The Vathi porphyry Cu-Au ± Mo mineralization is located in the Serbo-Macedonian metallogenic province of the Western Tethyan Metallogenic Belt. It is mainly hosted by a latite and is genetically associated with a quartz monzonite intrusion, which intruded the basement rocks of the Vertiskos Unit and the latite, 18 to 17 Ma ago. A phreatic breccia crosscuts the latite. The quartz monzonite was affected by potassic alteration, whereas the latite was subjected to local propylitic alteration. Both styles of alteration were subsequently overprinted by intense sericitic alteration. M-type and A-type veins are spatially associated with potassic alteration, whereas D-type veins are related to the sericitic alteration. Three ore assemblages are associated with the porphyry stage: (1) pyrite + chalcopyrite + bornite + molybdenite + magnetite associated with potassic alteration; (2) pyrite + chalcopyrite related to propylitic alteration; and (3) pyrite + chalcopyrite + native gold ± tetradymite associated with sericitic alteration. A fourth assemblage consisting of sphalerite + galena + arsenopyrite + pyrrhotite + pyrite ± stibnite ± tennantite is related to an epithermal overprint. Fluid inclusion data indicate that the A-type veins and related porphyry-style mineralization formed at 390–540 °C and pressures of up to 646 bars (<2.6 km depth) from boiling hydrothermal fluids. A later condensation of vapor-rich inclusions resulted in a moderately saline fluid (8.4–11.2 wt % NaCl equiv) at temperatures between 311 and 392 °C, which were related to sericitic alteration, D-type veins, and associated metallic mineralization. Subsequent dilution of the moderately saline fluid at lower temperatures (205–259 °C) produced a less saline (1.4–2.9 wt % NaCl equiv.) fluid, which is likely associated with the late epithermal overprint.

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The Maronia pluton is the youngest of the Tertiary plutons that occurred in Thrace. Three rock groups have been distinguished: a basic, an intermediate and an acid one. Based on geochemical and isotopie characteristics, the basic group probably represents a magma that isotopically equilibrated with the intermediate group at a certain point of its evolution. The evolution of the intermediate group can be described by an assimilation-fractional crystallization process (AFC). The acid group represents crustai melts that are not genetically related to the basic and intermediate groups. The emplacement of the pluton is related to post-collisional extension resulting from the subduction of the African under the European plate. The magma source of the basic and intermediate group is considered to be a LI LE- and LREE-enriched subcontinental lithospheric mantle. The acid group has probably derived by the partial melting of crustai rocks and in particular, gneiss.

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