Paleoclimatic and paleoenvironmental reconstruction of the territories of the Araucano floodplain based on the analysis of recent sediments, Arauca Department

Abstract

In the areas influenced by the Arauca Floodplains, the different processes of sedimentation, deposition, and paleoclimates in the sector are reconstructed, allowing the creation of a model of the history and evolution of the territory over at least the last stages of the Late Pleistocene and throughout the Holocene. The sedimentological characterization and stratigraphic correlation of the area allow for a direct relationship with periods of system evolution where the area was partially flooded, as well as dry periods where the sediment types were of aeolian origin.

The morphology observed in the territories, particularly those linked to the Casanare and Arauca rivers, includes landforms such as levees, floodplains, and lateral barriers, while the main sedimentary contributions from the fluvial systems come from drainage channels. The sediments originate from primary source areas in the geological formations of the eastern flank of the Eastern Cordillera. The wind regime responsible for their formation had a preferential East–West direction, which, combined with the sand sources from large rivers located in the eastern part of the area, facilitated the formation of significant aeolian deposits. Finally, the current geomorphological units are used as a reference for reconstructing the ancient systems and their associated climatic conditions.