The Vathi porphyry Cu-Au±Mo deposit is located in the Kilkis ore district, northern Greece. Hydrothermally altered and mineralized samples of latite and quartz monzonite are enriched with numerous rare and critical metals. The present study focuses on the bulk geochemistry and the mineral chemistry of pyrite, chalcopyrite, magnetite, and titanite. Pyrite and chalcopyrite are the most abundant ore minerals at Vathi and are related to potassic, propylitic, and sericitic hydrothermal alterations (A- and D-veins), as well as to the late-stage epithermal overprint (E-veins). Magnetite and titanite are found mainly in M-type veins and as disseminations in the potassic-calcic alteration of quartz monzonite. Disseminated magnetite is also present in the potassic alteration in latite, which is overprinted by sericitic alteration. Scanning electron microscopy and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analyses of pyrite and chalcopyrite reveal the presence of pyrrhotite, galena, and Bi-telluride inclusions in pyrite and enrichments of Ag, Co, Sb, Se, and Ti. Chalcopyrite hosts bornite, sphalerite, galena, and Bi-sulfosalt inclusions and is enriched with Ag, In, and Ti. Inclusions of wittichenite, tetradymite, and cuprobismutite reflect enrichments of Te and Bi in the mineralizing fluids. Native gold is related to A- and D-type veins and is found as nano-inclusions in pyrite. Titanite inclusions characterize magnetite, whereas titanite is a major host of Ce, Gd, La, Nd, Sm, Th, and W.

Due to unfavourable natural conditions (poor soils, lack of water, special relief conditions), karst terrains have always been relatively sparsely populated, and they have been seriously affected by recent depopulation processes. However, the creation of national parks on karst terrains and the recent increase of (geo)tourism may influence and even turn these population trends. Our study examines the validity of this statement in the context of Vikos Gorge and Tymphi Mountain (NW Greece). Geological and geomorphological values are presented first, including Vikos Gorge, the glaciokarst landscape of Tymphi and the particular spherical rock concretions. Digital terrain analysis is used to obtain scientifically based, reliable morphometric parameters about Vikos Gorge, and it is found that the maximum gorge depth is 1144 m, the maximum width is 2420 m, and the maximum of depth/width ratio is 0.76. Thereafter, rural depopulation trends are examined and it is found that this region (Zagori) is seriously affected by depopulation. It is observed that there are differences among settlements, and a relative stabilization of population is sensible in only few settlements around Vikos Gorge, which are linked to tourism. As for nature protection, while at the beginning conflicts were perceptible among management and local people, now new conflicts are emerging between growing tourism and nature protection goals.Key words: gorge morphometry, glaciokarst, spherical concretions, rural depopulation, geotourism, national park.Kraške oblike in s krasom povezane družbene spremembe na območju soteske Vikos ter v gorovju Timfi (narodni park Severni Pindi, Grčija)Zaradi neugodnih naravnih razmer, kot so manj rodovitna prst, pomanjkanje vode in svojstvena oblikovanost površja, je kraško površje od nekdaj relativno redko poseljeno, v zadnjem obdobju pa je podvrženo tudi procesom odseljevanja. V zadnjem času je vse več tudi geoturizma in z njim povezanega ustanavljanja geoparkov, ki trend depopulacije lahko tudi obrnejo. Pričujoča študija se nanaša na vrednotenje omenjenih procesov na primeru doline Vikos in gorovja Timfi (SZ Grčija). Najprej so predstavljene geomorfološke in geološke značilnosti območja, kjer so izpostavljene značilnosti soteske Vikos, glaciokras gorovja Timfi in za to območje značilne okrogle skalne konkrecije. Digitalni model višin je bil namenjen morfometrični analizi soteske Vikos. Ta je pokazala, da je njena največja globina 1144 m, največja širina 2420 m, največje razmerje med globino in širino pa 0,76. V nadaljevanju so analizirane značilnosti odseljevanja s podeželja, katerim je najbolj podvrženo območje Zagori. Demografski vzorci kažejo na razlike med posameznimi naselji, kjer je število prebivalcev stabilno le v nekaterih naseljih v bližini turistično zanimive soteske Vikos. Z ustanovitvijo parka so se pojavili tudi konflikti. V začetku so se navzkrižja interesov pojavila med lokalnim prebivalstvom in upravljavci, sedaj pa se konflikt pojavlja ob istočasnem naraščanju turizma in želji po varovanju narave.Kjučne besede: morfometrija soteske, glaciokras, okrogle konkrecije, depopulacija podeželja, geoturizem, narodni park.

