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Depositional modes and lake-level variability at Lake Towuti, Indonesia, during the past ~29kyr BP

Vogel, Hendrik ; Russell, James ; Cahyarini, Sri ; Bijaksana, Satria ; Wattrus, Nigel ; Rethemeyer, Janet ; Melles, Martin

In: Journal of Paleolimnology, 2015, vol. 54, no. 4, p. 359-377

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    Titre
    • Depositional modes and lake-level variability at Lake Towuti, Indonesia, during the past ~29kyr BP
    Auteur
    • Vogel, Hendrik. Institute of Geological Sciences & Oeschger Centre for Climate Change Research, University of Bern, Baltzerstr. 1+3, 3012, Bern, Switzerland
    • Russell, James. Department of Earth, Environmental, and Planetary Sciences, Brown University, Box 1846, 02912, Providence, RI, USA
    • Cahyarini, Sri. Research Centre for Geotechnology, Indonesian Institute of Sciences (LIPI), Bandung, Indonesia
    • Bijaksana, Satria. Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung, Jalan Ganesa 10, Bandung, Indonesia
    • Wattrus, Nigel. Large Lakes Observatory, University of Minnesota Duluth, 10 University Drive, 55812, Duluth, MN, USA
    • Rethemeyer, Janet. Institute of Geology and Mineralogy, University of Cologne, Zülpicher Straße 49a, 50674, Cologne, Germany
    • Melles, Martin. Institute of Geology and Mineralogy, University of Cologne, Zülpicher Straße 49a, 50674, Cologne, Germany
    Type de document
    • Postprint
    Langue
    • Anglais
    Publié dans
    • Journal of Paleolimnology, 2015, vol. 54, no. 4, p. 359-377. Springer Netherlands
    Autre version électronique
    Identifiant OAI-PMH
    • oai:doc.rero.ch:332679
    Summary
    Lake Towuti (2.5°S, 121.5°E) is a long-lived, tectonic lake located on the Island of Sulawesi, Indonesia, and in the center of the Indo-Pacific warm pool (IPWP). Lake Towuti is connected with upstream lakes Matano and Mahalona through the Mahalona River, which constitutes the largest inlet to the lake. The Mahalona River Delta is prograding into Lake Towuti's deep northern basin thus exerting significant control on depositional processes in the basin. We combine high-resolution seismic reflection and sedimentological datasets from a 19.8-m-long sediment piston core from the distal edge of this delta to characterize fluctuations in deltaic sedimentation during the past ~29kyr BP and their relation to climatic change. Our datasets reveal that, in the present, sedimentation is strongly influenced by deposition of laterally transported sediments sourced from the Mahalona River Delta. Variations in the amount of laterally transported sediments, as expressed by coarse fraction amounts in pelagic muds and turbidite recurrence rates and cumulative thicknesses, are primarily a function of lake-level induced delta slope instability and delta progradation into the basin. We infer lowest lake-levels between ~29 and 16, a gradual lake level rise between ~16 and 11, and high lake-levels between ~11 and 0kyr BP. Periods of highest turbidite deposition, ~26 to 24 and ~18 to 16kyr BP coincide with Heinrich events 2 and 1, respectively. Our lake-level reconstruction therefore supports previous observations based on geochemical hydroclimate proxies of a very dry last glacial and a wet Holocene in the region, and provides new evidence of millennial-scale variations in moisture balance in the IPWP.