El campo de esfuerzos compresivo neógeno en el NE de la Península Ibérica

Abstract

The Neogene stress field in the northeastern Iberian Peninsula is reconstructed from the analysis of brittle mesostructures (stylolytes, tension gashes, fault populations and joints). Compression directions obtained show three maxima: N-S to NNE, NW-SE and NE-SW. Stress trajectories can be interpreted according to two hypothesis: 1) An only primary stress field, with deflections due to the movement of large faults; however, some of the deflected trajectories and swapping of stress axes are anomalous and cannot be explained by classical models. 2) Two primary stress fields resulting from succesive convergence in the northern and southern margins of the Iberian plate. The N-S to NNE, «Pyrenean», compression is deflected in the Iberian Chain to NE and E-W directions. The NNW stress field, transmitted from the southern margin of the plate is more homogeneous. Both stress fields, NNE and NNW would alternate, or superimpose during the Neogene: regional deformation in the Iberian Chain agrees with a NNW compression late with respect to the Pyrenean NNE shortening