Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

Journal of the Geological Society

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (5) Citing Articles via Google Scholar Google Scholar Articles by Aranguren, A. Articles by Casas-Ponsati, A. Search for Related Content GeoRef GeoRef Citation

Granite laccolith emplacement in the Iberian arc: AMS and gravity study of the La Tojiza pluton (NW Spain)

^{1 1}Departamento de Geodinámica, Facultad de Ciencias, Universidad del País Vasco, 48080 Bilbao, Spain (e-mail: goparira@lg.ehu.es)
^{2 2}Departamento de Geología, Facultad de Ciencias, Universidad de Zaragoza, 50009 Zaragoza, Spain
^{3 3}Departamento de Petrología, Geoquímica i Prospecció Geològica, Facultat de Geología, Universitat de Barcelona, 08071 Barcelona, Spain

A laccolithic geometry is inferred from geological and geophysical data for the La Tojiza granitic body emplaced in an extensional regime. Nearly circular in outcrop, this 16 km diameter pluton, one of the so-called ‘post-tectonic granodioritic plutons’ of Galicia, is located in the northern Variscan arc of Iberia, within the Mondoñedo Nappe (Western Asturian–Leonese Zone). From anisotropy of magnetic susceptibility measurements and extensive microstructural data, the magnetic fabric of this pluton has been inferred to correlate with the magmatic fabric. Magnetic foliations strike NE–SW and dip gently SE. Magnetic lineations trend NW–SE and plunge gently SE. Gravity data suggest that the pluton has the shape of a sheet with a maximum preserved thickness of 1 km and a root zone located at its eastern border. This pluton is reinterpreted as late kinematic and emplaced during an extensional tectonic regime related to the ductile Vivero normal fault. It is suggested that the emplacement of most post-tectonic plutons of this part of the Variscan orogenic belt may have been controlled by the late extensional collapse of the Iberian Massif.

KEYWORDS: Iberian arc, plutons, magnetic susceptibility, gravity anomalies, extensional tectonics

This article has been cited by other articles:

				C. Teyssier, E. C. Ferre, D. L. Whitney, B. Norlander, O. Vanderhaeghe, and D. Parkinson Flow of partially molten crust and origin of detachments during collapse of the Cordilleran Orogen Geological Society, London, Special Publications, January 1, 2005; 245(1): 39 - 64. [Abstract] [PDF]