## 6 Results
### Fluid Inclusion Study
Halite and sylvite, where halite  
Figure 17: Photomicrographs of fluid inclusions in quartz from the Vathi deposit: (**a**) Equigranular quartz grains in association with the ore minerals, forming triple junctions with angles of \(\approx\)120\({}^{\circ}\); (**b**) A cluster of primary two-phase liquid–vapor fluid inclusions; (**c**) Vapor-only secondary inclusions in planes along healed fractures; (**d**) Type 1 fluid inclusions from hydrothermal quartz grains in the seritic alteration; (**e**) Type 2 three phase liquid–vapor–halite fluid inclusions; (**f**) Type 2 multiphase fluid inclusions containing halite, sylvite, and an opaque (possibly chalcopyrite or pyrite); (**g**) Type 3 vapor-rich inclusions; (**h**) Typical fluid inclusion assemblage in porphyry-style mineralization showing co-existing type 2 and 3 inclusions; (**i**) Type 2, 3, and 4 fluid inclusions; (**j**) A cluster of type 1 fluid inclusions in an epithermal vein; (**k**,**l**) Deformed and stretched fluid inclusions that leakage after trapping. FI = fluid inclusion; L = liquid; V = vapor; H = halite; S = sylvite; Op = opaque. is generally larger than sylvite, were identified by their colorless, isotropic cubic crystal morphology (Figure 17e,f). Halite dissolved at a higher temperature than sylvite during heating. The opaque phases (Figure 17f) are either cubic or triangular in shape and are possibly pyrite or chalcopyrite, respectively, but they do not dissolve during heating up to 600 \({}^{\circ}\)C.  
Type 3 two-phase inclusions are dominated by a vapor bubble comprising 70-90 vol.% of the inclusions (Figure 17b,g,h) and homogenize into the vapor phase. They are the most common type of inclusion. Type 3 fluid inclusions commonly locally coexist with type 2 inclusions (Figure 17h). Type 4 inclusions are usually dark in color and consist mainly of vapor. They occur along healed fractures and are considered to be secondary in origin (Figure 17c,i). None of the inclusions analyzed at the Vathi porphyry system contain visible liquid CO2, and clathrate formation was not observed during freezing experiments. This excludes the presence of significant quantities of CO2 (<2 mol.%). Quartz in the epithermal veins contains few fluid inclusions, but where present, they are <20 \(\upmu\)m in length. They are two-phase aqueous liquid-vapor inclusions (Type 1) containing a vapor bubble occupying 10-20 vol.% (Figure 17)). These inclusions homogenized into the liquid phase upon heating. Post-entrapment modifications, such as necking down or leakage, have affected this type of fluid inclusions (Figure 17k,l). They commonly occur along micro-cracks and demonstrate a variable liquid-to-vapor ratio. This is likely due to \"stretching\" processes during mechanical intracrystalline straining [64]. In order to eliminate the effects of the post-entrapment modifications, only inclusions with constant liquid-to-vapor ratios were selected for the microthermometric measurements. Microthermometric data from 78 fluid inclusions in hydrothermal quartz and A-type veins from the Vathi porphyry system are summarized in Table 3. Eutectic ice-melting temperatures (Te) obtained from a few type 1 inclusions are concentrated around \(-22\)\({}^{\circ}\)C, which suggests that NaCl is the dominant salt species in the inclusions [65]. Eutectic temperatures of type 3 inclusions were not possible to determine due to their small size. Final ice melting temperatures of type 1 inclusions vary from \(-7.6\) to \(-5.4\)\({}^{\circ}\)C, indicating salinities of 8.4 to 11.2 wt % NaCl equiv [66]. Due to the small size (mainly 5-11 \(\upmu\)m) of the meniscus liquid phase in type 3 inclusions, which made observation of the phase changes difficult, only a few freezing data could be obtained. On the basis of the freezing point depression (\(-14.1\) to \(-6.4\)\({}^{\circ}\)C), the salinities ranged from 9.7 to 18.5 wt % NaCl equiv.