Modeling the evolution of the Guadalquivir foreland basin (southern Spain)

Abstract

[1] Previous quantitative studies dealing with the origin of foreland basins have focused primarily either on the rheological basis of the lithosphere mechanical response or on the relationship between orogenic loading and sediment geometry. To link the evolution of the Guadalquivir foreland basin (South Iberia) with the thermomechanical stratification of the Iberian lithosphere, we combine quantitative approaches to deep and shallow processes: thrust loading, lithospheric flexure, thickness changes of the crust and the lithospheric mantle, and surface mass transport. A planform flexural analysis of the presentday load distribution shows that basement subsidence is related not only to upper crustal thrusting but also to a deep-seated additional load. On the basis of the observed gravity and geoid fields, we propose this additional load to be related to a lithospheric mantle thickening larger than the coeval crustal thickening. Further modeling of the evolution of a basin cross section reveals that the architecture of the sedimentary basin is additionally related to the lithosphere rheological response. The quantitative study of the evolution of basement faulting and the forebulge uplift of Sierra Morena leads us to conclude that viscous stress relaxation and/or plastic yielding within the lithosphere are key processes to explain the flexural evolution of the basin.

Thermo-Mechanical Models for Coupled Lithosphere-Surface Processes: Applications to Continental Convergence and Mountain Building Processes

“…Many recent models have investigated feedbacks between surface processes and isostatic reaction (e.g., Kooi and Beaumont, 1994;Snyder et al, 2000;Basile and Allemand, 2002;Garcia-Castellanos, 2002;Garcia-Castellanos et al, 2002Simpson and Schlunegger, 2003;Persson et al, 2004;Casteltort and Simpson, 2006). Redistribution of surface loads by erosion and sedimentation must induce tectonic deformation to maintain isostatic balance.…”

“…There is also a strong dependence of transport capacity on the grain size and climate episodicity (e.g., Davy and Crave, 2000). The long-range fluvial models were used with success by Beamount (1994, 1996), Garcia-Castellanos (2002), Garcia-Castellanos et al (2002, Persson et al (2004). The cumulative material flow, q fe, due to the fluvial transport can be presented, in most simple form, as:…”

Recent and active tectonics in the western part of the Betic Cordillera

“…Simultaneously, Lower to Middle Miocene extension was recorded at the sedimentary sequence of the Alborán basin (Chalouan and Michard, 2004) and at the metamorphic rocks of the Internal Zones (Aldaya et al, 1984;García-Dueñas et al, 1992;Platt and Vissers, 1989). Since the Late Tortonian, the main active processes have been volcanic activity, relief uplift, progressive individualization of intramontane sedimentary basins, and development of the Guadalquivir foreland basin due to the flexure of the Variscan Basement below the Betic Cordillera (Maury et al, 2000;García-Castellanos et al, 2002;Serrano et al, 2002;Sanz de Galdeano and Alfaro, 2004).The surface expression of recent and active tectonic structures is highly variable along the Betic Cordillera. The relief of the central and eastern sectors is mainly determined by E-W to ENE-WSW kilometer-size folds that deform up to Holocene sediments of the Alborán Sea (Galindo-Zaldívar et al, 2003;Marín-Lechado et al, 2006).…”

Crustal thickness and images of the lithospheric discontinuities in the Gibraltar arc and surrounding areas

“…From our observations this continental slab (hereafter referred to as the Iberian slab) shows a continuous connection to the crust under the Iberian Massif. Models of the Guadalquivir basin evolution by Garcia-Castellanos et al (2002) relate its formation to the loading of the Iberian crust under …”