C–O–H–N–S-bearing fluids are known as one of the most challenging geochemical systems due to scarcity of available experimental data. H₂S-rich fluid systems were recognized in a wide array of world-class mineral deposits and hydrocarbon reservoirs. Here we report on a nature of low-temperature (T ≥ −192 °C) phase transitions observed in natural CH₄–H₂S–CO₂–N₂–H₂O fluid inclusions, which are modeled as closed thermodynamic systems and thus serve as natural micro-laboratories representative of the C–O–H–N–S system. For the first time, we document solid–solid H₂S (α ↔ β ↔ γ) transitions, complex clathrates and structural transformations of solid state H₂S in natural inclusion gas mixtures. The new data on Raman spectroscopic features and a complete sequence of phase transition temperatures in the gas mixtures contribute to scientific advancements in fluid geochemistry. Enhanced understanding of the phase equilibria in the C–O–H–N–S system is a prerequisite for conscientious estimation of P-T-V-X properties, necessary to model the geologic evolution of hydrocarbon and mineral systems. Our findings are a driver for the future research expeditions to extraterrestrial H₂S-rich planetary systems owing to their low temperature environments.

由于缺乏可用的实验数据，含 C–O–H–N–S 的流体被认为是最具挑战性的地球化学系统之一。富含H ₂ S 的流体系统在广泛的世界级矿床和油气藏中得到认可。 在这里，我们报告了在天然 CH ₄ –H ₂ S–CO ₂ –N ₂ –H ₂ O 流体包裹体中观察到的低温 ( T ≥ −192 °C) 相变的性质，其被建模为封闭的热力学系统和因此作为C-O-H-N-S系统的天然微型实验室代表。我们第一次记录了固体-固体 H ₂天然包裹体气体混合物中固态 H ₂ S的 S (α ↔ β ↔ γ) 跃迁、复杂包合物和结构转变。有关拉曼光谱特征的新数据和气体混合物相变温度的完整序列有助于流体地球化学的科学进步。加强对 C–O–H–N–S 系统中相平衡的理解是认真估计PTVX特性的先决条件，这是模拟碳氢化合物和矿物系统的地质演化所必需的。_{由于地外富含 H 2} S 的行星系统的低温环境，我们的研究结果是未来研究探险的驱动力。