Skip to Main Content
Book Chapter

Lithospheric mantle domains beneath Antarctica

By
P. T. Leat
P. T. Leat
1
British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK (e-mail: p.leat@bas.ac.uk)
Search for other works by this author on:
A. A. Dean
A. A. Dean
1
British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK (e-mail: p.leat@bas.ac.uk)
Search for other works by this author on:
I. L. Millar
I. L. Millar
2
British Antarctic Survey, c/o NIGL, British Geological Survey, Key worth, Nottingham NG12 5GG, UK
Search for other works by this author on:
S. P. Kelley
S. P. Kelley
3
Department of Earth Sciences, The Open University, Milton Keynes MK7 6AA, UK
Search for other works by this author on:
A. P. M. Vaughan
A. P. M. Vaughan
1
British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK (e-mail: p.leat@bas.ac.uk)
Search for other works by this author on:
T. R. Riley
T. R. Riley
1
British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK (e-mail: p.leat@bas.ac.uk)
Search for other works by this author on:
Published:
January 01, 2005

Abstract

The chemistry of mafic volcanic rocks and minor intrusions erupted on continents can be used to define sub-continental asthenospheric and lithospheric mantle sources. Data have been collated from Antarctica and the Falkland Islands (adjacent in Gondwana) in order to identify lithospheric mantle sources beneath the continent. The lithosphere-derived magmas include lamproitic and some lamprophyric rocks and end-members in basaltic suites that are interpreted as mixtures of magmas from lithospheric and asthenospheric sources. The lithosphere-derived mafic rocks from Archaean to Middle Proterozoic cratonic and circumcratonic areas of East Antarctica have time-corrected εNd values of −20 to −3. This demands isolation of the LREE-enriched sources within pockets of stable sub-cratonic lithosphere for more than 1 Ga, consistent with the lithosphere thickness up to 250 km imaged by seismic tomography. In contrast, lithosphere-derived mafic rocks from Middle Proterozoic to Early Palaeozoic areas of West Antarctica, Victoria Land and the Falkland Islands that formed the Gondwana continental margin, have time-corrected εNd values of −3.6 to +3.5, implying more recent isolation from asthenosphere. In terms of mantle reservoirs, cratonic and circumcratonic areas trend toward EMI, with EMII possibly being a minor component. In contrast, Gondwana margin areas trend toward EMII, with EMI being, at most, a very minor component.

You do not currently have access to this article.

Figures & Tables

Contents

Geological Society, London, Special Publications

Terrane Processes at the Margins of Gondwana

A. P. M. Vaughan
A. P. M. Vaughan
British Antarctic Survey, UK
Search for other works by this author on:
P. T. Leat
P. T. Leat
British Antarctic Survey, UK
Search for other works by this author on:
R. J. Pankhurst
R. J. Pankhurst
British Geological Survey, UK
Search for other works by this author on:
Geological Society of London
Volume
246
ISBN electronic:
9781862394940
Publication date:
January 01, 2005

GeoRef

References

Related

Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal