Trace element mobilization in fulgurite: An experimental approach

Fulgurites are formed when lightning strikes ground material, producing glassy structures that can encapsulate information about the extreme conditions created by the discharge. In this study, we investigate the behavior of trace elements in fulgurites formed experimentally from tholeiitic basalt compared with those in tholeiite remelted under controlled high-temperature conditions. While remelted tholeiite provides insights into thermal processes approaching equilibrium, fulgurites represent the products of unique highly dynamic conditions that lead to distinct trace element distributions. Using ICP-MS, we analyze both experimental fulguritic tholeiite and remelted tholeiite to assess element mobility and volatility differences under extreme heat and rapid cooling. The results reveal that whereas magnesium, calcium, and aluminum show minimal variation in the remelted tholeiite, they display pronounced fluctuations in the fulgurites. Some elements exhibit more volatile behavior during lightning discharge. With fulgurite formation leading to phosphorus depletion, and an enrichment of nickel and uranium. This study provides the first comprehensive analysis of trace elements in tholeiitic fulgurites. It highlights the potential of lightning-induced geochemical processes to modify element behavior, offering new insights into the complex interactions between high-temperature events and rock composition.