Using neutron tomography to understand Neoproterozoic stromatolite morphology and mineral phase relationships

Stromatolites are laminated organo-sedimentary structures formed due to complex interactions between biological activity, sedimentation, and mineral precipitation. In this proposal, we seek to conduct high-resolution (spatial resolution = 0.06 mm) neutron tomography of diverse 1000–900 million-year-old fossil stromatolites from the Neoproterozoic Era, a period of environmental perturbations featuring major glacial events and rapid atmospheric oxygenation. We will acquire 3D volumes within three distinct stromatolites in order to understand relationships between biological layers and carbonate layers, identifying mineralogical phenomena and spatial distributions of diverse carbonate minerals to elucidate their mineralisation pathways, and provide 3D contextualisation of inorganic geochemical analyses that are also being conducted on these materials as part of a wider research programme.