Seafloor hydrothermal chimneys are significant metal resources and have fundamental effects on marine chemistry balance. Previous studies on growth of the chimneys focused on mineral composition and elemental distribution in chimney walls, but the isotopic composition of different elements and their correlations remain poorly understood. Here, we report lateral Fe and S isotopes from sulfides across a chimney wall in detail from the Deyin-1 hydrothermal field (DHF) on the South Mid-Atlantic Ridge. Pyrite was characterized by increases in both δ³⁴S and δ⁵⁶Fe from the exterior to the interior within the chimney wall, which is likely related to enhanced S and Fe isotope fractionation between pyrite and fluids derived from the temperature gradient. Furthermore, δ⁵⁶Fe displayed a well-defined, linear, positive correlation with δ³⁴S in pyrite from the DHF as well as in pyrite from other areas. A model of hydrothermal pyrite formation suggests that, under conditions with uniform hydrothermal fluid, different temperatures and similar pyrite–fluid exchange degrees could result in the observed linear relationships between δ³⁴S and δ⁵⁶Fe. The regular and coupled Fe–S isotope variations within the chimney wall efficiently constrain the process of hydrothermal sulfide formation.

海底热液烟囱是重要的金属资源，对海洋化学平衡具有根本性影响。以往关于烟囱生长的研究主要集中在烟囱壁中的矿物成分和元素分布，但对不同元素的同位素组成及其相关性仍知之甚少。在这里，我们详细报告了南大西洋中脊 Deyin-1 热液田 (DHF) 中穿过烟囱壁的硫化物的侧向 Fe 和 S 同位素。黄铁矿的特征是烟囱壁内的δ ³⁴ S 和δ ⁵⁶ Fe 从外向内增加，这可能与黄铁矿与温度梯度产生的流体之间增强的 S 和 Fe 同位素分馏有关。此外，δ ⁵⁶ Fe与 DHF 黄铁矿以及其他地区黄铁矿中的δ ³⁴ S显示出明确的线性正相关关系。热液黄铁矿形成模型表明，在热流体均匀的条件下，不同的温度和相似的黄铁矿-流体交换度可能导致观察到的δ ³⁴ S 和δ ⁵⁶ Fe 之间的线性关系。烟囱壁内规则和耦合的 Fe-S 同位素变化有效地限制了热液硫化物的形成过程。