U/Th dating of Quaternary travertines at the middle River Llobregat (NE Iberian Peninsula, Nortwestern Mediterranean). Correlation with sea-level changes

Abstract

The dating of the fluvial terraces of the middle River Llobregat enabled one to establish a correlation between the sedimentation episodes in continental zones and in neighbouring deltaic and coastal areas in the NE Iberian continental margin. The fluvial Terraces 4 (+85-95 m above river level) and 3 (+55-65 m above river level) are made up by or include travertines, which were deposited around 350,000 and 111,000 years ago, respectively. These radiometric ages correspond to two high sea level periods: the Eemian interglacial (isotopic stage 5e) and the interglacial related to isotopic stage 9. However, other travertine units in the valley, such as the Can Tobella staggered cascade travertines, were formed during the Holocene, probably due to hydrothermal spring activity related to the tectonic contact between the Catalan Coastal Ranges and the Ebro Basin.