The North-Lusitanian Subbasin (Portugal) from the Triassic to the Middle Jurassic: a model of an “aborted rift”

Abstract

The North-Lusitanian Subbasin has sustained a complex evolution whichcart be divided into five main stages: 1. Liassic Distension leading to the differentiation of the Arunca-Montemor lineament; 2. Lower Liassic Rifting with development of endemic ammonites-faunas (Upper Sinemurian); 3. Differential Subsidence (Middle Liassic to Lower Aalenian): eustatic changes were complicated by a strong acceleration of the differential subsidence; 4. Progradation of a carbonate platform (Middle Aalenian to Lower Callovian); 5. The closure of the subbasin began during the Middle Callovian and was followed by emersions.