Aeronian

Aeronian
Aeronian
440.8 ± 1.2 – 438.5 ± 1.1 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Chronology
	Subdivision of the Silurian according to the ICS, as of 2021.; Vertical axis scale: millions of years ago.;

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.^[7]

EtymologyName formalityFormalUsage informationCelestial bodyEarthRegional usageGlobal (ICS)Time scale(s) usedICS Time ScaleDefinitionChronological unitAgeStratigraphic unitStageTime span formalityFormalLower boundary definitionFAD of the graptolite Demirastrites triangulatusLower boundary GSSPHlásná Třebaň section, Czech RepublicLower GSSP ratified2024^[4]^[5]Upper boundary definitionFAD of the graptolite Spirograptus guerichiUpper boundary GSSPEl Pintado section, Seville, SpainUpper GSSP ratified2024^[4]^[6]

During the Aeronian the Sedgwickii Event occurred in which graptolite diversity was greatly reduced.^[8] 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).^[8]

GSSP

The GSSP is located in the Trefawr Track section, 500m north of Cwm-coed-Aeron Farm, Wales, UK.^[9] 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.^[10]

References

[7]

[3]

[4]

[5]

[6]

[8]

[9]

[10]

Aeronian
440.8 ± 1.2 – 438.5 ± 1.1 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Chronology

Subdivision of the Silurian according to the ICS, as of 2021.^[3] Vertical axis scale: millions of years ago.