[meteorite-list] Portion of Greenland Magnetism Comes from Extraterrestrial Source

[Ron Baalke]

http://www.innovations-report.de/html/berichte/geowissenschaften/bericht-30550.html

Portion of Greenland magnetism comes from extraterrestrial source
American Geophysical Union
June 24, 2004

Part of the magnetic dust observed in Greenland ice cores may come from
extraterrestrial sources, although most of the surface magnetism of ice
also comes from iron-rich particles deposited by airborne dust. Lanci et
al. used magnetic testing techniques on ice cores from central Greenland
to trace the iron oxide content and total dust concentration in polar
sources.

They suggest that measuring the magnetic strength of dust deposited on
the icy surface can provide researchers an improved method to estimate
the source of airborne aerosols and reconstruct ancient climate changes.
Such magnetic testing methods had previously been applied to
environmental analyses of windblown particles deposited on land but had
never been used within ice.

The authors examined the faint magnetic signal from mineral particles
trapped under layers of frozen sediment in Greenland and, although they
cannot rule out alternative sources of iron dust contamination, found
that the observed magnetization is closely correlated with the dust
concentration in the ice.

Title: Magnetization of Greenland ice and its relationship with dust
content