Orosirian
The Orosirian (; , meaning "mountain range") is the third geologic period in the Paleoproterozoic Era. It spans 250 million years and lasted from to million years ago (Ma), following the Rhyacian Period and preceding the Statherian Period. Instead of being based on stratigraphy, these dates are defined chronometrically.
Key facts
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- Orosirian
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- Orosirian
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- all time
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- 2000 Ma paleoglobe.png
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- A map of Earth as it appeared during the early Orosirian, c. 2 Ga
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- Orosirian
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- Formal
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- earth
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- Global (ICS)
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- ICS Time Scale
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- Period
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- System
Article
4 sectionsContents
- History
- Paleogeography
- References
- Further reading
The Orosirian (; , meaning "mountain range") is the third geologic period in the Paleoproterozoic Era. It spans 250 million years and lasted from to million years ago (Ma), following the Rhyacian Period and preceding the Statherian Period. Instead of being based on stratigraphy, these dates are defined chronometrically.
== History == 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., but , this has not yet been officially adopted by the IUGS.