Contrasting microfossil preservation and lake chemistries within the 1200–1000 Ma Torridonian Supergroup of NW Scotland

Wacey, D. et al. (2017) Contrasting microfossil preservation and lake chemistries within the 1200–1000 Ma Torridonian Supergroup of NW Scotland. Geological Society, London, Special Publications, 448, pp. 105-119. (doi: 10.1144/SP448.6)

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Abstract

Oxygenation of the Proterozoic atmosphere caused the progressive build-up of dissolved sulphate on the continents and in marine environments. However, oxygen levels in the Proterozoic were low enough to allow the early burial of biological material into low redox potential environments where permineralization and the authigenic replacement of organic material, including micro-organisms, occurred by a range of minerals. Consequently, microbial sulphate reduction caused the widespread degradation of organic matter and, where iron was available, the precipitation of pyrite. By contrast, where sulphate levels were low, early preservation by other minerals (e.g. phosphate or silica) could be excellent. We show, using two Proterozoic lake sequences with low and high sulphate chemistries, but with otherwise similar characteristics, that microbial sulphate reduction caused a profound loss of morphological detail and diversity within preserved microfossils. The results could imply that there is a significant bias in the Proterozoic fossil record towards low sulphate environments, which were in reality relatively scarce.

Item Type:Articles
Additional Information:We acknowledge the Australian Microscopy & Microanalysis Research Facility at the Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, a facility funded by the University, State and Commonwealth Governments. DW acknowledges funding from the European Commission and the Australian CONTRASTING MICROFOSSIL PRESERVATION, TORRIDONIAN 117 Research Council.
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Boyce, Professor Adrian
Authors: Wacey, D., Brasier, M., Parnell, J., Culwick, T., Bowden, S., Spinks, S., Boyce, A. J., Davidheiser-Kroll, B., Jeon, H., Saunders, M., and Kilburn, M. R.
College/School:College of Science and Engineering > Scottish Universities Environmental Research Centre
Journal Name:Geological Society, London, Special Publications
Publisher:Geological Society
ISSN:0305-8719
ISSN (Online):2041-4927
Published Online:15 September 2016
Copyright Holders:Copyright © 2017 The Authors
First Published:First published in Geological Society, London, Special Publications 448:105-119
Publisher Policy:Reproduced under a Creative Commons License

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