Lithospheric folding in Iberia

Abstract

[1] Integration of stress indicator data, gravity data, crustal kinematics data, and analysis of topography and recent vertical motions demonstrates the occurrence of consistently oriented spatial patterns of large-scale Alpine to recent intraplate deformation in Iberia. The inferred upper crustal and lithospheric deformation patterns and the timing of the associated expressions at or near the surface support the existence of a close coupling with plate boundary processes operating at the margins of Iberia. Patterns of lithosphere and upper crustal folds are oriented perpendicular to the main axis of present-day intraplate compression in Iberia inferred from structural analysis of stress indicator data and focal mechanism solutions. These findings suggest the presence of lithospheric folds, with wavelengths compatible with theoretical predictions of folding wavelengths of Variscan lithosphere. Stress-induced intraplate deformation set up by plate interactions is compatible with indications for the absence of present-day deep mantle-lithosphere interactions inferred from seismic tomography.

Long-term thermo-tectonic evolution of the Montes de Toledo area (Central Hercynian Belt, Spain): constraints from apatite fission-track analysis

“…In this respect, the extent of the far-field effects is closely related to the geometric position of the pre-existing weakness zones with respect to the direction of the regional stress fields. As a first approximation, the Sierra de Guadarrama would be mainly controlled by the interaction between the Iberian and the African plates, as the position of the Sierra de Guadarrama is parallel to the currently active Betic Cordillera (De Bruijne and Andriessen 2000;De Bruijne and Andriessen 2002;Cloetingh et al 2002), and in the same way, the Montes de Toledo area, which presents an E W trend, would be controlled by the interaction be tween the Iberian and Eurasian plates. This is not just consistent with the orientations of the stress fields with respect to the position of both mountain ranges but also with the timing of plate interactions, as the collision between Iberia and Eurasia occurred first, the Montes de Toledo area having more time to be dismantled.…”

Crustal deformation induced by mantle dynamics: insights from models of gravitational lithosphere removal

“…In some areas, the subsidence events are related to lithosphere extension, thermal subsidence and crustal buckling/folding (e.g. Lambeck 1983;Burg & Podladchikov 1999;Cloetingh et al 2002;Schmalholz et al 2002). In other basins, the subsidence mechanism is less clear, and some intracratonic basins have been linked to processes that originate in the mantle (e.g.…”

Recent tectonic model for the Upper Tagus Basin (central Spain)

“…Giner et al, 1996 ;Cloetingh et al, 2002 ;De Vicente et al, 2007). The shallow seismicity at the intraplate western area of Iberia is explained by Fernández-Lozano et al (2011) as a consequence of the stress transfer from the plate boundaries to the interiors.…”

“…The stress-field promoting SCS building corresponds with an intraplate response to far-field effect from the active tectonic boundaries. Commonly, the lithospheric folding instead of mantle process is invoked to explain the active tectonic deformation and vertical movements in this zone (Cloetingh et al, 2002;De Vicente et al, 2007. Polyphase deformation from the Miocene to the present may explain the stress convergence at the SCS (Cloetingh et al, 2002).…”

“…In this geological framework, the main tectonic structures have a conjugate orientation, with NE-SW and NW-SE trending . All of these structures are related with the aforementioned lithospheric flexure defined by the basement geometry and differential filling and thickness of Neogene sequences Giner et al, 1996;Cloetingh et al, 2002;De Vicente et al, 2007Martín-Velázquez et al, 2009).…”