The purpose of this work is to provide a data set of mineral chemistry of the sulfide-oxide mineralization and associated gold occurrences in samples drilled at Sites 1188 and 1189 in the PACMANUS hydrothermal field.

The PACMANUS hydrothermal field constitutes one of the most important active hydrothermal sites where it is possible to study recent sulfide mineralization related to felsic volcanic rocks. PACMANUS is located in Manus Basin, which is the backarc of the active New Britain volcanic arc, situated in the Bismarck Sea east of the Island of Papua New Guinea. PACMANUS consists of five active vent sites, namely Rogers Ruins, Roman Ruins, Satanic Mills, Tsukushi, and Snowcap. Ocean Drilling Program Leg 193 (November 2000-January 2001) was dedicated to drilling this hydrothermal field. Snowcap (Site 1188; 1654-1670 meters below sea level [mbsl]) is one of the major active hydrothermal sites at PACMANUS. It covers a knoll of altered dacite-rhyodacite lava and is characterized by low-temperature diffuse venting (Binns et al., 1997; Moss and Scott, 2001; Binns, Barriga, Miller, et al., 2002). Roman Ruins (Site 1189; 1693-1710 mbsl; 150 m across) contains numerous large columnar chimneys (as tall as 20 m). Many chimneys are broken and some show later regrowth. Although many chimneys are inactive, there are active structures including black smokers and diffuser-style chimneys that emit clear fluid (Binns, Barriga, Miller, et al., 2002). Roman Ruins constitutes a high-temperature, focused discharge hydrothermal area.