Age determination of three sediment cores

DOI

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.

Supplement to: Nowaczyk, Norbert R; Antonow, Martin; Knies, Jochen; Spielhagen, Robert 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 AMS 14C dating. Geophysical Journal International, 155(3), 1065-1080

Identifier
DOI https://doi.org/10.1594/PANGAEA.762397
Related Identifier https://doi.org/10.1111/j.1365-246X.2003.02115.x
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.762397
Provenance
Creator Nowaczyk, Norbert R; Antonow, Martin; Knies, Jochen; Spielhagen, Robert F (ORCID: 0000-0001-9740-667X)
Publisher PANGAEA
Publication Year 2003
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Representation
Resource Type Supplementary Publication Series of Datasets; Collection
Format application/zip
Size 3 datasets
Discipline Earth System Research
Spatial Coverage (-8.998W, 73.250S, 30.876E, 81.538N); Fram Strait; Norwegian Sea; Svalbard
Temporal Coverage Begin 1987-08-24T00:00:00Z
Temporal Coverage End 1991-07-18T21:03:00Z