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Centennial to millennial changes in maar-lake deposition during the last 45,000 years in tropical Southern Africa (Lake Masoko, Tanzania)

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dc.creator Garcina, Yannick
dc.creator Williamsona, David
dc.creator Taieba, Maurice
dc.creator Vincensa, Annie
dc.creator Mathéa, Pierre-Etienne
dc.creator Majule, Amos
dc.date 2016-02-22T08:53:19Z
dc.date 2016-02-22T08:53:19Z
dc.date 2006
dc.date.accessioned 2018-04-18T11:17:49Z
dc.date.available 2018-04-18T11:17:49Z
dc.identifier Garcin, Y; Williamson, D; Taieb, M.; Vincens, A.; Mathé, P-E and Majule, A (2006) Centennial to millennial changes in maar-lake deposition during the last 45,000 years in tropical Southern Africa: Lake Masoko, Tanzania. Elsevier B.V. PALEO. Available at www.elsevier.com/locate.paleo
dc.identifier 10.1016/j.palaeo.2006.02.002
dc.identifier http://hdl.handle.net/123456789/477
dc.identifier.uri http://hdl.handle.net/123456789/9353
dc.description The Masoko maar (southern Tanzania) provides one of the most continuous Late Quaternary lacustrine sedimentary records from Africa. A detailed chronostratigraphic framework coupled with sedimentological and magnetic measurements allows us construct a 30-year resolution continuous sedimentary sequence covering the last 45,000 years and to address local depositional environment and climate variability in the tropical Southern Africa. Based on present-day observations and measurements, our results indicate that the low-field magnetic susceptibility of the sediment is highly controlled by climate-driven processes (wind-stress and/or lake-level amplitude changes) acting on the titanomagnetite-rich shoreline reservoir. The tephra- and turbidite-free magnetic susceptibility record is strongly modulated by a persistent multi-decadal to centennial variability (∼80 to 200 years), probably linked to the Gleissberg and Suess cycles of solar activity. At lower frequency, the variability of deposition is controlled by the precessional cycle and its harmonics, suggesting a dominant multi-millennial forcing of low-latitude insolation on climatic changes in tropical Southern Africa. Inferred wetter conditions during the Last Glacial Maximum and the Younger Dryas at Masoko (9°S) indicate southward shifts of the Intertropical Convergence Zone associated with the North Atlantic glacial dynamics, and/or contrasted hydrological changes in the Rungwe highlands compared to the neighbouring areas. Finally, former regional transfer function between diatom assemblages and water chemistry suggested drier conditions during the Last Glacial Maximum at Lake Masoko [Barker, P., Williamson, D., Gasse, F., Gibert, E., 2003. Climatic and volcanic forcing revealed in a 50,000-year diatom record from Lake Massoko, Tanzania. Quaternary Research 60, 368–376]. In this context, further climate-proxy data (such as pollen) and hydrobiological studies in small, deep lakes are needed to support our alternative interpretation of the Masoko record.
dc.language en
dc.publisher Elsevier
dc.subject Lake Masoko
dc.subject Rungwe
dc.subject Southern Africa
dc.subject Late Quaternary
dc.subject Intertropical Convergence Zone
dc.subject Precession
dc.subject Solar cycles
dc.subject Magnetic susceptibility
dc.title Centennial to millennial changes in maar-lake deposition during the last 45,000 years in tropical Southern Africa (Lake Masoko, Tanzania)
dc.type Journal Article


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