气候变化领域集成服务门户(CCPortal): Organic matter based proxies from surface sediments along three transects on the Pakistan continental margin

CCPortal

DOI	https://doi.org/10.1594/PANGAEA.804009
	Organic matter based proxies from surface sediments along three transects on the Pakistan continental margin
	Bogus; Kara; Zonneveld; Karin A F; Fischer; David; Kasten; Sabine; Bohrmann; Gerhard; Versteegh; Gerard J M
发布日期	2012-12-13
数据集类型	dataset
英文简介	A valid assessment of selective aerobic degradation on organic matter (OM) and its impact on OM-based proxies is vital to produce accurate environmental reconstructions. However, most studies investigating these effects suffer from inherent environmental heterogeneities. In this study, we used surface samples collected along two meter-scale transects and one longer transect in the northeastern Arabian Sea to constrain initial OM heterogeneity, in order to evaluate selective aerobic degradation on temperature, productivity and alteration indices at the sediment-water interface. All of the studied alteration indices, the higher plant alkane index, alcohol preservation index, and diol oxidation index, demonstrated that they are sensitive indicators for changes in the oxygen regime. Several export production indices, a cholesterol-based stanol/stenol index and dinoflagellate lipid- and cyst-based ratios, showed significant (more than 20%) change only over the lateral oxygen gradients. Therefore, these compounds do not exclusively reflect surface water productivity, but are significantly altered after deposition. Two of the proxies, glycerol dibiphytanyl glycerol tetraether-based TEX86 sea surface temperature indices and indices based on phytol, phytane and pristane, did not show any trends related to oxygen. Nevertheless, unrealistic sea surface temperatures were obtained after application of the TEX86, TEX86L, and TEX86H proxies. The phytol-based ratios were likely affected by the sedimentary production of pristane. Our results demonstrate the selective impact of aerobic organic matter degradation on the lipid and palynomorph composition of surface sediments along a short lateral oxygen gradient and suggest that some of the investigated proxies may be useful tracers of changing redox conditions at the sediment-water interface.
空间范围	Median Latitude: 24.494287 * Median Longitude: 62.874816 * South-bound Latitude: 24.191783 * West-bound Longitude: 62.738450 * North-bound Latitude: 24.884533 * East-bound Longitude: 63.027350
时间范围	2007-11-05T05:38:00 - 2007-11-14T14:45:00
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/215548
推荐引用方式 GB/T 7714	Bogus,Kara,Zonneveld,et al. Organic matter based proxies from surface sediments along three transects on the Pakistan continental margin.2012-12-13.https://doi.org/10.1594/PANGAEA.804009.