Coupled Sb-Hg isotopes reveal mixed basement and deeply recycled mantle-related metal sources for the South China antimony belt

Understanding the sources of metals in hydrothermal ore systems is fundamental for improving exploration models. However, direct tracers of metal sources remain limited, especially for large, low-temperature deposits. Here we apply coupled antimony (Sb) and mercury (Hg) isotope analyses to Sb deposits from South China, the World’s largest antimony metallogenic province. The dataset reveals substantial variability in δ123Sb (−0.64 to +0.69‰), δ202Hg (−1.86 to +2.08‰), and Δ199Hg (−0.20 to +0.14‰). These data support a model involving two metal sources, namely a deep, recycled mantle-related reservoir and Precambrian basement metamorphic rocks. Our results demonstrate that coupled Sb and Hg isotopes provide a potentially powerful tool with which to identify the metal sources for Sb ore deposits, and that their application may help refine models for these deposits globally and help decode the dynamic interplay between Earth’s interior and crustal metal cycling. Coupled Sb-Hg isotope signatures from the South China antimony belt reveal that ore metals were sourced from both Precambrian basement rocks and a deep recycled mantle reservoir, demonstrating the utility of coupled Sb-Hg isotopes for tracing metal provenance, according to coupled Sb and Hg isotope analyses.