Regional variability of ice core dust composition and provenance in Greenland
Geochemistry, Geophysics, Geosystems, Vol. 4, No. 12, doi:10.1029/2003GC000627, 2003
A.J.-M. Bory
British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, UK. Also at Lamont-Doherty Earth Observatory, P.O. Box 1000, 61 Route 9W, Palisades, New York 10964, USA.
P.E. Biscaye and A.M. Piotrowski
Lamont-Doherty Earth Observatory, P.O. Box 1000, 61 Route 9W, Palisades, New York 10964, USA.
J.P. Steffensen
Geofysisk Afdeling, Niels Bohr Instituttet for Astronomi, Fysik og Geofysik, Københavns Universitet
ABSTRACT.
Mineralogical and isotopic composition (Sr and Nd) of six dust samples, obtained from six widely spread ice-coring sites in Greenland, were analyzed in order to investigate the regional geographic variability of dust provenance. We show that long-range transport from eastern Asian deserts provides mineral dust with essentially the same composition to all elevated interior sites (Dye 3, Site A, GRIP and NorthGRIP), while most material deposited at sites located closer to the edge at lower altitude (Hans Tausen and Renland) derives from proximal source regions. No contribution from other sources is apparent at any of the interior sites from the mineralogical and isotopic composition of the dust samples, each of which represents several decades of dust deposition during the 17th-18th century. These results provide additional evidence that African and North American deserts do not play a significant role in the dust deposited over Greenland, which has implications for ice core record interpretation and atmospheric dust transport model validation.