Volcanic-associated massive sulphide deposits

Abstract

The geological model for volcanogenic massive sulphide (VMS) deposits has been improved through research on modern hydrothermal systems, as well as through studies of ancient deposits. At the "bottom' of VMS-producing systems are subvolcanic intrusions, which represent focussed heat sources. In the immediate area of VMS deposits, major units of diachronous epiclastic breccia are evidence of local growth faults. These faults were the principal conduits for high-temperature hydrothermal fluids. Alteration pipes that developed in the portions of these faults that immediately underlie the deposits are dominated by minerals formed through progressively heated, locally advected seawater. -from Author