Fossil hydrothermal sulfide deposits at the Galapagos spreading centre near 85 degree 00 West: Geological setting, mineralogy and chronology
Lalou, C.; Brichet, E.; Lange, J. (1989). Fossil hydrothermal sulfide deposits at the Galapagos spreading centre near 85 degree 00 West: Geological setting, mineralogy and chronology. Oceanol. Acta 12(1): 1-8
In: Oceanologica Acta. Elsevier/Gauthier-Villars: Montreuil. ISSN 0399-1784; e-ISSN 1878-4143, more
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| Keywords |
Earth sciences > Geology > Tectonics
Mineralogy
Sediments > Chemical sediments > Hydrothermal deposits
Sediments > Chemical sediments > Sulphide deposits
Spreading centres
ISE, Galapagos Fracture Zone [Marine Regions]
Marine/Coastal |
| Authors | | Top |
- Lalou, C.
- Brichet, E.
- Lange, J.
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| Abstract |
In the context of the Garimas (Galapagos Rift massive sulfides) project, R/V Sonne has extensively studied a segment of the Galapagos Rift from 85 degree 50 to 85 degree 59, and found a large number of hydrothermal fossil deposits. Two locations around 85 degree 51 and 85 degree 55 have intensively sampled in a detailed navigation network. The sulfide deposits amount to some 100,000 metric tons and consist of chimney-like formations, hydrothermal crusts and ore bodies. There is no sign of present activity, but the presence of specific hydrothermal biotopes around fissures in the basement indicates that at least low-temperature emissions may be present. The mineral constituents are those commonly found in such deposits. In some samples, the two base metals, Zn and Co, reach very high concentrations. In two areas, zone A around 85 degree 50.75 (6 samples) and zone B around 85 degree 54.70 (25 samples), non-altered sulfide samples have been age-dated using the 230Th/ 234 U method. |
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