Objective The ambition with this proposal is to create ultimate paleo-environmental records for the oceans. This is a fundamental scientific challenge and the motivation is simple: The oceans take up 70% of the Earth’s surface area and represent an immense sink/source of, e.g. heat and CO2, which makes them key to the evolution of Earth’s climate. Assessing and understanding anthropogenic global climate change requires that role of the oceans is understood in detail. Proxies are needed to establish past ocean conditions with high accuracy. Calcite has played a fundamental role in these efforts because isotopic and trace element compositions of limestone and calcitic fossils are related to ocean conditions at the time of their formation. Geochemical studies of calcite in the ocean sediment record have therefore contributed enormously to the understanding of Earth’s climatic evolution over the last several hundred million years. However, our recent work (Bernard et al., Nature Communications, 2017) identifies a fundamental problem: Visually imperceptible, ultrastructure-level processes that occur during sediment diagenesis can introduce a very strong bias in these records, in particular those based on biogenic calcite; i.e. structures produced by living organisms such as foraminifera and brachiopods. Previously not investigated or taken into account, such ultrastructure-level diagenesis will (and does) create large errors in ocean paleo-environmental reconstructions, even under the close-to-ambient pressure and temperature conditions characterizing shallow sediment burial. This proposal offers a solution: An entirely new, interdisciplinary approach, including ultra-high-resolution isotopic imaging (NanoSIMS), is developed here to quantify these effects in a broad range of biogenic calcites, permitting genuinely non-biased, calcite-based paleo-ocean reconstructions to be created. The impact of this work on climate change research will be dramatic and immediate. Fields of science natural sciencesearth and related environmental sciencesatmospheric sciencesclimatologyclimatic changes Keywords Biogenic calcite diagenesis diffusion pseudomorphic replacement coupled dissolution and reprecipitation stable isotopes NanoSIMS fossils ultrastructure sediments foraminifera paleo-ocean Programme(s) H2020-EU.1.1. - EXCELLENT SCIENCE - European Research Council (ERC) Main Programme Topic(s) ERC-2017-ADG - ERC Advanced Grant Call for proposal ERC-2017-ADG See other projects for this call Funding Scheme ERC-ADG - Advanced Grant Host institution ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE Net EU contribution € 2 435 000,00 Address BATIMENT CE 3316 STATION 1 1015 Lausanne Switzerland See on map Region Schweiz/Suisse/Svizzera Région lémanique Vaud Activity type Higher or Secondary Education Establishments Links Contact the organisation Opens in new window Website Opens in new window Participation in EU R&I programmes Opens in new window HORIZON collaboration network Opens in new window Total cost € 2 435 000,00 Beneficiaries (1) Sort alphabetically Sort by Net EU contribution Expand all Collapse all ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE Switzerland Net EU contribution € 2 435 000,00 Address BATIMENT CE 3316 STATION 1 1015 Lausanne See on map Region Schweiz/Suisse/Svizzera Région lémanique Vaud Activity type Higher or Secondary Education Establishments Links Contact the organisation Opens in new window Website Opens in new window Participation in EU R&I programmes Opens in new window HORIZON collaboration network Opens in new window Total cost € 2 435 000,00