Arsenic (As) cycling in magmatic systems is influenced by tectonic and magmatic processes, yet its long-term behavior is not well understood. This study uses global whole-rock geochemical data of igneous rocks to examine As concentration variations over geological time. The results show a correlation between As fluctuations and supercontinent cycles, with lower concentrations during supercontinent assembly, linked to deep mantle-derived magmas, and higher concentrations during breakup, related to crustal recycling and shallower magmatic sources. Deeper magmas (< 34 km) have lower As levels, while shallower sources exhibit higher concentrations. Time-series analysis of As in igneous and sedimentary rocks reveals a 436-million-year cyclic pattern, driven by tectonic and magmatic events, with a 220-million-year lag between magmatic arsenic cycling and its effects on sedimentary systems. This study enhances understanding of arsenic cycling, its connections to magmatic differentiation, tectonic evolution, and mineralization, with implications for resource exploration.
Cheng et al. (2026) studied this question.