Continental Thinning and Passive Margin genesis: Towards a general model? Insights of the Gulf of Lion-Sardinia System
Due to its landlock situation, its youth, its thick sedimentary layers, the presence of the Messinian reflector which provides the paleo-geometry of the basin 5.3 Ma ago, its well constrained plate kinematic reconstructions and the huge amount of available data and multidisciplinary studies, the conjugate margins system of the Gulf of Lions and west Sardinia system represents a unique natural laboratory to address fundamental questions about rifting (i.e. crustal thinning, the nature of the continent–ocean transition zone and the style of rifting and subsequent evolution and the connections between deep and surface processes). The Gulf of Lions and west Sardinia system represents one of the rare case of entire contiguous system located in a small area, where deep structure and the thick (up to 6.2 km) sedimentary cover are well documented by three coincident multi-channel and wide-angle seismic profiles located on each conjugate margins, acquired during the SARDINIA Experiment. All these informations about deep structure could be effectively used to validate models of continental break-up and subsidence. Although rifting in back-arc basins might differ somewhat from cratonic rifting, the mechanics of thinning of the continental crust, which is the first-order question, ought to be similar. Moreover, despite some differences on the subsidence rates, the palinspastic reconstruction of the Liguro-Provençal basin shows the same initial configuration (Aslanian et al., 2012; Rabineau et al., 2014) as those of Central (Labails et al., 2009) and South Atlantic margins (Aslanian et al., 2009; Aslanian & Moulin, 2012) as well as intracontinental basins (Thybo & Nielsen, 2009). We will present that comparison of the P-wave velocity modelling & reflection seismic results from SARDINIA Experiment (Moulin et al., in press; Afilhado et al., in press) with the Atlantic passive margins and the intra-continental basins allows to propose general rules for the continental thinning process and the passive margin genesis.
AAPG Datapages/Search and Discovery Article #90226 © 2015 European Regional Conference and Exhibition, Lisbon, Portugal, May 18-19, 2015