This work presents the first record of boron-rich aqueous solutions in barite-, anhydrite-, and sassolite-hosted fluid inclusions found in the fumarolic deposits of the Guallatiri volcano, an active and quiescently degassing volcano located in northern Chile. These findings offer a unique opportunity to investigate the mineral-forming and depositional processes in fumarolic environments. Chemical and mineral characterization was performed using XRD and SEM-EDS techniques, whereas petrologic and microthermometry methods, in addition to Raman and FTIR spectroscopy, were conducted to the physicochemical characterization of fluid inclusions. Characterizations of these fluid inclusions show high‑boron concentrations associated with crystalline phases of sassolite and boron-rich aqueous solutions in fluid inclusions. Analyses based on fluid inclusions reveal two potentially fluid sources: (i) a deep source with higher temperatures (up to 220 °C) and saline fluids (>8 wt% NaCl equivalent), in the presence of CO₂, H₂S, SO_2, and CH₄; and (ii) a shallower source with lower temperatures (between 113 and 163 °C) and salinities (<6 wt% NaCl equivalent). Those fluids from the shallower source were affected by dilution processes within the hydrothermal system of the Guallatiri volcano. Concentrations up to 30 wt% B(OH)₃ were found in fluid inclusions from the deeper source. The mineralogical and petrological evidence suggests that sassolite was formed by direct deposition of the gas phase. In contrast, sulfate minerals were formed from condensation, leaching, and precipitation processes before being deposited at the surface. These results are a significant contribution to the knowledge of boron-rich fluid inclusions associated with active magmatic-hydrothermal systems.

这项工作首次发现了位于智利北部活跃而静态的脱气火山-瓜拉提里火山的富马酸沉积物中发现的重晶石，无水石膏和方解石携带的流体包裹体中的富硼水溶液。这些发现为研究富马岩环境中的矿物形成和沉积过程提供了独特的机会。使用XRD和SEM-EDS技术进行化学和矿物表征，而除了拉曼光谱和FTIR光谱学之外，还采用岩石学和显微热分析法对流体包裹体进行物理化学表征。这些流体包裹体的特征表明，流体包裹体中高硼浓度与人造卫星和富硼水溶液的结晶相有关。₂，H ₂ S，SO ₂和CH ₄；（ii）具有较低温度（113至163°C之间）和盐度（<6 wt％NaCl当量）的较浅来源。来自较浅来源的那些流体受到瓜拉提里火山火山热液系统内稀释过程的影响。浓度高达30 wt％B（OH）₃在更深的来源的流体包裹体中被发现。矿物学和岩石学证据表明，人造卫星是通过气相直接沉积形成的。相反，硫酸盐矿物是通过冷凝，浸出和沉淀过程形成的，然后才沉积在表面上。这些结果对与活跃岩浆-热液系统有关的富硼流体包裹体的认识作出了重大贡献。