Latest Pleistocene and Holocene chronology of an eventful fluvial history.- The Rio Galera in North-Eastern Andalusia

点击翻译按钮获取中文摘要

The main objective of the project is to establish a high-resolution chronology of the eventful fluvial history of the Rio Galera over the last 17000 years. The project will complete preliminary work that was done in order to detect characteristic fluvial sedimentation features. Dating will be realized on charcoal pieces, on organic macro remnants and on organogenic sediment layers, that are abundant in all profiles. We aim to reconstruct phases of the eventful fluvial history by dating the well distinctive and heterogenous sediment layers. From a first view we observed fine sedimentation in an early phase alternating with coarser layers indicating a change in flow velocity. The sequence (several profiles) is about 15 meters thick and ends with travertine layers alternating with intercalated floodplain sediments. Sedimentation is sometimes interrupted by short soil formation phases (initial soil forming features) or erosion phases indicated by incision features. Another objective of this project is to help solving the question whether the assumed climate forcing of the sedimentation process is superimposed by tectonic activity. Within the scope of the project we aim to supervise a Master thesis that will focus on the entire catchment of the Rio Galera (about 300 square kilometer) in order to investigate different river sections (upstream - downstream). The question is whether sedimentation features can be traced along the river course (degree of connectivity) or if different sections show different sedimentation features. The Baza-basin, in which the Rio Galera incised, is an endorheic depression formed during Plio-Pleistocene that was captured by the Rio Guadahortuna (Guadiana menor) which in fact is one of the frontal flow of the Rio Guadalquivir. The incision of the Rio Galera into the Plio-Pleistocene marls occurred during the middle and late Pleistocene indicated by fluvial stack terraces. After the youngest incision phase of the Rio Galera that is assumed to have happened during latest Pleistocene, this eventful but unexplored part of the fluvial history, in which sedimentation, stillstand and incision alternate, started. By means of a high-resolution chronology of the Rio Galera fluvial dynamics we will be able to contextualize this outstanding profile and compare them to important environmental archives of Andalusia and Central Spain.