Redox-dependent changes in manganese speciation in Baltic Sea sediments from the Holocene Thermal Maximum: An EXAFS, XANES and LA-ICP-MS study

Lenz, Conny; Behrends, Thilo; Jilbert, Tom; Silveira, M.E. da; Slomp, Caroline P.

doi:10.1016/j.chemgeo.2014.01.013

Cited by 41 publications

(40 citation statements)

References 53 publications

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“…Since MgCl 2 and NaOAc extractants were similar to reagents used in the first two Tessier sequential extraction procedure fractions (Tessier et al 1979), the Mn in the Fe(II) and Fe carb (Mn-Fe(II) and Mn-Fe carb ) fractions could be defined as the exchangeable Mn and Mn carbonates, respectively. The Mn carbonates accounted for around 70 % of active Mn, which was in line with sediments from the Baltic Sea studied with an EXAFS, XANES, and LA-ICP-MS (Lenz et al 2014). Most of the active Mn was extracted in the first three extraction steps, indicating that Mn was quite active in both FS and CS.…”

Section: Characteristics Of Fe and Mn Minerals In The Sedimentsmentioning

confidence: 59%

Arsenic Adsorption and its Fractions on Aquifer Sediment: Effect of pH, Arsenic Species, and Iron/Manganese Minerals

Guo

Lei

et al. 2015

Water Air Soil Pollut

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Effects of pH, As species, and Fe/Mn minerals on the fractions of adsorbed As in aquifer sediments were evaluated. Kinetic data showed that As adsorption was controlled by diffusion through the external film. Isothermal data of both As(III) and As(V) fitted the Langmuir isotherm well, revealing a monolayer adsorption process. Sequential extraction demonstrated that water-soluble As and non-specifically sorbed As were the major fractions of adsorbed As. Assessing the relationship between the Freundlich K F and the increases in the amounts of As fractions showed that the pH played a key role in weakly adsorbed As, especially water-soluble As. Although inorganic As species converted each other during the adsorption processes, more non-specifically sorbed As was adsorbed in As(V)-treated sediment than in As(III)-treated sediment, showing that the electrostatic selectivity controlled the non-specific adsorption.Additionally, specifically sorbed As and As associated with the amorphous phases were predominated by Fe/ Mn minerals, especially Fe(III) (hydr)oxides. These results suggested that pH, As species, and Fe/Mn minerals would regulate the As fractions in aquifer sediments, and therefore control As cycling in aquifer systems.

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Section: Characteristics Of Fe and Mn Minerals In The Sedimentsmentioning

confidence: 59%

Arsenic Adsorption and its Fractions on Aquifer Sediment: Effect of pH, Arsenic Species, and Iron/Manganese Minerals

Guo

Lei

et al. 2015

Water Air Soil Pollut

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“…The current Littorina Sea was established around 7 kyr BP (Sohlenius et al, 2001). Sediment records of molybdenum (Mo), which is a proxy for the presence of HS − near the sediment-water interface (Erickson and Helz, 2000), and C org have been used to identify hypoxic intervals that occurred during the Holocene Thermal Maximum and the Medieval Climate Anomaly in the Gotland Basin and Fårö Deep (Jilbert and Slomp, 2013b;Lenz et al, 2014;Zillén et al, 2008). Jilbert and Slomp (2013b) further indicate that multiple hypoxic events can be distinguished during the Holocene Thermal Maximum (HTM HI ) whereas the hypoxic interval during the Medieval Climate Anomaly appears to consist of two main events (i.e.…”

Section: Study Area and Sitementioning

confidence: 99%

Vivianite is a key sink for phosphorus in sediments of the Landsort Deep, an intermittently anoxic deep basin in the Baltic Sea

