Telychian

Telychian
438.5 ± 1.1 – 433.4 ± 0.8 Ma
Paleogeography of the Telychian, 435 Ma
Chronology
Etymology
Name formalityFormal
Usage information
Celestial bodyEarth
Regional usageGlobal (ICS)
Time scale(s) usedICS Time Scale
Definition
Chronological unitAge
Stratigraphic unitStage
Time span formalityFormal
Lower boundary definitionFAD of the graptolite Spirograptus guerichi
Lower boundary GSSPEl Pintado section, Seville, Spain
37°59′07″N 5°55′43″W / 37.9853°N 5.9285°W / 37.9853; -5.9285[4]
Lower GSSP ratified2024[5][6]
Upper boundary definitionImprecise. Currently placed between acritarch biozone 5 and LAD of Pterospathodus amorphognathoides. See Llandovery for more info.
Upper boundary definition candidatesA conodont boundary (Ireviken datum 2) which is close to the murchisoni graptolite biozone.
Upper boundary GSSP candidate section(s)None
Upper boundary GSSPHughley Brook, Apedale, UK
52°34′52″N 2°38′20″W / 52.5811°N 2.6389°W / 52.5811; -2.6389
Upper GSSP ratified1980[7]

In the geologic timescale, the Telychian is the third and final age of the Llandovery Epoch of the Silurian Period of the Paleozoic Era of the Phanerozoic Eon. The Telychian Age was between 438.5 ± 1.2 million years ago (Ma) and 433.4 ± 0.8 Ma. The Telychian Age succeeds the Aeronian Age and precedes the Sheinwoodian Age.[8] The name of the interval is derived from the Pen-lan-Telych Farm near Llandovery, Powys, Wales.

It ended with the Ireviken event.

Ireviken event

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The Ireviken event was the first of three relatively minor extinction events (the Ireviken, Mulde, and Lau events) during the Silurian Period. It occurred at the Llandovery/Wenlock boundary (mid Silurian, 433.4 ± 0.8  million years ago). The event is best recorded at Ireviken, Gotland, where over 50% of trilobite species became extinct; 80% of the global conodont species also become extinct in this interval.

References

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  1. ^ Jeppsson, L.; Calner, M. (2007). "The Silurian Mulde Event and a scenario for secundo—secundo events". Earth and Environmental Science Transactions of the Royal Society of Edinburgh. 93 (02): 135–154. doi:10.1017/S0263593300000377.
  2. ^ Munnecke, A.; Samtleben, C.; Bickert, T. (2003). "The Ireviken Event in the lower Silurian of Gotland, Sweden-relation to similar Palaeozoic and Proterozoic events". Palaeogeography, Palaeoclimatology, Palaeoecology. 195 (1): 99–124. doi:10.1016/S0031-0182(03)00304-3.
  3. ^ "Chart/Time Scale". www.stratigraphy.org. International Commission on Stratigraphy.
  4. ^ "Global Boundary Stratotype Section and Point". International Commission of Stratigraphy. Retrieved 3 August 2024.
  5. ^ Gutierrez-Marco, Juan Carlos (2021). "Silurian Treasures in Spanish UNESCO Global Geoparks" (PDF). Silurian Times. 29: 16–21. doi:10.13140/RG.2.2.13314.15044.
  6. ^ "Silurian Telychian and Aeronian stage GSSPs have been relocated". stratigraphy.org. International Commission on Stratigraphy. Retrieved 1 March 2024.
  7. ^ Holland, C. (1982). "The State of Silurian Stratigraphy" (PDF). Episodes. 1982: 21–23. Retrieved 11 December 2020.
  8. ^ Gradstein, Felix M.; Ogg, James G.; Smith, Alan G. (2004). A Geologic Time Scale 2004. ISBN 9780521786737.