Kinematics of syn-eclogite deformation in the Bergen Arcs, Norway, implications for exhumation mechanisms - Université Pierre et Marie Curie Accéder directement au contenu
Article Dans Une Revue Special Publication - Geological Society of London Année : 2005

Kinematics of syn-eclogite deformation in the Bergen Arcs, Norway, implications for exhumation mechanisms

Hugues Raimbourg
Laurent Jolivet
Loic Labrousse

Résumé

The northwestern part of Holsnøy island, in the Bergen Arcs, Norway, consists of a granulite-facies protolith partially transformed at depth in eclogite (700 °C, > 19 kbars) and amphibolite (650 °C, 8-10 kbars) facies during the Caledonian orogenesis. Eclogitized zones are mainly planar objects (fractures with parallel reaction bands and cm-to-100 m-scale shear zones). Eclogitic zones are distributed in two sets of orientations and the associated deformation can be described as 'bookshelf tectonics'. The major shear zones strike around N120 and dip to the North, and show consistent top-to-the-NE shear sense throughout the area. In the large-scale kinematic frame of Caledonian NW-dipping slab, eclogitic shear zones are interpreted as the way to detach crustal units from the subducting slab and to prevent their further sinking. As the retrograde amphibolitic deformation pattern is similar to the eclogitic one, the detached crustal units started their way up along these eclogitic shear zones. Radiometric ages of eclogitic and amphibolitic metamorphism and their comparison with the chronology of Caledonian orogenesis show that the deformation recorded on Holsnøy occurred in a convergent context. The mechanism we propose can thus account for the first steps of exhumation during collision.
Fichier principal
Vignette du fichier
Article-final2_2.pdf (2.21 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)
Loading...

Dates et versions

hal-00023451 , version 1 (26-11-2012)

Identifiants

Citer

Hugues Raimbourg, Laurent Jolivet, Loic Labrousse, Yves Leroy, Dov Avigad. Kinematics of syn-eclogite deformation in the Bergen Arcs, Norway, implications for exhumation mechanisms. Special Publication - Geological Society of London, 2005, 243, pp.175-192. ⟨10.1144/GSL.SP.2005.243.01.13⟩. ⟨hal-00023451⟩
293 Consultations
276 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More