The discovery of a new metallogenic Province in Sardinia (Italy): Au-Ag mineralisations of Tertiary age

The Oligo-Miocene volcanic cycle was accompanied by intense hydrothermal phenomena, which produced extensive alteration zones and ore deposition, mostly of precious metals. The low price of gold before the seventies prevented any considerations for these occurrences. The worldwide development of studies concerning volcanic-related deposits caused renewed interest in this kind of epithermal minaralizations in the island and a prospecting program was developed in the eighties. A series of field surveys showed that hydrothermal alteration halos are widespread in the volcanic terrains, and Au-Ag bearing mineralised outcrops were detactedin a few localities. An exploration program was performed which reached the ore evaluation stage in two areas. At present the Furtei mine is currently the only high sulfidation gold mine in Europe, while soil sampling confirmed that the Osilo area offer potential for low sulfidation precious metal occurrences. Several other precious metal indications will be explored in the near future.