Análisis de la evolución tectónica de los márgenes hiper-extendidos mediante la integración de datos sísmicos, gravimétricos y magnéticos

Resumo

Hyperextended margins show great transversal and longitudinal heterogeneity, such that definition of tectonic domains made exclusively from 2D seismic sections can have major limitations.The structure of the West Iberian margin (WIM) is heterogeneous along its entire length. This heterogeneity stems from the nature of the pre-rift basement (Murillas et al., 1990), and an added complexity, related to the fact that its formation involves several rifting episodes and a posterior partial tectonic inversion (Boillot and Malod, 1988).Classical first-order architecture of this (and other) hyperextended magma-poor rifted margin shows “idealized” cross sections with a set of key rift domains from continent to ocean (e.g., Tugend et al., 2015).The boundaries between the different tectonic domains of the WIM have been discussed by diverse authors (e.g., Péron-Pinvidic et al., 2013; Weldford et al., 2010; Nirrengarten et al., 2018; Druet et al., 2018), based on geophysical and structural criteria; among others the stretching factor, a measure of tectonic stretching and crustal thinning. These criteria are mainly supported by the interpretation of regional reflection seismic sections, by the few well data available, and, to a lesser extent, by potential field data. However, the criteria used to define the different domains does not always coincide among different authors (e.g., Péron-Pinvidic et al., 2013; Mohn et al., 2015; Tugend et al., 2015; Stanton et al., 2016). There are several reasons for this variability: the complexity of the extensional structure, the effects of structural and rheological inheritance on multiple phases of extension, later geological processes that have modified the extensional structure (e.g., compressive reactivation), and the fact that most previous studies have been based on limited/localized 2D seismic data...