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

Vogel, Hendrik; Russell, James M.; Cahyarini, Sri Yudawati; Bijaksana, Satria; Wattrus, Nigel; Rethemeyer, Janet; Melles, Martin (2015). Depositional modes and lake-level variability at Lake Towuti, Indonesia, during the past ~29 kyr BP. Journal of Paleolimnology, 54(4), pp. 359-377. Kluwer Academic 10.1007/s10933-015-9857-z

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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 ~29 kyr 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 0 kyr BP. Periods of highest turbidite deposition, ~26 to 24 and ~18 to 16 kyr 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.

Item Type:

Journal Article (Original Article)

Division/Institute:

10 Strategic Research Centers > Oeschger Centre for Climate Change Research (OCCR)
08 Faculty of Science > Institute of Geological Sciences

UniBE Contributor:

Vogel, Hendrik

Subjects:

500 Science > 550 Earth sciences & geology

ISSN:

0921-2728

Publisher:

Kluwer Academic

Language:

English

Submitter:

Hendrik Vogel

Date Deposited:

01 Dec 2015 14:32

Last Modified:

31 May 2019 14:09

Publisher DOI:

10.1007/s10933-015-9857-z

BORIS DOI:

10.7892/boris.73216

URI:

https://boris.unibe.ch/id/eprint/73216

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