A Positive Test of East Antarctica–Laurentia Juxtaposition Within the Rodinia Supercontinent
J. W. Goodge,1*
J. D. Vervoort,2
C. M. Fanning,3
D. M. Brecke,4
G. L. Farmer,5
I. S. Williams,3
P. M. Myrow,6
D. J. DePaolo7
The positions of Laurentia and other landmasses in the Precambrian
supercontinent of Rodinia are controversial. Although geological
and isotopic data support an East Antarctic fit with western
Laurentia, alternative reconstructions favor the juxtaposition
of Australia, Siberia, or South China. New geologic, age, and
isotopic data provide a positive test of the juxtaposition with
East Antarctica: Neodymium isotopes of Neoproterozoic rift-margin
strata are similar; hafnium isotopes of
1.4-billion-year-old
Antarctic-margin detrital zircons match those in Laurentian
granites of similar age; and a glacial clast of A-type granite
has a uraniun-lead zircon age of
1440 million years, an epsilon-hafnium
initial value of +7, and an epsilon-neodymium initial value
of +4. These tracers indicate the presence of granites in East
Antarctica having the same age, geochemical properties, and
isotopic signatures as the distinctive granites in Laurentia.
2 School of Earth and Environmental Sciences, Washington State University, Pullman, WA 99164, USA.
3 Research School of Earth Sciences, Australian National University, Canberra, ACT 0200, Australia.
4 Natural Resources Research Institute, University of Minnesota–Duluth, Duluth, MN 55811, USA.
5 Department of Geological Sciences and CIRES, University of Colorado, Boulder, CO 80309, USA.
6 Department of Geology, Colorado College, Colorado Springs, CO 80903, USA.
7 Department of Earth and Planetary Sciences, University of California, Berkeley, CA 94720, USA.
* To whom correspondence should be addressed. E-mail: jgoodge{at}d.umn.edu
