In 1992 and 1993, anomalous temperatures, transparencies and dissolved manganese concentrations were found in bottom water in the eastern part of the rift valley 30 km south of the fracture zone at 15°20′, in an area where these is geochemical and mineralogic evidence of hydrothermal deposition. Hence between November 1993 and February 1994, the study of this zone was pursued. Hydroacoustic and satellite navigation systems were used to locate this area. Analytical data suggests that in large ore deposits of the Atlantic, in contrast to small sulfide structures of the East Pacific Rise, copper predominates over zinc.