Shallow submarine gold mineralization at Conical Seamount, Papua New Guinea: Initial results of an alteration halo study

摘要

Trachybasalt of different alteration styles and intensities is the host to shallow submarine gold mineralization at Conical Seamount, Papua New Guinea. The gold-rich mineralization is confined to sulfide-bearing, black, amorphous silica-dominated veins hosted by silicic-altered trachybasalt as well as to disseminated sulfides or pyrite/marcasite veinlets contained in intensely argillic-altered host rocks. This association of gold is comparable to that of epithermal gold deposits occurring on land. The mineralogical composition of the hydrothermally altered trachybasalt suggests that the gold mineralization at Conical Seamount formed from near-neutral to weakly acidic and relatively reducing hydrothermal fluids.