DOI: 10.1016/j.quascirev.2014.06.015
Scopus记录号: 2-s2.0-84903883908
论文题名: Southern-ocean and glaciogenic nutrients control diatom export production on the Chile margin
作者: Chase Z. ; McManus J. ; Mix A.C. ; Muratli J.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2014
卷: 99 起始页码: 135
结束页码: 145
语种: 英语
英文关键词: 230-Thorium
; Chile margin
; ODP Leg 202
; Opal flux
; Paleoproductivity
; Sediment focusing
Scopus关键词: Carbonation
; Ocean currents
; Silicon
; Thorium
; 230 thoriums
; Antarctic Circumpolar Currents
; Chile margin
; Mass accumulation rates
; ODP Leg 202
; Organic carbon fluxes
; Paleoproductivity
; Reducing conditions
; Glacial geology
; biogenic material
; biological production
; carbonate
; deglaciation
; diatom
; glacial erosion
; Ocean Drilling Program
; opal
; organic carbon
; paleoceanography
; paleoecology
; paleoproductivity
; reconstruction
; thorium isotope
; Chilean Margin
; Pacific Ocean
; Southern Ocean
英文摘要: Biogenic particle flux was reconstructed using 230-Thorium normalization at two sites on the southern Chile margin. ODP Site 1233 at 41°S, 838m depth, is at the southern limit of the Peru-Chile upwelling system, where the northern extent of the Antarctic Circumpolar Current impinges on the South American continental margin. ODP Site 1234, at 36°S, 1014m depth, is located within the core of the coastal upwelling system near the mouths of the Bio Bio and Itata Rivers. At 41°S, opal, lithogenic and carbonate fluxes are greatest during the Last Glacial interval (26-20ka), carbonate has a secondary peak during the mid Holocene (~8ka) and organic carbon fluxes increase slightly from 17ka to the present. At 36°S, large lithogenic fluxes are observed both during the Last Glacial interval and the Holocene, and a maximum in organic carbon flux is observed during the late Holocene (~5ka) without an accompanying peak in opal flux. These reconstructed fluxes at 36°S and 41°S fit within a larger latitudinal pattern of a poleward increase in the magnitude of opal flux during the glacial period. The pattern of normalized opal flux, opal mass accumulation rate and opal:carbonate ratios is consistent with either i) enhanced supply of Si from the Southern Ocean, as proposed by the Silicic Acid Leakage Hypothesis or ii) enhanced Si and Fe delivery from land, driven by glacial erosion. The pattern of reconstructed export production supports our view that the appearance of more reducing conditions in the sediments upon deglaciation was most likely driven by decreased ventilation, rather than increased local productivity. © 2014 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/60191
Appears in Collections: 过去全球变化的重建
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作者单位: University of Tasmania, Institute for Marine and Antarctic Studies, Private Bag 129, Hobart, TAS, 7001, Australia; College of Earth, Ocean and Atmospheric Sciences, Oregon State University, 104 CEOAS Administration Building, Corvallis, OR, 97331-5503, United States; University of Akron, Department of Geosciences, Akron, OH 44325e4101, United States
Recommended Citation:
Chase Z.,McManus J.,Mix A.C.,et al. Southern-ocean and glaciogenic nutrients control diatom export production on the Chile margin[J]. Quaternary Science Reviews,2014-01-01,99