Rhyacian
The Rhyacian (/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 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
- ↑ "Rhyacian Period". GeoWhen Database. Archived from the original on August 19, 2006. Retrieved January 5, 2006.
- ↑ 2.0 2.1 James G. Ogg (2004). "Status on Divisions of the International Geologic Time Scale". Lethaia 37 (2): 183–199. doi:10.1080/00241160410006492.
- ↑ 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.
- ↑ 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.
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