Organic carbon, sulphur, and iron in recent semi-euxinic sediments of Kau Bay, Indonesia

Middelburg, Jack J.

doi:10.1016/0016-7037(91)90344-5

Cited by 143 publications

(41 citation statements)

References 70 publications

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“…Therefore, for analyses of the 1-turbidite samples of the in core MD1 0 we applied a more sensitive extraction scheme. This scheme was adapted from SUESS (1979) andMIDDELBURG (1991). This extraction procedure was developed specifically for the determination of authigenic mineral phases in anoxic sediments.…”

Section: Methodsmentioning

confidence: 99%

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Occurrence of thin, metal-rich layers in deep-sea sediments: a geochemical characterization of copper remobilization

Visser

Middelburg

et al. 1993

Deep Sea Research Part I: Oceanographic Research Papers

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Abstract-Distinctly coloured trace metal enriched fronts with a six-fold Cu-enrichment occur in the interbedded pelagic-turbiditic sediments from the Madeira Abyssal Plain. To decipher their mode of formation. two sequential extraction techniques, an acid-gradient and a "Tessier-type" scheme, were applied. Two different front types could be distinguished: Type-l fronts are mostly black and enriched in Co, Zn, Ni and Cu, and associated with the oxidation fronts that developed after deposition of turbidites. Type-2 fronts are purple, extremely enriched in Cu, and associated with sulphur. These fronts are sometimes found in relation with a relict oxidation front, but often show no clear relation with lithology. Two different modes of formation are postulated. (1) The transition-metal enrichment in the type-l fronts is typical for a manganese-oxide association often found in marine sediments. After the dissolution of manganese-oxide during sub-oxic diagenesis, the transition metals were liberated and subsequently relocated and precipitated in response to a redox-gradient. (2) The Cu-S association in type-2 fronts is also formed during sub-oxic diagenesis. The main process leading to the formation of this Cu-S enrichment is the mobilization of inherited Cu-S compounds from organic-rich turbidites. The accumulation of these compounds is possibly related to redox changes at relict oxidation fronts and to gradual. probably slowly evolving. redox changes that occur at present.

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Section: Methodsmentioning

confidence: 99%

“…The samples of the I-turbidite were subjected to an acid-gradient extraction (SUESS 1979;MIDDELBURG, 1991). No precautions were taken to avoid the contact of oxygen with the samples.…”

Section: Acid Gradient Extractionmentioning

confidence: 99%

Occurrence of thin, metal-rich layers in deep-sea sediments: a geochemical characterization of copper remobilization

Visser

Middelburg

et al. 1993

Deep Sea Research Part I: Oceanographic Research Papers

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“…However, the accumulated evidence appears to favor enhanced preservation potential under hypoxic to anoxic bottom waters (Moodley et al, 2005). Organic matter burial efficiencies (fraction of organic matter buried relative to organic matter delivery to sediments) correlate strongly with sediment accumulation rates but at low to intermediate sediment-accumulation rates burial efficiencies are often higher in anoxic and hypoxic than in oxic settings (Canfield, 1989(Canfield, , 1994Middelburg, 1991;Middelburg et al, 1993;Hedges and Keil, 1995), but not always (Cowie et al, 1991). Similarly, the organic-matter burial efficiency correlates strongly with oxygen-exposure time, a measure of the depth of oxygen penetration normalized to sediment-accumulation rates (Hartnett et al, 1998;Hedges et al, 1999).…”

Section: The Effect Of Bottom-water Oxygen On Sedimentary Organic Mattermentioning

confidence: 99%

Coastal hypoxia and sediment biogeochemistry

2009

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Abstract. The intensity, duration and frequency of coastal hypoxia (oxygen concentration <63 µM) are increasing due to human alteration of coastal ecosystems and changes in oceanographic conditions due to global warming. Here we provide a concise review of the consequences of coastal hypoxia for sediment biogeochemistry. Changes in bottomwater oxygen levels have consequences for early diagenetic pathways (more anaerobic at expense of aerobic pathways), the efficiency of re-oxidation of reduced metabolites and the nature, direction and magnitude of sediment-water exchange fluxes. Hypoxia may also lead to more organic matter accumulation and burial and the organic matter eventually buried is also of higher quality, i.e. less degraded. Bottom-water oxygen levels also affect the organisms involved in organic matter processing with the contribution of metazoans decreasing as oxygen levels drop. Hypoxia has a significant effect on benthic animals with the consequences that ecosystem functions related to macrofauna such as bio-irrigation and bioturbation are significantly affected by hypoxia as well. Since many microbes and microbial-mediated biogeochemical processes depend on animal-induced transport processes (e.g. re-oxidation of particulate reduced sulphur and denitrification), there are indirect hypoxia effects on biogeochemistry via the benthos. Severe long-lasting hypoxia and anoxia may result in the accumulation of reduced compounds in sediments and elimination of macrobenthic communities with the consequences that biogeochemical properties during trajectories of decreasing and increasing oxygen may be different (hysteresis) with consequences for coastal ecosystem dynamics.

