Further rock magnetic and chronostratigraphic results on reversal excursions during the last 50 ka as derived from northern high latitudes and discrepancies in precise AMS 14C dating
A total of five sediment cores from three sites, the Arctic Ocean, the Fram Strait and the Greenland Sea, yielded evidence for geomagnetic reversal excursions and associated strong lows in relative palaeointensity during oxygen isotope stages 2 and 3. A general similarity of the obtained relative pa...
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fthighwire:oai:open-archive.highwire.org:gji:155/3/1065 2023-05-15T15:13:20+02:00 Further rock magnetic and chronostratigraphic results on reversal excursions during the last 50 ka as derived from northern high latitudes and discrepancies in precise AMS 14C dating Nowaczyk, Norbert R. Antonow, Martin Knies, Jochen Spielhagen, Robert F. 2003-12-01 00:00:00.0 text/html http://gji.oxfordjournals.org/cgi/content/short/155/3/1065 https://doi.org/10.1111/j.1365-246X.2003.02115.x en eng Oxford University Press http://gji.oxfordjournals.org/cgi/content/short/155/3/1065 http://dx.doi.org/10.1111/j.1365-246X.2003.02115.x Copyright (C) 2003, Oxford University Press Articles TEXT 2003 fthighwire https://doi.org/10.1111/j.1365-246X.2003.02115.x 2013-05-27T00:23:20Z A total of five sediment cores from three sites, the Arctic Ocean, the Fram Strait and the Greenland Sea, yielded evidence for geomagnetic reversal excursions and associated strong lows in relative palaeointensity during oxygen isotope stages 2 and 3. A general similarity of the obtained relative palaeointensity curves to reference data can be observed. However, in the very detail, results from this high-resolution study differ from published records in a way that the prominent Laschamp excursion is clearly characterized by a significant field recovery when reaching the steepest negative inclinations, whereas only the N–R and R–N transitions are associated with the lowest values. Two subsequent excursions also reach nearly reversed inclinations but without any field recovery at that state. A total of 41 accelerator mass spectrometry (AMS) 14C ages appeared to allow a better age determination of these three directional excursions and related relative palaeointensity variations. However, although the three sites yielded more or less consistent chronological as well as palaeomagnetic results a comparison to another site, PS2644 in the Iceland Sea, revealed significant divergences in the ages of the geomagnetic field excursions of up to 4 ka even on basis of uncalibrated AMS 14C ages. This shift to older 14C ages cannot be explained by a time-transgressive character of the excursions, because the distance between the sites is small when compared with the size of and the distance to the geodynamo in the Earth's outer core. The most likely explanation is a difference of reservoir ages and/or mixing with old 14C-depleted CO 2 from glacier ice expelled from Greenland at site PS2644. Text Arctic Arctic Ocean Fram Strait glacier glacier Greenland Greenland Sea Iceland HighWire Press (Stanford University) Arctic Arctic Ocean Greenland Geophysical Journal International 155 3 1065 1080 |
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English |
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Articles |
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Articles Nowaczyk, Norbert R. Antonow, Martin Knies, Jochen Spielhagen, Robert F. Further rock magnetic and chronostratigraphic results on reversal excursions during the last 50 ka as derived from northern high latitudes and discrepancies in precise AMS 14C dating |
topic_facet |
Articles |
description |
A total of five sediment cores from three sites, the Arctic Ocean, the Fram Strait and the Greenland Sea, yielded evidence for geomagnetic reversal excursions and associated strong lows in relative palaeointensity during oxygen isotope stages 2 and 3. A general similarity of the obtained relative palaeointensity curves to reference data can be observed. However, in the very detail, results from this high-resolution study differ from published records in a way that the prominent Laschamp excursion is clearly characterized by a significant field recovery when reaching the steepest negative inclinations, whereas only the N–R and R–N transitions are associated with the lowest values. Two subsequent excursions also reach nearly reversed inclinations but without any field recovery at that state. A total of 41 accelerator mass spectrometry (AMS) 14C ages appeared to allow a better age determination of these three directional excursions and related relative palaeointensity variations. However, although the three sites yielded more or less consistent chronological as well as palaeomagnetic results a comparison to another site, PS2644 in the Iceland Sea, revealed significant divergences in the ages of the geomagnetic field excursions of up to 4 ka even on basis of uncalibrated AMS 14C ages. This shift to older 14C ages cannot be explained by a time-transgressive character of the excursions, because the distance between the sites is small when compared with the size of and the distance to the geodynamo in the Earth's outer core. The most likely explanation is a difference of reservoir ages and/or mixing with old 14C-depleted CO 2 from glacier ice expelled from Greenland at site PS2644. |
format |
Text |
author |
Nowaczyk, Norbert R. Antonow, Martin Knies, Jochen Spielhagen, Robert F. |
author_facet |
Nowaczyk, Norbert R. Antonow, Martin Knies, Jochen Spielhagen, Robert F. |
author_sort |
Nowaczyk, Norbert R. |
title |
Further rock magnetic and chronostratigraphic results on reversal excursions during the last 50 ka as derived from northern high latitudes and discrepancies in precise AMS 14C dating |
title_short |
Further rock magnetic and chronostratigraphic results on reversal excursions during the last 50 ka as derived from northern high latitudes and discrepancies in precise AMS 14C dating |
title_full |
Further rock magnetic and chronostratigraphic results on reversal excursions during the last 50 ka as derived from northern high latitudes and discrepancies in precise AMS 14C dating |
title_fullStr |
Further rock magnetic and chronostratigraphic results on reversal excursions during the last 50 ka as derived from northern high latitudes and discrepancies in precise AMS 14C dating |
title_full_unstemmed |
Further rock magnetic and chronostratigraphic results on reversal excursions during the last 50 ka as derived from northern high latitudes and discrepancies in precise AMS 14C dating |
title_sort |
further rock magnetic and chronostratigraphic results on reversal excursions during the last 50 ka as derived from northern high latitudes and discrepancies in precise ams 14c dating |
publisher |
Oxford University Press |
publishDate |
2003 |
url |
http://gji.oxfordjournals.org/cgi/content/short/155/3/1065 https://doi.org/10.1111/j.1365-246X.2003.02115.x |
geographic |
Arctic Arctic Ocean Greenland |
geographic_facet |
Arctic Arctic Ocean Greenland |
genre |
Arctic Arctic Ocean Fram Strait glacier glacier Greenland Greenland Sea Iceland |
genre_facet |
Arctic Arctic Ocean Fram Strait glacier glacier Greenland Greenland Sea Iceland |
op_relation |
http://gji.oxfordjournals.org/cgi/content/short/155/3/1065 http://dx.doi.org/10.1111/j.1365-246X.2003.02115.x |
op_rights |
Copyright (C) 2003, Oxford University Press |
op_doi |
https://doi.org/10.1111/j.1365-246X.2003.02115.x |
container_title |
Geophysical Journal International |
container_volume |
155 |
container_issue |
3 |
container_start_page |
1065 |
op_container_end_page |
1080 |
_version_ |
1766343904840384512 |