Person:
Gómez Barreiro, Juan

Profile Picture
First Name
Juan
Last Name
Gómez Barreiro
URI
https://hdl.handle.net/20.500.14352/86767
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Geológicas
Department
Mineralogía y Petrología
Area
Identifiers
UCM identifierORCIDScopus Author IDWeb of Science ResearcherIDDialnet IDGoogle Scholar ID

Filters

2009 - 200912010 - 20141
Reset filters

Settings

Author: Alcock, James E. ×

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    The late Variscan HT/LP metamorphic event in NW and Central Iberia: relationships to crustal thickening, extension, orocline development and crustal evolution
    (Geological Society, London, special publications, 2014) Martínez Catalán, José R.; Rubio Pascual, Francisco J.; Díez Montes, Alejandro; Díez Fernández, Rubén; Gómez Barreiro, Juan; Dias Da Silva, Ícaro; González Clavijo, Emilio; Ayarza, Puy; Alcock, James E.; Schulmann, K.
    The Variscan metamorphic evolution of the autochthonous domain of NW and Central Iberia is characterized by a Barrovian gradient followed by a high-temperature–low-pressure (HT/LP) event associated with voluminous granite magmatism. The structural, metamorphic and magmatic histories of the region are described briefly and the relations between them are explained. A coherent model for evolution of the continental crust is proposed using published radiometric ages, thermal models and seismic reflection profiles. The metamorphic evolution, including the high-temperature event, is explained by crustal thickening resulting from the Gondwana–Laurussia collision followed by a period of thermal relaxation and a long-lasting extensional stage. The fact that the highest temperatures were reached in the core of the Central Iberian arc, partly occupied by remnants of a huge allochthonous nappe stack, is discussed in relation to both the emplacement of the allochthon and subsequent oroclinal bending. The overburden provided by the allochthonous pile was decisive in triggering the high-temperature event. Orocline development mostly occurred later and had no significant effect on the metamorphic evolution, although it was important for the present localization of gneiss domes and granitoids. The possible role of the mantle in supplying additional heat to explain the HT/LP event is also discussed. It would seem that little mantle contribution was needed and there are no strong arguments for mantle delamination, although some kind of mantle–crust interaction is expected beneath the hot regions presently occupying the core of the Central Iberian arc.
  • Thumbnail Image
    Item
    A rootless suture and the loss of the roots of a mountain chain: The Variscan belt of NW Iberia
    (Comptes rendus. Géoscience, 2009) Martínez Catalán, José R.; Arenas Martín, Ricardo; Abati Gómez, Jacobo; Sánchez Martínez, Sonia; Díaz García, Florentino; Fernández Suárez, Javier; González Cuadra, Pablo; Castiñeiras García, Pedro; Gómez Barreiro, Juan; Díez Montes, Alejandro; González Clavijo, Emilio; Rubio Pascual, Francisco J.; Andonaegui Moreno, María Del Pilar; Jeffries, Teresa E.; Alcock, James E.; Díez Fernández, Rubén; López Carmona, Alicia
    Ophiolites of different Paleozoic ages occur in North-West (NW) Iberia in a rootless suture representing the remnants of the Rheic Ocean. Associated allochthonous terranes in the hanging- and foot-walls of the suture derive from the former margins, whereas the relative autochthon corresponds to the Paleozoic passive margin of northern Gondwana. The Paleozoic tectonic evolution of this part of the circum-Atlantic region is deduced from the stratigraphical, petrological, structural and metamorphic evolution of the different units and their ages. The tectonic reconstruction covers from Cambro-Ordovician continental rifting and the opening of the Rheic Ocean to its Middle to Upper Devonian closure. Then, the Variscan Laurussia–Gondwana convergence and collision is briefly described, from its onset to the late stages of collapse associated with the demise of the orogenic roots. [RÉSUMÉ] Une suture sans racines et la perte des racines d’une chaîne montagneuse : la chaîne varisque du Nord-Ouest de l’Ibérie. Des ophiolites d’âges différents affleurent dans le Nord-Ouest de l’Ibérie dans une suture sans racines, témoin de l’océan Rhéïque. Les terrains allochtones sur et sous la suture dérivent de ses deux marges, tandis que l’autochtone relatif appartient à la marge passive du Nord de Gondwana. On peut déduire l’évolution des plaques dans cette partie de la région circum-Atlantique à partir des données stratigraphiques, pétrologiques, structurales, métamorphiques et géochronologiques. Cette évolution inclut le développement d’un rift continental et l’ouverture de l’océan Rhéïque pendant le Cambro-Ordovicien ainsi que sa fermeture au Dévonien moyen à supérieur. On décrit aussi l’évolution de la convergence et collision varisque entre Laurussia et Gondwana, du début jusqu’aux derniers stades d’un effondrement associé à la perte des racines orogéniques.