THE PALEOGENE OF THE ALGARVE MARGIN: EVIDENCE FROM MULTICHANNEL SEISMIC DATA
Abstract
The Paleogene of the Algarve Margin is documented, based on multichannel seismic (MCS) data interpretation. Two tectono-sedimentary phases, late Campanian to middle Eocene and middle Eocene to Oligocene in age, are reported, separated by main compressive tectonic events related to the Africa- Eurasia convergence. Triggered by regional compressive tectonics that affect the basement, the Upper Triassic- Hettangian evaporites played an important role in the tectono-sedimentary evolution of this margin by localizing both extensional and thrust detachments and generating both salt structures and salt-withdrawal subbasins. During middle Eocene and Oligocene times, the coeval development of compressive structures and normal fault systems in the Eastern Algarve domain is interpreted as resulting from gravity gliding due to a general tilt of the margin.