Granite laccolith emplacement in the Iberian Arc; AMS and gravity study of the La Tojiza Pluton (NW Spain)

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doi: 10.1144/0016-764902-079
Authors:Aranguren, A.; Cuevas, J.; Tubía, J. M.; Román-Berdiel, T.; Casas-Sainz, A.; Casas-Ponsati, A.
Author Affiliations:Primary:
Universidad del País Vasco, Departamento de Geodinámica, Bilbao, Spain
Universidad de Zaragoza, Spain
Universitat de Barcelona, Spain
Volume Title:Journal of the Geological Society of London
Source:Journal of the Geological Society of London, 160(3), p.435-445. Publisher: Geological Society of London, London, United Kingdom. ISSN: 0016-7649
Publication Date:2003
Note:In English. 62 refs.; illus., incl. 1 table, geol. sketch maps
Summary: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 Mondonedo 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.
Subsections:Igneous petrology
Subjects:Accelerator mass spectra; Bouguer anomalies; Deformation; Extension; Faults; Geophysical methods; Granites; Gravity anomalies; Gravity methods; Hercynian Geosyncline; Igneous rocks; Intrusions; Island arcs; Kinematics; Laccoliths; Magnetic susceptibility; Mass spectra; Models; Normal faults; Orogeny; Paleomagnetism; Paleozoic; Plutonic rocks; Plutons; Spectra; Statistical analysis; Stratigraphic units; Structural analysis; Style; Variscan Orogeny; Europe; Iberian Peninsula; Southern Europe; Spain; La Tojiza Pluton
Coordinates:N424500 N434500 W0070000 W0080000
Abstract Numbers:03M/3238
Record ID:2003042097
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from The Geological Society, London, London, United Kingdom
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