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Iron Formation: The Sedimentary Product of a Complex Interplay among Mantle, Tectonic, Oceanic, and Biospheric Processes
Iron formations are economically important sedimentary rocks that are most common in Precambrian sedimentary successions. Although many aspects of their origin remain unresolved, it is widelyExpand
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Evidence for oxygenic photosynthesis half a billion years before the Great Oxidation Event
The early Earth was characterized by the absence of oxygen in the ocean–atmosphere system, in contrast to the well-oxygenated conditions that prevail today. Atmospheric concentrations first rose toExpand
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Geodynamo, Solar Wind, and Magnetopause 3.4 to 3.45 Billion Years Ago
Early Origin of Earth's Magnetic Field Earth's magnetic field protects us from stellar winds and radiation from the Sun. Understanding when, during the Earth's formation, the large-scale magneticExpand
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Rare Earth Element and yttrium compositions of Archean and Paleoproterozoic Fe formations revisited: New perspectives on the significance and mechanisms of deposition
The ocean and atmosphere were largely anoxic in the early Precambrian, resulting in an Fe cycle that was dramatically different than today's. Extremely Fe-rich sedimentary deposits i.e., FeExpand
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Sulfur record of rising and falling marine oxygen and sulfate levels during the Lomagundi event
Carbonates from approximately 2.3–2.1 billion years ago show markedly positive δ13C values commonly reaching and sometimes exceeding +10‰. Traditional interpretation of these positive δ13C valuesExpand
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Iron Formations: Their Origins and Implications for Ancient Seawater Chemistry
Iron formations are economically significant, iron- and silica-rich sedimentary rocks that are restricted to Precambrian successions. There are no known modern or Phanerozoic analogues for theseExpand
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Towards a complete magmatic barcode for the Zimbabwe craton: Baddeleyite U-Pb dating of regional dolerite dyke swarms and sill complexes
Abstract We present baddeleyite U–Pb ages of Neoarchaean to Palaeoproterozoic dyke swarms and the Mashonaland sill province in Zimbabwe. The 2575.0 ± 1.5 Ma age of the Umvimeela dyke isExpand
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Cyclicity of Triassic to Lower Jurassic continental red beds of the Argana Valley, Morocco: implications for palaeoclimate and basin evolution
Abstract Cyclical playa deposits form a prominent part of the continental clastic succession of the Argana Valley, Western High Atlas of Morocco. The red beds formed in Triassic to Lower JurassicExpand
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Multiple sulphur and iron isotope composition of detrital pyrite in Archaean sedimentary rocks: A new tool for provenance analysis
Abstract Multiple S ( δ 34 S and δ 33 S) and Fe ( δ 56 Fe) isotope analyses of rounded pyrite grains from 3.1 to 2.6 Ga conglomerates of southern Africa indicate their detrital origin, which supportsExpand
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Titanium isotopic evidence for felsic crust and plate tectonics 3.5 billion years ago
An early call for plate tectonics The composition of continental crust far back in Earth's history gives us insight into when plate tectonics ramped up and has influenced ocean chemistry. Greber etExpand
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