Distribution, sediment magnetism and geochemistry of the Saksunarvatn (10 180 ± 60 cal. yr BP) tephra in marine, lake, and terrestrial sediments, northwest Iceland
Abstract In 1997, seismic surveys in the troughs off northwest and north Iceland indicated the presence of a major, regional sub‐bottom reflector that can be traced over large areas of the shelf. Cores taken in 1997, and later in 1999 on the IMAGES V cruise, penetrated through the reflector. In core...
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crwiley:10.1002/jqs.727 2024-09-15T18:10:02+00:00 Distribution, sediment magnetism and geochemistry of the Saksunarvatn (10 180 ± 60 cal. yr BP) tephra in marine, lake, and terrestrial sediments, northwest Iceland Andrews, John T. Geirsdóttir, Aslaug Hardardóttir, Jórunn Principato, Sarah Grönvold, Karl Kristjansdóttir, Gréta B. Helgadóttir, Gudrún Drexler, John Sveinbjörnsdóttir, Arny National Science Foundation (USA) Marine Research Institute. Iceland Research Council Science Funds of the University of Iceland. National Geographic Society. 2002 http://dx.doi.org/10.1002/jqs.727 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjqs.727 https://onlinelibrary.wiley.com/doi/pdf/10.1002/jqs.727 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Journal of Quaternary Science volume 17, issue 8, page 731-745 ISSN 0267-8179 1099-1417 journal-article 2002 crwiley https://doi.org/10.1002/jqs.727 2024-07-25T04:21:22Z Abstract In 1997, seismic surveys in the troughs off northwest and north Iceland indicated the presence of a major, regional sub‐bottom reflector that can be traced over large areas of the shelf. Cores taken in 1997, and later in 1999 on the IMAGES V cruise, penetrated through the reflector. In core MD99‐2269 in Húnaflóaáll, this reflector is shown to be represented by a basaltic tephra with a geochemical signature and radiocarbon age correlative with the North Atlantic‐wide Saksunarvatn tephra. We trace this tephra throughout northwest Iceland in a series of marine and lake cores, as well as in terrestrial sediments; it forms a layer 1 to 25 cm thick of fine‐ to medium‐grained basaltic volcanic shards. The base of the tephra unit is always sharp but visual inspection and other measurements (carbonate and total organic carbon weight %) indicate a more diffuse upper boundary associated with bioturbation and with sediment reworking. Off northwest Iceland the Saksunarvatn tephra has distinct sediment magnetic properties. This is evident as a dramatic reduction in magnetic susceptibility, an increase in the frequency dependant magnetic susceptibility and ‘hard’ magnetisation in a −0.1T IRM backfield. Geochemical analyses from 11 sites indicate a tholeiitic basalt composition, similar to the geochemistry of a tephra found in the Greenland ice‐core that dates to 10 180 ± 60 cal. yr BP, and which was correlated with the 9000 14 C yr BP Saksunarvatn tephra. We present accelerator mass spectrometry 14 C dates from the marine sites, which indicate that the ocean reservoir correction is close to ca. 400 yr at 9000 14 C yr BP off northwest Iceland. Copyright © 2002 John Wiley & Sons, Ltd. Article in Journal/Newspaper Greenland Greenland ice core ice core Iceland North Atlantic Wiley Online Library Journal of Quaternary Science 17 8 731 745 |
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Open Polar |
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Wiley Online Library |
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crwiley |
language |
English |
description |
