Lead isotopic evidence for an Australian source of aeolian dust to Antarctica at times over the last 170,000 years

Systematic analysis of Pb, Sr and Nd isotopes of 32 fluvial clay samples (< 2 μm fraction) from many of the major tributaries of the vast (1.10 6 km 2 ) Murray Darling Basin (MDB), located in semiarid southeastern Australia, displays similar isotopic values between some MDB clays and dust from se...

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Bibliographic Details
Published in:Palaeogeography, Palaeoclimatology, Palaeoecology
Main Authors: De Deckker, Patrick, Norman, Marc, Goodwin, Ian D., Wain, Alan, Gingele, Franz X.
Format: Article in Journal/Newspaper
Language:English
Published: 2010
Subjects:
Airborne dust
Antarctic ice cores
Argentina
EPICA
Murray Darling Basin
Nd isotopes
Patagonia
Pb
Sr
Vostok
Antarctic
Southern Ocean
West Antarctica
Pacific
Indian
Antarc*
Antarctica
ice core
Online Access:https://researchers.mq.edu.au/en/publications/06d5512f-72b2-4fb8-99e8-f117d349a784
https://doi.org/10.1016/j.palaeo.2009.11.013
http://www.scopus.com/inward/record.url?scp=72749086798&partnerID=8YFLogxK
Description
Summary:Systematic analysis of Pb, Sr and Nd isotopes of 32 fluvial clay samples (< 2 μm fraction) from many of the major tributaries of the vast (1.10 6 km 2 ) Murray Darling Basin (MDB), located in semiarid southeastern Australia, displays similar isotopic values between some MDB clays and dust from several ice core samples from the EPICA Dome C in Antarctica. Close scrutiny of several ratios of the four Pb isotopes, and in particular 208 Pb/ 207 Pb versus 206 Pb/ 207 Pb, shows that several samples from the Darling-sub-basin of the MDB display similar values for the same isotopes for Dome C samples from different ages, and more particularly during wet phases in Australia [Marine Isotopic Stages 5e, 3 and 1]. The combination of Nd and Sr isotopic ratios from the same MDB fluvial clays clearly eliminates the Murray sub-basin, and supports the Darling sub-basin as a potential source of aeolian material to Antarctica. Overall, the Australian dust supply to Antarctica predominantly occurred during interglacial periods. The work presented here shows that aerosols generated in southeastern Australia can travel to parts of West Antarctica and this is supported by atmospheric observations and models. In addition, evidence of Australian dust in Antarctic ice cores further implies dust deposition in the Southern Ocean would have occurred in the past. Current meteorological observations also imply that the western Pacific and Indian Ocean sector of the Southern Ocean would frequently receive aeolian dust components originating from southeastern Australia.

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