2016

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a b s t r a c t Phosphorus (P) is an essential nutrient for marine organisms. Its burial in hypoxic and anoxic marine basins is still incompletely understood. Recent studies suggest that P can be sequestered in sediments of such basins as reduced iron (Fe)-P but the exact phase and the underlying mechanisms that lead to its formation are unknown. In this study, we investigated sediments from the deepest basin in the Baltic Sea, the Landsort Deep (site M0063), that were retrieved during the Integrated Ocean Drilling Project (IODP) Baltic Sea Paleoenvironment Expedition 347. The record comprises the whole brackish/marine Littorina Sea stage including past intervals of extensive hypoxia in the Baltic Sea that occurred during the Holocene Thermal Maximum (HTM HI ) and the Medieval Climate Anomaly (MCA1 HI and MCA2 HI ). Various redox proxies (e.g. the presence of laminations and high Mo contents) suggest almost permanent bottom water hypoxia during the Littorina Sea stage in the Landsort Deep. The bottom waters were likely even seasonally anoxic or sulfidic during the MCA1 HI and MCA2 HI , and permanently sulfidic during the HTM HI . With the use of micro-analysis of sieved minerals (SEM-EDS, XRD and synchrotron-based XAS), we show that Mn-and Mgrich vivianite crystals are present at various depths in the Littorina Sea sediments. We also have indications for vivianite in the MCA1 HI , MCA2 HI and HTM HI deposits. The formation of vivianite thus likely explains the high Febound P fraction throughout the whole Littorina Sea stage. Shuttling of Fe and Mn from the shelves into the basin and high inputs of P in settling organic matter are likely key drivers for vivianite formation. Our study shows that vivianite can likely form in near-surface sediments under a broad range of bottom water redox conditions, varying from hypoxic and anoxic to sulfidic.

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“…, utilising the trace-elemental composition of foraminiferal shells (tests) to reconstruct oxygen conditions is still in its infancy. One redox-sensitive element that has recently gained more interest is manganese (Mn), both as a trace element in biogenic foraminiferal calcite (Mn / Ca) and in bulk sediment samples (Reichart et al, 2003;Glock et al, 2012, Groeneveld andFilipsson, 2013;Lenz et al, 2014;Koho et al, 2015). Here we aim to explore the potential of Mn / Ca by analysing both benthic foraminiferal tests and comparing them to Mn / Al of bulk sediment samples from an upwelling record to determine if changes in oxygen conditions during different primary productivity regimes are detectable by these methods.…”

Section: L Mckay Et Al: a Comparison Of Benthic Foraminiferal Mnmentioning

confidence: 99%

A comparison of benthic foraminiferal Mn / Ca and sedimentary Mn / Al as proxies of relative bottom-water oxygenation in the low-latitude NE Atlantic upwelling system

et al. 2015

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Abstract. Trace element incorporation into foraminiferal shells (tests) is governed by physical and chemical conditions of the surrounding marine environment, and therefore foraminiferal geochemistry provides a means of palaeooceanographic reconstructions. With the availability of high-spatial-resolution instrumentation with high precision, foraminiferal geochemistry has become a major research topic over recent years. However, reconstructions of past bottom-water oxygenation using foraminiferal tests remain in their infancy. In this study we explore the potential of using Mn / Ca determined by secondary ion mass spectrometry (SIMS) as well as by flow-through inductively coupled plasma optical emission spectroscopy (FT-ICP-OES) in the benthic foraminiferal species Eubuliminella exilis as a proxy for recording changes in bottom-water oxygen conditions in the low-latitude NE Atlantic upwelling system. Furthermore, we compare the SIMS and FT-ICP-OES results with published Mn sediment bulk measurements from the same sediment core. This is the first time that benthic foraminiferal Mn / Ca is directly compared with Mn bulk measurements, which largely agree on the former oxygen conditions. Samples were selected to include different productivity regimes related to Marine Isotope Stage 3 (35-28 ka), the Last Glacial Maximum (28-19 ka), Heinrich Event 1 (18-15.5 ka), Bølling Allerød (15.5-13.5 ka) and the Younger Dryas (13.5-11.5 ka). Foraminiferal Mn / Ca determined by SIMS and FT-ICP-OES is comparable. Mn / Ca was higher during periods with high primary productivity, such as during the Younger Dryas, which indicates lowoxygen conditions. This is further supported by the benthic foraminiferal faunal composition. Our results highlight the proxy potential of Mn / Ca in benthic foraminifera from upwelling systems for reconstructing past variations in oxygen conditions of the sea floor environment as well as the need to use it in combination with other proxy records such as faunal assemblage data.

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Redox-dependent changes in manganese speciation in Baltic Sea sediments from the Holocene Thermal Maximum: An EXAFS, XANES and LA-ICP-MS study

Cited by 41 publications

References 53 publications

Arsenic Adsorption and its Fractions on Aquifer Sediment: Effect of pH, Arsenic Species, and Iron/Manganese Minerals

Arsenic Adsorption and its Fractions on Aquifer Sediment: Effect of pH, Arsenic Species, and Iron/Manganese Minerals

Vivianite is a key sink for phosphorus in sediments of the Landsort Deep, an intermittently anoxic deep basin in the Baltic Sea

A comparison of benthic foraminiferal Mn / Ca and sedimentary Mn / Al as proxies of relative bottom-water oxygenation in the low-latitude NE Atlantic upwelling system

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