Tunnel-valley fills in the Paraná Basin and their implications for the extent of late Paleozoic glaciation in SW Gondwana
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.jsames.2020.102969 http://hdl.handle.net/11449/205457 |
Resumo: | Tunnel valleys are subglacial incisions formed mainly by meltwater erosion on soft sediment overridden by glaciers. Despite being common in the Pleistocene and Ordovician glacial record, where their fills constitute excellent aquifers and hydrocarbon traps, tunnel valleys are poorly recognized in late Paleozoic strata. Other types of glacial and non-glacial valleys, on the other hand, have been widely reported from Carboniferous and Permian glacial successions, most cut into the basement or older sedimentary rocks and interpreted as glacial valleys eroded by outlet glaciers draining high-relief settings. The degree of glacial influence on the formation of these valleys has strong implications for the volume of ice during late Paleozoic glaciations. In this paper, we report the Lapa sandstone, an exhumed valley-fill succession encased in Pennsylvanian glacial rocks of eastern Paraná Basin, southern Brazil, and its subsurface counterparts. The Lapa sandstone forms a slightly sinuous ribbon several tens of kilometers long, 1500 m wide and 100 m thick composed essentially of glaciofluvial facies. By comparing the external geometry and the sediment fill of the valley with several types of erosive-based, elongated sediment bodies, we conclude that the Lapa formed as the infilling of a tunnel valley cut beneath an ice margin that advanced to the north onto poorly consolidated, mud-rich sediments. Valley fills previously mapped in the subsurface area to the west are considered to have been formed by the same mechanism and during the same glaciation event. The Lapa tunnel valley and its subsurface counterparts are the first example reported from the late Paleozoic glacial record in South America, but similar features are also expected in any formerly glaciated basin, and their recognition may help in estimating the extent of glaciation across the region and guiding exploration for hydrocarbon traps. |
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Tunnel-valley fills in the Paraná Basin and their implications for the extent of late Paleozoic glaciation in SW GondwanaGlacial valleysItararé groupLapa sandstoneLate Paleozoic ice ageSubglacial processesTunnel valleys are subglacial incisions formed mainly by meltwater erosion on soft sediment overridden by glaciers. Despite being common in the Pleistocene and Ordovician glacial record, where their fills constitute excellent aquifers and hydrocarbon traps, tunnel valleys are poorly recognized in late Paleozoic strata. Other types of glacial and non-glacial valleys, on the other hand, have been widely reported from Carboniferous and Permian glacial successions, most cut into the basement or older sedimentary rocks and interpreted as glacial valleys eroded by outlet glaciers draining high-relief settings. The degree of glacial influence on the formation of these valleys has strong implications for the volume of ice during late Paleozoic glaciations. In this paper, we report the Lapa sandstone, an exhumed valley-fill succession encased in Pennsylvanian glacial rocks of eastern Paraná Basin, southern Brazil, and its subsurface counterparts. The Lapa sandstone forms a slightly sinuous ribbon several tens of kilometers long, 1500 m wide and 100 m thick composed essentially of glaciofluvial facies. By comparing the external geometry and the sediment fill of the valley with several types of erosive-based, elongated sediment bodies, we conclude that the Lapa formed as the infilling of a tunnel valley cut beneath an ice margin that advanced to the north onto poorly consolidated, mud-rich sediments. Valley fills previously mapped in the subsurface area to the west are considered to have been formed by the same mechanism and during the same glaciation event. The Lapa tunnel valley and its subsurface counterparts are the first example reported from the late Paleozoic glacial record in South America, but similar features are also expected in any formerly glaciated basin, and their recognition may help in estimating the extent of glaciation across the region and guiding exploration for hydrocarbon traps.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)PetrobrasDepartamento de Geologia UFPR - Universidade Federal do Paraná, Caixa Postal 19001Departamento de Geologia UNESP - Universidade Estadual Paulista, Av. 24-A, 1515Programa de Pós-Graduação em Geologia UFPR - Universidade Federal do Paraná, Caixa Postal 19001Programa de Pós-Graduação em Geologia UNISINOS - Universidade do Vale do Rio dos Sinos, Av. Unisinos, 950Brazil Petroleum Studies, Av. Atlântica 1130Departamento de Geologia UNESP - Universidade Estadual Paulista, Av. 24-A, 1515CNPq: 461650/2014–2Petrobras: BG-01Petrobras: BG29CNPq: PQ 302842/2017-9CNPq: PQ 304925/2017-9CNPq: PQ 311175/2019-8Universidade Federal do Paraná (UFPR)Universidade Estadual Paulista (Unesp)UNISINOS - Universidade do Vale do Rio dos SinosBrazil Petroleum StudiesVesely, Fernando F.Assine, Mario L. [UNESP]França, Almerio B.Paim, Paulo S.G.Rostirolla, Sidnei P.2021-06-25T10:15:41Z2021-06-25T10:15:41Z2021-03-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlehttp://dx.doi.org/10.1016/j.jsames.2020.102969Journal of South American Earth Sciences, v. 106.0895-9811http://hdl.handle.net/11449/20545710.1016/j.jsames.2020.1029692-s2.0-85095874097Scopusreponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengJournal of South American Earth Sciencesinfo:eu-repo/semantics/openAccess2021-10-23T14:33:44Zoai:repositorio.unesp.br:11449/205457Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462021-10-23T14:33:44Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
