Abstract
Late Holocene hydroclimate variations have been extensively recognized in Amazonia, but the effects of such changes on riverine discharge within the Amazon lowlands are still poorly understood. We investigated a sediment core covering circa 4,000 to 300 cal yr BP collected in the lower valley of the Xingu River (Xingu Ria) in an area under the influence of the Amazon River. Our results indicate a decrease in precipitation in the Amazon lowlands throughout the studied period and reduced input of coarser and potassium-rich Amazon River sediments to the confluence from about 2,600 to 1,400 cal yr BP. We suggest that lower temperatures in the extratropical Southern Hemisphere weakened the South American Summer Monsoon and led to a decrease in the water discharge of the Amazon River during this period.
Original language | English |
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Pages (from-to) | 9013-9022 |
Number of pages | 10 |
Journal | Geophysical Research Letters |
Volume | 46 |
Issue number | 15 |
DOIs | |
State | Published - Aug 16 2019 |
Bibliographical note
Funding Information:The authors acknowledge funding through the São Paulo Research Foundation (FAPESP, grants 2017/50085-3, 2014/23334-4, 2016/11141-2, 2016/02656-9, and 2017/25735-4); the Brazilian Federal Agency for Support and Evaluation of Graduate Education (CAPES, grants AUXPE 1976/2014, 2043/2014, and 564/2015); and the National Council for Scientific and Technological Development (CNPq, grants 454609/2014-0, 302607/2016-1, 422255/2016-5, 306527/2017-0, and 302411/2018-6). This work was supported through the DFG Research Center/Cluster of Excellence The Ocean in the Earth System. We thank the Paleomagnetism Laboratory (USPMag) of the University of São Paulo (Brazil). We acknowledge Ralph Kreutz for laboratory support, Daniel Atencio for providing the XRF equipment, and Mauricio Parra, Tatiana Pereira and Leandro Souza for helping during the field surveys. All data presented in this study are permanently archived on the Pangaea data repository (www.pangaea.de). The authors declare no conflict of interest.
Funding Information:
The authors acknowledge funding through the São Paulo Research Foundation (FAPESP, grants 2017/50085‐3, 2014/23334‐4, 2016/11141‐2, 2016/02656‐9, and 2017/25735‐4); the Brazilian Federal Agency for Support and Evaluation of Graduate Education (CAPES, grants AUXPE 1976/2014, 2043/2014, and 564/2015); and the National Council for Scientific and Technological Development (CNPq, grants 454609/2014‐0, 302607/2016‐1, 422255/2016‐5, 306527/2017‐0, and 302411/2018‐6). This work was supported through the DFG Research Center/Cluster of Excellence . We thank the Paleomagnetism Laboratory (USPMag) of the University of São Paulo (Brazil). We acknowledge Ralph Kreutz for laboratory support, Daniel Atencio for providing the XRF equipment, and Mauricio Parra, Tatiana Pereira and Leandro Souza for helping during the field surveys. All data presented in this study are permanently archived on the Pangaea data repository ( www.pangaea.de ). The authors declare no conflict of interest. The Ocean in the Earth System
Publisher Copyright:
©2019. American Geophysical Union. All Rights Reserved.
Keywords
- Amazon
- Amazonia
- Holocene
- SASM
- late Holocene
- paleoclimate
ASJC Scopus subject areas
- Geophysics
- Earth and Planetary Sciences (all)