Foraminiferal sandy contourite of the Limpopo Corridor (Mozambique margin): Facies characterization and paleoceanographic record
Contourites encompass a wide variety of sedimentary facies. Some of them show common facies with others deep-water deposits, such as turbidites and hemipelagites. Sedimentological characterization at macro- and microscales is valuable to discriminate those close facies but the distinction is not alw...
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Language: | English |
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Elsevier BV
2023
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Online Access: | https://archimer.ifremer.fr/doc/00832/94396/101818.pdf https://doi.org/10.1016/j.margeo.2023.107031 https://archimer.ifremer.fr/doc/00832/94396/ |
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ftarchimer:oai:archimer.ifremer.fr:94396 2024-04-28T08:02:41+00:00 Foraminiferal sandy contourite of the Limpopo Corridor (Mozambique margin): Facies characterization and paleoceanographic record Lopes, U. Babonneau, Nathalie Fierens, R. Revillon, Sidonie Raisson, F. Miramontes, E. Rabineau, Marina Aslanian, Daniel Moulin, Maryline 2023-05 application/pdf https://archimer.ifremer.fr/doc/00832/94396/101818.pdf https://doi.org/10.1016/j.margeo.2023.107031 https://archimer.ifremer.fr/doc/00832/94396/ eng eng Elsevier BV https://archimer.ifremer.fr/doc/00832/94396/101818.pdf doi:10.1016/j.margeo.2023.107031 https://archimer.ifremer.fr/doc/00832/94396/ info:eu-repo/semantics/openAccess restricted use Marine Geology (0025-3227) (Elsevier BV), 2023-05 , Vol. 459 , P. 107031 (21p.) Bottom current Contourite Foraminiferal sand Paleoceanography Mozambique Channel Indian Ocean Quaternary text Article info:eu-repo/semantics/article 2023 ftarchimer https://doi.org/10.1016/j.margeo.2023.107031 2024-04-09T23:31:56Z Contourites encompass a wide variety of sedimentary facies. Some of them show common facies with others deep-water deposits, such as turbidites and hemipelagites. Sedimentological characterization at macro- and microscales is valuable to discriminate those close facies but the distinction is not always clear. Contourites are increasingly used in paleoceanographic and paleoclimatic reconstructions. Improving their characterization is therefore essential to their interpretations. This study aims at characterizing a foraminiferal sandy contourite facies from a sediment core collected on top of a contourite drift under the influence of the Antarctic Intermediate Water/North Atlantic Deep-Water interface located in the Limpopo Corridor (Mozambique margin, Indian Ocean) at 2000 m depth. This work is based on a detailed analysis of the sedimentary record using physical properties (gamma density and magnetic susceptibility) as well as laser grain size and X-Ray Fluorescence core scanning data. Our results show that: (1) the foraminiferal sand is vertically continuous and homogenous over 633 kyr with an average sedimentation rate of 0.26 cm.kyr−1; (2) this contourite facies results from sedimentation with low terrigenous inputs under stable hydrodynamic conditions over time, with relatively strong bottom currents for this water depth (∼16 cm.s−1); (3) during glacial stages, sedimentation rates are lower and bottom current speed is higher than during interglacial stages. We also propose the concept of “Contourite Graphical Chart” which summaries the theoretical distribution of contourite endmembers from cross-plot of “sorting versus grain-size median D50” and their related sedimentary processes. This study highlights the relevance of condensed foraminiferal sandy contourites as long time-scale paleoceanographic archives and provides new insights for studies related to paleoclimatology and paleoecology. Article in Journal/Newspaper Antarc* Antarctic North Atlantic Deep Water North Atlantic Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) Marine Geology 459 107031 |
institution |
Open Polar |
collection |
Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) |
op_collection_id |
ftarchimer |
language |
English |
topic |
Bottom current Contourite Foraminiferal sand Paleoceanography Mozambique Channel Indian Ocean Quaternary |
spellingShingle |
