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  2. Geological history of oxygen - Wikipedia

    en.wikipedia.org/wiki/Geological_history_of_oxygen

    Photosynthetic prokaryotic organisms that produced O 2 as a byproduct lived long before the first build-up of free oxygen in the atmosphere, [5] perhaps as early as 3.5 billion years ago. The oxygen cyanobacteria produced would have been rapidly removed from the oceans by weathering of reducing minerals, [citation needed] most notably ferrous ...

  3. Great Oxidation Event - Wikipedia

    en.wikipedia.org/wiki/Great_Oxidation_Event

    The Great Oxidation Event (GOE) or Great Oxygenation Event, also called the Oxygen Catastrophe, Oxygen Revolution, Oxygen Crisis or Oxygen Holocaust, [2] was a time interval during the Earth's Paleoproterozoic era when the Earth's atmosphere and shallow seas first experienced a rise in the concentration of free oxygen. [3]

  4. Neoproterozoic oxygenation event - Wikipedia

    en.wikipedia.org/wiki/Neoproterozoic_oxygenation...

    The Neoproterozoic Oxygenation Event (NOE), also called the Second Great Oxidation Event, was a geologic time interval between around 850 and 540 million years ago during the Neoproterozoic era, which saw a very significant increase in oxygen levels in Earth's atmosphere and oceans. [1]

  5. Oxygen cycle - Wikipedia

    en.wikipedia.org/wiki/Oxygen_cycle

    The oxygen cycle demonstrates how free oxygen is made available in each of these regions, as well as how it is used. The oxygen cycle is the biogeochemical cycle of oxygen atoms between different oxidation states in ions , oxides , and molecules through redox reactions within and between the spheres/reservoirs of the planet Earth. [ 1 ]

  6. Paleoatmosphere - Wikipedia

    en.wikipedia.org/wiki/Paleoatmosphere

    A paleoatmosphere (or palaeoatmosphere) is an atmosphere, particularly that of Earth, at some unspecified time in the geological past.. When regarding geological history of Earth, the paleoatmosphere can be chronologically divided into the Hadean first atmosphere, which resembled the compositions of the solar nebula; the Archean second atmosphere (also known as the prebiotic atmosphere), which ...

  7. Mineral evolution - Wikipedia

    en.wikipedia.org/wiki/Mineral_evolution

    In their chronology for Earth, Hazen et al. (2008) separated the changes in mineral abundance into three broad intervals: planetary accretion up to 4.55 Ga (billion years ago); reworking of Earth's crust and mantle between 4.55 Ga and 2.5 Ga; and biological influences after 2.5 Ga. [1] [12] They further divided the ages into 10 intervals, some ...

  8. Convicted felons, such as Trump, can get permits to enter ...

    www.aol.com/convicted-felons-trump-permits-enter...

    The claim: Donald Trump can't travel to Canada because he is a convicted felon. A Dec. 3 Threads post (direct link, archive link) offers a theory as to why Canadian Prime Minister Justin Trudeau ...

  9. Paleoclimatology - Wikipedia

    en.wikipedia.org/wiki/Paleoclimatology

    Due to the high levels of oxygen in the atmosphere from the GOE, CH 4 levels fell rapidly cooling the atmosphere causing the Huronian glaciation. For about 1 Ga after the glaciation (2-0.8 Ga ago), the Earth likely experienced warmer temperatures indicated by microfossils of photosynthetic eukaryotes, and oxygen levels between 5 and 18% of the ...