Further rock magnetic and chronostratigraphic results on reversal excursions during the last 50 ka as derived from northern high latitudes and discrepancies in precise AMS14C 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...
Published in: | Geophysical Journal International |
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Online Access: | https://oceanrep.geomar.de/id/eprint/47089/ https://oceanrep.geomar.de/id/eprint/47089/1/Nowaczyk_et_al-2003-Geophysical_Journal_International.pdf https://doi.org/10.1111/j.1365-246X.2003.02115.x |
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ftoceanrep:oai:oceanrep.geomar.de:47089 2023-05-15T15:13:35+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 AMS14C dating Nowaczyk, Norbert R. Antonow, Martin Knies, Jochen Spielhagen, Robert F. 2003 text https://oceanrep.geomar.de/id/eprint/47089/ https://oceanrep.geomar.de/id/eprint/47089/1/Nowaczyk_et_al-2003-Geophysical_Journal_International.pdf https://doi.org/10.1111/j.1365-246X.2003.02115.x en eng Wiley https://oceanrep.geomar.de/id/eprint/47089/1/Nowaczyk_et_al-2003-Geophysical_Journal_International.pdf Nowaczyk, N. R., Antonow, M., Knies, J. and Spielhagen, R. F. (2003) Further rock magnetic and chronostratigraphic results on reversal excursions during the last 50 ka as derived from northern high latitudes and discrepancies in precise AMS14C dating. Geophysical Journal International, 155 (3). pp. 1065-1080. DOI 10.1111/j.1365-246X.2003.02115.x <https://doi.org/10.1111/j.1365-246X.2003.02115.x>. doi:10.1111/j.1365-246X.2003.02115.x info:eu-repo/semantics/restrictedAccess Article PeerReviewed 2003 ftoceanrep https://doi.org/10.1111/j.1365-246X.2003.02115.x 2023-04-07T15:46:23Z 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 CO2 from glacier ice expelled from Greenland at site PS2644. Article in Journal/Newspaper Arctic Arctic Ocean Fram Strait glacier glacier Greenland Greenland Sea Iceland OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Arctic Arctic Ocean Greenland Geophysical Journal International 155 3 1065 1080 |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
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 CO2 from glacier ice expelled from Greenland at site PS2644. |
format |
Article in Journal/Newspaper |
author |
Nowaczyk, Norbert R. Antonow, Martin Knies, Jochen Spielhagen, Robert F. |
spellingShingle |
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 AMS14C dating |
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 AMS14C 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 AMS14C 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 AMS14C 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 AMS14C 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 AMS14C 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 ams14c dating |
publisher |
Wiley |
publishDate |
2003 |
url |
https://oceanrep.geomar.de/id/eprint/47089/ https://oceanrep.geomar.de/id/eprint/47089/1/Nowaczyk_et_al-2003-Geophysical_Journal_International.pdf 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 |
https://oceanrep.geomar.de/id/eprint/47089/1/Nowaczyk_et_al-2003-Geophysical_Journal_International.pdf Nowaczyk, N. R., Antonow, M., Knies, J. and Spielhagen, R. F. (2003) Further rock magnetic and chronostratigraphic results on reversal excursions during the last 50 ka as derived from northern high latitudes and discrepancies in precise AMS14C dating. Geophysical Journal International, 155 (3). pp. 1065-1080. DOI 10.1111/j.1365-246X.2003.02115.x <https://doi.org/10.1111/j.1365-246X.2003.02115.x>. doi:10.1111/j.1365-246X.2003.02115.x |
op_rights |
info:eu-repo/semantics/restrictedAccess |
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_ |
1766344124449947648 |