Stratigraphie du Dogger et crise lusitanienne dans la Serra de Candeeiros

Abstract

Key-words : Stratigraphy - Dogger - «Lusitanian» - Serra de Candeeiros. New elements about the stratigraphy of the Serra de Candeeiros Dogger and Lower «Lusitanian» are presented. The Lower Aalenian was recognized for the first time. Bathonian (more than 50 metres thick) is dated on brachiopods and foraminifera. It corresponds to a series of massive micritic, biadetritical, coral-reef, chaetetid, bryozoa and oolitic-limestones. Callovian (120 m) begins by whitish or yellowish limestones with ammonites and brachiopods of rhe Gracilis zone. Ir is followed by regressive limesrone sequences ending with thick oncolitic layers. The «Lusitanian» base is farmed by greyish lagoon brackish limesrones; it lies unconformably on the Dogger, with or without angular and/or cartographic uncanfarmiry. This radical facies change is related tO tecronic deformation of severa! blocks between the Nazaré and Tagus faults during Oxfordian rimes.