The Problematic Rise of Archean Oxygen
نویسندگان
چکیده
منابع مشابه
The problematic rise of Archean oxygen.
Archean Oxygen In their intricate study, Catling et al. (1) attempted to explain the rise of atmospheric oxygen on the early Earth. The model they presented relies on a unique anaerobic ecosystem in which necessarily complex microbial fermentations interact closely with methanogens to decompose cyanobacteria and control the global preservation rate of organic carbon. The model begins schematica...
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Molecular fossils of biological lipids are preserved in 2700-million-year-old shales from the Pilbara Craton, Australia. Sequential extraction of adjacent samples shows that these hydrocarbon biomarkers are indigenous and syngenetic to the Archean shales, greatly extending the known geological range of such molecules. The presence of abundant 2alpha-methylhopanes, which are characteristic of cy...
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Introduction According to Anbar & Knoll (2002), the Proterozoic ocean was in a transition stage from euxinic with oxygenated shallow water to the fully oxygenated water column of the present day. Though there is no direct proxy for the concentration of oxygen in the past, carbon and sulfur isotopes help constrain these concentrations. The carbon and sulfur cycles underwent vast transitions in t...
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The isotope record of sedimentary sulfides can help resolve the history of oxygen accumulation into the atmosphere. We measured sulfur isotopic fractionation during microbial sulfate reduction up to 88 degrees C and show how sulfate reduction rate influences the preservation of biological fractionations in sediments. The sedimentary sulfur isotope record suggests low concentrations of seawater ...
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ژورنال
عنوان ژورنال: Science
سال: 2002
ISSN: 0036-8075,1095-9203
DOI: 10.1126/science.295.5559.1419a