6533b85afe1ef96bd12b9764

RESEARCH PRODUCT

Shallow ocean oxygen decline during the end-Triassic mass extinction

T HeRj NewtonPb WignallS ReidJd CorsoS TakahashiH WuS TodaroP Di StefanoV RandazzoM RigoAm Dunhill

subject

Global and Planetary ChangeShallow ocean deoxygenationEnd-Triassic mass extinctionEnd-Triassic mass extinction I/(Ca + Mg) Shallow ocean deoxygenation Western TethysOceanographyEnd-Triassic mass extinction; I/(Ca + Mg); Shallow ocean deoxygenation; Western TethysI/(Ca + Mg)Western Tethys

description

The end-Triassic mass extinction (ETME) was associated with intensified deep-water anoxia in epicontinental seas and mid-depth waters, yet the absolute oxygenation state in the shallow ocean is uncharacterized. Here we report carbonate-associated iodine data from the peritidal Mount Sparagio section (Southern Italy) that documents the ETME (~ 200 Ma) in the western Tethys. We find a sharp drop in carbonate I/(Ca + Mg) ratios across the extinction horizon and persisting into the Early Jurassic. This records local dissolved oxygen and iodate decline in the near-surface ocean of low-latitude Tethys due to the development of depleted oxygen concentrations. Consequently, during the ETME even shallow-water animals, such as the megalodonts seen at Mount Sparagio, were likely the victims of oxygen-poor conditions. The shallow ocean deoxygenation coincides with the synchronous spread of deeper anoxic waters and widespread anoxic deposition on continental shelves and slopes. An upwards expansion of the mid-water oxygen minimum zone in the latest Triassic shoaled the oxycline and triggered a major marine crisis.

yearjournalcountryeditionlanguage
2022-03-01Global and Planetary Change
https://doi.org/10.1016/j.gloplacha.2022.103770