none 10.1144/SP448.6 Geological Society of London Geological Society of London 1881 85187791 65091 2024072316115600521 10.1144 2024-07-24T00:37:07Z 2016-09-15T21:43:28Z 3 Geological Society, London, Special Publications SP 0305-8719 2041-4927 05 24 2017 01 2017 448 1 David Wacey Centre for Microscopy Characterisation and Analysis, and Australian Research Council Centre of Excellence for Core to Crust Fluid Systems, The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia School of Earth Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK Martin Brasier Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN, UK John Parnell School of Geosciences, University of Aberdeen, Aberdeen AB24 3UE, UK Timothy Culwick Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN, UK Stephen Bowden School of Geosciences, University of Aberdeen, Aberdeen AB24 3UE, UK Sam Spinks CSIRO Mineral Resources Flagship, Australian Resources Research Centre, Perth, WA 6151, Australia Adrian J. Boyce Scottish Universities Environmental Research Centre, East Kilbride, Glasgow G75 0QF, UK Brett Davidheiser-Kroll Scottish Universities Environmental Research Centre, East Kilbride, Glasgow G75 0QF, UK Heejin Jeon Centre for Microscopy Characterisation and Analysis, and Australian Research Council Centre of Excellence for Core to Crust Fluid Systems, The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia Martin Saunders Centre for Microscopy Characterisation and Analysis, and Australian Research Council Centre of Excellence for Core to Crust Fluid Systems, The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia Matt R. Kilburn Centre for Microscopy Characterisation and Analysis, and Australian Research Council Centre of Excellence for Core to Crust Fluid Systems, The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia 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. 09 15 2016 01 2017 105 119 10.1144/SP448.6 2.0 10.1144/crossmark-policy lyellcollection.org true http://creativecommons.org/licenses/by/3.0/ 10.1144/SP448.6 https://www.lyellcollection.org/doi/10.1144/SP448.6 https://www.lyellcollection.org/doi/pdf/10.1144/SP448.6 https://pubs.geoscienceworld.org/books/book/2056/chapter/112697270/contrasting-microfossil-preservation-and-lake https://pubs.geoscienceworld.org/UrlRedirectHandler.ashx?routename=books&chapterdoi=10.1144/SP448.6&request=chapter 10.1144/0016-76492009-105 10.1016/j.precamres.2011.12.012 10.1111/jpy.12111 10.1016/j.gca.2011.12.008 10.1130/0091-7613(1991)019<1221:POSBFB>2.3.CO;2 10.2475/ajs.296.6.633 Electron Energy Loss Spectroscopy Brydson R. 2001 BrydsonR. 2001. Electron Energy Loss Spectroscopy. Springer, New York. 10.1111/pala.12139 10.1073/pnas.0902037106 10.1016/0009-2541(86)90078-1 10.1144/0016-76492006-115 10.1130/0016-7606(1971)82[3469:NPNFTS]2.0.CO;2 10.1017/pab.2015.25 10.1101/cshperspect.a016139 10.1073/pnas.1218851110 10.1038/nature02974 10.2110/palo.2013.p13-005r 10.1134/S0026261712040091 10.1016/j.precamres.2009.05.005 10.1002/9781118280874.ch20 10.1080/03115517608619066 10.1038/nature09538 10.1144/0016-76492010-099 10.1180/minmag.2014.078.1.04 10.1038/ncomms7996 10.1666/0094-8373(2000)026<0360:TAITNE>2.0.CO;2 10.1021/ac60357a026 10.1016/S0016-7037(99)00087-3 10.1038/ncomms6754 10.1016/j.precamres.2014.09.026 Geological Society, London, Memoirs The Later Proterozoic Torridonian Rocks of Scotland: Their Sedimentology, Geochemistry and Origin Stewart A.D. 2002 StewartA.D. 2002. The Later Proterozoic Torridonian Rocks of Scotland: Their Sedimentology, Geochemistry and Origin. Geological Society, London, Memoirs, 24, http://mem.lyellcollection.org/content/24/1.toc 10.1038/nature09943 Journal of Palaeogeography Tang D. 275 2 2013 Environment controls on Mesoproterozoic thrombolite morphogenesis: a case study from the North China Platform TangD., ShiX., JiangG., PeiY. & ZhangW. 2013. Environment controls on Mesoproterozoic thrombolite morphogenesis: a case study from the North China Platform. Journal of Palaeogeography, 2, 275–296. 10.1144/gsjgs.153.6.0955 10.1038/ngeo1238 10.1016/j.precamres.2012.08.005 10.1073/pnas.1221965110 10.1038/srep05841 10.1016/j.earscirev.2009.11.004 10.1111/pala.12172 10.4319/lo.1984.29.2.0236