RT Journal Article
T1 The late Variscan HT/LP metamorphic event in NW and Central Iberia: relationships to crustal thickening, extension, orocline development and crustal evolution
A1 Martínez Catalán, José R.
A1 Rubio Pascual, Francisco J.
A1 Díez Montes, Alejandro
A1 Díez Fernández, Rubén
A1 Gómez Barreiro, Juan
A1 Dias Da Silva, Ícaro
A1 González Clavijo, Emilio
A1 Ayarza, Puy
A1 Alcock, James E.
A2 Schulmann, K.
AB 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.
PB The Geological Society
SN 2041-4927
YR 2014
FD 2014-01
LK https://hdl.handle.net/20.500.14352/92039
UL https://hdl.handle.net/20.500.14352/92039
LA eng
DS Docta Complutense
RD 26 ago 2024