Precambrian atmospheric oxygen: evidence in the sedimentary distributions of carbon, sulfur, uranium, and iron

1976 ◽  
Vol 13 (9) ◽  
pp. 1161-1185 ◽  
Author(s):  
Erich Dimroth ◽  
Michael M. Kimberley
Keyword(s):  
Oxygen Pressure ◽  
Ferrous Iron ◽  
Atmospheric Oxygen ◽  
Sedimentary Rocks ◽  
Major Change ◽  
Free Atmosphere ◽  
Ambient Oxygen ◽  
Iron Formations ◽  
Organic Productivity ◽  
Sedimentary Pyrite

The sedimentary distributions of carbon, sulfur, uranium, and ferric and ferrous iron depend greatly upon ambient oxygen pressure and should reflect any major change in proportion of oxygen in the atmosphere or hydrosphere. The similar distributions of these elements in sedimentary rocks of all ages are here interpreted to indicate the existence of a Precambrian atmosphere containing much oxygen.Organic carbon contents and distributions are similar in Precambrian and Quaternary sedimentary rocks and sediments, although distributions in both would have been sensitive to variations in rates of organic productivity and atmospheric oxygen pressure. Sedimentary pyrite is almost invariably closely associated with organic carbon, suggestive of formation by sulfate reduction, in sedimentary rocks of any age. Archean and Middle Precambrian cherty iron formations and uranium ores resemble Phanerozoic ores and probably formed similarly by diagenetic concentration. In general, we find no evidence in the sedimentary distributions of carbon, sulfur, uranium, or iron, that an oxygen-free atmosphere has existed at any time during the span of geological history recorded in well preserved sedimentary rocks.

Iron Formations as Palaeoenvironmental Archives

2021 ◽  
Author(s):  
Kaarel Mänd ◽  
Leslie J. Robbins ◽  
Noah J. Planavsky ◽  
Andrey Bekker ◽  
Kurt O. Konhauser
Keyword(s):  
Sedimentary Rocks ◽  
Scientific Understanding ◽  
Significant Part ◽  
Formation Mechanisms ◽  
Redox States ◽  
Elemental Cycling ◽  
Ancient Iron ◽  
Iron Formations ◽  
Palaeoenvironmental Conditions ◽  
Chemical Sediments

Ancient iron formations - iron and silica-rich chemical sedimentary rocks that formed throughout the Precambrian eons - provide a significant part of the evidence for the modern scientific understanding of palaeoenvironmental conditions in Archaean (4.0–2.5 billion years ago) and Proterozoic (2.5–0.539 billion years ago) times. Despite controversies regarding their formation mechanisms, iron formations are a testament to the influence of the Precambrian biosphere on early ocean chemistry. As many iron formations are pure chemical sediments that reflect the composition of the waters from which they precipitated, they can also serve as nuanced geochemical archives for the study of ancient marine temperatures, redox states, and elemental cycling, if proper care is taken to understand their sedimentological context.

scholarly journals Porphyromonas gingivalis Ferrous Iron Transporter FeoB1 Influences Sensitivity to Oxidative Stress

2009 ◽  
Vol 78 (2) ◽  
pp. 688-696 ◽  
Author(s):  
Cecilia Anaya-Bergman ◽  
Jia He ◽  
Kevin Jones ◽  
Hiroshi Miyazaki ◽  
Andrew Yeudall ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Mutant Strain ◽  
Porphyromonas Gingivalis ◽  
Ferrous Iron ◽  
Atmospheric Oxygen ◽  
Host Cells ◽  
Periodontal Pathogen ◽  
Bacterial Survival ◽  
Deficient Mutant ◽  
Iron Transporter

ABSTRACT Porphyromonas gingivalis FeoB1 is a ferrous iron transporter. Analysis of parental and feoB1-deficient strains of the periodontal pathogen revealed that the feoB1-deficient mutant strain had an increased ability to survive oxidative stress. Specifically, survival of the mutant strain was increased 33% with exposure to peroxide and 5% with exposure to atmospheric oxygen compared to the parental strain. Interestingly, the ability to survive intracellularly also increased fivefold in the case of the feoB1-deficient mutant. Our data suggest that although the FeoB1 protein is required for ferrous iron acquisition in P. gingivalis, it also has an adverse effect on survival of the bacterium under oxidative stress conditions. Finally, we show that feoB1 expression is not iron dependent and is dramatically reduced in the presence of host cells, consistent with the observed deleterious role it plays in bacterial survival.

scholarly journals The reduction of ferric oxalate by isolated chloroplasts

1940 ◽  
Vol 129 (855) ◽  
pp. 238-255 ◽  
Keyword(s):  
Ferrous Iron ◽  
Atmospheric Oxygen ◽  
Dry Weight ◽  
Point Of View ◽  
Potassium Oxalate ◽  
Stellaria Media ◽  
Light Reaction ◽  
Different Strains ◽  
Whole Plants ◽  
Isolated Chloroplasts

