Impact of turbulence on magnetic alignment in sediments
Rapidly deposited layers (RDL) such as turbidites or hyperpycnites are mostly studied for their sedimentological properties, but are carefully avoided in paleomagnetic studies due to the disturbances caused by such sudden and rapid sediment accumulation. Therefore, these layers can also be seen as p...
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| Language: | English |
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Frontiers Media S.A.
2022-12-01
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| Series: | Frontiers in Earth Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/feart.2022.1079229/full |
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| author | Édouard G. H. Philippe Édouard G. H. Philippe Jean-Pierre Valet Guillaume St-Onge Ramon Egli |
| author_facet | Édouard G. H. Philippe Édouard G. H. Philippe Jean-Pierre Valet Guillaume St-Onge Ramon Egli |
| author_sort | Édouard G. H. Philippe |
| collection | DOAJ |
| description | Rapidly deposited layers (RDL) such as turbidites or hyperpycnites are mostly studied for their sedimentological properties, but are carefully avoided in paleomagnetic studies due to the disturbances caused by such sudden and rapid sediment accumulation. Therefore, these layers can also be seen as potential indicators of sediment parameters susceptible of affecting the alignment of magnetic grains and ultimately the acquisition of the natural remanent magnetization (NRM). We have compiled 13 Holocene rapidly deposited layers from core MD99-2222 in the Saguenay Fjord, eastern Canada (St-Onge and al., 2004) with varying thicknesses (from 7.1 cm to 1,510 cm) and 4 Quaternary turbidites of different origins, to document the influence of sedimentary and magnetic parameters on natural remanent magnetization acquisition. We found a logarithmic relationship between rapidly deposited layers thickness on the one hand, and the amplitude of inclination changes and magnetic grain sizes on the other. Inclination and magnetic grain sizes are themselves correlated to each other by a logarithmic law. As there is no relationship between inclination deviation and stratigraphic depth, compaction alone cannot account for such large effects on inclination. Flocculation is grain size sensitive, but it is expected to affect mainly the natural remanent magnetization intensity, rather than its direction. Turbulence that prevails during the rapid deposition of sediments during such events is most likely the dominant factor. |
| first_indexed | 2024-04-11T06:08:13Z |
| format | Article |
| id | doaj.art-0f9e859e753848d0a233c5c810a7d836 |
| institution | Directory Open Access Journal |
| issn | 2296-6463 |
| language | English |
| last_indexed | 2024-04-11T06:08:13Z |
| publishDate | 2022-12-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Earth Science |
| spelling | doaj.art-0f9e859e753848d0a233c5c810a7d8362022-12-22T04:41:23ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632022-12-011010.3389/feart.2022.10792291079229Impact of turbulence on magnetic alignment in sedimentsÉdouard G. H. Philippe0Édouard G. H. Philippe1Jean-Pierre Valet2Guillaume St-Onge3Ramon Egli4Institut de Physique du Globe de Paris, Sorbonne Paris-Cité, UMR 7154 CNRS, Paris, FranceInstitut des sciences de la mer de Rimouski (ISMER), Canada Research Chair in Marine Geology and GEOTOP, Université du Québec à Rimouski, Rimouski, QC, CanadaInstitut de Physique du Globe de Paris, Sorbonne Paris-Cité, UMR 7154 CNRS, Paris, FranceInstitut des sciences de la mer de Rimouski (ISMER), Canada Research Chair in Marine Geology and GEOTOP, Université du Québec à Rimouski, Rimouski, QC, CanadaCentral Institute for Meteorology and Geodynamics, Vienna, AustriaRapidly deposited layers (RDL) such as turbidites or hyperpycnites are mostly studied for their sedimentological properties, but are carefully avoided in paleomagnetic studies due to the disturbances caused by such sudden and rapid sediment accumulation. Therefore, these layers can also be seen as potential indicators of sediment parameters susceptible of affecting the alignment of magnetic grains and ultimately the acquisition of the natural remanent magnetization (NRM). We have compiled 13 Holocene rapidly deposited layers from core MD99-2222 in the Saguenay Fjord, eastern Canada (St-Onge and al., 2004) with varying thicknesses (from 7.1 cm to 1,510 cm) and 4 Quaternary turbidites of different origins, to document the influence of sedimentary and magnetic parameters on natural remanent magnetization acquisition. We found a logarithmic relationship between rapidly deposited layers thickness on the one hand, and the amplitude of inclination changes and magnetic grain sizes on the other. Inclination and magnetic grain sizes are themselves correlated to each other by a logarithmic law. As there is no relationship between inclination deviation and stratigraphic depth, compaction alone cannot account for such large effects on inclination. Flocculation is grain size sensitive, but it is expected to affect mainly the natural remanent magnetization intensity, rather than its direction. Turbulence that prevails during the rapid deposition of sediments during such events is most likely the dominant factor.https://www.frontiersin.org/articles/10.3389/feart.2022.1079229/fullnatural remanent magnetisationturbiditehyperpycnitesedimentdetrital remanent magnetizationdepositional remanence |
| spellingShingle | Édouard G. H. Philippe Édouard G. H. Philippe Jean-Pierre Valet Guillaume St-Onge Ramon Egli Impact of turbulence on magnetic alignment in sediments Frontiers in Earth Science natural remanent magnetisation turbidite hyperpycnite sediment detrital remanent magnetization depositional remanence |
| title | Impact of turbulence on magnetic alignment in sediments |
| title_full | Impact of turbulence on magnetic alignment in sediments |
| title_fullStr | Impact of turbulence on magnetic alignment in sediments |
| title_full_unstemmed | Impact of turbulence on magnetic alignment in sediments |
| title_short | Impact of turbulence on magnetic alignment in sediments |
| title_sort | impact of turbulence on magnetic alignment in sediments |
| topic | natural remanent magnetisation turbidite hyperpycnite sediment detrital remanent magnetization depositional remanence |
| url | https://www.frontiersin.org/articles/10.3389/feart.2022.1079229/full |
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