Respuesta topográfica a un proceso de delaminación litosférica: un modelo simple para el final del Orógeno Varisco en el NO de la Península Ibérica

Abstract

In order to establish a lithospheric scale scenario in which the geologic record is in agreement with the theoretical topographical evolution that results from lithospheric delamination process that took place at the end of the Variscan orogeny within the NW of the Iberian peninsula. A simple isostatic model is performed to reconcile geophysical and geologic data that may represent an approach to one of the possible lithospheric and topographical configurations that took place in the aftermath of the Variscan Orogeny. From this point of view, the results obtained, together with their comparison with the geologic, sedimentary and igneous record, during the Upper Carboniferous and the Permian, allow to explain most of the geological processes that took place in the studied region due to a process of lithospheric thickening under the Cantabrian Zone and the subsequent lithospheric delamination of the formerly generated root. The topographical response to this process consisted on an inversion of the polarity of the relief, from initially higher mountains in the western part of the Variscan Orogen (in present day coordinates) to subsequent dominant elevations in the east (Cantabrian Zone), contemporary with the lithospheric delamination. The genesis of the Stephanian and Permians basins in the Cantabrian and West Asturian-Leonese Zones are compatible with the topographical variations deduced in our model.