CONICET | Buscador de Institutos y Recursos Humanos

The Southern Patagonian Andes between 48° and 53° SL offers a unique opportunity to study the results of orogenic growth superimposed over a previously rifted region. In this sector the northern Austral or Magallanes basinwas affected by late to middle Jurassic extension followed by Late Cretaceous toNeogene tectonic compression. The resultant fold-thrust belt displays significant along-strike variations in width and lateral position of the structural domains that may be reflecting a first order control of the Jurassic extensional depocenters, as proposed in previous works. This hypothesis is tested using a series of scaled sandbox analog models involving the positive inversion of two adjacent depocenters with different extensional rates accommodated by a transfer fault. The correlation between structures in the Southern Patagonian Andes and the features in the model have important first order similarities supporting the theory of a positively inverted extensional basinwith a previous history of southward increase in extension. Moreover structural cross-sections analyzed from field and seismic data have a geometry that is consistent with serial cross sections resulting from the models.