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“…Sulphate reduction results in the formation of hydrogen sulphide which either reacts with reactive iron minerals or is oxidized chemically and particularly biologically by a diverse community of sulphide oxidizing bacteria. Oxygen limitation restricts the re-oxidation of hydrogen sulphide in sediments underlying hypoxic and anoxic bottom-waters and iron sulphide mineral formation therefore represents the main sink of hydrogen sulphide (Berner, 1994;Middelburg, 1991). Pyrite is normally the dominant iron sulphide mineral formed, but this usually involves acid volatile precursors (AVS, acid volatile sulphides) such as greigite.…”

Section: Chemical and Mineral Indicators 321 Sulphur And Sulphidesmentioning

confidence: 99%

“…In normal marine sediments underlying oxic bottom waters, organic carbon and sulphur are well correlated because a certain carbon delivery relates to a proportional preservation of organic carbon and reduced sulphur (Berner, 1984). In sediments underlying sulphide-rich waters there is also iron sulphide formation occurring in the water column with the result that sediment organic carbon and sulphur contents are unrelated (Berner, 1984;Middelburg, 1991;Passier et al, 1996). The preservation of sulphur has increased in sediments deposited in Chesapeake Bay during recent centuries, together with total organic carbon and total (mainly organic) nitrogen Brush, 1991, 1993) (Fig.…”

Section: Chemical and Mineral Indicators 321 Sulphur And Sulphidesmentioning

confidence: 99%

Historical records of coastal eutrophication-induced hypoxia

Jorissen²,

et al. 2009

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Abstract. Under certain conditions, sediment cores from coastal settings subject to hypoxia can yield records of environmental changes over time scales ranging from decades to millennia, sometimes with a resolution of as little as a few years. A variety of biological and geochemical indicators (proxies) derived from such cores have been used to reconstruct the development of eutrophication and hypoxic conditions over time. Those based on (1) the preserved remains of benthic organisms (mainly foraminiferans and ostracods), (2) sedimentary features (e.g. laminations) and (3) sediment chemistry and mineralogy (e.g. presence of sulphides and redox-sensitive trace elements) reflect conditions at or close to the seafloor. Those based on (4) the preserved remains of planktonic organisms (mainly diatoms and dinoflagellates), (5) pigments and lipid biomarkers derived from prokaryotes and eukaryotes and (6) organic C, N and their stable isotope ratios reflect conditions in the water column. However, the interpretation of these indicators is not straightforward. A central difficulty concerns the fact that hypoxia is strongly correlated with, and often induced by, organic enrichment caused by eutrophication, making it difficult to separate the effects of these phenomena in sediment records. The problem is compounded by the enhanced preservation in anoxic and hypoxic sediments of organic microfossils and biomarkers indicating eutrophication. The use of hypoxiaCorrespondence to: A. J. Gooday (ang@noc.soton.ac.uk) specific proxies, such as the trace metals molybdenum and rhenium and the bacterial biomarker isorenieratene, together with multi-proxy approaches, may provide a way forward. All proxies of bottom-water hypoxia are basically qualitative; their quantification presents a major challenge to which there is currently no satisfactory solution. Finally, it is important to separate the effects of natural ecosystem variability from anthropogenic effects. Despite these problems, in the absence of historical data for dissolved oxygen concentrations, the analysis of sediment cores can provide plausible reconstructions of the temporal development of humaninduced hypoxia, and associated eutrophication, in vulnerable coastal environments.

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Organic carbon, sulphur, and iron in recent semi-euxinic sediments of Kau Bay, Indonesia

Cited by 143 publications

References 70 publications

Occurrence of thin, metal-rich layers in deep-sea sediments: a geochemical characterization of copper remobilization

Occurrence of thin, metal-rich layers in deep-sea sediments: a geochemical characterization of copper remobilization

Coastal hypoxia and sediment biogeochemistry

Historical records of coastal eutrophication-induced hypoxia

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