Ediacaran-Cambrian bioturbation did not extensively oxygenate sediments in shallow marine ecosystems
Cribb, A.T.; van de Velde, S.J.; Berelson, W.M.; Bottjer, D.J.; Corsetti, F.A. (2023). Ediacaran-Cambrian bioturbation did not extensively oxygenate sediments in shallow marine ecosystems. Geobiol. 21(4): 435-453. https://dx.doi.org/10.1111/gbi.12550 In: Geobiology. Blackwell: Oxford. ISSN 1472-4677; e-ISSN 1472-4669, more |   |
| Authors | | Top | - Cribb, A.T.
- van de Velde, S.J., more
- Berelson, W.M.
| - Bottjer, D.J.
- Corsetti, F.A.
| |
| Abstract | The radiation of bioturbation during the Ediacaran–Cambrian transition has long been hypothesized to have oxygenated sediments, triggering an expansion of the habitable benthic zone and promoting increased infaunal tiering in early Paleozoic benthic communities. However, the effects of bioturbation on sediment oxygen are underexplored with respect to the importance of biomixing and bioirrigation, two bioturbation processes which can have opposite effects on sediment redox chemistry. We categorized trace fossils from the Ediacaran and Terreneuvian as biomixing or bioirrigation fossils and integrated sedimentological proxies for bioturbation intensity with biogeochemical modeling to simulate oxygen penetration depths through the Ediacaran–Cambrian transition. Ultimately, we find that despite dramatic increases in ichnodiversity in the Terreneuvian, biomixing remains the dominant bioturbation behavior, and in contrast to traditional assumptions, Ediacaran–Cambrian bioturbation was unlikely to have resulted in extensive oxygenation of shallow marine sediments globally. |
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