Genesis of submerged sandstones in Paraná State continental shelf, Southern Brazil, based on cementation patterns, ages and stable isotopes
Autor(a) principal: | |
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Data de Publicação: | 2018 |
Outros Autores: | , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Brazilian Journal of Oceanography |
Texto Completo: | https://www.revistas.usp.br/bjoce/article/view/153126 |
Resumo: | Beachrocks are a common feature along the Brazilian coast and although their occurrence in intertidal zones is concentrated in tropical regions, similar formations have been described submerged on the continental shelf in subtropical regions. In the state of Paraná, submerged sandstones are present on the continental shelf and their formation could be associated with the cementation of beach sediments. This would provide an excellent indicator of the stabilization of the coastline during lower sea-level periods. In this study, samples were identified and collected in Paraná State, Southern Brazil, at depths between 18 and 33 meters in the continental shelf and at 6 meters depth in the Paranaguá Bay inlet. As in situ observations proved problematic, analysis relied mainly on their petrography, mineralogy, ages and isotopic values (δ13C and δ18O). Whole rock dating demonstrated that the oldest acquired sample was formed 28109-26406 cal. years BP, being exposed to atmospheric conditions during the Last Glacial Maximum. This exposure is reflected in its cements, composed uniquely of microcrystalline and spar calcite, and on its δ18O/δ13C values, which indicates formation on a fresh water environment. Contrarily to most carbonate cemented products described along Brazilian coastline, δ13C values ranged between -26.36 and -51.07‰ on all other samples, interpreted as a result of cement precipitation prompted by methane, either: in a paleo-estuarine/ paleo-lagunar to transgressive environment buried under a pile of coarser material or; after transgression and drowning of organic-rich sediments by coarser sediments, and due to upward migration of methane on the sedimentary column. Both processes would result in cements identified on these samples, apart from the one collected closer to shore which indicates some freshwater influence. Two of the samples separated by 15km distance perpendicularly to the actual coastline and 11m depth difference yielded max and minimum ages of 7913 and 7452 cal. years BP. Such a short time span between these samples could be either the result of their formation on a linked environment or older carbon signature from drowned environments being present on younger cements. |
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Brazilian Journal of Oceanography |
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Genesis of submerged sandstones in Paraná State continental shelf, Southern Brazil, based on cementation patterns, ages and stable isotopesMethane-derived carbonatesbeachrockssubmerged sandstonescontinental shelfsea-level indicatorsBeachrocks are a common feature along the Brazilian coast and although their occurrence in intertidal zones is concentrated in tropical regions, similar formations have been described submerged on the continental shelf in subtropical regions. In the state of Paraná, submerged sandstones are present on the continental shelf and their formation could be associated with the cementation of beach sediments. This would provide an excellent indicator of the stabilization of the coastline during lower sea-level periods. In this study, samples were identified and collected in Paraná State, Southern Brazil, at depths between 18 and 33 meters in the continental shelf and at 6 meters depth in the Paranaguá Bay inlet. As in situ observations proved problematic, analysis relied mainly on their petrography, mineralogy, ages and isotopic values (δ13C and δ18O). Whole rock dating demonstrated that the oldest acquired sample was formed 28109-26406 cal. years BP, being exposed to atmospheric conditions during the Last Glacial Maximum. This exposure is reflected in its cements, composed uniquely of microcrystalline and spar calcite, and on its δ18O/δ13C values, which indicates formation on a fresh water environment. Contrarily to most carbonate cemented products described along Brazilian coastline, δ13C values ranged between -26.36 and -51.07‰ on all other samples, interpreted as a result of cement precipitation prompted by methane, either: in a paleo-estuarine/ paleo-lagunar to transgressive environment buried under a pile of coarser material or; after transgression and drowning of organic-rich sediments by coarser sediments, and due to upward migration of methane on the sedimentary column. Both processes would result in cements identified on these samples, apart from the one collected closer to shore which indicates some freshwater influence. Two of the samples separated by 15km distance perpendicularly to the actual coastline and 11m depth difference yielded max and minimum ages of 7913 and 7452 cal. years BP. Such a short time span between these samples could be either the result of their formation on a linked environment or older carbon signature from drowned environments being present on younger cements.Universidade de São Paulo. Instituto Oceanográfico2018-12-21info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionapplication/pdfhttps://www.revistas.usp.br/bjoce/article/view/15312610.1590/s1679-87592018019306603Brazilian Journal of Oceanography; Vol. 66 Núm. 3 (2018); 267-282Brazilian Journal of Oceanography; v. 66 n. 3 (2018); 267-282Brazilian Journal of Oceanography; Vol. 66 No. 3 (2018); 267-2821982-436X1679-8759reponame:Brazilian Journal of Oceanographyinstname:Universidade de São Paulo (USP)instacron:USPenghttps://www.revistas.usp.br/bjoce/article/view/153126/149649Copyright (c) 2018 Brazilian Journal of Oceanographyinfo:eu-repo/semantics/openAccessSimioni, Bruno IvanAngulo, Rodolfo JoséVeiga, Fernando AlvimOliveira, Luiz Henrique SielskiSouza, Maria Cristina de2018-12-27T14:33:21Zoai:revistas.usp.br:article/153126Revistahttps://www.revistas.usp.br/bjoce/indexPUBhttps://www.revistas.usp.br/bjoce/oaiio@usp.br||io@usp.br1982-436X1679-8759opendoar:2018-12-27T14:33:21Brazilian Journal of Oceanography - Universidade de São Paulo (USP)false |
