Duration and intensity of end-Permian Marine Anoxia
Abstract/Contents
- Abstract
- Ocean anoxia was an important kill mechanism in the end-Permian mass extinction and uranium isotope data are among the most powerful tools for quantifying the global extent and duration of ocean deoxygenation. Although coherent stratigraphic variation in uranium isotope ratios (δ238U) and uranium concentrations ([U]) indicative of prolonged deoxygenation is well established, the precise extent of anoxia and associated uncertainty have yet to be quantified. Uncertainty arises from both noise in the data and imprecise knowledge of key parameters within the uranium cycle. In this study, we use the Monte Carlo method to explore a range of scenarios and their implications for the uranium cycle across the Permian-Triassic boundary and through the first 1.7 million years of the Triassic. We then compare model predictions against measured data using principal component analysis to identify model runs and associated parameter values most compatible with trends in the observed data. The best-fitting models indicate a pronounced increase in the extent of seafloor anoxia across the Permian/Triassic transition, reaching ~17.8% of the seafloor (95% CI: [10.9%, 47.1%]), lasting anywhere from 20 kyr to 1.2 Myr. There is an inverse relationship between the extent and duration of anoxia in the set of best-fitting models. This initial pulse of pronounced anoxia is followed by a prolonged aftermath, which continues through the remainder of the study interval, of less extensive, yet still expanded, anoxia covering 7.8% of the seafloor (95% CI: 1.6%, 48.9%]). Both expanded and protracted anoxia are required to fit existing data, with no indication of re-oxygenation during the study interval.
Description
| Type of resource | text |
|---|---|
| Date created | August 20, 2021 |
| Date modified | December 5, 2022 |
| Publication date | August 23, 2021 |
Creators/Contributors
| Author | Pimentel-Galvan, Michael |
|---|---|
| Author | Payne, Jonathan |
| Author | Mukerji, Tapan |
| Author | Lau, Kimberly |
| Author | Maher, Katharine |
Subjects
| Subject | Anoxia |
|---|---|
| Subject | Uranium > Isotopes |
| Subject | Uranium > Concentrations |
| Subject | end-Permian |
| Subject | Monte Carlo method |
| Genre | Text |
| Genre | Thesis |
Bibliographic information
Access conditions
- Use and reproduction
- User agrees that, where applicable, content will not be used to identify or to otherwise infringe the privacy or confidentiality rights of individuals. Content distributed via the Stanford Digital Repository may be subject to additional license and use restrictions applied by the depositor.
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 4.0 International license (CC BY-NC).
Preferred citation
- Preferred citation
- Pimentel-Galvan, M., Payne, J., and Mukerji, T. (2021). Duration and intensity of end-Permian Marine Anoxia. Stanford Digital Repository. Available at https://purl.stanford.edu/yk734tv4224
Collection
Master's Theses, Doerr School of Sustainability
View other items in this collection in SearchWorksContact information
- Contact
- michaelpimentel65@gmail.com
Also listed in
Loading usage metrics...