Abstract




 
   

Vol. 1, No. 4 (November 1988) 219-241   

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  RECENT COMPLEX MASSIVE SULFIDE DEPOSITS BLACK SMOKERS AND HYDROTHERMAL METALLOGENESIS AT ACTIVELY SPREADING PLATE BOUNDARIES IN THE PACIFIC (EAST PACIFIC RISE, GALAPAGOS RIFT): POTENTIAL MARINE MINERAL RESOURCES AND A FUTURE FIELD OF ACTIVITY FOR DEEP-SEA MINING
 
 
W. Tufar

Fachbereich Geowissenschaften der philipps
University Marburg Lahnberge
Federal Republic of Germany
 
 
( Received: September 1998 )
 
 

Abstract    Actively spreading plate boundaries are the site of intensive recent hydrothermal activity and sulfide formations. Especially good examples can be found at the East Pacific Rise and the Galapagos Rift. The complex massive sulfide mineralization is characterized by a considerable variety in its mineralogical composition (mainly sulfides and mostly small amounts of gangue material) and a conspicuous porous, layered compositional texture with typical colloidal and/or gel textures and obvious zonal arrangements of sulfides. A farther characteristic of the complex massive sulfide ores is their chemical composition, exhibiting an extremely wide range of variation in the three major elemental constituents iron, zinc and copper, with occasionally very high contents of zinc and/or copper and, furthermore, an almost total absence of lead. A typical feature of the complex massive sulfide deposits from the East Pacific Rise is the presence of high-temperature sulfides (e.g. chalcopyrrhotite, high-temperature chalcopyrite) in close association with sulfides exhibiting colloidal and/or gel textures (e.g. marcasite, pyrite, melnikovite-pyrite, schalenblende). Connected with the recent hydrothermal spring activity on the ocean floor at the East Pacific Rise and the Galapagos Rift with their respective complex massive sulfide formations ("black smokers") is the creation of a unique deep-water environment which allows the development of an abundant number of organisms (e.g. worms, bivalves, crustaceans, fishes). Organisms can be found both living today and embedded as relics preserved by the sulfide mineralized "black smokers" . "Black smoker" deposits provide both a beneficial environment and an efficient preservation mechanisms for deep-sea life today as well as a potential economically important complex massive sulfide ore resource for the future. More importantly, they are he key to a future field of mining activity which is to say deep-sea mining.

 
 

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