Gold found in Lau back-arc sulfides


  • Anonymous


High concentrations of gold and visible gold-bearing phases have been found in sulfides from the Central Valu Fa Ridge, a spreading center in the Lau back-arc basin west of the Tonga Trench, southwest Pacific. This is believed to be the first known occurrence of visible gold in sulfides from active vents on the seafloor, according to Peter Herzig of the Aachen University of Technology, Federal Republic of Germany, and Mark D. Hannington of the Geological Survey of Canada, Ottawa. Samples were collected during the NAUTILAU Cruise April 17–May 10, 1989 (see Eos, May 1, 1990, p. 678), which consisted of a scientific team from France, Germany, and Tonga that studied the processes of seafloor ore-mineral formation associated with hydrothermal circulation along the volcanic Valu Fa Ridge. The cruise recorded the first observation of an active black smoker hydrothermal field in a back-arc environment.