New Mineral Occurrences in Massive Sulfide Deposits from Mănăilă, Eastern Carpathians, Romania

Abstract

The massive sulfide deposits (VMS) from Mănăilă are associated with the metamorphic formations of the Tulgheș Lithogroup from the Bucovinian Nappes of the Crystalline-Mesozoic Zone in the Eastern Carpathians, Romania. The following types of ore were identified: pyrite-polymetallic, pyrite copper, compact and precompact copper, and quartz-precompact copper. The polymetallic mineralization consists of pyrite, chalcopyrite, sphalerite, galena, and subordinately arsenopyrite and tennantite. The copper, especially the quartz-copper mineralizations, have a distinct mineralogical composition compared to the other metamorphosed mineralizations of the Tulgheș Lithogroup. These types of deposits from Mănăilă contain large amounts of bornite and chalcocite along with chalcopyrite. Tennantite is abundant and has up to a 3.57 wt.% of bismuth. Wittichenite was identified for the first time in the metamorphic mineralizations and mawsonite was identified as the first occurrence in Romania. An unnamed mineral with the formula: Cu,Fe11Pb,AgS7 was also identified, belonging to the sulfides group. The compact and precompact pyrite-rich ores, located in sericite ± quartzite schists and covered by rhyolitic metatuffs, are of hydrothermal-sedimentary type metamorphosed in the greenschist facies. The source of the quartz-copper mineralization would be the retromorphic or metasomatic hydrothermal solutions that circulated through major fractures.