Pietro Frizzo, Luca Peruzzo, & Elio Dellantonio
The copper-wolfram deposit of Bedovina (Trento, Italy)

Geo.Alp 7, 2010, p. 55-70

Abstract
The W (Mo, Sn, Bi) and Cu (Pb, Zn, Ag, Te, Co, Ni, etc.) deposits of Bedovina mark the closure of the Middle-Triassic magmatic cycle of the Predazzo-Monzoni Eruptive Complex, composed of latiandesitic and latibasaltic lavas, monzonitic stocks with shoshonitic affinity, K-alkaline monzosyenitic bodies, and some granitic masses. The mineralization is hosted in a stockwork of veins which intersects the volcanics and, occasionally, granitoid masses, and rarely acidic and mafic veins. Two different metalliferous phases can be recognized, the first mainly wolfram-bearing, the second copper-polymetallic. The wolfram phase is represented by quartz+K-feldspar+tourmaline veins, with scheelite, minor apatite and rutile, rare cassiterite, and hematite. Sporadic synchysite-(Ce) and molybdenite occur in granite breccias.
The copper-polymetallic phase was superimposed to the wolfram one after a brittle tectonic event; it comprises quartz, chalcopyrite, minor pyrite, sphalerite, galena and traces of other sulfides and sulfosalts such as cobaltite, argentite/acantite, members of the tetraedrite-tennantite series, bismutiferous sulfosalts (arcubisite/silver-copper-cosalite), Ag (hessite) and Bi tellurides (pilsenite) with native Bi and other bismutiferous phases
finely intergrown with chalcopyrite.
The mineralization of Bedovina is related to hydrothermal metal fluids derived from the crystallization of two distinct granitoid magmas: the first is of “S type” character, and probably would have generated the parageneses typical of the “wolfram phase” (W with minor Sn, REE, Th); the second is of “I type” character, is assumed to be responsible for the polymetallic associations (Cu, with Zn, Pb, Ag, Bi, etc.).


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