Sulfide-associated hydrothermal dolomite and calcite reveal a shallow burial depth for Alpine-type Zn-(Pb) deposits

Abstract Difficulties in dating Mississippi Valley–type (MVT) mineral deposits and the often closely associated dolomitization have led to controversy regarding their origin. We report first radiometric ages for Gorno mining district northern Italy, an example of Alpine subclass MVT deposits. U-Pb hydrothermal carbonates pre- postdating ore-forming event show that base-metal mineralization occurred shortly after deposition Carnian host rocks. This implies ore formed at shallow burial depth prior Early Jurassic western Tethys rifting phase. Contemporaneous Triassic magmatism extensional tectonics likely contributed high geothermal heat fluxes required drive mineralizing system. Our study reinforces need reliable geochronological data metallogenic models warns against a general application classic North American similar worldwide.