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Bakreno porfirno ležište Bučim smješteno je na kontaktnoj zoni Srpsko-makedonskog masiva i Vardarske zone, otprilike 90 km jugoistočno od Skopja u Republici Sjeverna Makedonija. Ukupna količina rude procijenjena je na 170 milijuna tona s 0.3 % Cu i 0.3-0.5 g/t Au. Mineralizacija je prostorno i vremenski vezana uz subvulkanske intruzije latitnog i latitno-andezitnog sastava koje intrudiraju u prekambrijski gnajseve i amfibolite Srpsko-makedonskog masiva. Mineralizacija se javlja diseminirano i u formama štokverka. Bučim se sastoji od četiri rudna tijela: Vršnik, Bunardžik, Centralno rudno tijelo i Čukar. Glavni rudni mineral je halkopirit u asocijaciji s piritom, magnetitom, hematitom, kvarcom i karbonatima. Istraživanje fluida i fluidnih inkluzija ključno je za razumijevanje nastanka magmatsko-hidrotermalnih i hidrotermalnih rudnih ležišta. Fluidne inkluzije iz rudnog tijela Vršnik promatrane su u kristalima kvarca. Zapaženo je sedam tipova fluidnih inkluzija te četiri tipa fluida. Visoko-slane (30 – 60 tež. % NaCl) i visoko-temperaturne (400°C - >660°C) inkluzije koje nose rudne minerale predstavljaju glavni rudonosni fluid. Njihovo koegzistiranje s parom bogatim inkluzijama ukazuje na ključanje tijekom odlaganja mineralizacije u rudnom tijelu Vršnik. Post-rudni fluidi karakterizirani su sniženim salinitetima i temperaturama te ukazuju na povećani utjecaj meteorske vode. The Bučim porphyry Cu deposit is located in the contact zone between the Serbo-Macedonian Massif and the Vardar Zone approximately 90 km south-east from Skopje, Republic of North Macedonia. The total ore reserves have been estimated at 170 million metric tons with 0.3 % Cu and 0.3-0.5 g/t Au. The mineralization is spatially and temporary associated with subvolcanic intrusions of the latitic and latitic-andesitic composition that intruded Precambrian gneisses and amphibolites of the Serbo-Macedonian Massif. Vršnik is one of four ore bodies in Bučim Cu deposit. The mineralization occurs in forms of disseminations and stockworks. The main ore mineral is chalcopyrite accompanied with variable amounts of pyrite, magnetite, hematite, quartz and carbonates. Research on fluids and fluid inclusions is crucial for understanding the formation of magmatic-hydrothermal and hydrothermal ore deposits. Fluid inclusions from the Vršnik ore body were studied in quartz crystals. Seven types of fluid inclusions and four types of fluids have been identified. High-salinity (30 – 60 wt% NaCl) and high-temperature (400°C - >660°C) fluid inclusions with ore daughter minerals represent the main ore-bearing fluid. Their coexistence with vapour-rich inclusions reflects as the main depositional mechanism in the Vršnik ore body. Post-ore fluids are characterized by lower salinity and decreased temperatures and reflect an increased contibution of meteoric waters. |
