TrekGEO > Mineral Trail > Occurrence > Mafic-Backarc type Massive Sulfide Deposit

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Mafic-Backarc type Massive Sulfide Deposit

Chemical Process (Liquid-phase Growth) - Under water


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

Illite-Chlorite zone, Interstratified mineral zone


A type of volcanic massive sulfide deposits associated with mafic volcanic rocks.

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

The host of deposits is composed of large amount of mafic volcanic rocks with minor mafic volcanic rocks less than 25 % and little siliciclastic sedimentary rocks such as shale. The deposit is concordant with the sedimentary structure of the host, and is considered to be formed on the ocean floor of back-arc basins at continental margins. Pyrite-Quartz veins and Pyrite-Chlorite veins are intruded in the mafic volcanic complex such as pillow lavas at the bottom of the deposit associated with sericite-chlorite-jasper alteration zones, which are covered with massive pyrite blocks. The massive pyrite blocks underlies conformably the sphalerite-chalcopyrite rich zone. The sphalerite-chalcopyrite rich zone is covered with the layered jasper. The whole deposit is again covered with mafic volcanic complex such as pillow lavas.

Mineral Assemblages (Ore)

Pyrite, Chalcopyrite, Sphalerite

Mineral Assemblages (Gangue)

Quartz, Jasper, Sericite, Chlorite

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