Redox state of the Archean atmosphere: evidence from detrital heavy minerals in ca. 3250-2750 Ma sandstones from the Pilbara Craton, Australia
Article Abstract:
Gelogists believed that the Archean atmosphere was mostly lacking in atmospheric oxygen. This was hypothesized due to the presence of detrital uraninite and pyrite, which are usually found in locations with very low levels of oxygen. However, new studies have revealed the possibility that their origins may be hydrothermal in nature. Detrital siderite is hardly found in post Archean sandstones, thereby, suggesting its instability during oxidation.
Publication Name: Geology
Subject: Earth sciences
ISSN: 0091-7613
Year: 1999
User Contributions:
Comment about this article or add new information about this topic:
Widespread bacterial populations at glacier beds and their relationship to rock weathering and carbon cycling
Article Abstract:
Chemical weathering in subglacial meltwaters and basal ice are usually thought to occur with inorganic materials. Research findings indicate the presence of organic carbon and microbially mediated reduction-oxidation reactions (redox) in glacial waters. These microorganisms are a major source of protons that may be the precondition for the increase in the rate of sulfide oxidation and subglacial conditioning.
Publication Name: Geology
Subject: Earth sciences
ISSN: 0091-7613
Year: 1999
User Contributions:
Comment about this article or add new information about this topic:
The emergence of life from iron monosulphide bubbles at a submarine hydrothermal redox and pH front
Article Abstract:
hjkkjj
Publication Name: Journal of the Geological Society
Subject: Earth sciences
ISSN: 0016-7649
Year: 1997
User Contributions:
Comment about this article or add new information about this topic:
- Abstracts: Indirect crustal contamination: evidence from isotopic and chemical disequilibria in minerals from alkali basalts and nephelinites from northern Tanzania
- Abstracts: Melt percolation and reaction atop a plume: evidence from the poikiloblastic peridotite xenoliths from Boree (Massif Central, France)
- Abstracts: Mechanical twin sets in calcite as markers of recent collisional events in a fold-and-thrust belt: evidence from the reefal limestones of southwestern Taiwan
- Abstracts: Nd isotopic evidence for juvenile crust in the Carolina terrane, southern Appalachians. U-Pb isotopic evidence for the accretion of different crustal blocks to form the Lewisian Complex of northwest Scotland
- Abstracts: Stable isotropic evidence for relative and eustatic sea-level changes in Eocence to Oligocene carbonates, Baldwin County, Alabama: discussion