Felsic-Siliclastic type Massive Sulfide Deposit

Synonym

Volcanogenic massive sulfide deposit (semi-interpretative term), Stratabound massive sulfide deposit (descriptive), Stratiform massive sulfide deposit (descriptive), Volcanic-associated massive sulfide deposit (descriptive), Volcanic-hosted massive sulfide deposit (descriptive), Submarine exhalative sedimentary deposit (interpretative)

Required Geological Setting

Caldera complexes

Associated metasomatic zones

High-T silicified zone, Illite-Chlorite zone, Interstratified mineral zone

Occurrence

A type of volcanic massive sulfide deposits associated with siliciclastic rocks and felsic volcanic rocks.

Host of the deposit: Siliciclastic rocks (Sedimentary rocks) > Felsic volcanic rocks >> Mafic volcanic rocks

The host of deposits is composed of large amount of siliciclastic rocks and felsic volcanic rocks with minor mafic volcanic rocks such as alkaline basalt. The deposit is concordant with the sedimentary structure of the host, and is considered to be formed on the ocean floor of sedimented back-arc basins at continental margins. Pyrite-Pyrrhotite-Chalcopyrite veins are intruded in the siliciclastic rocks and felsic volcanic rocks at the bottom of the deposit associated with quartz-chlorite alteration zones, which are covered with massive pyrrhotite-chalcopyrite-pyrite blocks. The upper part of the massive blocks is rich in sphalerite and galena, which is covered with the hematite-magnetite-carbonate layer. The whole deposit is again covered with siliciclastic rocks associated with bedded Fe-Mn deposits.

Mineral Assemblages (Ore)

Pyrite, Pyrrhotite, Chalcopyrite, Sphalerite, Galena, Hematite, Magnetite

Mineral Assemblages (Gangue)

Quartz, Chlorite