Abstract

SALVARREDY-ARANGUREN, Matías Miguel; PROBST, Anne  and  ROULET, Marc. Sedimentary and geochemical evidences of the little Ice Age in the Milluni Grande Lake of the Bolivia high-platean. Rev. Asoc. Geol. Argent. [online]. 2009, vol.65, n.4, pp.660-673. ISSN 0004-4822.

Milluni Grande Lake (MGL) is located Milluni Valley, west-side of Eastern Andes, Bolivia. The Milluni area presents a classic U shaped valley, product of the last glacial regression. MGL is the biggest lake of the valley, and it is at the end of Milluni Valley, a strategic position that allow a complete sedimentary record of last 450 years. The sediment record was studied with a lake core. A full description and analysis of physical and chemical parameters, sedimentology, mineralogy and geochemical proxys allow to conclude that sediment record shows an important climate change (CC). Complementary, a ²¹⁰Pb datation over the superficial core levels was used to establish a sedimention rate and estimate a chronology for no dated levels. The chronology point out that the detected climate change clearly occurs during the Last Ice Age (LIA). Moreover, a detailed correlation has been established between sandy levels in the sedimentary record of MGL and Charquini mountain glacier moraines. Finally, some well documented facts about the development of Last Ice Age in this area of Bolivia are mentioned.

Keywords : Milluni Lake; Bolivia; Little Ice Age; Climate change; Geochemistry.

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