Seafloor massive sulfide (SMS) deposits are important deep-sea mineral resources expected to occur predominantly on slow- and ultraslow-spreading mid-ocean ridges. Resource estimates are already available for some of the largest SMS deposits on slow-spreading ridges but not on ultraslow-spreading ridges. Based on geological mapping and sampling, this study investigates the distribution and content of sulfide-rich deposits in the Yuhuang-1 hydrothermal field (YHF), located on the ultraslow-spreading Southwest Indian Ridge. The sulfide-rich deposits in the YHF are composed of two areas ~500 m apart: the southwest sulfide area (SWS) and the northeast sulfide area (NES). We calculated the volume of sulfide-rich moundsin the YHF and arrived at a total accumulation of ~10.6 × 10⁶ tons, including at least ~7.5 × 10⁵ tons of copper and zinc and ~18 tons of gold. Furthermore, considering the coverage of layered hydrothermal sediment mixed with sulfide-rich breccias, which may have underlying massive sulfide deposits, the maximum total mass was estimated at ~45.1 × 10⁶ tons. This suggests that the YHF is one of the largest SMS deposits worldwide and confirm that ultraslow-spreading ridges have the greatest potential to form large-scale SMS deposits.

海底块状硫化物（SMS）矿床是重要的深海矿物资源，预计主要发生在慢速和超慢扩散的中海脊上。对于缓慢扩张的山脊上一些最大的SMS沉积物，已经提供了资源估算，但对于超缓慢扩张的山脊，则没有资源估算。基于地质测绘和采样，本研究调查了位于西南印度洋超缓分布的Yuhuang-1热液田（YHF）中富含硫化物的矿床的分布和含量。YHF中富含硫化物的矿床由两个相距约500 m的区域组成：西南硫化物区（SWS）和东北硫化物区（NES）。我们计算了YHF中富含硫化物的土堆的体积，得出的总堆积量约为10.6×10 ⁶吨，包括至少〜7.5 ×10⁵吨铜和锌，约18吨金。此外，考虑到层状热液沉积物与富含硫化物的角砾岩混合的覆盖物，其可能具有潜在的大量硫化物沉积物，最大总质量估计为〜45.1×10 ⁶吨。这表明YHF是全球最大的SMS矿床之一，并证实了超慢扩散脊具有形成大规模SMS矿床的最大潜力。