DOI: 10.1038/ngeo2542
论文题名: Substantial iron sequestration during green-clay authigenesis in modern deep-sea sediments
作者: Baldermann A. ; Warr L.N. ; Letofsky-Papst I. ; Mavromatis V.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2015
卷: 8, 期: 11 起始页码: 885
结束页码: 889
语种: 英语
Scopus关键词: authigenesis
; biogeochemical cycle
; clay mineral
; deep-sea sediment
; global ocean
; iron
; pelagic deposit
; pyrite
; sequestration (chemistry)
; Cote d'Ivoire
; Ghana
英文摘要: In much of the global ocean, iron is a limiting nutrient for marine productivity. The formation of pyrite has been considered the most important sink of reactive iron in modern, organic-rich sediments. However, clay mineral transformations can also lead to long-term sequestration of iron during late diagenesis and in hydrothermal settings. Here we present evidence for substantial iron sequestration during the early diagenetic formation of ferruginous clay minerals, also called green-clay authigenesis, in the deep-sea environment of the Ivory Coast-Ghana Marginal Ridge. Using high-resolution electron microscopic methods and sequential sediment extraction techniques, we demonstrate that iron uptake by green-clay authigenesis can amount to 76 ± 127μmol Fecm -2 kyr -1, which is on average six times higher than that of pyrite in suboxic subsurface sediments 5m below the sea floor or shallower. Even at depths of 15m below the sea floor or greater, rates of iron burial by green clay and pyrite are almost equal at -1/480μmol Fecm -2 kyr -1. We conclude that green-clay formation significantly reduces the pore water inventory of dissolved iron in modern and ancient pelagic sediments, which challenges the long-standing conceptual view that clay mineral diagenesis is of little importance in current biogeochemical models of the marine iron cycle. © 2015 Macmillan Publishers Limited. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/106140
Appears in Collections: 气候减缓与适应 科学计划与规划
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作者单位: Institute of Applied Geosciences, Graz University of Technology, Rechbauerstrasse 12, Graz, Austria; Department of Geography and Geology, Ernst-Moritz-Arndt-University Greifswald, F.-L.-Jahnstrasse 17a, Greifswald, Germany; Institute of Electron Microscopy and Nanoanalysis (FELMI-ZFE), Graz University of Technology, Steyrergasse 17, Graz, Austria
Recommended Citation:
Baldermann A.,Warr L.N.,Letofsky-Papst I.,et al. Substantial iron sequestration during green-clay authigenesis in modern deep-sea sediments[J]. Nature Geoscience,2015-01-01,8(11)