Caractérisaton minéralogique et signifiance métallogénique des sulfures bismuthifères des minéralisations de La Galite et du Jebel Chouichia (NW de la tunisie)

Two occurrences of Bi-minerals have been identified during systematic study of hydrothermal sulfide ores from northwestern Tunisia. In La Galite island, together with major pyrite and chalcopyrite, are encountered various sulfosalts, among which gustavite and matildite (=destabilized schapbachite). At jebel Chouichia, tetrahedrite contains horobetsuite inclusions, (Bi 1,07 Sb 0.94 ) 2.01 S 3 , in part replaced by native bismuth and Bi-rich chalcostibite, sometimes with a rim of wittichenite. These two mineralogical expressions of bismuth, spatially related to an alpine intrusion through oligocene formations (La Galite) on one hand, to a deep fault with the outcrop of mesozoic formations (Chouichia) on the other hand, emphasize the existence, in the metallogenic process, of a deep endogeneous source, linked to the paleozoic basement