25T11:14:00 - 2012-06-24T00:00:00
语种	英语
国家	国际
学科大类	气候变化
学科子类	气候变化
文献类型	数据集
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/215294
推荐引用方式 GB/T 7714	Warden,Lisa,Kim,et al. Branched GDGTs in the Tagus River drainage basin and its outflow into the Atlantic Ocean.2016-10-08.https://doi.org/10.1594/PANGAEA.881561.