DOI: 10.1016/j.palaeo.2014.02.009
论文题名: An offset in TEX86 values between interbedded lithologies: Implications for sea-surface temperature reconstructions
作者: Littler K. ; Robinson S.A. ; Bown P.R.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2014
卷: 399 起始页码: 42
结束页码: 51
语种: 英语
英文关键词: Cretaceous
; GDGTs
; Proxy validation
; Sea-surface temperatures
; Stable-isotopes
; TEX86
英文摘要: The TEX86 (TetraEther indeX of tetraethers consisting of 86 carbon atoms) sea-surface temperature (SST) proxy is based on the distribution of isoprenoid glycerol dialkyl glycerol tetraether (GDGT) membrane lipids of pelagic Thaumarchaeota that are preserved in marine sediments. It is a valuable tool for reconstructing past SSTs from sedimentary archives; however there are still major uncertainties as to the effects of variables other than temperature on the proxy. Here we present the first study of GDGT variability across early Cretaceous interbedded pelagic and shelf-sourced turbiditic sediments from two Deep Sea Drilling Project (DSDP) sites in the western North Atlantic. The results indicate that a small, but consistent, offset in TEX86 ratios, equivalent to ~1-2°C of temperature difference, occurs between interbedded lithologies of a similar age. The offset can be attributed to spatial differences in sea-surface temperatures or thaumarchaeotal populations between the shelf and the open ocean, or to secondary diagenetic effects related to oxic degradation of the GDGTs. Of these, a difference in either thaumarchaeotal taxa or ecology between those living in the shelf and ocean areas seems most plausible. Regardless of the root cause of the offset, these findings highlight the necessity of careful sample selection prior to TEX86 analysis, to ensure robust interpretation of palaeotemperature trends. © 2014 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/69405
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, United Kingdom; Camborne School of Mines, University of Exeter, Penryn Campus, Cornwall, TR10 9FE, United Kingdom; Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN, United Kingdom
Recommended Citation:
Littler K.,Robinson S.A.,Bown P.R.. An offset in TEX86 values between interbedded lithologies: Implications for sea-surface temperature reconstructions[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2014-01-01,399