Investigating Palaeoclimate Using Spherules in the Geological Column

Sedimentary rocks contain trace amount of microspherules. These tiny grains have uncertain origins but provide important constraints on environmental, volcanological and cosmic environments. High-energy processes forming such materials include the atmospheric entry of cosmic dust, lightning strikes, wildfires, impacts and volcanic activity.

Characterising microspherules and linking them to a formation mechanism will support palaeo-environment and palaeo-climate reconstructions. This project aims to produce a classification scheme for microspherules generated by different natural processes, to enable their use as proxies throughout the geologic record.

The project includes fieldwork to collect modern and ancient microspherules and subsequent analytical methods (such as electron microscopy) to understand their compositional and textural features. Assessments of sedimentary environments will support evaluations of formation environments. Modelling will be performed, where relevant, to replicate spherule-producing processes and the features observed in collected samples. Ultimately, it is geochemistry that is likely to be the most important tool in evaluating the origins of microspherules and thus an interest in the qualitative behaviour of elements under a wide range of conditions is key.