Microbial processes during deposition and diagenesis of Banded Iron Formations

AbstractBanded Iron Formations (BIFs) are marine chemical sediments consisting of alternating iron (Fe)-rich and silica (Si)-rich bands which were deposited throughout much of the Precambrian era. BIFs represent important proxies for the geochemical composition of Precambrian seawater and provide evidence for early microbial life. Iron present in BIFs was likely precipitated in the form of Fe3+ (Fe(III)) minerals, such as ferrihydrite (Fe(OH)3), either through the metabolic activity of anoxygenic photoautotrophic Fe2+ (Fe(II))-oxidizing bacteria (photoferrotrophs), by microaerophilic bacteria, or by the oxidation of dissolved Fe(II) by O2 produced by early cyanobacteria. However, in addition to oxidized Fe-bearing minerals such as hematite (FeIII2O3), (partially) reduced minerals such as magnetite (FeIIFeIII2O4) and siderite (FeIICO3) are found in BIFs as well. The presence of reduced Fe in BIFs has been suggested to reflect the reduction of primary Fe(III) minerals by dissimilatory Fe(III)-reducing bacteria, or by metamorphic (high pressure and temperature) reactions occurring in presence of buried organic matter. Here, we present the current understanding of the role of Fe-metabolizing bacteria in the deposition of BIFs, as well as competing hypotheses that favor an abiotic model for BIF deposition. We also discuss the potential abiotic and microbial reduction of Fe(III) in BIFs after deposition. Further, we review the availability of essential nutrients (e.g. P and Ni) and their implications on early Earth biogeochemistry. Overall, the combined results of various ancient seawater analogue experiments aimed at assessing microbial iron cycling pathways, coupled with the analysis of the BIF rock record, point towards a strong biotic influence during BIF genesis.

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Review Lecture - Ore-deposition through geological time

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1978.0135 ◽

1978 ◽

Vol 362 (1710) ◽

pp. 305-328 ◽

Cited By ~ 12

Keyword(s):

Mineral Deposits ◽

Banded Iron Formations ◽

Geological Time ◽

The Earth ◽

Recent Developments ◽

Changing Role ◽

Iron Formations ◽

Ore Deposition

Economic mineral deposits represent abnormal concentrations of metals which must be regarded as records of unusual geological events. The recognition of any long-term changes in styles of mineralization must depend on the identification of anomalies within the geological régimes characteristic of successive stages of the Earth’s history. This question will be discussed in relation to recent developments in the Earth sciences. The recognition of structural and chemical inhomogeneities in the lithospheric mantle suggests that mapping of mantle age-provinces may become possible; such studies bear on the significance of certain metallogenic provinces. Coordinated geochemical, structural and palaeomagnetic studies which are throwing light on the evolution of early tectonic systems should help to illuminate the significance of changes in style of mineralization at the Archaean/Proterozoic boundary, as well as the distribution of some types of Proterozoic deposits. Geochemical evidence concerning the changing rôle of organic processes in sedimentation and diagenesis has a bearing on the origin of sedimentary ores, especially over the controversial period characterized by accumulation of banded iron-formations.

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Minimal biomass deposition in banded iron formations inferred from organic matter and clay relationships

Nature Communications ◽

10.1038/s41467-019-12975-z ◽

2019 ◽

Vol 10 (1) ◽

Cited By ~ 1

Author(s):

Matthew S. Dodd ◽

Dominic Papineau ◽

Franco Pirajno ◽

Yusheng Wan ◽

Juha A. Karhu

Keyword(s):

Organic Matter ◽

Primary Productivity ◽

Iron Reduction ◽

Biogeochemical Cycle ◽

Complete Oxidation ◽

Iron Cycling ◽

Banded Iron Formations ◽

Iron Formations

Abstract The cycling of iron and organic matter (OM) is thought to have been a major biogeochemical cycle in the early ferruginous oceans which contributed to the deposition of banded iron formations (BIF). However, BIF are deficient in OM, which is postulated to be the result of near-complete oxidation of OM during iron reduction. We test this idea by documenting the prevalence of OM in clays within BIF and clays in shales associated with BIF. We find in shales >80% of OM occurs in clays, but <1% occurs in clays within BIF. Instead, in BIF OM occurs with 13C-depleted carbonate and apatite, implying OM oxidation occurred. Conversely, BIF which possess primary clays would be expected to preserve OM in clays, yet this is not seen. This implies OM deposition in silicate-bearing BIF would have been minimal, this consequently stifled iron-cycling and primary productivity through the retention of nutrients in the sediments.

