NERC award to develop geochemical palaeoproxy indicators of past seawater temperature

Dr Nicola Allison has been awarded a £913,000 NERC Pushing the Frontiers award to develop marine geochemical palaeoproxy indicators of past seawater temperature. The chemistry of the mineral structures of corals (skeletons), molluscs (shells) and foraminifera (tests) are influenced by the environmental conditions prevailing at the time the organisms lived, and analysis of fossil structures provides a route to reconstruct past seawater temperatures. However, the factors influencing the chemistry of these structures are not understood and recent research shows that organisms do not directly deposit the structures but rather produce precursor phases (amorphous calcium carbonates) which eventually convert to crystalline minerals.

This ambitious project will identify how amorphous calcium carbonates form in marine calcifiers and determine how the precursor phase, influences the eventual chemistry of the crystalline minerals. The research will use innovative apparatus developed by Dr Allison at the University of St Andrews to simulate the conditions that occur in marine organisms. The project brings together multi-disciplinary researchers from earth, biological and chemical sciences at the Universities of St Andrews and Edinburgh and involves collaborators at the University of Sydney and University of California Santa Cruz. The team will produce calibrations relating the chemistry of crystalline minerals formed via the precursor phase to water temperature for application to fossil specimens.