Shell beds from the Low Head Member (Polonez Cove Formation, early Oligocene) at King George Island, west Antarctica: new insights on facies analysis, taphonomy and environmental significance
Shell bed levels in the Low Head Member of the early Oligocene Polonez Cove Formation at King George Island, West Antarctica, are re-interpreted based on sedimentological and taphonomic data. The highly fossiliferous Polonez Cove Formation is characterized by basal coastal marine sandstones, overlai...
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Language: | English |
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Cambridge Univ Press
2015
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Online Access: | http://acervodigital.unesp.br/handle/11449/116822 http://hdl.handle.net/11449/116822 https://doi.org/10.1017/S0954102013000783 |
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ftunivesp:oai:acervodigital.unesp.br:11449/116822 2023-05-15T13:49:05+02:00 Shell beds from the Low Head Member (Polonez Cove Formation, early Oligocene) at King George Island, west Antarctica: new insights on facies analysis, taphonomy and environmental significance Quaglio, Fernanda Warren, Lucas Verissimo Anelli, Luiz Eduardo Dos Santos, Paulo Roberto Rocha-Campos, Antonio Carlos Gazdzicki, Andrzej Strikis, Pedro Carlos Ghilardi, Renato Pirani Tiossi, Andressa Barraviera Simoes, Marcello Guimaraes Universidade Estadual Paulista (UNESP) 2015-03-18T15:54:13Z http://acervodigital.unesp.br/handle/11449/116822 http://hdl.handle.net/11449/116822 https://doi.org/10.1017/S0954102013000783 eng eng Cambridge Univ Press Antarctic Science Antarctic Science. New York: Cambridge Univ Press, v. 26, n. 4, p. 400-412, 2014. 0954-1020 http://hdl.handle.net/11449/116822 http://acervodigital.unesp.br/handle/11449/116822 doi:10.1017/S0954102013000783 WOS:000339377300011 http://dx.doi.org/10.1017/S0954102013000783 info:eu-repo/semantics/closedAccess Antarctic coquina Leoclunipecten pecten conglomerate pectinids sedimentology shell-bed genesis outro 2015 ftunivesp https://doi.org/10.1017/S0954102013000783 2021-07-18T09:00:45Z Shell bed levels in the Low Head Member of the early Oligocene Polonez Cove Formation at King George Island, West Antarctica, are re-interpreted based on sedimentological and taphonomic data. The highly fossiliferous Polonez Cove Formation is characterized by basal coastal marine sandstones, overlain by conglomerates and breccias deposited in fan-delta systems. The shell beds are mainly composed of pectinid bivalve shells of Leoclunipecten gazdzickii and occur in the basal portion of the Low Head Member. Three main episodes of bioclastic deposition are recorded. Although these shell beds were previously interpreted as shelly tempestites, we present an alternative explanation: the low fragmentation rates and low size sorting of the bioclasts resulted from winnowing due to tidal currents (background or diurnal condition) in the original bivalve habitat. The final deposition (episodic condition) was associated with subaqueous gravity driven flows. This new interpretation fits with the scenario of a prograding fan-delta front, which transported shell accumulations for short distances near the depositional site, possibly between fair-weather and storm wave bases. This work raises the notion that not every shell bed with similar sedimentological and taphonomic features (such as geometry, basal contact, degree of packing and shell orientation in the matrix) is made in the same way. Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Other/Unknown Material Antarc* Antarctic Antarctic Science Antarctica King George Island West Antarctica Universidade Estadual Paulista São Paulo: Acervo Digital da UNESP / São Paulo State University Antarctic King George Island Low Head ENVELOPE(-58.133,-58.133,-62.150,-62.150) Polonez Cove ENVELOPE(-58.131,-58.131,-62.153,-62.153) West Antarctica Antarctic Science 26 4 400 412 |
institution |
Open Polar |
collection |
Universidade Estadual Paulista São Paulo: Acervo Digital da UNESP / São Paulo State University |
op_collection_id |
ftunivesp |
language |
English |
topic |
Antarctic coquina Leoclunipecten pecten conglomerate pectinids sedimentology shell-bed genesis |
spellingShingle |
Antarctic coquina Leoclunipecten pecten conglomerate pectinids sedimentology shell-bed genesis Quaglio, Fernanda Warren, Lucas Verissimo Anelli, Luiz Eduardo Dos Santos, Paulo Roberto Rocha-Campos, Antonio Carlos Gazdzicki, Andrzej Strikis, Pedro Carlos Ghilardi, Renato Pirani Tiossi, Andressa Barraviera Simoes, Marcello Guimaraes Shell beds from the Low Head Member (Polonez Cove Formation, early Oligocene) at King George Island, west Antarctica: new insights on facies analysis, taphonomy and environmental significance |
