ICG2022-497, updated on 20 Jun 2022
10th International Conference on Geomorphology
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Fluvial fans and terraces in the foothills of the Eastern Cordillera of Colombia: morphology, sediments, and luminescence ages

Fabiano Pupim1, Caio Breda2, Carolina Leite2, Ian Del Rio2, Sebastian Gómez2, André Sawakuchi2, and Mauricio Parra2
Fabiano Pupim et al.
  • 1Universidade Federal de São Paulo, Department Environmental Science, Diadema, Brazil (f.pupim@unifesp.br)
  • 2Universidade de São Paulo, Institute of Geosciences, São Paulo, Brazil

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)

How to cite: Pupim, F., Breda, C., Leite, C., Del Rio, I., Gómez, S., Sawakuchi, A., and Parra, M.: Fluvial fans and terraces in the foothills of the Eastern Cordillera of Colombia: morphology, sediments, and luminescence ages, 10th International Conference on Geomorphology, Coimbra, Portugal, 12–16 Sep 2022, ICG2022-497, https://doi.org/10.5194/icg2022-497, 2022.