Biogenic Nontronite from Marine White Smoker Chimneys

Köhler, B

doi:10.1346/ccmn.1994.0420605

Cited by 68 publications

(35 citation statements)

References 52 publications

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“…Their association with the Omdraaivlei microalgae-like organisms may therefore be an indirect evidence for their existence in 26 dysoxic or at least not highly oxygenated environment. Generally, precipitation of metal silicates and oxides by various strains of free-living heterotrophic bacteria, cyanobacteria and diminutive green algae is a well-known phenomenon, particularly in metal-loaded, weakly acidic to circum-neutral environments (e.g., West et al, 1980;Steinberg and Klee, 1984;Köhler et al, 1994;Konhauser et al, 1994;Urrutia and Beveridge, 1994;Tazaki, 1997;Bischoff, 1997;Konhauser and Urrutia, 1999).…”

Section: Discussionmentioning

confidence: 99%

Tubular microfossils from ∼2.8 to 2.7Ga-old lacustrine deposits of South Africa: A sign for early origin of eukaryotes?

Kaźmierczak

Kremer

Altermann

et al. 2016

Precambrian Research

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Unequivocal evidence for Archean eukaryotic life has been long sought for and is a matter of lively debate. In the absence of unambiguous fossils this debate has focused on biogeochemical signatures and molecular phylogenies. Most researchers agree that fossil forms comparable with modern eukaryotic cells can be credibly identified only in Proterozoic (~1.8-1.6 Ga) and younger rocks. Herein, we report for the first time, Neoarchean mineralized tubular microfossils from ~2.8-2.7 Ga lacustrine deposits of South Africa. The exceptional preservation of these microfossils allows recognition of important morphological details in petrographic thin section and in HF-macerates that links them to modern siphonous (coenocytic) green or yellow-green microalgae (Chlorophyta and Xanthophyta). The microfossil identification is supported by Raman spectroscopic analyses, EPMA, SEM/BSE 2 and SEM/EDS microprobe analytical results, NanoSIMS elemental mapping and microtomographic sectioning of the thalli. All results point to indigenous, bona fide eukaryotic microfossils of algal affinity. These Neoarchean microalgae-like remains and their assumingly combined in vivo and early post-mortem precipitated mineral envelopes greatly improve our knowledge of early life and its habitats and may have far-reaching consequences for the studies of the evolution of life.

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Section: Discussionmentioning

confidence: 99%

Tubular microfossils from ∼2.8 to 2.7Ga-old lacustrine deposits of South Africa: A sign for early origin of eukaryotes?

Kaźmierczak

Kremer

Altermann

et al. 2016

Precambrian Research

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“…Nontronite deposits have been described with sulphur deposits near active high temperature black and white smokers (Bischoff, 1972;Thompson et al, 1985;Köhler et al, 1994), but also in lower temperature off-axis hydrothermal systems (Corliss et al, 1978;Moorby and Cronan, 1983).…”

Section: Introductionmentioning

confidence: 99%

Conditions and mechanism for the formation of iron-rich Montmorillonite in deep sea sediments (Costa Rica margin): Coupling high resolution mineralogical characterization and geochemical modeling

