气候变化领域集成服务门户(CCPortal): Geochemical focusing and sequestration of manganese during eutrophication of Lake Stechlin (NE Germany)

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DOI	10.1007/s10533-020-00729-9
	Geochemical focusing and sequestration of manganese during eutrophication of Lake Stechlin (NE Germany)
	Scholtysik G.; Dellwig O.; Roeser P.; Arz H.W.; Casper P.; Herzog C.; Goldhammer T.; Hupfer M.
发表日期	2020
ISSN	0168-2563
起始页码	313
结束页码	334
卷号	151 期号:2020-02-03
英文摘要	Significant sedimentation of manganese (Mn) in form of manganese oxides (MnOx) and the subsequent formation of authigenic calcium-rich rhodochrosite (Mn(Ca)CO3) were observed in the seasonally stratified hard water Lake Stechlin in north-eastern Germany. This manganese enrichment was assumed to be associated with recent eutrophication of the formerly oligotrophic lake. The mechanisms and processes involved were examined by analysing: (i) short sediment cores obtained from seven locations along a depth transect ranging from 69.5 m (the deepest point) to 38 m; (ii) sediment traps located at 20 m and 60 m water depths; (iii) water column profiles; and (iv) porewater profiles at 69.5 m and 58 m depths. Sedimentary Mn enrichment was observed at water depths below 56 m and increased to more than 25 wt% at the deepest site. Between 2010 and 2017, Mn accumulation at the deepest site was 815 g Mn m−2. Transfer of Mn from the shallower towards the deepest parts of the lake was initiated by reductive dissolution of MnOx and diffusion of dissolved Mn from the sediment to the overlying water column. Manganese was then dissipated via turbulent mixing and subsequently oxidised to MnOx before being transported towards the deepest zone. Transformation of the redeposited MnOx to Mn(Ca)CO3 favoured the final burial of Mn. We show that eutrophication and the areal spreading of anoxic conditions may intensify diagenetic processes and cause the spatial redistribution of Mn as well as its effective burial. Contrary to many previous findings, we show that increases of Mn and Mn/Fe can also be used as indicators for increasing anoxic conditions in previously oligotrophic lakes. © 2020, The Author(s).
英文关键词	Diagenesis; Eutrophication; Geochemical focusing; Lacustrine sediments; Rhodochrosite; Varves
语种	英语
来源期刊	Biogeochemistry
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/153079
作者单位	Department of Chemical Analytics and Biogeochemistry, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Müggelseedamm 301, Berlin, 12587, Germany; Department of Marine Geology, Leibniz Institute for Baltic Sea Research Warnemünde (IOW), Seestrasse 15, Rostock, 18119, Germany; Department Experimental Limnology, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Alte Fischerhütte, Stechlin, 216775, Germany
推荐引用方式 GB/T 7714	Scholtysik G.,Dellwig O.,Roeser P.,et al. Geochemical focusing and sequestration of manganese during eutrophication of Lake Stechlin (NE Germany)[J],2020,151(2020-02-03).
APA	Scholtysik G..,Dellwig O..,Roeser P..,Arz H.W..,Casper P..,...&Hupfer M..(2020).Geochemical focusing and sequestration of manganese during eutrophication of Lake Stechlin (NE Germany).Biogeochemistry,151(2020-02-03).
MLA	Scholtysik G.,et al."Geochemical focusing and sequestration of manganese during eutrophication of Lake Stechlin (NE Germany)".Biogeochemistry 151.2020-02-03(2020).