Strength of the Iberian intraplate lithosphere: Cenozoic deformations and seismicity

Previous studies about the strength of the lithosphere in the Iberia centre fail to resolve the depth of earthquakes because of the rheological uncertainties. Therefore, new contributions are considered (the crustal structure from a density model) and several parameters (tectonic regime, mantle rheology, strain rate) are checked in this paper to properly examine the role of lithospheric strength in the intraplate seismicity and the Cenozoic evolution. The strength distribution with depth, the integrated strength, the effective elastic thickness and the seismogenic thickness have been calculated by a finite element modelling of the lithosphere across the Central System mountain range and the bordering Duero and Madrid sedimentary basins. Only a dry mantle under strike-slip/extension and a strain rate of 10-15 s-1, or under extension and 10-16 s-1, causes a strong lithosphere. The integrated strength and the elastic thickness are lower in the mountain chain than in the basins. These anisotropies have been maintained since the Cenozoic and determine the mountain uplift and the biharmonic folding of the Iberian lithosphere during the Alpine deformations. The seismogenic thickness bounds the seismic activity in the upper–middle crust, and the decreasing crustal strength from the Duero Basin towards the Madrid Basin is related to a parallel increase in Plio–Quaternary deformations and seismicity. However, elasto–plastic modelling shows that current African–Eurasian convergence is resolved elastically or ductilely, which accounts for the low seismicity recorded in this region.

The gift of the ungiven: Jean-Luc Marion’s phenomenology of giveness facing Levinas’ “there is”

Jean-Luc Marion’s phenomenology of giveness constitutes one of the most outstanding attempts to set up a universal theory of the phenomenologically given as a whole within the framework of contemporary philosophical thought. The aim of the present study is to apply the main categories of this phenomenological theory concerning gift to the singular type of phenomenon represented by the pure indeterminate and anonymous being to which Emmanuel Levinas refers by the name of il y a (“there is”) in his early writings (and also subsequently). Therefore, this concerns examining the multiple specific modes of giveness proper to the impersonal “there is” and also its paradoxical relationship both with the donor and with the receiver of such gift in order to show the possibility of a “third way” of phenomenological investigation. This is a way equally distant from the western traditional concept of Being as “stable presence” and from Levinas’ proposal geared to substitute ontology for ethics as “first philosophy”.

Mental logic and its difficulties with disjunction

The mental logic theory does not accept the disjunction introduction rule of standard propositional calculus as a natural schema of the human mind. In this way, the problem that I want to show in this paper is that, however, that theory does admit another much more complex schema in which the mentioned rule must be used as a previous step. So, I try to argue that this is a very important problem that the mental logic theory needs to solve, and claim that another rival theory, the mental models theory, does not have these difficulties.