Charpentier

Buatier

Jacquot³

et al. 2011

Geochimica et Cosmochimica Acta

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Wheat. Conditions and mechanism for the formation of iron-rich Montmorillonite in deep sea sediments (Costa Rica margin): Coupling high resolution mineralogical characterization and geochemical modeling. Geochimica et Cosmochimica Acta, Elsevier, 2011Elsevier, , 75 (6), pp.1397Elsevier, -1410Elsevier, . 10.1016Elsevier, /j.gca.2010 Conditions and mechanism for the formation of iron- AbstractIron-rich smectite is commonly described in the diagenetic fraction of deep-sea sediment, as millimeter to centimeter aggregates dispersed in the sediment, or as a coating on sedimentary particles or nodules. This study examines several factors to elucidate formation mechanisms of a particular iron-rich smectite and its potential transformation to glauconite. The study combines a detailed mineralogical investigation on natural samples and a chemical modeling approach to assess mineralogical reactions and pathways.Transmission electron microscopy (TEM) observations and analytical electron microscopy (TEM-AEM) analyses were conducted on microtomed samples of millimeter-to centimeter-long green grains. These grains are widespread in pelagic calcareous sediment from the Costa Rica margin. They are composed of pyrites that are partially dissolved and are surrounded by amorphous or very poorly crystallized iron-rich particles. Iron-rich montmorillonite grows from an amorphous precursor and its formation requires the input of Si, O, Mg, K, Na and Ca; our results suggest that these inputs are supported by the dissolution of sedimentary phases such as volcanic glasses, siliceous fossils and silicates.Thermodynamic modeling of fluid-sediment interactions was conducted with the geochemical computer code PhreeqC, using mineralogical and pore fluid compositions from sediment samples and calculated estimates for thermodynamic constants of smectites that are not maintained by the computer code. Simulations confirm the possibility that the green grains are the product of pyrite alteration by seawater under oxidizing conditions. The extent of smectite production is controlled by the kinetics of pyrite dissolution and fluid migration. The absence of aluminum in the Costa Rica margin system explains the formation of an iron-rich montmorillonite instead of glauconite, whereas the presence of calcite that buffers the system explains the formation of an iron-rich montmorillonite instead of iron oxides.

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“…This polymorphic Fe-A1 silicate was chamosite [(FesA1)(Si3A1)OI0(OH)s]. Kohler et al (1994) reported the formation of biogenic nontronite developed from marine white smoker chimneys. This hydrothermal nontronite is almost monomineralic, has a low AI content and formed at a temperature between 21.5 and 67.3 ~ The objective of this study is to determine the natural occurrence of layer silicates in freshwater systems and conduct laboratory simulation experiments to understand the role of bacteria in nucleating and crystallizing them.…”

Section: Introductionmentioning

confidence: 99%

Biomineralization of Layer Silicates and Hydrated Fe/Mn Oxides In Microbial Mats: An Electron Microscopical Study

Tazaki

1997

Clays and clay miner.

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Abstract--The formation of layer silicates on capsuled bacterial cell walls was studied in freshwater microbial mats. The trends associated wtih A1, Si, Mn and Fe deposits with capsules are consistent with occurrence of layer silicates with 14, 10 and 7 A X-ray diffraction (XRD) patterns. Scanning electron microscope and transmission electron microscope (SEM and TEM) observations of the microbial mats revealed the presence of microcolonies of rod-and coccus-shaped bacteria with layer-silicate thin films. Field measurements of pH, temperature and Eh indicated that these conditions for bacterial crystallization of layer silicates and hydrated Fe/Mn oxides in freshwaters are as follows: pH 6.3 to 7.8, 12 to 20 ~ and Eh -24 to +200 mV. Glass slides kept for 3 weeks in the beakers with natural freshwater and river sediments were coated with brown materials. These materials were identified as layer silicates and colonized bacteria formed under photosynthetic conditions. The well-developed holdfasts on Leptothrix discophora bacterial cells are mainly associated with poorly crystalline layer silicates and hydrated Fe-Mn oxides. Semiquantitative elemental analyses of holdfasts using energy-dispersive X-rays (EDX) indicated that layer-silicate crystallization covers the cell at an early stage. Iron and manganese crystallization develops at a later stage, where aluminum substitution occurs in crystal structures. Laboratory experimental results indicated that layer silicates grew from a biochemical origin, rather than from inorganic origins in freshwater. Layer-silicate formation is linked with bacteria in microbial mats.

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Biogenic Nontronite from Marine White Smoker Chimneys

Cited by 68 publications

References 52 publications

Tubular microfossils from ∼2.8 to 2.7Ga-old lacustrine deposits of South Africa: A sign for early origin of eukaryotes?

Tubular microfossils from ∼2.8 to 2.7Ga-old lacustrine deposits of South Africa: A sign for early origin of eukaryotes?

Conditions and mechanism for the formation of iron-rich Montmorillonite in deep sea sediments (Costa Rica margin): Coupling high resolution mineralogical characterization and geochemical modeling

Biomineralization of Layer Silicates and Hydrated Fe/Mn Oxides In Microbial Mats: An Electron Microscopical Study

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