Architecture, sedimentary facies and chronology of a composite island: A model from the Upper Paraná River, Brazil
Autor(a) principal: | |
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Data de Publicação: | 2021 |
Outros Autores: | , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UNESP |
Texto Completo: | http://dx.doi.org/10.1016/j.geomorph.2020.107457 http://hdl.handle.net/11449/205363 |
Resumo: | Composite islands that originate from central bars are one of the most frequent types of islands in the Paraná River and in many large rivers in the world. The aim of this study is to highlight island-forming processes and the evolution of an island on a large anabranching tropical river over a period of 101–104 yr. Mutum Island in the Upper Paraná River, Brazil (mean discharge = 9000 m3 s−1), was chosen because of its large size (>15 km in length) and by the formative processes that have been active over the last 8 ka. Our analysis used a 60-yr series of satellite images and aerial photos, and 16 absolute dates (14C and OSL) from 11 vibro-cores and outcrops. Mutum Island was formed by the stabilization, vertical aggradation, and vegetal development of a central bar. Island expansion occurred through the addition of lateral and frontal bars. Island deposits exhibit three main lithosomes: coarse to fine basal sand deposits more than 3 m below the island surface related to channel processes; middle sandy mud layers 2–4 m thick formed by annexation processes; and upper massive mud formed by flood flow deceleration over the island. The age of deposits decreased from the center (8200 BP) to the banks (present day) of the island. The predominantly lateral expansion of island deposits resulted in a different depositional architecture to that described for other anabranching rivers. This study demonstrates that the formation and evolution of Mutum Island has been relatively stable since the beginning of the Holocene. The model presented for the Mutum Island represents a useful contribution on the understanding of large anabranching river systems. |
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Architecture, sedimentary facies and chronology of a composite island: A model from the Upper Paraná River, BrazilAnabranching riverFluvial sedimentologyRiver islandSand-barComposite islands that originate from central bars are one of the most frequent types of islands in the Paraná River and in many large rivers in the world. The aim of this study is to highlight island-forming processes and the evolution of an island on a large anabranching tropical river over a period of 101–104 yr. Mutum Island in the Upper Paraná River, Brazil (mean discharge = 9000 m3 s−1), was chosen because of its large size (>15 km in length) and by the formative processes that have been active over the last 8 ka. Our analysis used a 60-yr series of satellite images and aerial photos, and 16 absolute dates (14C and OSL) from 11 vibro-cores and outcrops. Mutum Island was formed by the stabilization, vertical aggradation, and vegetal development of a central bar. Island expansion occurred through the addition of lateral and frontal bars. Island deposits exhibit three main lithosomes: coarse to fine basal sand deposits more than 3 m below the island surface related to channel processes; middle sandy mud layers 2–4 m thick formed by annexation processes; and upper massive mud formed by flood flow deceleration over the island. The age of deposits decreased from the center (8200 BP) to the banks (present day) of the island. The predominantly lateral expansion of island deposits resulted in a different depositional architecture to that described for other anabranching rivers. This study demonstrates that the formation and evolution of Mutum Island has been relatively stable since the beginning of the Holocene. The model presented for the Mutum Island represents a useful contribution on the understanding of large anabranching river systems.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Universidade Estadual PaulistaConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Graduate Program in Geography Western State of Paraná UNIOESTE/Marechal Cândido RondonInstitute of Geosciences São Paulo State University UNESPGraduate Program in Freshwater Ecology State University of Maringá UEM/MaringáGraduate Program in Geography Federal University of Mato Grosso do Sul UFMS/CPTLInstitute of Geosciences São Paulo State University UNESPCNPq: 304925/2017-9CNPq: 308846/2010-9CNPq: 405190/2018-2CNPq: 474245/2011-01UNIOESTE/Marechal Cândido RondonUniversidade Estadual Paulista (Unesp)Universidade Estadual de Maringá (UEM)Universidade Federal de Mato Grosso do Sul (UFMS)Leli, Isabel T. [UNESP]Stevaux, José C.Assine, Mario L. [UNESP]2021-06-25T10:14:04Z2021-06-25T10:14:04Z2021-01-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlehttp://dx.doi.org/10.1016/j.geomorph.2020.107457Geomorphology, v. 372.0169-555Xhttp://hdl.handle.net/11449/20536310.1016/j.geomorph.2020.1074572-s2.0-85093676445Scopusreponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengGeomorphologyinfo:eu-repo/semantics/openAccess2021-10-23T12:39:38Zoai:repositorio.unesp.br:11449/205363Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462024-08-05T22:52:53.228368Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
