Taphonomy of ammonites from the Santonian-lower Campanian Santa Marta Formation, Antarctica: sedimentological controls on vertically embedded ammonites
Different morphotypes of vertically embedded ammonoid shells are abundant in the 1-km-thick deposits of the Santa Marta Formation, Antarctica, that record the evolution of a deep-water delta system. Vertical shells deposited in water depths well below the theoretical limit imposed by hydrodynamic an...
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ftconicet:oai:ri.conicet.gov.ar:11336/156233 2023-10-09T21:44:48+02:00 Taphonomy of ammonites from the Santonian-lower Campanian Santa Marta Formation, Antarctica: sedimentological controls on vertically embedded ammonites Olivero, Eduardo Bernardo application/pdf application/msword http://hdl.handle.net/11336/156233 eng eng Society for Sedimentary Geology info:eu-repo/semantics/altIdentifier/doi/10.2110/palo.2005.p05-118r info:eu-repo/semantics/altIdentifier/url/https://pubs.geoscienceworld.org/sepm/palaios/article/22/6/586/145914/TAPHONOMY-OF-AMMONITES-FROM-THE-SANTONIAN-LOWER?searchresult=1 http://hdl.handle.net/11336/156233 Olivero, Eduardo Bernardo; Taphonomy of ammonites from the Santonian-lower Campanian Santa Marta Formation, Antarctica: sedimentological controls on vertically embedded ammonites; Society for Sedimentary Geology; Palaios; 22; 6; 12-2007; 586-597 0883-1351 CONICET Digital CONICET info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by-nc-sa/2.5/ar/ Antarctica Upper Cretaceous Ammonites Taphonomy https://purl.org/becyt/ford/1.5 https://purl.org/becyt/ford/1 info:eu-repo/semantics/article info:ar-repo/semantics/artículo info:eu-repo/semantics/publishedVersion ftconicet https://doi.org/10.2110/palo.2005.p05-118r 2023-09-24T18:15:29Z Different morphotypes of vertically embedded ammonoid shells are abundant in the 1-km-thick deposits of the Santa Marta Formation, Antarctica, that record the evolution of a deep-water delta system. Vertical shells deposited in water depths well below the theoretical limit imposed by hydrodynamic and hydrostatic analyses are preserved as isolated specimens, dense concentrations associated with abundant wood fragments (pod preservation), or as dense concentrations inside and around large ammonites (sheltered preservation). Taphonomic analysis indicates that (1) vertical shell orientation is primary; (2) postburial reworking was minimum or absent, as indicated by consistent shell orientation parallel to regional paleocurrents and complete preservation of fragile shells with phragmocones filled with drusy calcite; and (3) vertical orientation is not biased towards a preferred morphotype. Rapid sedimentation, including deposition from high- and low-density currents, tempestites, and weak bottom currents carrying a dense suspension of ammonoid shells and wood fragments, was one of the main factors controlling the vertical preservation below the limits imposed by theoretical hydrostatic analyses. Another important factor was the plugging of the siphuncular tube with clay particles during transportation. The clay plug was stiff enough to resist the ambient hydrostatic pressure, avoiding or delaying the waterlogging of the phragmocone. Fil: Olivero, Eduardo Bernardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina Article in Journal/Newspaper Antarc* Antarctica CONICET Digital (Consejo Nacional de Investigaciones Científicas y Técnicas) Austral Argentina Olivero ENVELOPE(-63.600,-63.600,-66.133,-66.133) PALAIOS 22 6 586 597 |
institution |
Open Polar |
collection |
CONICET Digital (Consejo Nacional de Investigaciones Científicas y Técnicas) |
op_collection_id |
ftconicet |
language |
English |
topic |
Antarctica Upper Cretaceous Ammonites Taphonomy https://purl.org/becyt/ford/1.5 https://purl.org/becyt/ford/1 |
spellingShingle |
Antarctica Upper Cretaceous Ammonites Taphonomy https://purl.org/becyt/ford/1.5 https://purl.org/becyt/ford/1 Olivero, Eduardo Bernardo Taphonomy of ammonites from the Santonian-lower Campanian Santa Marta Formation, Antarctica: sedimentological controls on vertically embedded ammonites |