The Gerakario Cu-Au porphyry deposit in the Kilkis ore district, northern Greece, contains epithermal quartz-stibnite veins on the eastern side of the deposit, which crosscut a two-mica gneiss. Metallic mineralization in these veins consists of stibnite + berthierite + native antimony + pyrite + arsenopyrite, and minor marcasite, pyrrhotite, chalcopyrite, löllingite, and native gold. Bulk geochemical analyses of the ore reveal an enrichment in critical and rare metals, including Ag, Au, Bi, Ce, Co, Ga, La, and Sb. Analysis of stibnite with LA-ICP-MS showed an enrichment in base metals (As, Cu, Pb), as well as weak to moderate contents of critical and rare metals (Ag, Bi, Ce, La, Re, Sm, Th, Ti, Tl). A statistical analysis of the trace elements show a positive correlation for the elemental pairs Ce-La, Ce-Sb, and La-Sb, and a negative correlation for the pair Bi-Sb. Fluid inclusions in the A-type veins of the porphyry-style mineralization show the presence of fluid boiling, resulting in a highly saline aqueous fluid phase (35.7 to 45.6 wt.% NaCl equiv.) and a moderately saline gas phase (14 to 22 wt.% NaCl equiv.) in the system H₂O-NaCl-KCl at temperatures varying between 380° and 460 °C and pressures from 100 to 580 bar. Mixing of the moderate saline fluid with meteoric water produced less saline fluids (8 to 10 wt.% NaCl equiv.), which are associated with the epithermal quartz-stibnite vein mineralization. This process took place under hydrostatic pressures ranging from 65 to 116 bar at a depth between 600 and 1000 m, and at temperatures mainly from 280° to 320 °C.

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.

The stibnite mineralization at Rizana (Kilkis ore district; Serbo-Macedonian metallogenic province; northern Greece) occurs along a NE–SW-trending brittle shear-zone, which transects a two-mica and an augen-gneiss of the Vertiskos Unit. Barren Triassic A-type granites and satellite pegmatites and aplites, as well as Oligocene-Miocene plutonic, subvolcanic and volcanic rocks that are variably hydrothermally altered and mineralized, outcrop in the broader region. The mineralization appears as veins, discordant lodes and disseminations. Veins and discordant lodes exhibit massive and brecciated textures. Historic underground mining (1930s–1950s) produced 9000 t of stibnite ore, grading 40% Sb on average. The main ore mineral assemblage includes stibnite + berthierite + sphalerite + pyrite + chalcopyrite + native antimony and traces of wolframite, galena, tetrahedrite, marcasite, pyrrhotite, arsenopyrite, realgar, native arsenic and native gold. Quartz, minor barite and ankerite are the gangue minerals. Sericitization and silicification developed along the shear-zone, forming hydrothermal halos of moderate intensity in the two-mica gneiss. Locally, valentinite, goethite and claudetite are present due to the supergene oxidation of the stibnite mineralization. Bulk ore geochemistry shows enrichments in specific elements including As, Au, Cd, Se, Tl and W. Fluid inclusion microthermometry showed that the mineralization was formed under a limited range of temperatures and salinities. The fluids had low to slightly moderate salinities (6.6–8.1 wt% equiv. NaCl) with low homogenization temperatures (217–254 °C, with a maximum at 220 °C).