Neoteetonics of the eastern border of the Madrid basin

[Abstract] An analysis ofthe neotectonic activity and the current stress state of the eastern border of Madrid Basin has been carried ont using structural-methods (fault population analysis), as well as seismological methods. Two stress tensors have been established: - Tensor 1: with a N1500E shortening trend, characterized mainly by strikeslip faults. This tensor corresponds to the «Guadarrama» stress field (Capote et al., 1990), wihch causes the Central System structure; dated middle Aragonian -lower Pleistocene in the eastern border ofMadrid Basin (Muñoz Martín, 1993). - Tensor 2: dated post-Iower Pleistocene, with a N150° E extension trend, characterized basically by normal faults. Actual stress tensor deduced focal mechanisms by the seismological method is compatible with the paleostress field deduced for the middle-Iower Pleistocene (tensor 2)