气候变化领域集成服务门户(CCPortal): A long-term; high-latitude record of Eocene hydrological change in the Greenland region

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DOI	10.1016/j.palaeo.2019.109378
	A long-term; high-latitude record of Eocene hydrological change in the Greenland region
	Inglis G.N.; Carmichael M.J.; Farnsworth A.; Lunt D.J.; Pancost R.D.
发表日期	2020
ISSN	0031-0182
卷号	537
英文摘要	A range of proxy approaches have been used to reconstruct short-term changes to Earth's hydrological cycle during the early Eocene hyperthermals. However, little is known about the response of Earth's hydrological and biogeochemical systems to long-term Cenozoic cooling, which began following the Early Eocene Climatic Optimum (53.3 – 49.4 million years ago; Ma). Here, we use the molecular distribution and isotopic composition of terrestrial biomarkers preserved in marine sediments of ODP Site 913, East Greenland, to develop a long-term record of high-latitude hydrological change between 50 and 34 Ma. There is a marked decline in the concentration of conifer-derived diterpenoids and angiosperm-derived triterpenoids during the Eocene. As the input of wind-blown conifer pollen remains stable during this interval, this implies that decreasing di- and triterpenoid concentrations reflect declining influence of fluvial inputs – and perhaps terrestrial runoff – throughout the Eocene. Branched GDGTs and bacterial-derived hopanes indicate an increased input of soil- and kerogen-derived organic matter, respectively, after 38 Ma. This coincides with evidence for ice rafted debris and suggests input of organic matter via glacial processes. This also implies some continental glaciation occurred on East Greenland in the middle-to-late Eocene. Leaf wax hydrogen isotopes extending throughout this section – the first such long-term record from the Paleogene - indicate that precipitation δ2H was persistently higher than that of modern coastal Greenland, consistent with warmer ocean source waters and enhanced poleward moisture transport. Non-intuitively, however, this effect appears to have been smallest during the warmest part of the record, and higher δ2H values occur in the middle Eocene. Although interpretation of these hydrogen isotope trends is unclear, they clearly indicate – alongside the changes in biomarker abundances – a perturbed hydrological cycle through the Eocene in coastal Greenland. More long-term records are required to ascertain if this represents regional or global hydrological reorganisation. © 2019 Elsevier B.V.
英文关键词	Alkanes; Biomarkers; Cenozoic; Palaeogene; Vegetation
语种	英语
scopus关键词	alkane; angiosperm; biomarker; Cenozoic; coastal zone; coniferous tree; cooling; Eocene; glaciation; hydrogen isotope; hydrological change; hydrological cycle; ice-rafted debris; latitude; organic matter; Paleogene; pollen; precipitation (climatology); reconstruction; seawater; vegetation type; Arctic; East Greenland; Greenland; Bacteria (microorganisms); Coniferophyta; Magnoliophyta
来源期刊	Palaeogeography, Palaeoclimatology, Palaeoecology
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/150750
作者单位	Organic Geochemistry Unit, School of Chemistry, School of Earth Science, University of Bristol, United Kingdom; Cabot Institute for the Environment, University of Bristol, United Kingdom; BRIDGE, School of Geographical Sciences, University of Bristol, United Kingdom
推荐引用方式 GB/T 7714	Inglis G.N.,Carmichael M.J.,Farnsworth A.,et al. A long-term; high-latitude record of Eocene hydrological change in the Greenland region[J],2020,537.
APA	Inglis G.N.,Carmichael M.J.,Farnsworth A.,Lunt D.J.,&Pancost R.D..(2020).A long-term; high-latitude record of Eocene hydrological change in the Greenland region.Palaeogeography, Palaeoclimatology, Palaeoecology,537.
MLA	Inglis G.N.,et al."A long-term; high-latitude record of Eocene hydrological change in the Greenland region".Palaeogeography, Palaeoclimatology, Palaeoecology 537(2020).