Drilling the Snake Pit hydrothermal sulfide deposit on the Mid-Atlantic Ridge, lat 23°22′N

Abstract

A major high-temperature hydrothermal area has been discovered in the Mid-Atlantic Ridge rift valley about 25 km south of the Kane Fracture Zone. The vent field consists of u wide area (>40000 m²) of dark hydrothermal deposits, numerous sulfide chimneys and mounds, some up to 11 m high, and high-temperature “black-smoker” vents. Ten shallow holes, the first ever drilled in an active submarine hydrothermal area, recovered friable, unconsolidated Fe, Cu-Fe, and Zn sulfides and several large fragments of massive sulfide (mainly chalcopyrite) from the locally thick (>13 m) hydrothermal deposits. The vents are also associated with an unusual biological community of smaller, more mobile organisms than reported from the East Pacific Rise.