Earth:Rhyacian

From HandWiki

The Rhyacian (/raɪˈeɪsiən/) is the second geologic period in the Paleoproterozoic Era. It spans 250 million years and lasted from 2300 to 2050 million years ago (Ma), following the Siderian Period and preceding the Orosirian Period. Instead of being based on stratigraphy, these dates are defined chronometrically.

Etymology and history

The name Rhyacian is derived from the Greek word rhyas, meaning "stream of lava", and refers to the layered intrusions of the Bushfeld Complex in South Africa. The term was proposed by the Subcommission on Precambrian Stratigraphy as a subdivision of the Proterozoic Eon, and was ratified by the International Union of Geological Sciences in 1990.[1][2] In 2012, there have been suggestions to replace the Rhyacian with an alternate name, bearing a time interval of 2250 to 2060 Ma, and decided on the basis of its stratigraphy. The name Jatulian was proposed in reference to the Lomagundi-Jatuli excursion event, while the term Eukaryian was chosen due to the period's existing signs of the earliest eukaryotic fossils.[3] As of December 2024, a replacement for the Rhyacian has not been officially adopted by the IUGS.Template:Ref icc The term Jatulian, however, has been used in the regional stratigraphy of Fennoscandia.[4]

Paleogeography

The Bushveld Igneous Complex and some other similar intrusions formed during this period.[5]

Climate

The Huronian (Makganyene) global glaciation began at the start of the Rhyacian and lasted 100 million years. It lasted about 80% of this period.[6]

Life

This period is when the eukaryotes are thought to have originated from the symbiosis between asgardarchaea and alphaproteobacteria, as well as the sexual reproduction found within the eukaryotes only, thus the alternative name Eukaryian.[7][8][9] Possible signs of Macroscopic life have been found in Rhyacian aged rocks,[10][11] although these are heavily disputed due their age and probable abiotic origins.[12][13]

References

Citations

  1. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named EP-Proterozoic
  2. ↑ Cowie, John W.; Ziegler, Willi; Remane, Jürgen (June 1989). "Stratigraphic Commission Accelerates Progress, 1984 to 1989". Episodes 12 (2): 79–82. doi:10.18814/epiiugs/1989/v12i2/003. ISSN 0705-3797. OCLC 4130038. https://pdf.medrang.co.kr/IUGS/1989/012/IUGS012-02-03.pdf. Retrieved December 11, 2025.  open access
  3. ↑ Kranendonk 2012, pp. 361, 363.
  4. ↑ Bernard, Bingen; Solli, Arne; Viola, Giulio; Torgersen, Espen; Sandstad, Jan Sverre; Whitehouse, Martin J.; Røhr, Torkil S.; Ganerød, Morgan et al. (2015). "Geochronology of the Palaeoproterozoic Kautokeino Greenstone Belt, Finnmark, Norway: Tectonic implications in a Fennoscandia context". Norwegian Journal of Geology 95 (3–4): 365–396. doi:10.17850/njg95-3-09. ISSN 0029-196X. OCLC 1760475. http://www.geologi.no/images/NJG_articles/NJG_Vol95_No3_4_Art7_Bingen.pdf. Retrieved January 21, 2026. 
  5. ↑ James G. Ogg (2004). "Status on Divisions of the International Geologic Time Scale". Lethaia 37 (2): 183–199. doi:10.1080/00241160410006492. 
  6. ↑ Kopp et al. (August 2005). "The Paleoproterozoic Snowball: A climate disaster triggered by the evolution of oxygenic photosynthesis". PNAS 102 (32): 11131–6. doi:10.1073/pnas.0504878102. PMID 16061801. PMC 1183582. Bibcode: 2005PNAS..10211131K. http://authors.library.caltech.edu/1015/1/KOPpnas05.pdf. 
  7. ↑ Strassert, Jürgen F. H.; Irisarri, Iker; Williams, Tom A.; Burki, Fabien (2021). "A molecular timescale for eukaryote evolution with implications for the origin of red algal-derived plastids". Nature 12 (1): 1879. doi:10.1038/s41467-021-22044-z. PMID 33767194. Bibcode: 2021NatCo..12.1879S. 
  8. ↑ Mänd, Kaarel; Lalonde, Stefan V.; Robbins, Leslie J.; Thoby, Marie; Paiste, Kärt; Kreitsmann, Timmu; Paiste, Päärn; Reinhard, Christopher T. et al. (April 2020). "Palaeoproterozoic oxygenated oceans following the Lomagundi–Jatuli Event". Nature Geoscience 13 (4): 302–306. doi:10.1038/s41561-020-0558-5. Bibcode: 2020NatGe..13..302M. 
  9. ↑ Van Kranendonk, Martin J. (2012). "16: A Chronostratigraphic Division of the Precambrian: Possibilities and Challenges". in Felix M. Gradstein. The geologic time scale 2012 (1st ed.). Amsterdam: Elsevier. pp. 359–365. doi:10.1016/B978-0-444-59425-9.00016-0. ISBN 978-0-44-459425-9. 
  10. ↑ Chi Fru, Ernest; Aubineau, Jérémie; Bankole, Olabode; Ghnahalla, Mohamed; Tamehe, Landry Soh; El Albani, Abderrazak (August 2024). "Hydrothermal seawater eutrophication triggered local macrobiological experimentation in the 2100 Ma Paleoproterozoic Francevillian sub-basin". Precambrian Research 409. doi:10.1016/j.precamres.2024.107453. https://linkinghub.elsevier.com/retrieve/pii/S0301926824001669. 
  11. ↑ "Complex life on Earth began around 1.5 billion years earlier than previously thought, new study claims". 2024-07-29. https://phys.org/news/2024-07-complex-life-earth-began-billion.html. 
  12. ↑ Ossa Ossa, Frantz; Pons, Marie-Laure; Bekker, Andrey; Hofmann, Axel; Poulton, Simon W.; Andersen, Morten B.; Agangi, Andrea; Gregory, Daniel et al. (June 2023). "Zinc enrichment and isotopic fractionation in a marine habitat of the c. 2.1 Ga Francevillian Group: A signature of zinc utilization by eukaryotes?" (in en). Earth and Planetary Science Letters 611. doi:10.1016/j.epsl.2023.118147. Bibcode: 2023E&PSL.61118147O. 
  13. ↑ Fakhraee, Mojtaba; Tarhan, Lidya G.; Reinhard, Christopher T.; Crowe, Sean A.; Lyons, Timothy W.; Planavsky, Noah J. (May 2023). "Earth's surface oxygenation and the rise of eukaryotic life: Relationships to the Lomagundi positive carbon isotope excursion revisited" (in en). Earth-Science Reviews 240. doi:10.1016/j.earscirev.2023.104398. Bibcode: 2023ESRv..24004398F. 

Sources

Further reading

Template:Proterozoic footer



Retrieved from "https://handwiki.org/wiki/index.php?title=Earth:Rhyacian&oldid=4232420"