Iron-bacterial mediation in Phanerozoic red limestones: State of the art

Mamet, Bernard; Préat, Alain

doi:10.1016/j.sedgeo.2005.12.009

Cited by 84 publications

(63 citation statements)

References 33 publications

(37 reference statements)

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“…The dispersion of submicrometric hematite was found to be responsible for the red pigmentation (Mamet and Préat, 2006). This, and the occurrence of a variety of Fe-(hydr)oxide encrustations (Della Porta et al, 2003;Mamet and Préat, 2006), link the light isotopic Mo signature of the sediment (−0.9 to −1.0‰) to Mo isotope fractionation during adsorption to Fe-(hydr)oxide surfaces. Fe-(oxyhydr)oxides, in analogy to ferromanganese crusts, adsorb Mo and are associated with the preferential uptake of light isotopes (Goldberg et al, submitted for publication).…”

Section: Cements and Matrix Micrites From Spainmentioning

confidence: 96%

“…The red staining is the result of early diagenetic processes in suboxic porewaters below the sediment surface involving iron-oxidizing bacteria ( Van der Kooij et al, 2007). The dispersion of submicrometric hematite was found to be responsible for the red pigmentation (Mamet and Préat, 2006). This, and the occurrence of a variety of Fe-(hydr)oxide encrustations (Della Porta et al, 2003;Mamet and Préat, 2006), link the light isotopic Mo signature of the sediment (−0.9 to −1.0‰) to Mo isotope fractionation during adsorption to Fe-(hydr)oxide surfaces.…”

Section: Cements and Matrix Micrites From Spainmentioning

confidence: 99%

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Molybdenum isotopic composition of modern and Carboniferous carbonates

et al. 2009

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We investigate the redox-sensitive isotope system of molybdenum (Mo) in marine carbonates to evaluate their potential as archive of the Mo isotopic composition of coeval seawater. We present Mo isotope data (δ 98/95 Mo) of modern skeletal and non-skeletal carbonates as well as a variety of precipitates from the mid and late Carboniferous. The external reproducibility is determined by repeated analyses of two commercially available carbonate standards. The resulting uncertainty of the low concentration samples is ±0.1‰ (2σ). Analysis of modern ooid sands from the Bahamas shows a consistently heavy Mo isotopic composition (δ 98/95 Mo between 2 and 2.2‰), approaching modern mean seawater values (δ 98/95 Mo = 2.3‰ ± 0.1‰ (2σ)). This suggests that isotope fractionation during Mo uptake into non-skeletal carbonate precipitates is small. In contrast, modern skeletal carbonates show variable isotopic compositions (0.1 to 2.2‰) which suggests a biologically controlled fractionation process. The varying Mo signatures found in Carboniferous cement phases point to a strong response to local changes in fluid composition from which they precipitated. Overall, we recognized three important factors to cause an offset relative to ocean water: Mo derived from skeletal components, input of detrital Mo and admixture of light, hydroxide derived Mo via diagenetic fluids. All of these factors cause a lighter Mo isotopic composition relative to seawater. Due to the apparent small isotope fractionation during Mo uptake into non-skeletal carbonates, their δ 98/95Mo closely reflects the ambient fluid composition. From these results we conclude that carbonates represent a promising new tool to characterize the water mass Mo isotopic composition of marine paleo-environments.

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Section: Cements and Matrix Micrites From Spainmentioning

confidence: 96%

Section: Cements and Matrix Micrites From Spainmentioning

confidence: 99%

Molybdenum isotopic composition of modern and Carboniferous carbonates

et al. 2009

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“…Di Stefano and Mindszenty, 2000;Preat et al, 2000;Ramajo et al, 2002;Gradzinski et al, 2004;Mamet and Preat, 2006;Reolid et al, 2008), but are identified throughout the whole stratigraphic record since the Proterozoic. Their genesis has been interpreted in diverse ways that include subaerial and submarine environments, with the iron being supplied from volcanic to hydrothermal, lateritic or continental sources (e.g.…”

Section: Ferruginizationmentioning

confidence: 99%

“…This process can be produced by a variety of both phototrophic and non-phototrophic microorganisms. Due to the lack of light dependence of these organisms, they probably formed under dim conditions and required slow sedimentation rates, the presence of low-oxygen water masses and a source of iron (Mamet and Preat, 2006;Preat et al, 2008). Such conditions were likely associated with dysaerobic sediment-water interfaces (Mamet and Preat, 2006).…”

Section: Ferruginization Glauconite and Environmental Stressmentioning

confidence: 99%

“…Due to the lack of light dependence of these organisms, they probably formed under dim conditions and required slow sedimentation rates, the presence of low-oxygen water masses and a source of iron (Mamet and Preat, 2006;Preat et al, 2008). Such conditions were likely associated with dysaerobic sediment-water interfaces (Mamet and Preat, 2006). Under such conditions the stability of the soluble reduced state of iron is higher and the metabolic activity of Fe oxidizing bacteria can induce ferric oxide and hydroxide precipitation as a secondary by-product (Konhauser, 1998;Mamet and Preat, 2006).…”

Section: Ferruginization Glauconite and Environmental Stressmentioning

confidence: 99%

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Major palaeoenvironmental perturbation in an Early Aptian carbonate platform: Prelude of the Oceanic Anoxic Event 1a?

Najarro

Rosales

Martı́n-Chivelet

2011

Sedimentary Geology

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Clay mineral diagenesis and red bed colouration: A SEM study of the Gercus Formation (Middle Eocene), northern Iraq

et al. 2020

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Detailed high magnification scanning electron microscopic (SEM) study supported by petrographic, mineralogical, and geochemical (major and trace element) analysis of the Gercus Formation clastics (sandstones and mudstones) from northern Iraq shows that the main authigenic components are carbonate (dolomite and calcite), clay and haematite minerals with rare quartz, feldspar, and gypsum. The carbonates and sulphate minerals were the main early diagenetic phase in the Gercus Formation and were produced from the post-depositional breakdown of ferromagnesian minerals. These latter are unstable in the oxidizing conditions of the interstitial waters below the desert surface. The main authigenic clay minerals are illite, illite-smectite, and palygorskite. The presence of tangential illite coating and illite-smectite in the sandstones can be related to their desert origin. Palygorskite is associated with dolomite, calcite, and haematite. These mineral associations may indicate early diagenesis in evaporitic and saline conditions. It also confirms the syndepositional and diagenetic origin for the clayey-haematitic matrix and pigment of the Gercus Formation. Haematite occurs as extremely fine-grained crystals mixed with authigenic clays and exhibits a range of shapes (e.g., fibrous to lath-shaped aggregates, small spherical grains, specularite crystals, blade-shaped, rosette-like clusters, and a lump of bright spheroidshaped haematite/goethite). The arid to semi-arid conditions together with the oxidizing and alkaline interstitial water favoured the noted mineral assemblage within the Gercus Formation.

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Iron-bacterial mediation in Phanerozoic red limestones: State of the art

Cited by 84 publications

References 33 publications

Molybdenum isotopic composition of modern and Carboniferous carbonates

Molybdenum isotopic composition of modern and Carboniferous carbonates

Major palaeoenvironmental perturbation in an Early Aptian carbonate platform: Prelude of the Oceanic Anoxic Event 1a?

Clay mineral diagenesis and red bed colouration: A SEM study of the Gercus Formation (Middle Eocene), northern Iraq

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