Abstract In 1997, seismic surveys in the troughs off northwest and north Iceland indicated the presence of a major, regional sub‐bottom reflector that can be traced over large areas of the shelf. Cores taken in 1997, and later in 1999 on the IMAGES V cruise, penetrated through the reflector. In core MD99‐2269 in Húnaflóaáll, this reflector is shown to be represented by a basaltic tephra with a geochemical signature and radiocarbon age correlative with the North Atlantic‐wide Saksunarvatn tephra. We trace this tephra throughout northwest Iceland in a series of marine and lake cores, as well as in terrestrial sediments; it forms a layer 1 to 25 cm thick of fine‐ to medium‐grained basaltic volcanic shards. The base of the tephra unit is always sharp but visual inspection and other measurements (carbonate and total organic carbon weight %) indicate a more diffuse upper boundary associated with bioturbation and with sediment reworking. Off northwest Iceland the Saksunarvatn tephra has distinct sediment magnetic properties. This is evident as a dramatic reduction in magnetic susceptibility, an increase in the frequency dependant magnetic susceptibility and ‘hard’ magnetisation in a −0.1T IRM backfield. Geochemical analyses from 11 sites indicate a tholeiitic basalt composition, similar to the geochemistry of a tephra found in the Greenland ice‐core that dates to 10 180 ± 60 cal. yr BP, and which was correlated with the 9000 14 C yr BP Saksunarvatn tephra. We present accelerator mass spectrometry 14 C dates from the marine sites, which indicate that the ocean reservoir correction is close to ca. 400 yr at 9000 14 C yr BP off northwest Iceland. Copyright © 2002 John Wiley & Sons, Ltd. |
author2 |
National Science Foundation (USA) Marine Research Institute. Iceland Research Council Science Funds of the University of Iceland. National Geographic Society. |
format |
Article in Journal/Newspaper |
author |
Andrews, John T. Geirsdóttir, Aslaug Hardardóttir, Jórunn Principato, Sarah Grönvold, Karl Kristjansdóttir, Gréta B. Helgadóttir, Gudrún Drexler, John Sveinbjörnsdóttir, Arny |
spellingShingle |
Andrews, John T. Geirsdóttir, Aslaug Hardardóttir, Jórunn Principato, Sarah Grönvold, Karl Kristjansdóttir, Gréta B. Helgadóttir, Gudrún Drexler, John Sveinbjörnsdóttir, Arny Distribution, sediment magnetism and geochemistry of the Saksunarvatn (10 180 ± 60 cal. yr BP) tephra in marine, lake, and terrestrial sediments, northwest Iceland |
author_facet |
Andrews, John T. Geirsdóttir, Aslaug Hardardóttir, Jórunn Principato, Sarah Grönvold, Karl Kristjansdóttir, Gréta B. Helgadóttir, Gudrún Drexler, John Sveinbjörnsdóttir, Arny |
author_sort |
Andrews, John T. |
title |
Distribution, sediment magnetism and geochemistry of the Saksunarvatn (10 180 ± 60 cal. yr BP) tephra in marine, lake, and terrestrial sediments, northwest Iceland |
title_short |
Distribution, sediment magnetism and geochemistry of the Saksunarvatn (10 180 ± 60 cal. yr BP) tephra in marine, lake, and terrestrial sediments, northwest Iceland |
title_full |
Distribution, sediment magnetism and geochemistry of the Saksunarvatn (10 180 ± 60 cal. yr BP) tephra in marine, lake, and terrestrial sediments, northwest Iceland |
title_fullStr |
Distribution, sediment magnetism and geochemistry of the Saksunarvatn (10 180 ± 60 cal. yr BP) tephra in marine, lake, and terrestrial sediments, northwest Iceland |
title_full_unstemmed |
Distribution, sediment magnetism and geochemistry of the Saksunarvatn (10 180 ± 60 cal. yr BP) tephra in marine, lake, and terrestrial sediments, northwest Iceland |
title_sort |
distribution, sediment magnetism and geochemistry of the saksunarvatn (10 180 ± 60 cal. yr bp) tephra in marine, lake, and terrestrial sediments, northwest iceland |
publisher |
Wiley |
publishDate |
2002 |
url |
http://dx.doi.org/10.1002/jqs.727 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjqs.727 https://onlinelibrary.wiley.com/doi/pdf/10.1002/jqs.727 |
genre |
Greenland Greenland ice core ice core Iceland North Atlantic |
genre_facet |
Greenland Greenland ice core ice core Iceland North Atlantic |
op_source |
Journal of Quaternary Science volume 17, issue 8, page 731-745 ISSN 0267-8179 1099-1417 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1002/jqs.727 |
container_title |
Journal of Quaternary Science |
container_volume |
17 |
container_issue |
8 |
container_start_page |
731 |
op_container_end_page |
745 |
_version_ |
1810447628640452608 |