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Isothermal remanent magnetization of Greenland ice: Preliminary results

Luca Lanci; Dennis V. Kent; Pierre E. Biscaye; Aloys Jean-Mathias Bory

Title:
Isothermal remanent magnetization of Greenland ice: Preliminary results
Author(s):
Lanci, Luca
Kent, Dennis V.
Biscaye, Pierre E.
Bory, Aloys Jean-Mathias
Date:
Type:
Articles
Department:
Lamont-Doherty Earth Observatory
Volume:
28
Permanent URL:
Book/Journal Title:
Geophysical Research Letters
Abstract:
The magnetic mineral content of wind‐transported dust should reflect atmospheric transport dynamics and conditions in its source areas, and could thus be used as an environmental proxy. To test the feasibility of determining the magnetic mineral content in polar ice, isothermal remanent magnetization (IRM) was measured on a small suite of Greenland ice samples of Holocene (interglacial) and Last Glacial Maximum (LGM) age. Although the extremely low dust concentrations limit weak field (susceptibility) measurements, all samples contained an easily measurable concentration of magnetic minerals that can be estimated using IRM intensity provided that special precautions are used. IRM experiments at liquid nitrogen temperatures indicate ice magnetic properties which are consistent with that expected from varying concentrations of magnetite or maghemite. Interestingly, the Holocene ice samples tend to have higher magnetic concentrations, despite having much lower total polar dust contents, than the few LGM ice samples tested thus far.
Subject(s):
Geophysics
Publisher DOI:
http://dx.doi.org/10.1029/2000GL012594
Item views:
101
Metadata:
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