The onset of widespread marine red beds and the evolution of ferruginous oceans
Document Type
Article
Publication Date
1-1-2017
Publication Title
Nature Communications
Volume
8
Issue
1
Abstract
Banded iron formations were a prevalent feature of marine sedimentation ~3.8-1.8 billion years ago and they provide key evidence for ferruginous oceans. The disappearance of banded iron formations at ~1.8 billion years ago was traditionally taken as evidence for the demise of ferruginous oceans, but recent geochemical studies show that ferruginous conditions persisted throughout the later Precambrian, and were even a feature of Phanerozoic ocean anoxic events. Here, to reconcile these observations, we track the evolution of oceanic Fe-concentrations by considering the temporal record of banded iron formations and marine red beds. We find that marine red beds are a prominent feature of the sedimentary record since the middle Ediacaran (~580 million years ago). Geochemical analyses and thermodynamic modelling reveal that marine red beds formed when deep-ocean Fe-concentrations were > 4 nM. By contrast, banded iron formations formed when Fe-concentrations were much higher (> 50 μM). Thus, the first widespread development of marine red beds constrains the timing of deep-ocean oxygenation. © 2017 The Author(s).
Language
english
Repository Citation
Song, H.,
Jiang, G.,
Poulton, S. W.,
Wignall, P. B.,
Tong, J.,
Song, H.,
An, Z.,
Chu, D.,
Tian, L.,
She, Z.,
Wang, C.
(2017).
The onset of widespread marine red beds and the evolution of ferruginous oceans.
Nature Communications, 8(1),
http://dx.doi.org/10.1038/s41467-017-00502-x