Estratigrafía del subsuelo y evolución sedimentaria del sector sur de la cuenca terciaria del Duero

Abstract

This paper describes the main stratigraphic characters of the Palaeogene and Neogene subsurface successions of the southern sector of the Tertiary Duero Basin. Data have been obtained by the analysis of several hundred wells performed in this area. These successions are separated by the Alba-Villoria fault; which acted as a normal fault during the Neogene. The Palaeogene successions develop a wedge geometry thickening towards the northeast and show a complex internal organization with a high degree of lateral and vertical variability making difficult its correlation. They have been interpreted as meandering and braided fluvial channels. The Neogene successions show an mostly lobe geometry emerging from the Alba-Villoria fault and the southern margin of the basin. These coarse-grained lobes change to the east and the northeast into a lutitic realm. The main features of the infilling of the Neogene basin have been illustrated through five coarse detrital percentage maps.