DOI: 10.1016/j.quascirev.2018.04.006
Scopus记录号: 2-s2.0-85046650774
论文题名: Modelling silicon supply during the Last Interglacial (MIS 5e) at Lake Baikal
作者: Panizzo V.N. ; Swann G.E.A. ; Mackay A.W. ; Pashley V. ; Horstwood M.S.A.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2018
卷: 190 起始页码: 114
结束页码: 122
语种: 英语
英文关键词: Diatoms
; Eemian
; Kazantsevo
; Palaeoproductivity
; Siberia
; Silicon isotopes
Scopus关键词: Catchments
; Isotopes
; Lakes
; Mixing
; Phytoplankton
; Repair
; Runoff
; Silica
; Silicon
; Weathering
; Diatoms
; Eemian
; Kazantsevo
; Palaeoproductivity
; SIBERIA
; Silicon isotopes
; Climate change
; Bacillariophyta
英文摘要: Limnological reconstructions of primary productivity have demonstrated its response over Quaternary timescales to drivers such as climate change, landscape evolution and lake ontogeny. In particular, sediments from Lake Baikal, Siberia, provide a valuable uninterrupted and continuous sequence of biogenic silica (BSi) records, which document orbital and sub-orbital frequencies of regional climate change. We here extend these records via the application of stable isotope analysis of silica in diatom opal (δ30Sidiatom) from sediments covering the Last Interglacial cycle (Marine Isotope Stage [MIS] 5e; c. 130 to 115 ka BP) as a means to test the hypothesis that it was more productive than the Holocene. δ30Sidiatom data for the Last Interglacial range between +1.29 and +1.78‰, with highest values between c. 127 to 124 ka BP (+1.57 to +1.78‰). Results show that diatom dissolved silicon (DSi) utilisation, was significantly higher (p = 0.001) during MIS 5e than the current interglacial, which reflects increased diatom productivity over this time (concomitant with high diatom biovolume accumulation rates [BVAR] and warmer pollen-inferred vegetation reconstructions). Diatom BVAR are used, in tandem with δ30Sidiatom data, to model DSi supply to Lake Baikal surface waters, which shows that highest delivery was between c. 123 to 120 ka BP (reaching peak supply at c. 120 ka BP). When constrained by sedimentary mineralogical archives of catchment weathering indices (e.g. the Hydrolysis Index), data highlight the small degree of weathering intensity and therefore representation that catchment-weathering DSi sources had, over the duration of MIS 5e. Changes to DSi supply are therefore attributed to variations in within-lake conditions (e.g. turbulent mixing) over the period, where periods of both high productivity and modelled-DSi supply (e.g. strong convective mixing) account for the decreasing trend in δ30Sidiatom compositions (after c. 124 ka BP). © 2018 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/112187
Appears in Collections: 气候减缓与适应
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作者单位: School of Geography, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom; Centre for Environmental Geochemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom; Environmental Change Research Centre, Department of Geography, University College London, Gower Street, London, WC1E 6BT, United Kingdom; NERC Isotope Geosciences Laboratory, British Geological Survey, Keyworth, Nottingham, NG12 5GG, United Kingdom
Recommended Citation:
Panizzo V.N.,Swann G.E.A.,Mackay A.W.,et al. Modelling silicon supply during the Last Interglacial (MIS 5e) at Lake Baikal[J]. Quaternary Science Reviews,2018-01-01,190