Rhyacian

Rhyacian Period 2300–2050 million years ago PreЄ Є O S D C P T J K Pg N

The Rhyacian (pronunciation: /raɪˈeɪsiən/; Greek: Ρυαξ (rhyax), meaning "stream of lava") is the second geologic period in the Paleoproterozoic Era and lasted from 2300 Mya to 2050 Mya (million years ago).^[1] Instead of being based on stratigraphy, these dates are defined chronometrically.^[2]

The Bushveld Igneous Complex and other similar intrusions formed during this period.^[2]

The Huronian (Makganyene) global glaciation began at the start of the Rhyacian and lasted until 2200 Mya^[3]

The first known eukaryotes began to evolve in the Rhyacian period. The multicellular Francevillian Group Fossils, at 2.1-Gyr-old are from the Rhyacian period.^[4]

References

1. "Rhyacian Period". GeoWhen Database. Archived from the original on August 19, 2006. Retrieved January 5, 2006.
2. James G. Ogg (2004). "Status on Divisions of the International Geologic Time Scale". Lethaia 37 (2): 183–199. doi:10.1080/00241160410006492.
3. Kopp; Kirschvink, JL; Hilburn, IA; Nash, CZ; et al. (August 2005). "The Paleoproterozoic Snowball: A climate disaster triggered by the evolution of oxygenic photosynthesis". PNAS 102 (32): 11131–6. Bibcode:2005PNAS..10211131K. doi:10.1073/pnas.0504878102. PMC 1183582. PMID 16061801.
4. El Albani, Abderrazak; Bengtson, Stefan; Canfield, Donald E.; Bekker, Andrey; Macchiarelli, Reberto (July 2010). "Large colonial organisms with coordinated growth in oxygenated environments 2.1 Gyr ago". Nature 466 (7302): 100–104. Bibcode:2010Natur.466..100A. doi:10.1038/nature09166. PMID 20596019.