SKŁAD IZOTOPOWY SIARKI MINERAŁÓW SIARCZKOWYCH I SIARCZANOWYCH Z KOPALNI LUBIN

Abstract

SULPHUR ISOTOPIC COMPOSITION OF SULPHIDE AND SULPHATE MINERALS FROM LUBIN MINE, SW POLANDAbstract. The paper presents the results of sulphur isotopic analyses conducted on 130 samples of sulphides and 50 samples of sulphates, collected in different parts of the Lubin Mine. Simple copper sulphides contain isotopically very light sulphur. The average value of δ34S for digenite is –35.9‰, and for chalcocite –32.0‰. Bornite also has a low value of δ34S, on average –31.7‰. Slightly higher values were found for chalcopyrite and covellite: –29.6 and –27.9‰ on average, respectively. The heaviest sulphur is in the tennantite tetrahedrite series: –9.3‰. Sphalerite and galena also have isotopically light sulphur, –27.1 and –25.4‰, respectively. The lightest isotopic composition of sulphur was found in pyrite and marcasite (–37.9‰). There were found consistent differences in the isotopic composition of sulphides depending on their formation and location within the deposit. Barite from the Lubin Mine shows higher values of δ34S: 12.3‰ on average, like gypsum and anhydrite: 12.1‰. When occurring in veins with sulphides, all those minerals have lighter composition compared with those in barren veins. Weathering sulphates (chalcantite and epsomite) have the lowest values of δ34S, similar to the composition of copper sulphides.