Accéder directement au contenu Accéder directement à la navigation
Article dans une revue

A drastic lower Miocene regolith evolution triggered by post obduction slab break-off and uplift in New Caledonia

Abstract : A lower Miocene coarse conglomerate that crops out in the Népoui Peninsula does not represent the base of the marine transgression that followed obduction in New Caledonia. Instead, the conglomeratic alluvial fan that contains peridotite cobbles and reworked weathering products records a short-lived episode of terrestrial erosion intercalated between two intervals of subsidence marked by marine carbonate deposition. Considering the Miocene sea level evolution reported in the literature, it is concluded that neither lower Miocene transgression nor erosion were driven by sea level variation. In contrast, a southeastward propagating slab tear that initiated at the latitude of the high pressure/low temperature metamorphic complex of northern New Caledonia likely generated east to west tilting of New Caledonia, subsidence along the West Coast and hence fringing reef development together with moderate erosion of older regolith. Coincidence between conglomerate deposition and hence prominent erosion that closely followed emplacement of postobduction granitoids influenced by a slab window suggests a genetic link. Therefore, it is concluded that short-lived lower Miocene erosion was due to slab breakoff and subsequent uplift that occurred at ~ 22 Ma. Lower Miocene erosion profoundly dissected the Peridotite Nappe and in the northern half of New Caledonia only left isolated klippes along the West Coast.
Type de document :
Article dans une revue
Liste complète des métadonnées

Littérature citée [67 références]  Voir  Masquer  Télécharger
Contributeur : Anne-Marie Pouget Connectez-vous pour contacter le contributeur
Soumis le : mardi 28 juillet 2015 - 13:32:41
Dernière modification le : mercredi 3 août 2022 - 04:03:15
Archivage à long terme le : : jeudi 29 octobre 2015 - 10:53:02


Fichiers éditeurs autorisés sur une archive ouverte




Brice Sevin, Dominique Cluzel, Pierre Maurizot, Caroline Ricordel-Prognon, George Chaproniere, et al.. A drastic lower Miocene regolith evolution triggered by post obduction slab break-off and uplift in New Caledonia. Tectonics, American Geophysical Union (AGU), 2014, 33 (9), pp.1787-1801. ⟨10.1002/2014TC003588⟩. ⟨hal-01171278⟩



Consultations de la notice


Téléchargements de fichiers