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  2. Geologic time scale - Wikipedia

    en.wikipedia.org/wiki/Geologic_time_scale

    The geologic time scale is a way of representing deep time based on events that have occurred throughout Earth's history, a time span of about 4.54 ± 0.05 Ga (4.54 billion years). [3] It chronologically organises strata, and subsequently time, by observing fundamental changes in stratigraphy that correspond to major geological or ...

  3. Proterozoic - Wikipedia

    en.wikipedia.org/wiki/Proterozoic

    The Proterozoic (IPA: / ˌ p r oʊ t ər ə ˈ z oʊ ɪ k, ˌ p r ɒ t-,-ər oʊ-,-t r ə-,-t r oʊ-/ PROH-tər-ə-ZOH-ik, PROT-, -⁠ər-oh-, -⁠trə-, -⁠troh-) [3] [4] [5] is the third of the four geologic eons of Earth's history, spanning the time interval from 2500 to 538.8 Mya, [6] and is the longest eon of Earth's geologic time scale.

  4. Geological history of Earth - Wikipedia

    en.wikipedia.org/wiki/Geological_history_of_Earth

    Geologic time shown in a diagram called a geological clock, showing the relative lengths of the eons of Earth's history and noting major events The geological history of the Earth follows the major geological events in Earth's past based on the geological time scale , a system of chronological measurement based on the study of the planet's rock ...

  5. History of Earth - Wikipedia

    en.wikipedia.org/wiki/History_of_Earth

    The history of the Earth can be organized chronologically according to the geologic time scale, which is split into intervals based on stratigraphic analysis. [2] [21] The following five timelines show the geologic time scale to scale. The first shows the entire time from the formation of the Earth to the present, but this gives little space ...

  6. Relative dating - Wikipedia

    en.wikipedia.org/wiki/Relative_dating

    The principle of Uniformitarianism states that the geologic processes observed in operation that modify the Earth's crust at present have worked in much the same way over geologic time. [2] A fundamental principle of geology advanced by the 18th century Scottish physician and geologist James Hutton, is that "the present is the key to the past ...

  7. Timeline of natural history - Wikipedia

    en.wikipedia.org/wiki/Timeline_of_natural_history

    Geologic time is the timescale used to calculate dates in the planet's geologic history from its origin (currently estimated to have been some 4,600 million years ago) to the present day. Radiometric dating measures the steady decay of radioactive elements in an object to determine its age. It is used to calculate dates for the older part of ...

  8. Geon (geology) - Wikipedia

    en.wikipedia.org/wiki/Geon_(geology)

    A geon is a specified 100-million-year interval of geologic time, counted backward from the present. The geon scale can be likened to a ladder, each interval between rungs representing 100 million years. Geons are named for the leftmost part of the number representing age.

  9. Historical geology - Wikipedia

    en.wikipedia.org/wiki/Historical_geology

    Geologic Time Spiral Historical geology or palaeogeology is a discipline that uses the principles and methods of geology to reconstruct the geological history of Earth . [ 1 ] Historical geology examines the vastness of geologic time, measured in billions of years, and investigates changes in the Earth , gradual and sudden, over this deep time .