Mulde event

The Mulde event was an anoxic event,^[4] and marked the second of three¹ relatively minor mass extinctions (the Ireviken, Mulde, and Lau events) during the Silurian period. It coincided with a global drop in sea level, and is closely followed by an excursion^{[clarification needed]} in geochemical isotopes. Its onset is synchronous with the deposition of the Fröjel Formation in Gotland.^[4] Perceived extinction in the conodont fauna, however, likely represent a change in the depositional environment of sedimentary sequences rather than a genuine biological extinction.^[5]

Silurian graphical timeline
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−444 — – −442 — – −440 — – −438 — – −436 — – −434 — – −432 — – −430 — – −428 — – −426 — – −424 — – −422 — – −420 — – −418 —	Paleozoic Ordovician Silurian Devonian Llandovery Wenlock Ludlow Přídolí Rhuddanian Aeronian Telychian Sheinwoodian Homerian Gorstian Ludfordian	← Lau event ← Mulde event[1] ← Ireviken event[2]
Subdivision of the Silurian according to the ICS, as of 2023.[3] Vertical axis scale: Millions of years ago

Higher resolution δ¹³C isotope analysis identifies differences in the organic and carbonate carbon isotope curves (Δ¹³C), allowing the inference of a sustained drop in CO₂ levels coincident with the extinction once sedimentological data are taken into account.^[6]

Notes

^1 The Ireviken, Mulde, and Lau events were all closely followed by isotopic excursions.