The University of Southampton
University of Southampton Institutional Repository

Normalised natural remanent magnetisation intensity during the last 240 000 years in piston cores from the central North Atlantic Ocean: geomagnetic field intensity or environmental signal?

Weeks, Robin J., Laj, Carlo, Endignoux, Lionel, Mazaud, Alain, Labeyrie, Laurent, Roberts, Andrew P., Kissel, Catherine and Blanchard, Erick (1995) Normalised natural remanent magnetisation intensity during the last 240 000 years in piston cores from the central North Atlantic Ocean: geomagnetic field intensity or environmental signal? Physics of the Earth and Planetary Interiors, 87, (3-4), pp. 213-229. (doi:10.1016/0031-9201(94)02966-F).

Record type: Article

Abstract

We have examined in detail the stratigraphic variations in magnetic parameters of four cores from the North Atlantic Ocean in areas where the depositional environment has varied with climatic changes. Our objective is to assess whether normalisation of the natural remanent magnetisation (NRM) intensity can cancel the effect of climatically induced variations in magnetic mineral content and grain size and whether a reliable record of relative changes in geomagnetic field intensity can be obtained. After selecting the core sections which meet published criteria for paleointensity normalisation, we have attempted to obtain a record of the geomagnetic field intensity variations over the past 240 kyear, using both ARM and IRM as normalising factors for the NRM. The two methods yield overall similar results, except for the interval 20–30 kyear, where IRM normalisation yields a record more consistent with previous sedimentary and volcanic results, than does the more frequently employed ARM normalisation. The final intensity record docmments a picture of the dipole field moment which presents large similarities with profiles obtained from sediments deposited in different environmental conditions in various regions around the world. We observe a major low at about 42 kyear, which could correspond to the Laschamp event, a broad low in the interval 90–130 kyear, possibly connected to the Blake event, and another low at about 190 kyear, which could reflect the Biwa I event. The processes of acquisition of depositional and postdepositional remanent magnetisation and the physics of the normalising methods are still insufficiently understood. However, these results, obtained from a region characterised by complex environmental dynamics, confirm the potential of sedimentary deep sea cores for relative paleointensity determinations.

Full text not available from this repository.

More information

Published date: January 1995

Identifiers

Local EPrints ID: 66143
URI: http://eprints.soton.ac.uk/id/eprint/66143
ISSN: 0031-9201
PURE UUID: 568c6f57-0f0c-404a-8e47-f358ab190687

Catalogue record

Date deposited: 05 May 2009
Last modified: 19 Jul 2017 00:27

Export record

Altmetrics

Contributors

Author: Robin J. Weeks
Author: Carlo Laj
Author: Lionel Endignoux
Author: Alain Mazaud
Author: Laurent Labeyrie
Author: Andrew P. Roberts
Author: Catherine Kissel
Author: Erick Blanchard

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×