Abstract
<p>Alluvial fans and terraces are well developed and preserved in the foothills of the Eastern Cordillera of Colombia, being potential archives of tectonic uplift and climatic variations in a poorly studied tropical region. The main aim of the work is to investigate the evolution of fluvial terraces and alluvial fans in the upper Caqueta river basin. We used Landsat imagens and Copernicus digital elevation model (DEM; GLO-30) to map landforms and optically stimulated luminescence (OSL) dating in quartz grains to estimate burial ages. Our results show that most landforms have an alluvial origin, organized in wide fluvial fans with distinct lobes, at least two terrace levels (7 and 13 m above the river level), and connected incised floodplains along the landscape. The sedimentary facies of the fluvial fans and terraces are dominated by clast-supported massive gravels, with thin layers of coarse-grained sandstones. The modern floodplains are related with braided-like to sinuous channels from up to downstream; gravels dominate their sedimentary facies, but fine sand and mudstones are frequent. This sediment finning from terraces/fans to modern floodplains suggests a significant sediment-to-water discharge ratio change through the late Quaternary. New OSL ages will allow us to estimate the burial ages of the mapped landforms and give new insights into the timing and driving factors related to changes in the fluvial dynamic and landscape evolution of the tropical Andean piedmont. (FAPESP #2020/11047-1)</p>
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.