Aeronian
| Aeronian | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chronology | |||||||||||||
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| Etymology | |||||||||||||
| Name formality | Formal | ||||||||||||
| Usage information | |||||||||||||
| Celestial body | Earth | ||||||||||||
| Regional usage | Global (ICS) | ||||||||||||
| Time scale(s) used | ICS Time Scale | ||||||||||||
| Definition | |||||||||||||
| Chronological unit | Age | ||||||||||||
| Stratigraphic unit | Stage | ||||||||||||
| Time span formality | Formal | ||||||||||||
| Lower boundary definition | FAD of the graptolite Demirastrites triangulatus | ||||||||||||
| Lower boundary GSSP | Hlásná Třebaň section, Czech Republic 49°55′23″N 14°12′43″E / 49.9230°N 14.2119°E[4] | ||||||||||||
| Lower GSSP ratified | 2024[5][6] | ||||||||||||
| Upper boundary definition | FAD of the graptolite Spirograptus guerichi | ||||||||||||
| Upper boundary GSSP | El Pintado section,
Seville, Spain 37°59′07″N 5°55′43″W / 37.9853°N 5.9285°W[4] | ||||||||||||
| Upper GSSP ratified | 2024[5][7] | ||||||||||||
In the geologic timescale, the Aeronian is an age of the Llandovery Epoch of the Silurian Period of the Paleozoic Era of the Phanerozoic Eon that began 440.8 ± 1.2 Ma and ended 438.5 ± 1.1 Ma (million years ago). The Aeronian Age succeeds the Rhuddanian Age and precedes the Telychian Age, all in the same epoch.[8]
During the Aeronian the Sedgwickii Event occurred in which graptolite diversity was greatly reduced.[9] This event has been attested in locations such as today's Canada, Libya as well as in La Chilca Formation in Argentina (then part of Gondwana).[9]
GSSP
[edit]The GSSP is located in the Trefawr Track section, 500m north of Cwm-coed-Aeron Farm, Wales, UK.[10] The GSSP lies within the gently-dipping blocky mudstones of the Trefawr Formation, which principally yield abundant and diverse shelly faunas, but also contain enough graptolites to allow recognition of several biozones.[11]
References
[edit]- ^ 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.
- ^ 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.
- ^ "International Chronostratigraphic Chart" (PDF). International Commission on Stratigraphy. September 2023. Retrieved December 16, 2024.
- ^ a b "Global Boundary Stratotype Section and Point". International Commission of Stratigraphy. Retrieved 3 August 2024.
- ^ a b "Silurian Telychian and Aeronian stage GSSPs have been relocated". stratigraphy.org. International Commission on Stratigraphy. Retrieved 1 March 2024.
- ^ Štorch, Petr. "Formal proposal for a new Global Boundary Stratotype Section and Point (GSSP) for the Aeronian Stage at Hlásná Třebaň, Czech Republic" (PDF). International Commission on Stratigraphy. Retrieved 16 April 2024.
- ^ Gutierrez-Marco, Juan Carlos (August 2022). "SILURIAN TREASURES IN SPANISH UNESCO GLOBAL GEOPARKS. Silurian Times, 29 (for 2021), 16-21. -Aparecido en 2022-". doi:10.13140/RG.2.2.13314.15044. Retrieved 1 March 2024.
{{cite journal}}: Cite journal requires|journal=(help) - ^ "GSSP Table - All Periods". International Commission on Stratigraphy. Retrieved 2018-09-15.
- ^ a b Lopez, Fernando Enrique; Kaufmann, Cintia (2023). "New insights on the Silurian graptolite biostratigraphy of the La Chilca Formation, Poblete Norte section, Central Precordillera of San Juan, Argentina: faunal replacement and paleoenvironmental implications". Andean Geology. 50 (2). doi:10.5027/andgeov50n2-3617.
- ^ Gradstein, Felix M.; Ogg, James G.; Smith, Alan G. (2004). A Geologic Time Scale 2004. ISBN 9780521786737.
- ^ "GSSP for Aeronian Stage". International Commission on Stratigraphy. Retrieved September 15, 2018.
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