Cenozoic Basins of Western Iberia: Mondego, Lower Tejo and Alvalade Basins

Abstract

Since middle Campanian times, the Iberian Peninsula experienced an increasing intraplate deformation as a result of stress transmission from its successive active borders; first the northern and later the southeastern border. Following this process a wide range of Cenozoic major geological features were generated in western Iberia, namely: the Plateaus and Mountains of NW Portugal (PMNW), that extend towards the reliefs of NW Iberia (Galicia); the Portuguese Central Range (Lousã–Açor–Estrela and Gardunha ranges) and the uplifted Western Mesozoic Terrains (Montejunto–Sintra reliefs), with their intervening craton, and other significant topographic features related to onshore (e.g. the Arrábida Chain, located west of Setúbal) and offshore tectonic structures that are all elongated SW–NE (e.g. Estremadura Spur); relatively well-developed sedimentary basins (Mondego, Lower Tejo and Alvalade Cenozoic basins), with an overall E–W to NE–SW orientation, providing evidence for their geologic evolution.