The Plavica epithermal polymetallic system: mineralogical and geochemical data

摘要

The latest results from the mineralogical and geochemical investigations and studies of the Plavica polymetallic mineral deposit, Eastern Macedonia, are presented. These results improve our knowledge about the development of typical mineral parageneses and geochemical associations of the basic ore metals and elements. The most common minerals are pyrite and chalcopyrite, followed by enargite, chal-cocite, bornite, tetrahedrite, and some rare minerals such as luzonite, seligmannite, pirseite, etc. The geochemical studies of ore minerals and soils established a wide association of rare, scattered elements and rare earth elements, with increased contents of La (6-21 ppm), Ce (4-28 ppm), Pr (1-3 ppm), Eu (11 ppm), Tm (3 ppm), which are clear evidence that the formation of ore fluids was in the deeper parts of the Earth's crust. The analyses performed during the investigation of the borehole samples (from stocwork-disseminated mineralizations) shows the average contents of 0.2-0.3 %Cu, 0.25 g/t Au, 5-10 g/t Ag, etc. Gold contents in the secondary quartzites are within range of 0.1-10 g/t Au.