Gold mineralization in hydrothermal systems at slow- to ultraslow-spreading ridges commonly occurs either in the hangingwall or the footwall of the detachment fault. However, the Tianxiu Vent Field (TVF) on Carlsberg Ridge is, to our knowledge, the only known example where the mineralization occurs directly at the termination zone of a detachment fault. Located approximately 5 km south of the rift axis near 3°48′N on the slow-spreading Carlsberg Ridge, TVF provides a unique opportunity for studying gold mineralization in this context. Detailed analyses of the mineralogy, mineral chemistry, and bulk geochemistry of massive sulfides from Tianxiu reveal several key findings: (1) both visible gold (native gold and electrum) and invisible gold are predominantly hosted in Cu-rich minerals such as isocubanite and covellite; (2) the content of Au (mean = 5.72 ± 4.38 ppm, n = 43) is positively correlated with Co, Cu, Bi, and Se; and (3) the gold mineralization occurs primarily at high-temperatures under strongly reducing conditions, with additional gold mineralization during late-stage silicification and seafloor weathering. When compared to other detachment-fault-associated deposits along slow- to ultraslow-spreading ridges, the ultramafic source rocks and the strongly reducing conditions at TVF appear to have facilitated Au mineralization. Additionally, the intensity of the fluid/rock interaction is possibly an important factor controlling the distribution of gold. The heterogeneous distribution of gold in Tianxiu is likely due to the spatial variability of fluid pathways within a highly permeable termination zone of the detachment fault. This study underscores a unique mineralization model of gold at the termination of a detachment fault on slow-spreading ridges, which has significant implications for the exploration of massive sulfide resource in off-axis regions.

热液系统中的金矿化在缓慢到超慢扩展的山脊上，通常发生在分离断层的上盘或下盘。然而，据我们所知，嘉士伯山脊的天秀喷口田 （TVF） 是已知的唯一一个矿化作用直接发生在分离断层的终止带的例子。TVF 位于裂谷轴以南约 5 公里处，靠近缓慢扩张的嘉士伯山脊北纬 3°48′，为在此背景下研究金矿化提供了独特的机会。对天秀块状硫化物的矿物学、矿物化学和块状地球化学的详细分析揭示了几个关键发现：（1） 可见金（原生金和金银）和不可见金主要存在于富含铜的矿物中，例如异方石和钙铁矿;（2） Au 的含量 （平均值 = 5.72 ± 4.38 ppm，n = 43） 与 Co、Cu、Bi 和 Se 呈正相关;（3） 金矿化主要发生在高温和强还原条件下，在后期硅化和海底风化期间会有额外的金矿化。与沿慢速至超慢扩张山脊的其他分离断层相关矿床相比，超基性烃源岩和 TVF 的强烈还原条件似乎促进了金矿化。此外，流体/岩石相互作用的强度可能是控制金分布的重要因素。天秀金的异质分布可能是由于分离断层高渗透性终止带内流体路径的空间变化。 本研究强调了在缓慢扩展的山脊上分离断层终止处金的独特矿化模型，这对离轴区域块状硫化物资源的勘探具有重要意义。