Two possible source regions for central Greenland last glacial dust

Document Type

Article

Publication Date

12-16-2015

Publication Title

Geophysical Research Letters

Keywords

clay mineralogy, Greenland dust, origin, provenance, Sr-Nd-Hf isotopes

Abstract

Dust in Greenland ice cores is used to reconstruct the activity of dust-emitting regions and atmospheric circulation. However, the source of dust material to Greenland over the last glacial period is the subject of considerable uncertainty. Here we use new clay mineral and <10 μm Sr-Nd isotopic data from a range of Northern Hemisphere loess deposits in possible source regions alongside existing isotopic data to show that these methods cannot discriminate between two competing hypothetical origins for Greenland dust: an East Asian and/or central European source. In contrast, Hf isotopes (<10 μm fraction) of loess samples show considerable differences between the potential source regions. We attribute this to a first-order clay mineralogy dependence of Hf isotopic signatures in the finest silt/clay fractions, due to absence of zircons. As zircons would also be absent in Greenland dust, this provides a new way to discriminate between hypotheses for Greenland dust sources.

Volume

42

Issue

23

First Page

10399

Last Page

10408

ISSN

00948276

E-ISSN

19448007

DOI

10.1002/2015GL066153

Link to Full Text

Share

COinS