Temporal and spatial variations in tectonic subsidence in the Iberian Basin (eastern Spain): inferences from automated forward modelling of high-resolution stratigraphy (Permian-Mesozoic)

By subsidence analysis on eighteen surface sections and 6 wells, which cove r large part of the Iberian Basin(E Spain) and which are marked by high-res olution stratigraphy of the Permian, Triassic, Jurassic and Cretaceous, we quantify the complex Permian and Mesozoic tectonic subsidence history of th e basin. Backstripping analysis of the available high resolution and high s urface density of the database allows to quantify spatial and temporal patt erns of tectonically driven subsidence to a much higher degree than previou s studies. The sections and wells have also been forward modelled with a ne w 'automated' modelling technique, with unlimited number of stretching phas es, in order to quantify variations in timing and magnitude of rifting. It is demonstrated that the tectonic subsidence history in the Iberian Basin i s characterized by pulsating periods of stretching intermitted by periods o f relative tectonic quiescence and thermal subsidence. The number of stretc hing phases appears to be much larger than found by earlier studies, showin g a close match with stretching phases found in other parts of the Iberian Peninsula and allowing a clear correlation with discrete phases in the open ing of the Tethys and Atlantic. (C) 1998 Elsevier Science B.V. All rights r eserved.