The Pantanal is the world's largest tropical wetland and a biodiversity hotspot, yet its response to Quaternary environmental change is unclear. To address this problem, sediment cores from shallow lakes connected to the Upper Paraguay River (PR) were analyzed and radiocarbon dated to track changes in sedimentary environments. Stratal relations, detrital particle size, multiple biogeochemical indicators, and sponge spicules suggest fluctuating lake-level lowstand conditions between ~11,000 and 5300. cal. yr BP, punctuated by sporadic and in some cases erosive flood flows. A hiatus has been recorded from ~5300 to 2600. cal. yr BP, spurred by confinement of the PR within its channel during an episode of profound regional drought. Sustained PR flooding caused a transgression after ~2600. cal. yr BP, with lake-level highstand conditions appearing during the Little Ice Age. Holocene PR flood pulse dynamics are best explained by variability in effective precipitation, likely driven by insolation and tropical sea-surface temperature gradients. Our results provide novel support for hypotheses on: (1) stratigraphic discontinuity of floodplain sedimentary archives; (2) late Holocene methane flux from Southern Hemisphere wetlands; and (3) pre-colonial indigenous ceramics traditions in western Brazil.
|Original language||English (US)|
|Number of pages||10|
|Journal||Quaternary Research (United States)|
|State||Published - Sep 2012|
Bibliographical noteFunding Information:
IBAMA, ECOA, EMBRAPA, UFMS, Fazenda Santa Teresa, the citizens of Amolar, K. Wendt, B. Lima de Paula, D. Calheiros, the LRC, and UA AMS deserve special thanks for supporting our research. We acknowledge the American Chemical Society (PRF grant 45910-AC8 ), the São Paulo Research Foundation (FAPESP grant 2007/55987-3 ) and ExxonMobil for funding. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Copyright 2012 Elsevier B.V., All rights reserved.
- Flood pulse
- Floodplain lakes
- Pantanal wetlands
- Upper Paraguay River
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