EGU22-1521, updated on 27 Mar 2022
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Sediment composition and depositional environments in tropical Lake Sentani, Papua Province, Indonesia

Jens Kallmeyer1, Sulung Nomosatryo1,2, Rik Tjallingii3, Cynthia Henny2, Iwan Ridwansyah2, Dirk Wagner1,4, and Sara Tomás4
Jens Kallmeyer et al.
  • 1GFZ German Research Centre for Geosciences, Geomicrobiology, Potsdam, Germany (
  • 2Research Center for Limnology, National Research and Innovation Agency (BRIN), Cibinong, Indonesia
  • 3GFZ German Research Centre for Geosciences, Climate Dynamics and Landscape Evolution, Potsdam, Germany
  • 4Institute of Geosciences, University of Potsdam, Potsdam, Germany

Tropical Lake Sentani in the Indonesian Province Papua consists of four separate sub-basins and is surrounded by a geologically  diverse catchment. Also, strong morphological differences between the sub-basins result in a unique water column structure for each basin, ranging from fully mixed to meromictic. We characterized the surface sediment (upper 5 cm) of the lake’s four sub-basins based on multivariate statistical analyses (Principal Component Analysis, hierarchical clustering) of major element compositions obtained by X-ray Fluorescence (XRF) scanning. Three types of sediment are identified based on distinct compositional differences between rivers, shallow/proximal and deep/distal lake sediments. The different sediment types are mainly characterized by the amounts of organic carbon (TOC) and sulfur on one side and elements associated with siliciclastic rocks (Ti, Al, Si, K) on the other. Our study shows large spatial heterogeneity within the lake’s sub-basins that is mainly caused by catchment geology and topography, river runoff as well as the bathymetry and the depth of the oxycline.The samples from rivers and river mouths are dominated by siliciclastic elements and linked with coarser grain sizes as well as an abundance of mafic rock fractions or carbonates, depending on catchment geology. The sedimentary environment also controls the behavior of Fe and Mn, as these elements change from a positive correlation with siliciclastic elements in river samples to a negative correlation in the lake, indicating a more redox-sensitive behavior. These highly variable conditions make Lake Sentani a natural laboratory, with its different sub-basins representing different depositional environments under identical tropical climate conditions

How to cite: Kallmeyer, J., Nomosatryo, S., Tjallingii, R., Henny, C., Ridwansyah, I., Wagner, D., and Tomás, S.: Sediment composition and depositional environments in tropical Lake Sentani, Papua Province, Indonesia, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-1521,, 2022.