The Plio-Pleistocene boundary in southeast Spain: a review

Abstract

The Plio-Pleistocene boundary in the Mediterranean region has been defined by the entry of the so-called 'northern guests'. The absence of this characteristic cold fauna in the sedimentary record of littoral marine basins in SE Spain has led to the local establishment of this boundary by other means. Most outcropping upper Pliocene and Pleistocene marine sediments in this area have a very shallow character, resulting in the absence of the planktonic foraminiferal assemblages that characterize the upper Pliocene. As a result the only means of determining this boundary has been through regional correlation, detailed mapping and sedimentological analysis, as well as palaeomagnetism. After studies were carried out in different basins, and accepting the age of 1.64 (now recalibrated to 1.8) Ma for the Plio-Pleistocene boundary (Aguirre and Pasini, 1985), we conclude that this boundary does not bear any climatic, environmental or tectonic signature. The changes in most of these basins seem to occur either before or after this date.