topic_facet |
Antarctic coquina Leoclunipecten pecten conglomerate pectinids sedimentology shell-bed genesis |
description |
Shell bed levels in the Low Head Member of the early Oligocene Polonez Cove Formation at King George Island, West Antarctica, are re-interpreted based on sedimentological and taphonomic data. The highly fossiliferous Polonez Cove Formation is characterized by basal coastal marine sandstones, overlain by conglomerates and breccias deposited in fan-delta systems. The shell beds are mainly composed of pectinid bivalve shells of Leoclunipecten gazdzickii and occur in the basal portion of the Low Head Member. Three main episodes of bioclastic deposition are recorded. Although these shell beds were previously interpreted as shelly tempestites, we present an alternative explanation: the low fragmentation rates and low size sorting of the bioclasts resulted from winnowing due to tidal currents (background or diurnal condition) in the original bivalve habitat. The final deposition (episodic condition) was associated with subaqueous gravity driven flows. This new interpretation fits with the scenario of a prograding fan-delta front, which transported shell accumulations for short distances near the depositional site, possibly between fair-weather and storm wave bases. This work raises the notion that not every shell bed with similar sedimentological and taphonomic features (such as geometry, basal contact, degree of packing and shell orientation in the matrix) is made in the same way. Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) |
author2 |
Universidade Estadual Paulista (UNESP) |
format |
Other/Unknown Material |
author |
Quaglio, Fernanda Warren, Lucas Verissimo Anelli, Luiz Eduardo Dos Santos, Paulo Roberto Rocha-Campos, Antonio Carlos Gazdzicki, Andrzej Strikis, Pedro Carlos Ghilardi, Renato Pirani Tiossi, Andressa Barraviera Simoes, Marcello Guimaraes |
author_facet |
Quaglio, Fernanda Warren, Lucas Verissimo Anelli, Luiz Eduardo Dos Santos, Paulo Roberto Rocha-Campos, Antonio Carlos Gazdzicki, Andrzej Strikis, Pedro Carlos Ghilardi, Renato Pirani Tiossi, Andressa Barraviera Simoes, Marcello Guimaraes |
author_sort |
Quaglio, Fernanda |
title |
Shell beds from the Low Head Member (Polonez Cove Formation, early Oligocene) at King George Island, west Antarctica: new insights on facies analysis, taphonomy and environmental significance |
title_short |
Shell beds from the Low Head Member (Polonez Cove Formation, early Oligocene) at King George Island, west Antarctica: new insights on facies analysis, taphonomy and environmental significance |
title_full |
Shell beds from the Low Head Member (Polonez Cove Formation, early Oligocene) at King George Island, west Antarctica: new insights on facies analysis, taphonomy and environmental significance |
title_fullStr |
Shell beds from the Low Head Member (Polonez Cove Formation, early Oligocene) at King George Island, west Antarctica: new insights on facies analysis, taphonomy and environmental significance |
title_full_unstemmed |
Shell beds from the Low Head Member (Polonez Cove Formation, early Oligocene) at King George Island, west Antarctica: new insights on facies analysis, taphonomy and environmental significance |
title_sort |
shell beds from the low head member (polonez cove formation, early oligocene) at king george island, west antarctica: new insights on facies analysis, taphonomy and environmental significance |
publisher |
Cambridge Univ Press |
publishDate |
2015 |
url |
http://acervodigital.unesp.br/handle/11449/116822 http://hdl.handle.net/11449/116822 https://doi.org/10.1017/S0954102013000783 |
long_lat |
ENVELOPE(-58.133,-58.133,-62.150,-62.150) ENVELOPE(-58.131,-58.131,-62.153,-62.153) |
geographic |
Antarctic King George Island Low Head Polonez Cove West Antarctica |
geographic_facet |
Antarctic King George Island Low Head Polonez Cove West Antarctica |
genre |
Antarc* Antarctic Antarctic Science Antarctica King George Island West Antarctica |
genre_facet |
Antarc* Antarctic Antarctic Science Antarctica King George Island West Antarctica |
op_relation |
Antarctic Science Antarctic Science. New York: Cambridge Univ Press, v. 26, n. 4, p. 400-412, 2014. 0954-1020 http://hdl.handle.net/11449/116822 http://acervodigital.unesp.br/handle/11449/116822 doi:10.1017/S0954102013000783 WOS:000339377300011 http://dx.doi.org/10.1017/S0954102013000783 |
op_rights |
info:eu-repo/semantics/closedAccess |
op_doi |
https://doi.org/10.1017/S0954102013000783 |
container_title |
Antarctic Science |
container_volume |
26 |
container_issue |
4 |
container_start_page |
400 |
op_container_end_page |
412 |
_version_ |
1766250803640664064 |