Accueil > Documentations scientifiques > Revues récentes > Madagascar : revue de géographie > Archives > Volume 9, juillet-décembre 1966 > Progrès des connaissances sur les fonds de l’Océan Indien

• 
  Progrès des connaissances sur les fonds de l’Océan Indien
  Madagascar : revue de géographie, Volume 9, juillet-décembre 1966 pp:7 - 15

  Auteur(s) : Guilcher A

  Auteur correspondant :

  Mots-clés : GEOMORPHOLOGIE/FONDS MARINS/GEOLOGIE SOUS-MARINE/ OCEANOGRAPHIE/OCEAN INDIEN
  
  

  Résumé de l’article

  [FR]

  [MG]

  [EN] Since a few years, the knowledge of the geomorphology and constitution of the Indian Ocean deep-sea floor was considerably improved, as a result of the International Indian Ocean Expedition which started in 1962 and consisted of a cooperation of the surrounding countries and the large maritime nations in the world. Since this ocean had been strongly neglected before, the purpose of this project was to rise the status of knowledge at the same level as in the other parts of the World Ocean. The most interesting feature recently discovered in a series of prominent fracture zones running from NNE to SSW, which offset the Mid-Oceanic Ridge. Some of them continue continental fractures, e.g. along the southern Arabian coast. It may be recalled that the East Pacific Rise is similarly cut and displaced by fracture zones. As in the Atlantic Ocean, the Mid-Oceanic Ridge in the Indian Ocean includes a rift along its axis. Such a median rift is not evident in the East Pacific Rise. New data are given on Java Trench, and on volcanic plateaus and seamounts, abyssal hill and plains, and continental slope and rise. On the other hand, the International Ocean Expedition brings new informations about the origin and distribution of glacial marine sediments, which occur on wide areas around Antarctica ; of volcanogenic sediments ; of other terrigenous deposits, which are widespread in the Gulf of Bengal and in the Arabian Sea, where turbidity currents seem to have played an outstanding part in their deposition. Informations are also given on the skeletal deep-sea deposits, particularly the Radiolarian oozes, and on the accumulation of manganese nodules.