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Lettre Dorsales. 01/2000; 7(1-2):15-19.
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J-M. Auzende,
J. Ishibashi,
Y. Beaudoin,
J-L. Charlou,
J. Delteil,
J-P. Donval,
Y. Fouquet,
J.P. Gouillou,
B. Ildefonse,
B. Kimura,
Y. Nishio,
J. Radford-Knoery, E. Ruellan
EOS, Transactions, AGU. 01/2000; 81(39):449, 452-453.
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J. M. Auzende,
J. Ishibashi,
Y. Beaudoin,
J. L. Charlou,
J. Delteil,
J. P. Donval,
Y. Fouquet,
J. P. Gouillou,
B. Ildefonse,
H. Kimura,
Y. Nishio,
J. Radford-Knoery, E. Ruellan
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ABSTRACT: The objective of the Manaute cruise of the R.V. L'Atalante with the submersible Nautile was the in situ study of accretion processes, magmatic activity and hydrothermalism in the Manus Basin. Twelve dives and 18 dredges, focusing on the eastern and western tips of the basin, allowed us to demonstrate that in the eastern part of the basin the oceanic accretion is reduced to two axes propagating between Djaul and Weitin FZ. However the magmatic and hydrothermal activity is widely spread along the axes but also on volcanoes and ridges aligned on a N110 oblique direction. In the western part of Man-us basin the oceanic accretion is located along two axes propagating rapidly to the southwest. The magmatic and hydrothermal activities are variable and diffuse over the whole area. The effect of the subduction of the Australian Plate in the New Britain Trench is evident throughout the basin. (C) 2000 Academie des sciences/Editions scientifiques et medicales Elsevier SAS.
Comptes Rendus De L Academie Des Sciences Serie Ii Fascicule a-Sciences De La Terre Et Des Planetes. 01/2000; 331(2):119-126.
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ABSTRACT: During the last three years, the North Fiji Basin (SW Pacific) has been intensively studied on three oceanographic cruises
carried out by French, American and Japanese ships. One of the main goals of these cruises was to study by means of precise
SeaBeam, SEAMARC II, seismic and magnetic surveys, the active spreading system and its associated hydrothermal processes.
The North Fiji basin, bounded by the major Pacific and Indo-Australian plates, shows a complex polyphased tectonic evolution.
One of the last phases of this evolution is the functioning since 3 Ma of a NS spreading center in the axial part of the basin.
The tectonic instability of the area resulted in a permanent rearrangement of the ridge axis. Among others, the 16°40′ S triple
junction is one of the major manifestations of such an instability. Sinistral strike-slip motion 1 Ma ago, along the North
Fiji Fracture Zone induced the change in direction of two segments of the axis from NS to N15 and N160. The first segment
is characterized by a typical spreading ridge similar to various parts of the EPR, while the second shows an atypical ‘en
echelon’ fan-shape opening. The N15 and N160 ridges converging with the North Fiji Fracture Zone constitute the 16°40′ S Ridge-Ridge-Fracture
Zone triple junction. The detailed morphologic and kinematic study of this junction allows us to understand one of the mechanisms
of the deformation in the North Fiji basin.
Marine Geophysical Researches 01/1990; 12(4):285-296. · 0.45 Impact Factor
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Jean-Marie Auzende,
T Urabe,
R. Binns,
J.L. Charlou,
K. Gena,
T. Gamo,
K. Henry,
O. Matsubayashi,
T Matsumoto,
R. Moss,
J. Naka,
Y. Nagaya,
K Okamura, E. Ruellan
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E. Gracia,
H. Ondréas,
V. Bendel,
Jean-Marie Auzende,
Jean-Philippe Eissen,
E. Honza,
P. Huchon,
Y. Iwabuchi,
M. Joshima,
K. Kisimoto, [......],
P. Maillet,
T Matsumoto,
J.P. Mazé,
K. Mitsuzawa,
J. Naka,
Y. Nojiri,
Y Okuda,
M. Tanahashi, E. Ruellan,
T Urabe
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Y. Lagabrielle, E. Ruellan,
M. Tanahashi,
J. Bourgois,
G. Buffet,
G. de Alteriis,
J. Goslin,
E. Gracia-Mont,
Y. Iwabuchi,
P. Jarvis,
M. Joshima,
A.M. Karpoff,
T. Lui,
T Matsumoto,
H. Ondréas,
Bernard Pelletier,
O. Sardou,
E. Tupua
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ABSTRACT: La campagne NOFI du NIO L'Atalante (Programme franco-japonais NEW STARMER, 25 août - 19 septembre, 1994), avait pour objectif l'étude bathymétrique et géophysique des axes d'accrétion dans la partie septentrionale du bassin arrière-arc nord-fidjien. Les dorsales actives "Sud Pandora" et "Tripartite", orientées de N75 à N110, ont été cartographiées à l'aide du sondeur multifaisceaux SIMRAD EM12-dual, de 171°E à 178°E et de 13°S à 15°S. L'axe actif des dorsales est découpé en segments de 80 à 120 km de long, présentant des caractères morphologiques très variés; il s'agit soit d'un graben parfois occupé par une ride néovolcanique ou obstrué par un volcan, soit d'un puissant dôme volcanique allongé. Les segments sont décalés de 10 à 30 km par des zones de relais de natures variées (décalages simples, "OSC", propagateurs, ...). La dorsale Sud Pandora fonctionne au moins depuis 3 Ma, tandis que la dorsale Tripartite est une structure très récente se propageant au sein d'une croûte plus ancienne jusqu'à 178°E, où elle disparaît. Bien que ressemblant aux centres d'accrétion des grands océans, ce système actif se distingue par l'absence de véritables failles transformantes et par sa position orthogonale à la fois au système central N-S d'accrétion du bassin nord-fidjien et à la frontière convergente des Nouvelles Hébrides. (Résumé d'auteur)
