Earth:Orosirian

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Short description: Third period of the Paleoproterozoic Era
Orosirian
2050 – 1800 Ma
2000 Ma paleoglobe.png
A map of Earth as it appeared during the early Orosirian, c. 2 Ga
Chronology
Etymology
Name formalityFormal
Usage information
Celestial bodyEarth
Regional usageGlobal (ICS)
Time scale(s) usedICS Time Scale
Definition
Chronological unitPeriod
Stratigraphic unitSystem
Time span formalityFormal
Lower boundary definitionDefined chronometrically
Upper boundary definitionDefined chronometrically

The Orosirian Period ( /ˌɒrˈsɪəriən/; Ancient Greek:, meaning "mountain range") is the third geologic period in the Paleoproterozoic Era and lasted from 2050 Mya to 1800 Mya (million years ago).[2] Instead of being based on stratigraphy, these dates are defined chronometrically.

Vredefort impact structure is believed to have formed in this period

The later half of the period was an episode of intensive orogeny on virtually all continents.

Two of the largest known impact events on Earth occurred during the Orosirian. Early in the period, 2023 Mya, a large asteroid collision created the Vredefort impact structure. The event that created the Sudbury Basin structure occurred near the end of the period, 1850 Mya.

For the time period from about 2060 to 1780 Mya, an alternative period based on stratigraphy rather than chronometry, named the Columbian, was suggested in the geological timescale review 2012 edited by Gradstein et al.,[3] but (As of February 2022), this has not yet been officially adopted by the IUGS.

Paleogeography

The supercontinent Columbia formed at the end of this period.

References

  1. 1.0 1.1 Plumb, K. A. (June 1, 1991). "New Precambrian time scale". Episodes 14 (2): 139–140. doi:10.18814/epiiugs/1991/v14i2/005. 
  2. David Huddart; Tim Stott (16 April 2013). Earth Environments: Past, Present and Future. John Wiley & Sons. pp. 1599–. ISBN 978-1-118-68812-0. https://books.google.com/books?id=_64G6cYuz3AC&pg=PT1599. 
  3. Gradstein, F.M., ed (2012). The Geologic Time Scale 2012. 1. Elsevier. pp. 361–365. ISBN 978-0-44-459390-0.