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Accueil du site > Séminaires, conférences et RS > Réunions Scientifiques

« The geological evolution of the Tejo River in Portugal, during the last 3.6 Ma - a continental archive of climate and sea-level changes, but also active tectonics and primitive human occupation »

Jeudi 23 novembre 2017, 17h00 (IPH, Amphi)

par Daujeard Camille - publié le

« The geological evolution of the Tejo River in Portugal, during the last 3.6 Ma - a continental archive of climate and sea-level changes, but also active tectonics and primitive human occupation » par Pedro P. Cunha (Géologue, Université de Coimbra, Portugal)

The Lower Tejo and Madrid basins have endorheic units deposited during the Iberian Central Range uplift, under a hot and dry climate (9.5-3.7Ma). The culminant unit of both basins (3.7-1.8Ma) records a hot and humid climate. Comprises marine and deltaic deposits that pass upstream into sandy and gravelly braided fluvial and alluvial deposits. In both basins, it occupies a culminant position in the landscape and predates the stage of fluvial incision that produced narrow valleys with terrace staircases : T1 (ca. 1000-900ka) ; T2 (ca. 700-600ka) ; T3 (ca. 460-360ka) ; T4 (ca. 335-155ka), Acheulian at basal and middle levels but early Middle Paleolithic at top levels ; T5 (135-73 ka), Middle Palaeolithic ; T6 (62-32ka), late Middle Palaeolithic ; aeolian sands and colluvium (32-12ka), Upper Palaeolithic to Epipalaeolithic ; alluvial plain (12ka to present), Mesolithic and recent industries. ESR and TNC will provide the aggradation interval of the units that record the transition from basin infilling to the incision stage.