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Y. Lagabrielle, E. Ruellan,
M. Tanahashi,
J. Bourgois,
G. Buffet,
G. de Alteriis,
J. Dyment,
J. Goslin,
E. Gracia-Mont,
Y. Iwabushi,
P. Jarvis,
M. Joshima,
A.M. Karpoff,
T Matsumoto,
H. Ondréas,
Bernard Pelletier,
O. Sardou
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ABSTRACT: The South Pandora and the Tripartite Ridges are active spreading centers located in the northern part of the North Fiji Basin. These spreading centers were surveyed over a distance of 750 km during the NOFI cruise of R/V L'Atalante (August-September 1994) which was conducted in the frame of the french-japanese Newstarmer cooperation project. SIMRAD EM12-dual full coverage swath bathymetric and imagery data as well as airgun 6-channel seismic, magnetics and gravity profiles were recorded along an off-axis from 170°40'E to 178°E. Dredging and piston coring were also performed along and off-axis. The axial domain of the South Pandora Ridge is divided into 5 first-order segments characterized by contrasted morphologies. The average width of the active domain is 20 km and corresponds either to bathymetric highs or to deep elongated grabens. The bathymetric highs are volcanic constructions, locally faulted and rifted, which can obstruct totally the axial valley. The grabens show the typical morphology of slow spreading axes, with two steep walls flanking a deep axial valley. Elongated lateral ridges may be present on both sides of the grabens. Numerous volcanoes, up to several kilometers in diameter, occur on both flanks of the South Pandora Ridge. The Tripartite Ridge consists of three main segments showing a sigmoid shape. Major changes in the direction of the active zones are observed at the segment discontinuities. These discontinuities show various geometrical patterns which suggest complex transform relay zones. Preliminary analysis of seismic reflection profiles suggest that the Tripartite Ridge is a very young feature which propagates into an older oceanic domain characterized by a significant sedimentary cover. By contrast, a very thin to absent sedimentary cover is observed about 100 km on both flanks of the South Pandora Ridge active axis. The magnetic anomaly profiles give evidence of long and continuous lineations, parallel to the South Pandora Ridge spreading axis. (Résumé d'auteur)
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Jean-Marie Auzende,
E. Honza,
J.P. Maze,
V. Bendel,
Jean-Philippe Eissen,
E. Gracia-Mont,
P. Huchon,
Y. Lafoy,
Y. Lagabrielle, E. Ruellan, [......],
T Matsumoto,
K. Mitsuzawa,
H. Momma,
T Naganuma,
J. Naka,
Y. Nojiri,
K Otsuka,
M. Tanahashi,
T Tanaka,
T Urabe
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J.M. Auzende,
E. Honza,
X. Boespflug,
S. Deo,
Jean-Philippe Eissen,
J Hashimoto,
P. Huchon,
J. Ishibashi,
Y. Iwabuchi,
P. Jarvis, [......],
S Ohta,
K Otsuka,
Y Okuda,
H. Ondreas,
A. Otsuki, E. Ruellan,
M. Sibuet,
M. Tanahashi,
T Tanaka,
T Urabe
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J.M. Auzende,
Y Okuda,
V. Bendel,
J.P. Ciabrini,
Jean-Philippe Eissen,
E. Gracia-Mont,
K Hirose,
Y. Iwabuchi,
M. Joshima,
K. Kisimoto, [......],
K. Mitsuzawa,
H. Momma,
H. Mukai,
J. Naka,
Y. Nojiri,
A. Ortega-Osorio, E. Ruellan,
M. Tanahashi,
E. Tupua,
K Yamaguchi
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ABSTRACT: Du 10 janvier au 6 février 1991, la campagne Yokosuka 90 a eu pour objet l'étude géologique, géophysique et géochimique de la branche de direction N10 de la dorsale du Bassin nord-fidjien (SW Pacifique). Ce segment est caractérisé par un système d'accrétion actuel constitué d'une succession "en échelon" de grabens dont certains dépassent 4000 m de profondeur. Ces grabens sont bordés par des murs abrupts d'environ 1000 m de hauteur. Ces caractéristiques sont habituellement celle des dorsales lentes, alors que le taux d'ouverture dans cette zone est estimé à 5 cm/an. (Résumé d'auteur)
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J.-P. Foucher,
Jacques Dupont,
P. Bouysse,
J.L. Charlou,
M. Davagnier,
Jean-Philippe Eissen,
Y. Fouquet,
S. Gueneley,
F. Harmegnies,
Y. Lafoy,
André Lapouille,
J.P. Mazé,
J. Morton,
H. Ondreas, E. Ruellan,
J.C. Sibuet
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J.M. Auzende,
T Urabe,
C. Deplus,
Jean-Philippe Eissen,
D. Grimaud,
P. Huchon,
J. Ishibashi,
M. Joshima,
Y. Lagabrielle,
C. Mével,
J. Naka, E. Ruellan,
T Tanaka,
M. Tanahashi
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J.M. Auzende,
T Urabe,
V. Bendel,
C. Deplus,
Jean-Philippe Eissen,
D. Grimaud,
P. Huchon,
J. Ishibashi,
M. Joshima,
Y. Lagabrielle,
C. Mével,
J. Naka, E. Ruellan,
T Tanaka,
M. Tanahashi
