Not so non-marine? Revisiting the Stoer Group and the Mesoproterozoic biosphere
Abstract
The Poll a’Mhuilt Member of the Stoer Group (Torridonian Supergroup) in Scotland has been heralded as a rare window into the ecology of Mesoproterozoic terrestrial environments. Its unusually high molybdenum concentrations and large sulphur isotope fractionations have been used as evidence to suggest that lakes 1.2 billion years ago were better oxygenated and enriched in key nutrients relative to contemporaneous oceans, making them ideal habitats for the evolution of eukaryotes. Here we show with new Sr and Mo isotope data, supported by sedimentological evidence, that the depositional setting of this unit was likely connected to the ocean and that the elevated Mo and S contents can be explained by evapo-concentration of seawater. Thus, it remains unresolved if Mesoproterozoic lakes were important habitats for early eukaryotic life.
Citation
Stueeken , E E , Bellefroid , E , Prave , A R , Asael , D , Planavsky , N & Lyons , T 2017 , ' Not so non-marine? Revisiting the Stoer Group and the Mesoproterozoic biosphere ' , Geochemical Perspectives Letters , vol. 3 , no. 2 , pp. 221-229 . https://doi.org/10.7185/geochemlet.1725
Publication
Geochemical Perspectives Letters
Status
Peer reviewed
ISSN
2410-339XType
Journal article
Rights
Copyright © 2017 European Association of Geochemistry. This work has been made available online in accordance with the publisher’s policies. This is the final published version of the work, which was originally published at https://doi.org/10.7185/geochemlet.1725
Description
Funding for this project was provided by the NASA postdoctoral program (EES), the Lewis and Clark Fund (EES), an NSERC PGS-D grant (EJB), the NSF ELT (TWL, NJP) and FESD (TWL) programs, and the NASA Astrobiology Institute (TWL, NJP).Collections
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