The tectono-stratigraphic evolution of an Atlantic-type basin: an example from the Arrábida sector of the Lusitanian Basin

Abstract

The Arrábida chain is an impressive basin inversion structure of Miocene age that is exposed over almost the entire Mesozoic sedimentary sequence of the southern sector of the Lusitanian Basin (LB). This field trip provides a complete cross-section through some of the key outcrops, illustrating important moments in the tectono-stratigraphic evolution of an Atlantic-type basin, namely: a)the extensional tectonic control on Early–Middle Jurassic sedimentation in a low- to high-energy carbonate ramp setting; b) the presence of a basin-wide unconformity at the Middle–Upper Jurassic transition; c) the tectonic rejuvenation of the eastern border of the LB, the effects of rift shouldering, and the progressive exhumation of the eastern margin in the sedimentary infill; d) the distal expression of the basin’s breakup unconformity (rift to drift stage); and e) magmatism in a passive margin.