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Oxidation of the Ediacaran Ocean
Oxygenation of the Earth’s surface is increasingly thought to have occurred in two steps. The first step, which occurred ∼2,300 million years (Myr) ago, involved a significant increase in atmosphericExpand
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Environmental Genomics Reveals a Single-Species Ecosystem Deep Within Earth
DNA from low-biodiversity fracture water collected at 2.8-kilometer depth in a South African gold mine was sequenced and assembled into a single, complete genome. This bacterium, CandidatusExpand
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Long-Term Sustainability of a High-Energy, Low-Diversity Crustal Biome
Geochemical, microbiological, and molecular analyses of alkaline saline groundwater at 2.8 kilometers depth in Archaean metabasalt revealed a microbial biome dominated by a single phylotypeExpand
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Geochemical and climatic effects of increased marine organic carbon burial at the Cenomanian/Turonian boundary
Perhaps the most significant event in the Cretaceous record of the carbon isotope composition of carbonate1,2, other than the 1–2.5 ‰ negative shift in the carbon isotope composition of calcareousExpand
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Superheavy pyrite (δ34Spyr > δ34SCAS) in the terminal Proterozoic Nama Group, southern Namibia: A consequence of low seawater sulfate at the dawn of animal life
Sulfur isotope analysis (δ^(34)S) of well-preserved carbonates spanning an ~10 Ma interval of the terminal Proterozoic Nama Group reveals that disseminated pyrite is consistently enriched in ^(34)SExpand
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Effects of Rapid Global Warming at the Paleocene-Eocene Boundary on Neotropical Vegetation
Hot Tropical Explosion The Paleocene-Eocene Thermal Maximum (PETM), 55 million years ago, was a unique episode of rapid global warming (∼5°C), often used as an ancient analog for future globalExpand
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Isotopic signatures of CH4 and higher hydrocarbon gases from Precambrian Shield sites: A model for abiogenic polymerization of hydrocarbons
Abstract Previous studies of methane and higher hydrocarbon gases in Precambrian Shield rocks in Canada and the Witwatersrand Basin of South Africa identified two major gas types. PaleometeoricExpand
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Speciation and weathering of selenium in upper cretaceous chalk and shale from South Dakota and Wyoming, USA
Abstract In geologic materials, petroleum, and the environment, selenium occurs in various oxidation states (VI, IV, 0, -II), mineralized forms, and organo-Se complexes. Each of these forms isExpand
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