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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Holocene stratigraphic evolution of saline lakes in Nhecolandia, southern Pantanal wetlands (Brazil)

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Author(s):
McGlue, Michael M. [1] ; Guerreiro, Renato Lada [2, 3] ; Bergier, Ivan [4] ; Silva, Aguinaldo [5] ; Pupim, Fabiano N. [6] ; Oberc, Victoria [1] ; Assine, Mario L. [2]
Total Authors: 7
Affiliation:
[1] Univ Kentucky, Dept Earth & Environm Sci, 106 Slone Res Bldg, Lexington, KY 40506 - USA
[2] Univ Estadual Paulista Rio Claro, Inst Geociencias & Ciencias Exatas, BR-13506900 Sao Paulo - Brazil
[3] Inst Fed Parana, Assis Chateaubriand Campus, BR-85935000 Assis Chateaubriand, Parana - Brazil
[4] Embrapa Pantanal, Lab Biomass Convers, BR-79320900 Corumba, MS - Brazil
[5] Univ Fed Mato Grosso do Sul CPAN, Dept Geog, 1270 Ave Rio Branco, BR-79304902 Corumba, MS - Brazil
[6] Univ Fed Sao Paulo, Dept Environm Sci, BR-09913030 Diadema, SP - Brazil
Total Affiliations: 6
Document type: Journal article
Source: Quaternary Research; v. 88, n. 3, p. 472-490, NOV 2017.
Web of Science Citations: 6
Abstract

Nhecolandia is a fossil lobe of the Taquari River megafan and a prominent geomorphic subunit of the Pantanal wetlands because of the presence of >10,000 small lakes. We investigated the stratigraphic records of three saline lakes from Nhecolandia to explore their potential as Quaternary hydroclimate archives. Radiocarbon data indicate that accumulation at two lakes was approximately continuous in the late Holocene, and chemostratigraphic variability suggests sensitivity to environmental change with multicentennial resolution. A basal sandy unit and an upper muddy unit comprise the shallow stratigraphy of each lake. A pronounced change in depositional environment from freshwater wetlands to saline lakes at similar to 3300-3200 cal yr BP best explains the lithofacies transition. Ephemeral freshwater wetlands formed on the abandoned megafan lobe, which was molded by deflation in the arid early Holocene. Wind-scouring of the megafan lobe generated topographically closed depressions with complex marginal sand ridges, which allowed permanent lakes to evolve when rainfall increased in the late Holocene. The lakes became highly saline and alkaline after similar to 910 cal yr BP, which influences biogeochemistry and aquatic ecology. The results hold implications for understanding the response of the southern Pantanal to climate change, as well as the development of pans in tropical megafan settings. (AU)

FAPESP's process: 14/23334-4 - Coupling optically stimulated luminescence (OSL) and terrestrial cosmogenic nuclides (TCN) analysis to reconstruct changes in the Amazonian fluvial system in the Late Cenozoic (<5 ma)
Grantee:Fabiano Do Nascimento Pupim
Support type: Scholarships in Brazil - Post-Doctorate
FAPESP's process: 14/06889-2 - Paleohydrological changes, chronology of events and sediment dynamics in the quaternary of the Pantanal Wetland
Grantee:Mario Luis Assine
Support type: Research Program on Global Climate Change - Regular Grants