Bottom current Contourite Foraminiferal sand Paleoceanography Mozambique Channel Indian Ocean Quaternary Lopes, U. Babonneau, Nathalie Fierens, R. Revillon, Sidonie Raisson, F. Miramontes, E. Rabineau, Marina Aslanian, Daniel Moulin, Maryline Foraminiferal sandy contourite of the Limpopo Corridor (Mozambique margin): Facies characterization and paleoceanographic record |
topic_facet |
Bottom current Contourite Foraminiferal sand Paleoceanography Mozambique Channel Indian Ocean Quaternary |
description |
Contourites encompass a wide variety of sedimentary facies. Some of them show common facies with others deep-water deposits, such as turbidites and hemipelagites. Sedimentological characterization at macro- and microscales is valuable to discriminate those close facies but the distinction is not always clear. Contourites are increasingly used in paleoceanographic and paleoclimatic reconstructions. Improving their characterization is therefore essential to their interpretations. This study aims at characterizing a foraminiferal sandy contourite facies from a sediment core collected on top of a contourite drift under the influence of the Antarctic Intermediate Water/North Atlantic Deep-Water interface located in the Limpopo Corridor (Mozambique margin, Indian Ocean) at 2000 m depth. This work is based on a detailed analysis of the sedimentary record using physical properties (gamma density and magnetic susceptibility) as well as laser grain size and X-Ray Fluorescence core scanning data. Our results show that: (1) the foraminiferal sand is vertically continuous and homogenous over 633 kyr with an average sedimentation rate of 0.26 cm.kyr−1; (2) this contourite facies results from sedimentation with low terrigenous inputs under stable hydrodynamic conditions over time, with relatively strong bottom currents for this water depth (∼16 cm.s−1); (3) during glacial stages, sedimentation rates are lower and bottom current speed is higher than during interglacial stages. We also propose the concept of “Contourite Graphical Chart” which summaries the theoretical distribution of contourite endmembers from cross-plot of “sorting versus grain-size median D50” and their related sedimentary processes. This study highlights the relevance of condensed foraminiferal sandy contourites as long time-scale paleoceanographic archives and provides new insights for studies related to paleoclimatology and paleoecology. |
format |
Article in Journal/Newspaper |
author |
Lopes, U. Babonneau, Nathalie Fierens, R. Revillon, Sidonie Raisson, F. Miramontes, E. Rabineau, Marina Aslanian, Daniel Moulin, Maryline |
author_facet |
Lopes, U. Babonneau, Nathalie Fierens, R. Revillon, Sidonie Raisson, F. Miramontes, E. Rabineau, Marina Aslanian, Daniel Moulin, Maryline |
author_sort |
Lopes, U. |
title |
Foraminiferal sandy contourite of the Limpopo Corridor (Mozambique margin): Facies characterization and paleoceanographic record |
title_short |
Foraminiferal sandy contourite of the Limpopo Corridor (Mozambique margin): Facies characterization and paleoceanographic record |
title_full |
Foraminiferal sandy contourite of the Limpopo Corridor (Mozambique margin): Facies characterization and paleoceanographic record |
title_fullStr |
Foraminiferal sandy contourite of the Limpopo Corridor (Mozambique margin): Facies characterization and paleoceanographic record |
title_full_unstemmed |
Foraminiferal sandy contourite of the Limpopo Corridor (Mozambique margin): Facies characterization and paleoceanographic record |
title_sort |
foraminiferal sandy contourite of the limpopo corridor (mozambique margin): facies characterization and paleoceanographic record |
publisher |
Elsevier BV |
publishDate |
2023 |
url |
https://archimer.ifremer.fr/doc/00832/94396/101818.pdf https://doi.org/10.1016/j.margeo.2023.107031 https://archimer.ifremer.fr/doc/00832/94396/ |
genre |
Antarc* Antarctic North Atlantic Deep Water North Atlantic |
genre_facet |
Antarc* Antarctic North Atlantic Deep Water North Atlantic |
op_source |
Marine Geology (0025-3227) (Elsevier BV), 2023-05 , Vol. 459 , P. 107031 (21p.) |
op_relation |
https://archimer.ifremer.fr/doc/00832/94396/101818.pdf doi:10.1016/j.margeo.2023.107031 https://archimer.ifremer.fr/doc/00832/94396/ |
op_rights |
info:eu-repo/semantics/openAccess restricted use |
op_doi |
https://doi.org/10.1016/j.margeo.2023.107031 |
container_title |
Marine Geology |
container_volume |
459 |
container_start_page |
107031 |
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1797573970547965952 |