Microanalysis of fluid inclusions in crustal hydrothermal systems using laser ablation methods

Quantitative analysis of microscopic fluid inclusions has greatly improved our understanding of fluid–rock interaction and ore deposit formation. Spatially resolved analyses track the chemical evolution of distinct fluids, within texturally complex veins and along extensive fluid pathways. Chemical (e.g., Br/Cl) and isotopic tracers (e.g., Pb) identify sources of fluids and timescales of transient fluid flow. Selectively metal-enriched fluids, compared to normal rock-buffered fluids, control the formation of major magmatic-hydrothermal and sediment hosted ore deposits. Besides chloride as dominant anion of crustal fluids, sulfur decisively influences the partitioning, transport and precipitation of ore metals by single-phase and two-phase fluids of sedimentary, metamorphic and magmatic origin.