Skip to Main content Skip to Navigation
Journal articles

The Loyalty-New Hebrides Arc collision: Effects on the Loyalty Ridge and basin system, Southwest Pacific (first results of the ZoNéCo programme)

Abstract : The ZoNéCo 1 and 2 cruises of Ifremer's Research Vessel L'Atalante, collected new swath bathymetry and geophysical data over the southern and northern segments of the basins and ridges forming the Loyalty system. Between the two surveyed areas, previous studies found evidence for the resistance of the Loyalty Ridge to subduction beneath the New Hebrides trench near 22°S–169°E. On the subducted plate, except for seismicity related to the downbending of the Australian plate, recorded shallow seismicity is sparse within the Loyalty system (Ridge and Basin) where reliable focal mechanism solutions are almost absent. Swath bathymetry, seismic reflection and magnetic data acquired during the ZoNéCo 1 and 2 cruises revealed a transverse asymmetric morphology in the Loyalty system, and an along-strike horst and graben structure on the discontinuous Loyalty Ridge. South of 23°50primeS and at 20°S, the two WSW-ENE-trending fault systems, respectively, sinistral and dextral, that crosscut the southern and northern segments of the Loyalty system, are interpreted as due to the early effects of collision with the New Hebrides Arc. A NNW-SSE trend, evident along the whole Loyalty system and on the island of New Caledonia, is interpreted as an inherited structural trend that may have been reactivated through flexure of the Australian lithospheric plate at the subduction zone. Overall then, the morphology, structure and evolution of the southern and northern segments of the Loyalty system probably result from the combined effects of the Australian plate lithospheric bulge, the active Loyalty-New Hebrides collision and the overthrust of the New Caledonian ophiolite.
Document type :
Journal articles
Complete list of metadatas

Cited literature [12 references]  Display  Hide  Download

https://hal-insu.archives-ouvertes.fr/hal-00122516
Contributor : Nathalie Pothier <>
Submitted on : Wednesday, January 3, 2007 - 9:42:18 AM
Last modification on : Friday, October 23, 2020 - 4:41:40 PM
Long-term archiving on: : Tuesday, April 6, 2010 - 7:46:30 PM

File

010012126.pdf
Publisher files allowed on an open archive

Identifiers

Collections

Citation

Yves Lafoy, François Missegue, Dominique Cluzel, Raymond Le Suavé. The Loyalty-New Hebrides Arc collision: Effects on the Loyalty Ridge and basin system, Southwest Pacific (first results of the ZoNéCo programme). Marine Geophysical Research, Springer Verlag, 1996, 18, pp.337-356. ⟨10.1007/BF00286084⟩. ⟨hal-00122516⟩

Share

Metrics

Record views

413

Files downloads

572