Dynamics of floodplain lakes in the Upper Amazon Basin during the late Holocene

Fraizy, Pascal; Moreira-Turcq, Patricia; Quintana-Cobo, Isabel; Crave, Alain; Moreira, Luciane S.; de Aguiar Duarte Contrera, Julia Maria; Cordeiro, Renato C.; Aniceto, Keila; Turcq, Bruno

dc.contributor.author	Quintana-Cobo, Isabel
dc.contributor.author	Moreira-Turcq, Patricia
dc.contributor.author	Cordeiro, Renato C.
dc.contributor.author	Aniceto, Keila
dc.contributor.author	Crave, Alain
dc.contributor.author	Fraizy, Pascal
dc.contributor.author	Moreira, Luciane S.
dc.contributor.author	de Aguiar Duarte Contrera, Julia Maria
dc.contributor.author	Turcq, Bruno
dc.date.accessioned	2018-11-30T23:41:32Z
dc.date.available	2018-11-30T23:41:32Z
dc.date.issued	2018
dc.identifier.uri	https://hdl.handle.net/20.500.12866/4230
dc.description.abstract	To better understand the impact of channel migration processes and climate change on the depositional dynamics of floodplain lakes of the upper Amazon Basin during the late Holocene, we collected three sediment cores from floodplain lakes of the Ucayali River and one from the Maranon River. The cores were dated with C-14, radiographed and described. Bulk density, grain size analysis and total organic carbon (TOC) were determined. The results show that sedimentation in Ucayali floodplain lakes was marked by variations during the late Holocene, with periods of intense hydrodynamic energy and abrupt accumulations, a gap in the record between about 2870 and 690 cal yr BP, and periods of more lacustrine conditions. These changes in sedimentation were associated with variations in the river's influence related to changes in its meandering course (2870 cal yr BP) and a period of severe flooding between 3550 and 3000 cal yr BP. Lake Lagarto on the Maranon River floodplain exhibits a different sedimentary environment of low hydrodynamics with palm trees and macrophytes. Apparently, the lake has not experienced intense migration processes during the last 600 cal yr BP (base of the core). Nevertheless, the river sediment flux to the lake was important from 600 to 500 cal yr BP, although it decreased thereafter until the present. This decrease in the mineral accumulation rate indicates a decrease in river discharge since 500 cal yr BP, which coincides with precipitation records from the central Andes. In the upper part of the three Ucayali floodplain cores, a 30- to 250-cm-thick layer of reworked sediments has been deposited since 1950 AD (post-bomb). In Lake Carmen, this layer is associated with invasion of the lake by the levee of a migrating meander of the Ucayali. In Lakes Hubos and La Moringa, however, the river is still far away and the deposition must be interpreted as the result of extreme flooding. The beginning of the Ucayali meander migration is dated back to 2000 AD, suggesting that these extreme floods could be very recent and linked to hydrologic extremes registered instrumentally in the Amazon Basin.	en_US
dc.language.iso	eng
dc.publisher	Elsevier
dc.relation.ispartofseries	Comptes Rendus. Géoscience
dc.rights	info:eu-repo/semantics/restrictedAccess
dc.rights.uri	https://creativecommons.org/licenses/by-nc-nd/4.0/deed.es
dc.subject	Abrupt accumulation events	en_US
dc.subject	Amazon Basin	en_US
dc.subject	bulk density	en_US
dc.subject	depositional environment	en_US
dc.subject	floodplain	en_US
dc.subject	grain size	en_US
dc.subject	Holocene	en_US
dc.subject	lake dynamics	en_US
dc.subject	Lake sedimentation	en_US
dc.subject	Late Holocene	en_US
dc.subject	Maranon River	en_US
dc.subject	Moringa	en_US
dc.subject	Peru	en_US
dc.subject	sediment core	en_US
dc.subject	sedimentation	en_US
dc.subject	total organic carbon	en_US
dc.subject	Ucayali River	en_US
dc.subject	Upper Amazon Basin	en_US
dc.title	Dynamics of floodplain lakes in the Upper Amazon Basin during the late Holocene	en_US
dc.type	info:eu-repo/semantics/article
dc.identifier.doi	https://doi.org/10.1016/j.crte.2017.10.004
dc.subject.ocde	https://purl.org/pe-repo/ocde/ford#1.05.00
dc.relation.issn	1778-7025