Lithium fingerprints across the silicic volcanic life cycle

Speaker: Dr Julia Neukampf (University of Manchester)
Series: Department of Earth Sciences Seminars (downtown)

Lithium is a powerful tracer of processes occurring in volcanic systems, offering unique insights into how silicic magmas evolve during storage in magma chambers, ascent, eruption, and cooling at the Earth’s surface. Owing to its rapid diffusion and large isotopic mass difference, lithium is highly sensitive to processes such as degassing, chemical exchange, and cooling, making it an effective tracer of shallow magmatic processes. However, the extent to which lithium records primary magmatic degassing, as opposed to post-eruptive modification, remains poorly constrained due to its rapid mobility and the overprinting of magmatic signatures during cooling and hydration after eruption.

In this talk, I present results from studies of lithium concentrations and isotopes across a range of volcanic materials, including melt inclusions, minerals, groundmass glass, ignimbrites, and lavas. These data reveal how lithium records degassing processes operating in magma chambers, but also how these signals can be modified during post-eruptive cooling. The results demonstrate that rapidly quenched materials can preserve primary magmatic signatures, whereas more slowly cooled deposits often experience significant overprinting due to lithium mobility. These findings have important implications for interpreting geochemical records of volcanic degassing, constraining timescales of magmatic processes, and understanding how lithium becomes concentrated and redistributed in silicic magmas and volcanic deposits.