Ìgbà Ọ̀rdòfísíà
| Ìgbà Ọ̀rdòfísíà 488.3–443.7 ẹgbẹgbẹ̀rún ọdun sẹ́yìn | |
| Mean atmospheric O2 content over period duration | ca. 13.5 Vol %[1] (68 % of modern level) |
| Mean atmospheric CO2 content over period duration | ca. 4200 ppm[2] (15 times pre-industrial level) |
| Mean surface temperature over period duration | ca. 16 °C[3] (2 °C above modern level) |
| Sea level (above present day) | 180m; rising to 220m in Caradoc and falling sharply to 140m in end-Ordovician glaciations[4] |
The Ordovician (pronounced /ɔrdəˈvɪʃən/) is a geologic period and system, the second of six of the Paleozoic Era, and covers the time between 488.3±1.7 to 443.7±1.5 million years ago (ICS, 2004,[5] chart). It follows the Cambrian Period and is followed by the Silurian Period. The Ordovician, named after the Celtic tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same rock beds in northern Wales into the Cambrian and Silurian periods respectively. Lapworth, recognizing that the fossil fauna in the disputed strata were different from those of either the Cambrian or the Silurian periods, realized that they should be placed in a period of their own.
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Àyọkà yìí tàbí apá rẹ̀ únfẹ́ àtúnṣe sí. Ẹ le fẹ̀ jù báyìí lọ tàbí kí ẹ ṣàtúnṣe rẹ̀ lọ́nà tí yíò mu kúnrẹ́rẹ́. Ẹ ran Wikipedia lọ́wọ́ láti fẹ̀ẹ́ jù báyìí lọ. |
Itokasi
àtúnṣe- ↑ Image:Sauerstoffgehalt-1000mj.svg
- ↑ Image:Phanerozoic Carbon Dioxide.png
- ↑ Image:All palaeotemps.png
- ↑ Haq, B. U.; Schutter, SR (2008). "A Chronology of Paleozoic Sea-Level Changes". Science 322 (5898): 64–68. doi:10.1126/science.1161648. PMID 18832639.
- ↑ Gradstein, Felix M.; Ogg, J. G.; Smith, A. G. (2004). A Geologic Time Scale 2004. Cambridge: Cambridge University Press. ISBN 0521786738.
| Preceded by Proterozoic Eon | 542 Ma - Phanerozoic Eon - Present | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 542 Ma - Paleozoic Era - 251 Ma | 251 Ma - Mesozoic Era - 65 Ma | 65 Ma - Cenozoic Era - Present | ||||||||||
| Kámbríà | Ọ̀rdòfísíà | Sílúríà | Dẹfoníà | Eléèédú | Pẹ́rmíà | Tríásíkì | Jùrásíkì | Ẹlẹ́fun | Ìbíniàtijọ́ | Ìbíniọ̀tun | Quaternary | |