Naslov
Žune ore body, boiling phenomena in hydrothermal system of Ljubija ore field, NW Bosnia

Autori
Borojević, Sibila ; Palinkaš, Ladislav

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
PANCARDI Meeting Abstracts / - , 2001, DP-5

Mjesto i datum
,

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
siderite deposit; Inner Dinarides; Erzberg; fluid inclusion; hydrothermal deposit

Sažetak
Ljubija is a huge siderite-barite-Pb-Zn sulfide ore deposit situated within the Sana-Una Paleozoic terrain. It belongs to a series of similar siderite deposits stretching along the NW Inner Dinarides, like Trgovska gora, Petrova gora, Samoborska gora, Bistra, Rudanbanya and eventually Slovakian siderite- magnesite-polysulfide deposits in Gemerides. Its well-known equivalent is Erzberg siderite deposit in Austria. The genesis of Ljubija has been interpreted in a variety of ways, ranging from hydrothermal- metasomatic formed in Permian or Triassic time, synsedimentary SEDEX or as resedimented terrestrial iron crusts in Carboniferous time. The diversity of the proposed genetical models stems from different ore body appearance and ore-structures primarily and some isotopic studies as well. The new evidence came from fluid inclusion study (PALINKAŠ, 1988), supporting strongly hydrothermal-metasomatic origin. One of the most import locality, to built a genetic model in the Ljubija ore field, is Zune ore deposit where hydrothermal ore forming process is evidently controlled by hydrothermal boiling phenomena. A small-scale, barite-fluorite deposit Žune is situated in the Upper Paleozoic dolomites, 2.5 km W from Ljubija town and close to the contact with Lower Triassic schists and sandstones. Barite-fluorite vein, 3 to 9 m thick, cuts vertically Upper Palaeozoic dolomites in E- W direction. The contact zone consists of metasomaticaly recrystallized host dolomite with strings of tiny barite veins and impregnations. The central part of the vein consists of pure barite and some fluorite. The accessories are calcite, feldspars, quartz, sulfides and sulfosalts (tetrahedrite, cinnabarite, pyrite, realgar) and Au (JEREMIĆ, 1958). Zune ore deposit, together with other siderite-barite deposits in the Sana-Una pz terrains was formed in "Permo- Triassic" time during an early stage of intra-continental rifting of Tethys. The source of heat and hydrothermal fluids was deeply placed thermal diapirs (PALINKAŠ, 1988). Microthermometric measurements were performed on Chaixmeca stage mounted on Leitz- Wetzlar microscope. The object of the study was fluid inclusions (FI-s) from primary fluorite growth zones. Chemical characteristics of hydrothermal fluids were a product of several concurrent processes. Ca- Na-CI brines were formed by metasomatic replacement of dolomite. High concentration of electrolytes might be attributed to boiling phenomena recognized by micro thermometric measurements and petrography of the FI-s. Influence of the Permian sea water (highly concentrated in evaporitic pans and lagoons), or brines formed by interaction of subsurface waters and buried Permian evaporates in Triassic time, can not be rejected as well. The open questions could be solved by extensive analytical work on stable aItd radiogenic isotopes and ion chromatography. Hydrothermal process, recognised with microthermetric measurements, in any way cannot be neglected and high temperature of fluids is not consequence of some later regional metamorphism during orogenesis, since the host rocks are not metamorphosed to the stage, appropriate to temperatures of Žune fluids.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

Napomena
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