|Les Marquises (Polynésie française): Volcanologie, géochronologie, discussion d'un modèle de point chaud|
Brousse, R.; Barsczus, H.G.; Bellon, H.; Cantagrel, J.-M.; Diraison, Ch.; Guillou, H.; Leotot, Ch. (1990). Les Marquises (Polynésie française): Volcanologie, géochronologie, discussion d'un modèle de point chaud. Bull. Soc. Géol. Fr. 6(6): 933-949
In: Bulletin de la Société Géologique de France. Société Géologique de France: Paris. ISSN 0037-9409, more
Geochronometry; Hot spots; Magma; Models; Volcanism; ISE, French Polynesia, Marquesas I. [Marine Regions]; Marine; Fresh water
|Authors|| || Top |
- Brousse, R.
- Barsczus, H.G.
- Bellon, H.
- Cantagrel, J.-M.
- Diraison, Ch.
- Guillou, H.
- Leotot, Ch.
We propose a hot spot model for the Marquesas alignment, which takes account of the age of each phase in the volcanic activity (submarine, then aerial). The duration of construction of the older external volcanoes is fixed at 1.12 m.y. and allows 1.57 m.y. for the duration of submarine activity. The N120 degree E crossing of the hot spot zone would be 300 plus or minus 10 km long and the geometry of this zone is thought to be imposed by the N160 degree E old discontinuities of the Pacific plate; in this case, the width of the active stripe is 190 km. If we assume that the duration of the internal volcanoes construction also was directly controlled by the hot spot, then we must raise the width of the active stripe by about 60 km. The model brings out the major role of interactions between the hot and the Marquesas fracture zone: indeed, it seems that the Marquesas fracture zone, when moving over the supposed fixed hot spot, would make it progressively inactive. This theoretical model for the Marquesan hot spot must account for the chronological synthesis of aerial volcanism just outlined.