1.The isolated chloroplasts from Stellaria media show a progressive fall in activity approaching zero in 3-6 hr. Four different strains of the plant were grown which showed differences in the stability of chloroplasts after removal. 2. Two methods have been used to measure the activity of chloroplasts: ( a ) The measurement with HbO 2 of oxygen produced from ferric potassium oxalate as previously described. ( b ) The measurement of the rate of reduction of methaemoglobin in presence of atmospheric oxygen, the methaemoglobin being reduced by the ferrous iron. 3. The Q o 2 , measured as rate of oxygen production calculated on the basis of dry weight of leaf taken, is about 20. The Q o 2 , measured as rate of methaemoglobin reduction, generally appeared less as the reduction of methaemoglobin by ferrous iron is relatively slow. 4. The reduction of methaemoglobin in presence of ferric potassium oxalate has been studied quantitatively from the point of view of iron, methaemoglobin, and chloroplast concentration. 5. The effect of different light intensities on the ferric oxalate reaction is similar to the effect of varying light intensity on photosynthesis in whole plants and lies within the range of values found by different workers. 6. The ferric oxalate reaction is inhibited by urethane. Phenyl urethane inhibits in much smaller concentrations than ethyl urethane. The effective concentrations of urethane are similar to those affecting photosynthesis. 7. It is concluded from the present observations that the light reaction in vegetable photosynthesis is the production of the oxygen molecule and is not the reduction of carbon dioxide.

scholarly journals Uranium in iron formations and the rise of atmospheric oxygen

2013 ◽  
Vol 362 ◽  
pp. 82-90 ◽  
Author(s):  
C.A. Partin ◽  
S.V. Lalonde ◽  
N.J. Planavsky ◽  
A. Bekker ◽  
O.J. Rouxel ◽  
...  
Keyword(s):  
Atmospheric Oxygen ◽  
Iron Formations

Origin, tectonic environment and age of the Bibole banded iron formations, northwestern Congo Craton, Cameroon: geochemical and geochronological constraints

2021 ◽  
pp. 1-19
Author(s):  
Arlette Pulcherie Djoukouo Soh ◽  
Sylvestre Ganno ◽  
Lianchang Zhang ◽  
Landry Soh Tamehe ◽  
Changle Wang ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Atmospheric Oxygen ◽  
Banded Iron Formations ◽  
True Negative ◽  
Low Concentrations ◽  
Heavy Rare Earth Elements ◽  
Geochronological Constraints ◽  
Geochemical Studies ◽  
Iron Formations

Abstract The newly discovered Bibole banded iron formations are located within the Nyong Group at the northwest of the Congo Craton in Cameroon. The Bibole banded iron formations comprise oxide (quartz-magnetite) and mixed oxide-silicate (chlorite-magnetite) facies banded iron formations, which are interbedded with felsic gneiss, phyllite and quartz-chlorite schist. Geochemical studies of the quartz-magnetite banded iron formations and chlorite-magnetite banded iron formations reveal that they are composed of >95 wt % Fe2O3 plus SiO2 and have low concentrations of Al2O3, TiO2 and high field strength elements. This indicates that the Bibole banded iron formations were not significantly contaminated by detrital materials. Post-Archaean Australian Shale–normalized rare earth element and yttrium patterns are characterized by positive La and Y anomalies, a relative depletion of light rare earth elements compared to heavy rare earth elements and positive Eu anomalies (average of 1.86 and 1.15 for the quartz-magnetite banded iron formations and chlorite-magnetite banded iron formations, respectively), suggesting the influence of low-temperature hydrothermal fluids and seawater. The quartz-magnetite banded iron formations display true negative Ce anomalies, while the chlorite-magnetite banded iron formations lack Ce anomalies. Combined with their distinct Eu anomalies consistent with Algoma- and Superior-type banded iron formations, we suggest that the Bibole banded iron formations were deposited under oxic to suboxic conditions in an extensional basin. SIMS U–Pb data indicate that the Bibole banded iron formations were deposited at 2466 Ma and experienced metamorphism and metasomatism at 2078 Ma during the Eburnean/Trans-Amazonian orogeny. Overall, these findings suggest that the studied banded iron formations probably marked the onset of the rise of atmospheric oxygen, also known as the Great Oxidation Event in the Congo Craton.

Transport superconducting properties of ambient oxygen pressure-fabricated Y124/Ag wires

1998 ◽  
Vol 37 (6) ◽  
pp. 299-303 ◽  
Author(s):  
H Matsui ◽  
X.G Zheng ◽  
S Tanaka ◽  
M Suzuki
Keyword(s):  
Oxygen Pressure ◽  
Superconducting Properties ◽  
Ambient Oxygen

Thermal properties of PrBa2Cu4O8 prepared at ambient oxygen pressure

1997 ◽  
Vol 282-287 ◽  
pp. 1407-1408 ◽  
Author(s):  
H.D. Yang ◽  
C.W. Lin ◽  
J.-Y. Lin ◽  
T.H. Meen ◽  
H.L. Tsay ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Oxygen Pressure ◽  
Ambient Oxygen

THE EFFECT OF THE AMBIENT OXYGEN ON THE ELECTRICAL PROPERTIES OF AN EVAPORATED FILM OF PENTACENE

1961 ◽  
Vol 39 (10) ◽  
pp. 1981-1988 ◽  
Author(s):  
Haruo Kuroda ◽  
E. A. Flood
Keyword(s):  
Electrical Properties ◽  
Oxygen Pressure ◽  
Dark Current ◽  
Charge Carriers ◽  
Oxygen Effect ◽  
Surface Complex ◽  
Ambient Oxygen ◽  
Additional Charge ◽  
Photocurrent Decay

The "oxygen effect" on the dark current as well as that on the photocurrent was investigated using thin evaporated films of pentacene, 1,2-benzpentacene, 1,2,8,9-dibenzpentacene, 6,13-diphenylpentacene, and 5,7,12,14-tetraphenylpentacene. No oxygen effect could be detected in the dark current.From the photocurrent dependence on oxygen pressure and from the rate of photocurrent decay, it is concluded that additional charge carriers are produced on illumination by photoexcitation of a surface complex.

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