UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

Unique Neoproterozoic carbon isotope excursions sustained by coupled evaporite dissolution and pyrite burial

Shields, G; Mills, B; Zhu, M; Daines, S; Lenton, T; (2019) Unique Neoproterozoic carbon isotope excursions sustained by coupled evaporite dissolution and pyrite burial. Nature Geoscience , 12 pp. 823-827. 10.1038/s41561-019-0434-3. Green open access

[thumbnail of Article]
Preview
Text (Article)
Shields NGS-2019-01-00062B - final manuscript.pdf - Accepted version

Download (1MB) | Preview
[thumbnail of Figures]
Preview
Text (Figures)
Figures - combined.pdf - Accepted version

Download (730kB) | Preview

Abstract

The Neoproterozoic era witnessed a succession of biological innovations that culminated in diverse animal body plans and behaviours during the Ediacaran–Cambrian radiations. Intriguingly, this interval is also marked by perturbations to the global carbon cycle, as evidenced by extreme fluctuations in climate and carbon isotopes. The Neoproterozoic isotope record has defied parsimonious explanation because sustained 12C-enrichment (low δ13C) in seawater seems to imply that substantially more oxygen was consumed by organic carbon oxidation than could possibly have been available. We propose a solution to this problem, in which carbon and oxygen cycles can maintain dynamic equilibrium during negative δ13C excursions when surplus oxidant is generated through bacterial reduction of sulfate that originates from evaporite weathering. Coupling of evaporite dissolution with pyrite burial drives a positive feedback loop whereby net oxidation of marine organic carbon can sustain greenhouse forcing of chemical weathering, nutrient input and ocean margin euxinia. Our proposed framework is particularly applicable to the late Ediacaran ‘Shuram’ isotope excursion that directly preceded the emergence of energetic metazoan metabolisms during the Ediacaran–Cambrian transition. Here we show that non-steady-state sulfate dynamics contributed to climate change, episodic ocean oxygenation and opportunistic radiations of aerobic life during the Neoproterozoic era.

Type: Article
Title: Unique Neoproterozoic carbon isotope excursions sustained by coupled evaporite dissolution and pyrite burial
Open access status: An open access version is available from UCL Discovery
DOI: 10.1038/s41561-019-0434-3
Publisher version: https://doi.org/10.1038/s41561-019-0434-3
Language: English
Additional information: This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions.
Keywords: Carbon cycle, Palaeoceanography
UCL classification: UCL
UCL > Provost and Vice Provost Offices > UCL BEAMS
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Earth Sciences
URI: https://discovery.ucl.ac.uk/id/eprint/10080712
Downloads since deposit
83Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item