Tunnel-valley fills in the Paraná Basin and their implications for the extent of late Paleozoic glaciation in SW Gondwana |
title |
Tunnel-valley fills in the Paraná Basin and their implications for the extent of late Paleozoic glaciation in SW Gondwana |
spellingShingle |
Tunnel-valley fills in the Paraná Basin and their implications for the extent of late Paleozoic glaciation in SW Gondwana Vesely, Fernando F. Glacial valleys Itararé group Lapa sandstone Late Paleozoic ice age Subglacial processes |
title_short |
Tunnel-valley fills in the Paraná Basin and their implications for the extent of late Paleozoic glaciation in SW Gondwana |
title_full |
Tunnel-valley fills in the Paraná Basin and their implications for the extent of late Paleozoic glaciation in SW Gondwana |
title_fullStr |
Tunnel-valley fills in the Paraná Basin and their implications for the extent of late Paleozoic glaciation in SW Gondwana |
title_full_unstemmed |
Tunnel-valley fills in the Paraná Basin and their implications for the extent of late Paleozoic glaciation in SW Gondwana |
title_sort |
Tunnel-valley fills in the Paraná Basin and their implications for the extent of late Paleozoic glaciation in SW Gondwana |
author |
Vesely, Fernando F. |
author_facet |
Vesely, Fernando F. Assine, Mario L. [UNESP] França, Almerio B. Paim, Paulo S.G. Rostirolla, Sidnei P. |
author_role |
author |
author2 |
Assine, Mario L. [UNESP] França, Almerio B. Paim, Paulo S.G. Rostirolla, Sidnei P. |
author2_role |
author author author author |
dc.contributor.none.fl_str_mv |
Universidade Federal do Paraná (UFPR) Universidade Estadual Paulista (Unesp) UNISINOS - Universidade do Vale do Rio dos Sinos Brazil Petroleum Studies |
dc.contributor.author.fl_str_mv |
Vesely, Fernando F. Assine, Mario L. [UNESP] França, Almerio B. Paim, Paulo S.G. Rostirolla, Sidnei P. |
dc.subject.por.fl_str_mv |
Glacial valleys Itararé group Lapa sandstone Late Paleozoic ice age Subglacial processes |
topic |
Glacial valleys Itararé group Lapa sandstone Late Paleozoic ice age Subglacial processes |
description |
Tunnel valleys are subglacial incisions formed mainly by meltwater erosion on soft sediment overridden by glaciers. Despite being common in the Pleistocene and Ordovician glacial record, where their fills constitute excellent aquifers and hydrocarbon traps, tunnel valleys are poorly recognized in late Paleozoic strata. Other types of glacial and non-glacial valleys, on the other hand, have been widely reported from Carboniferous and Permian glacial successions, most cut into the basement or older sedimentary rocks and interpreted as glacial valleys eroded by outlet glaciers draining high-relief settings. The degree of glacial influence on the formation of these valleys has strong implications for the volume of ice during late Paleozoic glaciations. In this paper, we report the Lapa sandstone, an exhumed valley-fill succession encased in Pennsylvanian glacial rocks of eastern Paraná Basin, southern Brazil, and its subsurface counterparts. The Lapa sandstone forms a slightly sinuous ribbon several tens of kilometers long, 1500 m wide and 100 m thick composed essentially of glaciofluvial facies. By comparing the external geometry and the sediment fill of the valley with several types of erosive-based, elongated sediment bodies, we conclude that the Lapa formed as the infilling of a tunnel valley cut beneath an ice margin that advanced to the north onto poorly consolidated, mud-rich sediments. Valley fills previously mapped in the subsurface area to the west are considered to have been formed by the same mechanism and during the same glaciation event. The Lapa tunnel valley and its subsurface counterparts are the first example reported from the late Paleozoic glacial record in South America, but similar features are also expected in any formerly glaciated basin, and their recognition may help in estimating the extent of glaciation across the region and guiding exploration for hydrocarbon traps. |
publishDate |
2021 |
dc.date.none.fl_str_mv |
2021-06-25T10:15:41Z 2021-06-25T10:15:41Z 2021-03-01 |
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.jsames.2020.102969 Journal of South American Earth Sciences, v. 106. 0895-9811 http://hdl.handle.net/11449/205457 10.1016/j.jsames.2020.102969 2-s2.0-85095874097 |
url |
http://dx.doi.org/10.1016/j.jsames.2020.102969 http://hdl.handle.net/11449/205457 |
identifier_str_mv |
Journal of South American Earth Sciences, v. 106. 0895-9811 10.1016/j.jsames.2020.102969 2-s2.0-85095874097 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Journal of South American Earth Sciences |
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) |
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UNESP |
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UNESP |
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Repositório Institucional da UNESP |
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Repositório Institucional da UNESP |
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Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP) |
repository.mail.fl_str_mv |
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