Hydrothermal fluids were collected over a three-year interval (2016–2018) from two sublacustrine vent fields in Yellowstone Lake, Wyoming: Stevenson Island Deep Hole (YL16 and YL17 series in 2016 and 2017, respectively) and West Thumb (YL18 series in 2018). The TOC content in SI Deep Hole vent fluids varies from 2.7 mg/L to 6.3 mg/L in YL16 and 5.0 mg/L to 16.2 mg/L in YL17. Compared to YL16, the average TOC value of YL17 has more than doubled. The range of TOC is from 7.3 mg/L to 13.7 mg/L in the West Thumb samples. A positive correlation between TOC and dissolved CO₂ concentration is observed in most samples, suggesting their close relationship with sublacustrine heat and mass transfer processes. The organic compounds detected at both vent fields are diverse in molecular structure. In the SI Deep Hole, complex cyclic and unsaturated organic compounds are dominant, with cyclic hydrocarbons having the highest abundance, followed by carboxylic acids, PAHs, and alcohols. At West Thumb vents, propanol is most abundant, followed by alcohols, PAHs, alkanes, and carboxylic acids. This difference in structural complexity and relative quantity of organic compounds may be attributed to the involvement of hydrothermal processes. The vapor-dominated hydrothermal system and extensive fluid-rock interactions in SI Deep Hole facilitate alteration/decomposition of organic precursors. While CO_2(aq) is predominant in vent fluids, dissolved CH₄ is much less abundant. In SI Deep Hole, the carbon isotopic composition of CH₄ in most samples ranges from −20.4‰ to −38.0‰, with values of less than −60‰ in three samples, while CO₂ ranges from −4.4‰ to −10.5‰. A temporal variation of δ¹³C values was obtained for CO₂, with the average increasing from −9.2‰ (YL16) to −5.2‰ (YL17). In West Thumb, the δ¹³C value of CO₂ and CH₄ fall in a similar range, with an average of −10.5‰ and −19.0‰, respectively. There are multiple sources for observed carbon species: the interaction of vent fluids with subsurface rocks and lake sediments is the predominant process, followed by thermal decomposition of organic matter. Microbial activity on the lake floor may contribute to methane formation, while magmatic degassing is the major process that produces CO₂. The connection between vapor-dominated hydrothermal alteration, elevated TOC contents and dissolved CO₂ in vent fluids, and enrichment of ¹³C in CO₂ in YL17 in SI Deep Hole suggests an interplay of geological, chemical, and biological processes and their imprints on vent fluids, all of which make significant contribution to the carbon cycle in the Yellowstone Lake ecosystem.

从怀俄明州黄石湖的两个湖底喷口油田收集了三年时间段（2016-2018）的热液流体：史蒂文森岛深孔（分别为 2016 年和 2017 年的 YL16 和 YL17 系列）和西拇指（2018 年的 YL18 系列） ）。SI 深孔泄放液中的 TOC 含量在 YL16 中从 2.7 mg/L 到 6.3 mg/L 和在 YL17 中从 5.0 mg/L 到 16.2 mg/L 不等。与YL16相比，YL17的平均TOC值增加了一倍多。West Thumb 样品中的 TOC 范围为 7.3 mg/L 至 13.7 mg/L。TOC 与溶解 CO ₂呈正相关在大多数样品中观察到浓度，表明它们与湖底传热和传质过程密切相关。在两个喷口场检测到的有机化合物的分子结构各不相同。在SI深孔中，复杂的环状和不饱和有机化合物占主导地位，其中环状烃的丰度最高，其次是羧酸、多环芳烃和醇。在 West Thumb 通风口，丙醇含量最高，其次是醇类、多环芳烃、烷烃和羧酸。这种结构复杂性和有机化合物相对数量的差异可能归因于热液过程的参与。SI深孔中以蒸汽为主的热液系统和广泛的流体-岩石相互作用促进了有机前体的蚀变/分解。而 CO _2(aq)CH ₄在排放流体中占主导地位，溶解的 CH ₄含量要少得多。在SI Deep Hole中，大部分样品中CH ₄的碳同位素组成范围为-20.4‰～-38.0‰，其中三个样品的碳同位素组成小于-60‰，而CO _{2 的}范围为-4.4‰～-10.5‰。CO ₂的δ ¹³ C 值随时间变化，平均值从-9.2‰ (YL16) 增加到-5.2‰ (YL17)。在 West Thumb 中，CO ₂和 CH ₄的 δ ¹³ C 值落在相似的范围内，平均值分别为-10.5‰和-19.0‰。观察到的碳种类有多种来源：喷口流体与地下岩石和湖泊沉积物的相互作用是主要过程，其次是有机物的热分解。湖底的微生物活动可能有助于甲烷的形成，而岩浆脱气是产生 CO ₂的主要过程。蒸气为主的热液蚀变，TOC升高内容和溶解的CO之间的连接₂在排气孔的流体，和富集¹³中COÇ ₂ 在 SI Deep Hole 的 YL17 中，地质、化学和生物过程的相互作用及其对喷口流体的影响，所有这些都对黄石湖生态系统中的碳循环做出了重大贡献。