Late Barremian to early Aptian calcareous nannofossil paleoceanography and paleoecology from the Ocean Drilling Program Hole 641C (Galicia Margin)
Calcareous nannofossil assemblages at Site 641C (Galicia Margin, North Atlantic) were investigated in order to determine changes in fertility and temperature of surface waters. Taxa such as Zeughrabdotus spp. < 3.5 mu m, Biscutum constans, Discorhabdus rotatorius and Diazomatolithus lehmanii, whi...
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Online Access: | http://hdl.handle.net/2434/23047 https://doi.org/10.1016/j.cretres.2006.04.007 |
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ftunivmilanoair:oai:air.unimi.it:2434/23047 2024-02-11T10:06:32+01:00 Late Barremian to early Aptian calcareous nannofossil paleoceanography and paleoecology from the Ocean Drilling Program Hole 641C (Galicia Margin) F. TREMOLADA T. J. BRALOWER E. ERBA F. TREMOLADA E. ERBA T.J. BRALOWER 2006 http://hdl.handle.net/2434/23047 https://doi.org/10.1016/j.cretres.2006.04.007 eng eng Academic Press info:eu-repo/semantics/altIdentifier/wos/WOS:000242714000016 volume:27 issue:6 firstpage:887 lastpage:897 journal:CRETACEOUS RESEARCH http://hdl.handle.net/2434/23047 doi:10.1016/j.cretres.2006.04.007 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-33751116126 calcareous nannofossil Barremian-Aptian interval primary productivity palcoecology Settore GEO/01 - Paleontologia e Paleoecologia info:eu-repo/semantics/article 2006 ftunivmilanoair https://doi.org/10.1016/j.cretres.2006.04.007 2024-01-23T23:17:48Z Calcareous nannofossil assemblages at Site 641C (Galicia Margin, North Atlantic) were investigated in order to determine changes in fertility and temperature of surface waters. Taxa such as Zeughrabdotus spp. < 3.5 mu m, Biscutum constans, Discorhabdus rotatorius and Diazomatolithus lehmanii, which thrived in higher fertility conditions, are particularly abundant across the CM0 interval as opposed to those with oligotrophic affinities such as Watznaueria spp. and Nannoconus spp., which are generally reduced in abundance. The abundances of nannoconids are much lower than those observed in Tethyan sections, indicating higher fertility conditions. Slumpings and low recovery prevent the identification of the onset of the "nannoconid crisis", but a sharp drop in nannoconid abundances, observed prior to the CM0 interval, correlates with the "nannoconid decline" observed in several Tethys sections. The normalized ratio between low and high fertility taxa (Fertility Index) was used to characterize the nannofossil assemblages in terms of productivity changes. The highest values of the Fertility Index were observed across magnetic chron CM0. The paucity of cold water taxa such as Seribiscutum spp. and Repagulum parvidentatum suggests warm water conditions throughout the deposition of upper Barremian-lower Aptian sediments on the Galicia Margin. (c) 2006 Elsevier Ltd. All rights reserved. Article in Journal/Newspaper North Atlantic The University of Milan: Archivio Istituzionale della Ricerca (AIR) Cretaceous Research 27 6 887 897 |
institution |
Open Polar |
collection |
The University of Milan: Archivio Istituzionale della Ricerca (AIR) |
op_collection_id |
ftunivmilanoair |
language |
English |
topic |
calcareous nannofossil Barremian-Aptian interval primary productivity palcoecology Settore GEO/01 - Paleontologia e Paleoecologia |
spellingShingle |
calcareous nannofossil Barremian-Aptian interval primary productivity palcoecology Settore GEO/01 - Paleontologia e Paleoecologia F. TREMOLADA T. J. BRALOWER E. ERBA Late Barremian to early Aptian calcareous nannofossil paleoceanography and paleoecology from the Ocean Drilling Program Hole 641C (Galicia Margin) |
topic_facet |
calcareous nannofossil Barremian-Aptian interval primary productivity palcoecology Settore GEO/01 - Paleontologia e Paleoecologia |
description |
Calcareous nannofossil assemblages at Site 641C (Galicia Margin, North Atlantic) were investigated in order to determine changes in fertility and temperature of surface waters. Taxa such as Zeughrabdotus spp. < 3.5 mu m, Biscutum constans, Discorhabdus rotatorius and Diazomatolithus lehmanii, which thrived in higher fertility conditions, are particularly abundant across the CM0 interval as opposed to those with oligotrophic affinities such as Watznaueria spp. and Nannoconus spp., which are generally reduced in abundance. The abundances of nannoconids are much lower than those observed in Tethyan sections, indicating higher fertility conditions. Slumpings and low recovery prevent the identification of the onset of the "nannoconid crisis", but a sharp drop in nannoconid abundances, observed prior to the CM0 interval, correlates with the "nannoconid decline" observed in several Tethys sections. The normalized ratio between low and high fertility taxa (Fertility Index) was used to characterize the nannofossil assemblages in terms of productivity changes. The highest values of the Fertility Index were observed across magnetic chron CM0. The paucity of cold water taxa such as Seribiscutum spp. and Repagulum parvidentatum suggests warm water conditions throughout the deposition of upper Barremian-lower Aptian sediments on the Galicia Margin. (c) 2006 Elsevier Ltd. All rights reserved. |
author2 |
F. TREMOLADA E. ERBA T.J. BRALOWER |
format |
Article in Journal/Newspaper |
author |
F. TREMOLADA T. J. BRALOWER E. ERBA |
author_facet |
F. TREMOLADA T. J. BRALOWER E. ERBA |
author_sort |
F. TREMOLADA |
title |
Late Barremian to early Aptian calcareous nannofossil paleoceanography and paleoecology from the Ocean Drilling Program Hole 641C (Galicia Margin) |
title_short |
Late Barremian to early Aptian calcareous nannofossil paleoceanography and paleoecology from the Ocean Drilling Program Hole 641C (Galicia Margin) |
title_full |
Late Barremian to early Aptian calcareous nannofossil paleoceanography and paleoecology from the Ocean Drilling Program Hole 641C (Galicia Margin) |
title_fullStr |
Late Barremian to early Aptian calcareous nannofossil paleoceanography and paleoecology from the Ocean Drilling Program Hole 641C (Galicia Margin) |
title_full_unstemmed |
Late Barremian to early Aptian calcareous nannofossil paleoceanography and paleoecology from the Ocean Drilling Program Hole 641C (Galicia Margin) |
title_sort |
late barremian to early aptian calcareous nannofossil paleoceanography and paleoecology from the ocean drilling program hole 641c (galicia margin) |
publisher |
Academic Press |
publishDate |
2006 |
url |
http://hdl.handle.net/2434/23047 https://doi.org/10.1016/j.cretres.2006.04.007 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/WOS:000242714000016 volume:27 issue:6 firstpage:887 lastpage:897 journal:CRETACEOUS RESEARCH http://hdl.handle.net/2434/23047 doi:10.1016/j.cretres.2006.04.007 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-33751116126 |
op_doi |
https://doi.org/10.1016/j.cretres.2006.04.007 |
container_title |
Cretaceous Research |
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27 |
container_issue |
6 |
container_start_page |
887 |
op_container_end_page |
897 |
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1790604308682637312 |