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Please use this identifier to cite or link to this item: http://repositorio.ufba.br/ri/handle/ri/7789

Title: Late-glacial cooling in Amazonia inferred from pollen at Lagoa do Caco, northern Brazil
Other Titles: Quaternary Research
Authors: Ledru, Marie-Pierre
Cordeiro, Renato Campello
Dominguez, José Maria Landim
Martin, Louis
Mourguiart, Philippe
Sifeddine, Abdelfetah
Turcq, Bruno
Keywords: palynology;South America;Brazil;late-glacial;Podocarpus;Amazonia;polar advection;meteorological equator
Issue Date: 2001
Abstract: New pollen data from a core at Lagoa do Caçó, Maranhão state, Brazil (2°58′S 43°25′W; 120 m elevation), show higher frequencies of Podocarpus at the end of the Pleistocene than today. The increase in Podocarpus, which follows the successive increase of various pioneer species such as Didymopanax, Melastomataceae/Combretaceae, and Cecropia, implies a progressive late-glacial increase of moist and cool climatic conditions. A comparable increase in Podocarpus is found in other lowland records in Amazonia. A review of published pollen data from Amazonia suggests that the moisture source was from the southeast. By contrast, present-day moisture comes from the tropical Atlantic and from the Amazon basin, with its convective precipitation. The likely cause for the southeastern moisture source between ca. 15,000 and 14,500 cal yr B.P. was enhanced polar (Antarctic) advection that reached low latitudes and maintained year-round the meteorological equator in its austral-winter position at northern latitudes or reduced drastically its southward summer displacement. This hypothesis is consistent with marine and ice core records.
Description: Texto completo: acesso restrito. p.47–56
URI: http://www.repositorio.ufba.br/ri/handle/ri/7789
ISSN: 0033-5894
Appears in Collections:Artigos Publicados em Periódicos (IGEO)

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