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The role of microaerophilic Fe-oxidizing micro-organisms in producing banded iron formations

Geobiology ◽

10.1111/gbi.12192 ◽

2016 ◽

Vol 14 (5) ◽

pp. 509-528 ◽

Cited By ~ 32

Author(s):

C. S. Chan ◽

D. Emerson ◽

G. W. Luther

Keyword(s):

Banded Iron Formations ◽

Micro Organisms ◽

Iron Formations

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Origin and significance of Si and O isotope heterogeneities in Phanerozoic, Archean, and Hadean zircon

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1808335115 ◽

2018 ◽

Vol 115 (41) ◽

pp. 10287-10292 ◽

Cited By ~ 18

Author(s):

Dustin Trail ◽

Patrick Boehnke ◽

Paul S. Savage ◽

Ming-Chang Liu ◽

Martha L. Miller ◽

...

Keyword(s):

Critical Role ◽

Water Soluble ◽

Detrital Zircons ◽

Banded Iron Formations ◽

Sedimentary Deposits ◽

O Isotope ◽

Si Isotope ◽

Iron Formations ◽

4.1 Ga ◽

Chemical Sediments

Hydrosphere interactions and alteration of the terrestrial crust likely played a critical role in shaping Earth’s surface, and in promoting prebiotic reactions leading to life, before 4.03 Ga (the Hadean Eon). The identity of aqueously altered material strongly depends on lithospheric cycling of abundant and water-soluble elements such as Si and O. However, direct constraints that define the character of Hadean sedimentary material are absent because samples from this earliest eon are limited to detrital zircons (ZrSiO4). Here we show that concurrent measurements of Si and O isotope ratios in Phanerozoic and detrital pre-3.0 Ga zircon constrain the composition of aqueously altered precursors incorporated into their source melts. Phanerozoic zircon from (S)edimentary-type rocks contain heterogeneous δ18O and δ30Si values consistent with assimilation of metapelitic material, distinct from the isotopic character of zircon from (I)gneous- and (A)norogenic-type rocks. The δ18O values of detrital Archean zircons are heterogeneous, although yield Si isotope compositions like mantle-derived zircon. Hadean crystals yield elevated δ18O values (vs. mantle zircon) and δ30Si values span almost the entire range observed for Phanerozoic samples. Coupled Si and O isotope data represent a constraint on Hadean weathering and sedimentary input into felsic melts including remelting of amphibolites possibly of basaltic origin, and fractional addition of chemical sediments, such as cherts and/or banded iron formations (BIFs) into source melts. That such sedimentary deposits were extensive enough to change the chemical signature of intracrustal melts suggests they may have been a suitable niche for (pre)biotic chemistry as early as 4.1 Ga.

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Sulfate-reducing bacteria and silica solubility: a possible mechanism for evaporite diagenesis and silica precipitation in banded iron formations

Canadian Journal of Earth Sciences ◽

10.1139/e85-206 ◽

1985 ◽

Vol 22 (12) ◽

pp. 1904-1909 ◽

Cited By ~ 23

Author(s):

Stuart J. Birnbaum ◽

John W. Wireman

Keyword(s):

Desulfovibrio Desulfuricans ◽

Sulfate Reducing Bacteria ◽

Sulfide Mineral ◽

Banded Iron Formations ◽

Dissolved Silica ◽

Sulfate Reducing ◽

Silica Precipitation ◽

Reducing Bacteria ◽

Iron Formations

Selective replacement of sulfate-evaporite minerals by silica and the precipitation of silica in association with sulfide mineral phases in banded iron formations may be mediated by the metabolic activities of sulfate-reducing bacteria. Hydrogen sulfide is known to be a product of this metabolism and is often called upon as a source of sulfur for metallic sulfides in sedimentary rocks. We report here on the influence that chemical changes induced by bacterial sulfate reduction have on silica solubility.Controlled in vitro growth experiments with Desulfovibrio desulfuricans and silica show (1) this organism can grow in silica concentrations as great as 400 ppm with no inhibition and (2) growth in the presence of silica yields a decrease in dissolved silica.Growth experiments with 80 ppm silica produced a lowering in dissolved silica from 80 ppm to 60 ppm, a 25% decrease, in just 30 h. Control experiments in the absence of cells resulted in no effective decrease in dissolved silica. The ability of sulfate-reducing bacteria to remove silica from solution may be related to local changes in pH and to hydrogen bonding of amorphous silica followed by polymerization to higher weight molecules.

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