topic_facet |
Antarctica Upper Cretaceous Ammonites Taphonomy https://purl.org/becyt/ford/1.5 https://purl.org/becyt/ford/1 |
description |
Different morphotypes of vertically embedded ammonoid shells are abundant in the 1-km-thick deposits of the Santa Marta Formation, Antarctica, that record the evolution of a deep-water delta system. Vertical shells deposited in water depths well below the theoretical limit imposed by hydrodynamic and hydrostatic analyses are preserved as isolated specimens, dense concentrations associated with abundant wood fragments (pod preservation), or as dense concentrations inside and around large ammonites (sheltered preservation). Taphonomic analysis indicates that (1) vertical shell orientation is primary; (2) postburial reworking was minimum or absent, as indicated by consistent shell orientation parallel to regional paleocurrents and complete preservation of fragile shells with phragmocones filled with drusy calcite; and (3) vertical orientation is not biased towards a preferred morphotype. Rapid sedimentation, including deposition from high- and low-density currents, tempestites, and weak bottom currents carrying a dense suspension of ammonoid shells and wood fragments, was one of the main factors controlling the vertical preservation below the limits imposed by theoretical hydrostatic analyses. Another important factor was the plugging of the siphuncular tube with clay particles during transportation. The clay plug was stiff enough to resist the ambient hydrostatic pressure, avoiding or delaying the waterlogging of the phragmocone. Fil: Olivero, Eduardo Bernardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina |
format |
Article in Journal/Newspaper |
author |
Olivero, Eduardo Bernardo |
author_facet |
Olivero, Eduardo Bernardo |
author_sort |
Olivero, Eduardo Bernardo |
title |
Taphonomy of ammonites from the Santonian-lower Campanian Santa Marta Formation, Antarctica: sedimentological controls on vertically embedded ammonites |
title_short |
Taphonomy of ammonites from the Santonian-lower Campanian Santa Marta Formation, Antarctica: sedimentological controls on vertically embedded ammonites |
title_full |
Taphonomy of ammonites from the Santonian-lower Campanian Santa Marta Formation, Antarctica: sedimentological controls on vertically embedded ammonites |
title_fullStr |
Taphonomy of ammonites from the Santonian-lower Campanian Santa Marta Formation, Antarctica: sedimentological controls on vertically embedded ammonites |
title_full_unstemmed |
Taphonomy of ammonites from the Santonian-lower Campanian Santa Marta Formation, Antarctica: sedimentological controls on vertically embedded ammonites |
title_sort |
taphonomy of ammonites from the santonian-lower campanian santa marta formation, antarctica: sedimentological controls on vertically embedded ammonites |
publisher |
Society for Sedimentary Geology |
url |
http://hdl.handle.net/11336/156233 |
long_lat |
ENVELOPE(-63.600,-63.600,-66.133,-66.133) |
geographic |
Austral Argentina Olivero |
geographic_facet |
Austral Argentina Olivero |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.2110/palo.2005.p05-118r info:eu-repo/semantics/altIdentifier/url/https://pubs.geoscienceworld.org/sepm/palaios/article/22/6/586/145914/TAPHONOMY-OF-AMMONITES-FROM-THE-SANTONIAN-LOWER?searchresult=1 http://hdl.handle.net/11336/156233 Olivero, Eduardo Bernardo; Taphonomy of ammonites from the Santonian-lower Campanian Santa Marta Formation, Antarctica: sedimentological controls on vertically embedded ammonites; Society for Sedimentary Geology; Palaios; 22; 6; 12-2007; 586-597 0883-1351 CONICET Digital CONICET |
op_rights |
info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by-nc-sa/2.5/ar/ |
op_doi |
https://doi.org/10.2110/palo.2005.p05-118r |
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PALAIOS |
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22 |
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6 |
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586 |
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597 |
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