Due to mercury (Hg) is a global pollutant, the biogeochemistry of Hg in Earth's surface environment has been well studied. However, the cycling of Hg in interior reservoirs remains less clear, limiting our understanding of the global Hg geochemical cycle. Here, we use Hg isotopes to constrain the sources of Hg in typical alkaline lamprophyres in South China: the Early Ordovician lamprophyres in the Zhenyuan area and the Late Cretaceous lamprophyres in the Zhenfeng area. Lamprophyres from both areas are enriched in large-ion-lithophile elements (LILEs) and light rare earth elements (LREEs) but depleted in high-field-strength elements (HSFEs), typical of subduction-related igneous rocks. The Early Ordovician and Late Cretaceous lamprophyres show significantly positive to near-zero Δ¹⁹⁹Hg values of 0.18 to 0.37‰ and − 0.08 to 0.36‰, respectively. The positive Δ¹⁹⁹Hg values are consistent with that reported for marine sediments and seawaters, suggesting Hg in these lamprophyres was sourced from marine reservoirs. This study suggests a heterogeneous distribution of Hg in the mantle and demonstrates that subducted marine materials can have contributed a substantial amount of Hg into the mantle.

由于汞 (Hg) 是一种全球性污染物，地球表面环境中汞的生物地球化学已经得到很好的研究。然而，内部储层中汞的循环仍然不太清楚，限制了我们对全球汞地球化学循环的理解。在这里，我们使用汞同位素来约束华南典型碱性斑岩中汞的来源：镇远地区的早奥陶世斑岩和镇丰地区的晚白垩世斑岩。来自这两个地区的灯藻富含大离子亲石元素 (LILE) 和轻稀土元素 (LREE)，但缺乏高场强元素 (HSFE)，这是与俯冲相关的火成岩的典型特征。早奥陶世和晚白垩世的斑岩显示出显着正至接近零的 Δ ¹⁹⁹Hg 值分别为 0.18 至 0.37‰ 和 - 0.08 至 0.36‰。正 Δ ¹⁹⁹ Hg 值与海洋沉积物和海水的报告一致，表明这些灯藻中的 Hg 来自海洋水库。这项研究表明，地幔中汞的分布不均匀，并表明俯冲的海洋物质可能向地幔中贡献了大量的汞。