Journal
EARTH AND PLANETARY SCIENCE LETTERS
Volume 577, Issue -, Pages -Publisher
ELSEVIER
DOI: 10.1016/j.epsl.2021.117274
Keywords
DOM (Dissolved Organic Matter); carbon isotope perturbations; strontium isotopes; sulfur isotopes; uranium isotopes; metazoans
Categories
Funding
- Strategic Priority Research Program (B) of the Chinese Academy of Sciences [XDB26000000, XDB18000000]
- National Natural Science Foundation of China [41661134048, 41921002]
- NERC [N018559/1, NE/S009663/1]
- NERC-NSFC programme 'Biosphere Evolution, Transitions and Resilience' [NE/P013643/1]
- State Key Laboratory of Palaeobiology and Stratigraphy, Chinese Academy of Sciences [20172101, 2018KF03]
- Royal Society Wolfson Research Merit Award
Ask authors/readers for more resources
The Ediacaran Period was characterized by major carbon isotope perturbations, including anomalies similar to the Shuram/DOUNCE anomaly at 570 Ma and the WANCE anomaly at 610 Ma. These anomalies were associated with expansions in oxygenated seawater and environmental perturbations. New uranium isotope data, as well as strontium and sulfur isotope data, provide evidence of environmental changes during these anomalies.
The Ediacaran Period was characterised by major carbon isotope perturbations. The most extreme of these, the similar to 570 Ma Shuram/DOUNCE (Doushantuo Negative Carbon isotope Excursion) anomaly, coincided with early radiations of benthic macrofauna linked to a temporary expansion in the extent of oxygenated seawater. Here we document an earlier negative excursion (the similar to 610 Ma WANCE (Weng'An Negative Carbon isotope Excursion)) anomaly in the Yangtze Gorges area, South China, that reached equally extreme carbon isotope values and was associated with a similar degree of environmental perturbation. Specifically, new uranium isotope data evidence a significant, but transient, shift towards more oxygenated conditions in tandem with decreasing carbon isotope values, while strontium and sulfur isotope data support an increase in continental weathering through the excursion. We utilize a biogeochemical modelling approach to demonstrate that the influx of such a weathering pulse into an organically-laden, largely anoxic ocean, fully reproduces each of these distinct isotopic trends. Our study directly supports the hypothesis that a large dissolved marine organic pool effectively buffered against widespread oxygenation of the marine environment through the Proterozoic Eon, and in doing so, substantially delayed the radiation of complex aerobic life on Earth. (C) 2021 Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available