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  2. Geologic time scale - Wikipedia

    en.wikipedia.org/wiki/Geologic_time_scale

    An eon is the largest geochronologic time unit and is equivalent to a chronostratigraphic eonothem. [13] ... eon, era, period, epoch, subepoch, age, and subage. [14]

  3. Hadean - Wikipedia

    en.wikipedia.org/wiki/Hadean

    The Hadean (/ h eɪ ˈ d iː ə n, ˈ h eɪ d i ə n / hay-DEE-ən, HAY-dee-ən) is the first and oldest of the four known geologic eons of Earth's history, starting with the planet's formation about 4.6 billion years ago [4] [5] (estimated 4567.30 ± 0.16 million years ago [2] set by the age of the oldest solid material in the Solar System — protoplanetary disk dust particles — found as ...

  4. List of time periods - Wikipedia

    en.wikipedia.org/wiki/List_of_time_periods

    Geologic TimePeriod prior to humans. 4.6 billion to 3 million years ago. (See "prehistoric periods" for more detail into this.) Primatomorphid Era – Period prior to the existence of Primatomorpha; Simian Era – Period prior to the existence of Simiiformes; Hominoid Era – Period prior to the existence of Hominoidea

  5. Aeon - Wikipedia

    en.wikipedia.org/wiki/Aeon

    The word aeon / ˈ iː ɒ n /, also spelled eon ... to mean "during a long period"; thus, there was a time before the aeons, and the aeonian period is finite. After ...

  6. Archean - Wikipedia

    en.wikipedia.org/wiki/Archean

    Instead of being based on stratigraphy, the beginning and end of the Archean Eon are defined chronometrically. The eon's lower boundary or starting point of 4,031±3 million years ago is officially recognized by the International Commission on Stratigraphy, [1] which is the age of the oldest known intact rock formations on Earth. Evidence of ...

  7. Proterozoic - Wikipedia

    en.wikipedia.org/wiki/Proterozoic

    The Proterozoic Eon was a very tectonically active period in the Earth's history. Oxygen changed the chemistry allowing for extensive geological changes. Volcanism was also extensive resulting in more geologic changes. The late Archean Eon to Early Proterozoic Eon corresponds to a period of increasing crustal recycling, suggesting subduction.

  8. Timeline of the evolutionary history of life - Wikipedia

    en.wikipedia.org/wiki/Timeline_of_the...

    The Phanerozoic Eon (Greek: period of well-displayed life) marks the appearance in the fossil record of abundant, shell-forming and/or trace-making organisms. It is subdivided into three eras, the Paleozoic , Mesozoic and Cenozoic , with major mass extinctions at division points.

  9. Eon - Wikipedia

    en.wikipedia.org/wiki/Eon

    Aeon, an indefinite long period of time; Eon (geology), ... Eon, in the 2007 film Ben 10: Race Against Time; Eon, in the 1976 TV special Rudolph's Shiny New Year;