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Ciências Geológicas: Ensino e Investigação. Vol. I: 357-363 Plant remains and the palynological record provide important data on the climate evolution in Portugal during Miocene and Pliocene. During the Miocene, the vegetation shows a progressive decrease in the average temperature and humidity. There were shifts to drier environments, mainly during low sea levels (Lower and Upper Burdigalian; Tortonian). An arid event has even been recorded in Langhian times. Otherwise, high sea levels correspond to humid climate events, as in the Middle Burdigalian and Serravallian. As far as Pliocene is concerned, climate evolution has been controlled by Atlantic and Mediterranean influences. The climatic changes were moderate and mostly controlled by humidity. In comparison to late Miocene times, there was in Zanclean times some warming with fluctuations, followed by a temperature and humidity decrease during Piacenzian. A new warming did occur in the Middle Piacenzian ensued by a climate deterioration into the setting up of a Mediterranean regime. Palynology allows the recognition throughout the Pliocene of a decrease of thermal arboreal taxa as well as an increase of Mediterranean elements. |
