A Fluid Inclusion and Critical/Rare Metal Study of Epithermal Quartz-Stibnite Veins Associated with the Gerakario Porphyry Deposit, Northern Greece

Applied Sciences

Paul G. Spry¹  Panagiotis Voudouris²  Lambrini Papadopoulou³  Vasilios Melfos³  Christos L. Stergiou³  Elitsa Stefanova⁴  Irena Peytcheva⁴  Dimitrina Dimitrova⁴ 

[1] Department of Geological and Atmospheric Sciences, Iowa State University, Ames, IA 50011-1027, USA;Faculty of Geology and Geoenvironment, National and Kapodistrian University of Athens, 15784 Athens, Greece;Faculty of Geology, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece;Geological Institute, Bulgarian Academy of Sciences, 241113 Sofia, Bulgaria;

关键词: rare metals;    critical metals;    rare earth elements;    stibnite;    epithermal veins;    Gerakario;   

DOI  :  10.3390/app12020909

来源: DOAJ

【 摘 要 】

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.

【 授权许可】

Unknown