P ACM ANUS: The subsurface sulfide/oxide/gold mineralization

摘要

ODP leg 193 in the eastern Manus basin permitted subsurface examination of an active marine hydrothermal system in a back arc. Pyrite is the dominant sulphide together with lesser amounts of chalcopy-rite, sphalerite, pyrrhotite, marcasite and galena, and traces of smythite (?) as relics in pyrite in close association with pyrrhotite. Native gold has been found in a single sample from Hole 1189B (Roman Ruins). The PACMANUS native gold occurrence represents the second record of gold in cores of the entire ODP program. Oxide minerals are represented by Ti-magnetite, magnetite, ilmenite, Fe-spinel (hercynite) and less frequent Al -