%0 Journal Article
%A Martín Velázquez, Silvia
%A Vicente Muñoz, Gerardo de
%A Elorza, Francisco José
%T Intraplate stress state from finite element modelling: The southern border of the Spanish Central System
%D 2009
%@ 0040-1951
%U https://hdl.handle.net/20.500.14352/50363
%X An elastic finite element approach has been used with the dual aim of determining the most appropriatereference state of stress, namely a uniaxial strain state or a lithostatic state, and re fining the understanding ofthe Iberian intraplate stresses. A cross-section model with an average crustal rheology and a flat topographyhas been analysed first in order to evaluate the in fluence of boundary conditions and rheological propertiesin the reference and tectonic stress states. The uniaxial and lithostatic states are obtained by including theoverburden weight and a compressive horizontal load, which equals the uniaxial and lithostatic stressrespectively, and provided that Poisson's ratio equals ~0.5 in the lithostatic state. On the other hand, atectonic state with a σHNσV regime is reproduced by adding a horizontal constant load. Subsequently,constraints on the magnitude of the predicted Cenozoic stresses along a NW–SE cross-section in the southernborder of the Spanish Central System (in the Variscan granitic basement of El Berrocal) have been estimatedincorporating the topographic loading, lithological variations and the most recent far tectonic stresses. Thedeep geological structure has been established from gravity modelling and geological data. To simulate theactive strike-slip to uniaxial extension regimes in the interior of Iberian Peninsula, a lithostatic initial statehas to be considered and a tectonic load in the range of 15–20 MPa has to be applied. The gradient ofmaximum horizontal stress originated under these conditions is in the range of–350 MPa km− 1. Theseresults are in accordance with the estimated intraplate tectonic stress, the force along the convergent plateboundary of Eurasia–Africa, the lithospheric strength of Iberia, and the direct measurements of stresses.
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