MlNERALOGICAL STUDY OF BISMUTH - GOLD - ANTIMONY MINERALIZATION AT THE AREA OF KAMARIZA, LAVRION

Abstract

At the Lavrion mine, area, near the village of Kamariza, an oxidized mineralization unusually rich in bismuth, gold, antimony and copper has been studied. Three different parageneses have been recognized and described: a) a copper-rich assemblage, containing chalcopyrite, chalcocine, digenite, covelline, azurite, malachite and georgeite, b) a bismuth-gold-rich assemblage, consisting of native bismuth, bismuthinite, native gold, bismite, bismutite, beyerite, kettnerite, preisingerite, rooseveltite and mixité and c) an antimony-rich one, comprising stibiconite, bindheimite, mimetite and gartrellite. The mineral study suggests that the primary mineralization should consist of pyrite ± arsenopyrite, chalcopyrite, bismuthinite (and/or bismuth sulphosalts), native bismuth, maldonite (which has been exsoluted to gold and bismuth) and bournonite. The oxidation of this primary mineralization and the reac ion with supergene solutions containing significant amounts of HCO3" and HAsCV2 - H2ASO4", caused the formation of 17 secondary minerals.

The Gersdorffite-Bismuthinite-Native Gold Association and the Skarn-Porphyry Mineralization in the Kamariza Mining District, Lavrion, Greece

“…Carbonate-replacement mineralization is especially enriched close to the contacts between dikes and the surrounding marbles and schists. It is suggested here that these intrusive bodies fed the deposit with metals and volatiles, as has been proposed previously [2][3][4][5].…”

“…Maldonite was not observed as part of the present study, although its presence in Lavrion ore was reported in association with native bismuth and native gold by Wendel and Markl [8] and Rieck [52]. However, Solomos et al [3] argued for a contemporaneous deposition of chalcopyrite with bismuthinite, native bismuth, and maldonite (which was later decomposed to native gold and native bismuth) for oxidized Au-Bi ores in the Ilarion deposit in the Kamariza district. Native gold also occurs as isolated grains within galena but not in contact with bismuthinite, thus suggesting that the hydrothermal fluids were probably buffered along the boundary Au + Bi 2 S 3 /Au 2 Bi during gold deposition.…”

“…The Lavrion district in Greece is part of the Attic-Cycladic metamorphic core complex, and contains a variety of ore types including porphyry Mo-W, skarn Fe-Cu-Bi-Te, carbonate-replacement Pb-Zn-Cu-As-Sb-Ag ± Au-Bi, and vein/breccia Pb-Zn-Cu-As-Sb-Ag-Au-Ni-Bi [1][2][3][4][5][6][7]. Mineralization was synchronous with the intrusion of a Miocene granodiorite body in the footwall and hanging wall of the Western Cycladic detachment system (WCDS) and related felsic dikes and sills within marbles and schists, which locally crosscut the detachment.…”