Architecture, sedimentary facies and chronology of a composite island: A model from the Upper Paraná River, Brazil |
title |
Architecture, sedimentary facies and chronology of a composite island: A model from the Upper Paraná River, Brazil |
spellingShingle |
Architecture, sedimentary facies and chronology of a composite island: A model from the Upper Paraná River, Brazil Leli, Isabel T. [UNESP] Anabranching river Fluvial sedimentology River island Sand-bar |
title_short |
Architecture, sedimentary facies and chronology of a composite island: A model from the Upper Paraná River, Brazil |
title_full |
Architecture, sedimentary facies and chronology of a composite island: A model from the Upper Paraná River, Brazil |
title_fullStr |
Architecture, sedimentary facies and chronology of a composite island: A model from the Upper Paraná River, Brazil |
title_full_unstemmed |
Architecture, sedimentary facies and chronology of a composite island: A model from the Upper Paraná River, Brazil |
title_sort |
Architecture, sedimentary facies and chronology of a composite island: A model from the Upper Paraná River, Brazil |
author |
Leli, Isabel T. [UNESP] |
author_facet |
Leli, Isabel T. [UNESP] Stevaux, José C. Assine, Mario L. [UNESP] |
author_role |
author |
author2 |
Stevaux, José C. Assine, Mario L. [UNESP] |
author2_role |
author author |
dc.contributor.none.fl_str_mv |
UNIOESTE/Marechal Cândido Rondon Universidade Estadual Paulista (Unesp) Universidade Estadual de Maringá (UEM) Universidade Federal de Mato Grosso do Sul (UFMS) |
dc.contributor.author.fl_str_mv |
Leli, Isabel T. [UNESP] Stevaux, José C. Assine, Mario L. [UNESP] |
dc.subject.por.fl_str_mv |
Anabranching river Fluvial sedimentology River island Sand-bar |
topic |
Anabranching river Fluvial sedimentology River island Sand-bar |
description |
Composite islands that originate from central bars are one of the most frequent types of islands in the Paraná River and in many large rivers in the world. The aim of this study is to highlight island-forming processes and the evolution of an island on a large anabranching tropical river over a period of 101–104 yr. Mutum Island in the Upper Paraná River, Brazil (mean discharge = 9000 m3 s−1), was chosen because of its large size (>15 km in length) and by the formative processes that have been active over the last 8 ka. Our analysis used a 60-yr series of satellite images and aerial photos, and 16 absolute dates (14C and OSL) from 11 vibro-cores and outcrops. Mutum Island was formed by the stabilization, vertical aggradation, and vegetal development of a central bar. Island expansion occurred through the addition of lateral and frontal bars. Island deposits exhibit three main lithosomes: coarse to fine basal sand deposits more than 3 m below the island surface related to channel processes; middle sandy mud layers 2–4 m thick formed by annexation processes; and upper massive mud formed by flood flow deceleration over the island. The age of deposits decreased from the center (8200 BP) to the banks (present day) of the island. The predominantly lateral expansion of island deposits resulted in a different depositional architecture to that described for other anabranching rivers. This study demonstrates that the formation and evolution of Mutum Island has been relatively stable since the beginning of the Holocene. The model presented for the Mutum Island represents a useful contribution on the understanding of large anabranching river systems. |
publishDate |
2021 |
dc.date.none.fl_str_mv |
2021-06-25T10:14:04Z 2021-06-25T10:14:04Z 2021-01-01 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://dx.doi.org/10.1016/j.geomorph.2020.107457 Geomorphology, v. 372. 0169-555X http://hdl.handle.net/11449/205363 10.1016/j.geomorph.2020.107457 2-s2.0-85093676445 |
url |
http://dx.doi.org/10.1016/j.geomorph.2020.107457 http://hdl.handle.net/11449/205363 |
identifier_str_mv |
Geomorphology, v. 372. 0169-555X 10.1016/j.geomorph.2020.107457 2-s2.0-85093676445 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Geomorphology |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.source.none.fl_str_mv |
Scopus reponame:Repositório Institucional da UNESP instname:Universidade Estadual Paulista (UNESP) instacron:UNESP |
instname_str |
Universidade Estadual Paulista (UNESP) |
instacron_str |
UNESP |
institution |
UNESP |
reponame_str |
Repositório Institucional da UNESP |
collection |
Repositório Institucional da UNESP |
repository.name.fl_str_mv |
Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP) |
repository.mail.fl_str_mv |
|
_version_ |
1808129469540466688 |