An off-axis hydrothermal vent field near the Mid-Atlantic Ridge at 30 degrees N.
Nature
; 412(6843): 145-9, 2001 Jul 12.
Article
em En
| MEDLINE
| ID: mdl-11449263
ABSTRACT
Evidence is growing that hydrothermal venting occurs not only along mid-ocean ridges but also on old regions of the oceanic crust away from spreading centres. Here we report the discovery of an extensive hydrothermal field at 30 degrees N near the eastern intersection of the Mid-Atlantic Ridge and the Atlantis fracture zone. The vent field--named 'Lost City'--is distinctly different from all other known sea-floor hydrothermal fields in that it is located on 1.5-Myr-old crust, nearly 15 km from the spreading axis, and may be driven by the heat of exothermic serpentinization reactions between sea water and mantle rocks. It is located on a dome-like massif and is dominated by steep-sided carbonate chimneys, rather than the sulphide structures typical of 'black smoker' hydrothermal fields. We found that vent fluids are relatively cool (40-75 degrees C) and alkaline (pH 9.0-9.8), supporting dense microbial communities that include anaerobic thermophiles. Because the geological characteristics of the Atlantis massif are similar to numerous areas of old crust along the Mid-Atlantic, Indian and Arctic ridges, these results indicate that a much larger portion of the oceanic crust may support hydrothermal activity and microbial life than previously thought.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Microbiologia da Água
/
Sedimentos Geológicos
Idioma:
En
Revista:
Nature
Ano de publicação:
2001
Tipo de documento:
Article
País de afiliação:
Estados Unidos