dc.title.none.fl_str_mv |
Genesis of submerged sandstones in Paraná State continental shelf, Southern Brazil, based on cementation patterns, ages and stable isotopes |
title |
Genesis of submerged sandstones in Paraná State continental shelf, Southern Brazil, based on cementation patterns, ages and stable isotopes |
spellingShingle |
Genesis of submerged sandstones in Paraná State continental shelf, Southern Brazil, based on cementation patterns, ages and stable isotopes Simioni, Bruno Ivan Methane-derived carbonates beachrocks submerged sandstones continental shelf sea-level indicators |
title_short |
Genesis of submerged sandstones in Paraná State continental shelf, Southern Brazil, based on cementation patterns, ages and stable isotopes |
title_full |
Genesis of submerged sandstones in Paraná State continental shelf, Southern Brazil, based on cementation patterns, ages and stable isotopes |
title_fullStr |
Genesis of submerged sandstones in Paraná State continental shelf, Southern Brazil, based on cementation patterns, ages and stable isotopes |
title_full_unstemmed |
Genesis of submerged sandstones in Paraná State continental shelf, Southern Brazil, based on cementation patterns, ages and stable isotopes |
title_sort |
Genesis of submerged sandstones in Paraná State continental shelf, Southern Brazil, based on cementation patterns, ages and stable isotopes |
author |
Simioni, Bruno Ivan |
author_facet |
Simioni, Bruno Ivan Angulo, Rodolfo José Veiga, Fernando Alvim Oliveira, Luiz Henrique Sielski Souza, Maria Cristina de |
author_role |
author |
author2 |
Angulo, Rodolfo José Veiga, Fernando Alvim Oliveira, Luiz Henrique Sielski Souza, Maria Cristina de |
author2_role |
author author author author |
dc.contributor.author.fl_str_mv |
Simioni, Bruno Ivan Angulo, Rodolfo José Veiga, Fernando Alvim Oliveira, Luiz Henrique Sielski Souza, Maria Cristina de |
dc.subject.por.fl_str_mv |
Methane-derived carbonates beachrocks submerged sandstones continental shelf sea-level indicators |
topic |
Methane-derived carbonates beachrocks submerged sandstones continental shelf sea-level indicators |
description |
Beachrocks are a common feature along the Brazilian coast and although their occurrence in intertidal zones is concentrated in tropical regions, similar formations have been described submerged on the continental shelf in subtropical regions. In the state of Paraná, submerged sandstones are present on the continental shelf and their formation could be associated with the cementation of beach sediments. This would provide an excellent indicator of the stabilization of the coastline during lower sea-level periods. In this study, samples were identified and collected in Paraná State, Southern Brazil, at depths between 18 and 33 meters in the continental shelf and at 6 meters depth in the Paranaguá Bay inlet. As in situ observations proved problematic, analysis relied mainly on their petrography, mineralogy, ages and isotopic values (δ13C and δ18O). Whole rock dating demonstrated that the oldest acquired sample was formed 28109-26406 cal. years BP, being exposed to atmospheric conditions during the Last Glacial Maximum. This exposure is reflected in its cements, composed uniquely of microcrystalline and spar calcite, and on its δ18O/δ13C values, which indicates formation on a fresh water environment. Contrarily to most carbonate cemented products described along Brazilian coastline, δ13C values ranged between -26.36 and -51.07‰ on all other samples, interpreted as a result of cement precipitation prompted by methane, either: in a paleo-estuarine/ paleo-lagunar to transgressive environment buried under a pile of coarser material or; after transgression and drowning of organic-rich sediments by coarser sediments, and due to upward migration of methane on the sedimentary column. Both processes would result in cements identified on these samples, apart from the one collected closer to shore which indicates some freshwater influence. Two of the samples separated by 15km distance perpendicularly to the actual coastline and 11m depth difference yielded max and minimum ages of 7913 and 7452 cal. years BP. Such a short time span between these samples could be either the result of their formation on a linked environment or older carbon signature from drowned environments being present on younger cements. |
publishDate |
2018 |
dc.date.none.fl_str_mv |
2018-12-21 |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
https://www.revistas.usp.br/bjoce/article/view/153126 10.1590/s1679-87592018019306603 |
url |
https://www.revistas.usp.br/bjoce/article/view/153126 |
identifier_str_mv |
10.1590/s1679-87592018019306603 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
https://www.revistas.usp.br/bjoce/article/view/153126/149649 |
dc.rights.driver.fl_str_mv |
Copyright (c) 2018 Brazilian Journal of Oceanography info:eu-repo/semantics/openAccess |
rights_invalid_str_mv |
Copyright (c) 2018 Brazilian Journal of Oceanography |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Universidade de São Paulo. Instituto Oceanográfico |
publisher.none.fl_str_mv |
Universidade de São Paulo. Instituto Oceanográfico |
dc.source.none.fl_str_mv |
Brazilian Journal of Oceanography; Vol. 66 Núm. 3 (2018); 267-282 Brazilian Journal of Oceanography; v. 66 n. 3 (2018); 267-282 Brazilian Journal of Oceanography; Vol. 66 No. 3 (2018); 267-282 1982-436X 1679-8759 reponame:Brazilian Journal of Oceanography instname:Universidade de São Paulo (USP) instacron:USP |
instname_str |
Universidade de São Paulo (USP) |
instacron_str |
USP |
institution |
USP |
reponame_str |
Brazilian Journal of Oceanography |
collection |
Brazilian Journal of Oceanography |
repository.name.fl_str_mv |
Brazilian Journal of Oceanography - Universidade de São Paulo (USP) |
repository.mail.fl_str_mv |
io@usp.br||io@usp.br |
_version_ |
1800223771839168512 |