Zircon U-Pb Ages from an Ultra-High Temperature Metapelite, Rauer Group, East Antarctica: Implications for Overprints by Grenvillian and Pan-African Events
Open-File Report
2007-1047-SRP-023
By: Yanbin Wang, Laixi Tong, and Dunyi Liu
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Abstract
SHRIMP U-Pb dating of zircon from an ultra-high temperature (UHT, ~1000 °C) granulite-facies metapelite
from the Rauer Group, Mather Peninsula, east Antarctica, has yielded evidence for two episodes of metamorphic zircon
growth, at ~1.00 Ga and ~530 Ma, and two episodes of magmatism in the source region for the protolith sediment, at
~2.53 and ~2.65 Ga, were identified from the zircon cores. Successive zircon growth at ~1.00 Ga and ~530 Ma records
a sequence of distinct, widely spaced high-temperature metamorphic and/or anatectic events related to Grenvillian and
Pan-African orogenesis. This study presents the first robust geochronological evidence for the timing of UHT
metamorphism of the Rauer Group, supporting arguments that the peak UHT metamorphic event occurred at ~1.00 Ga
and was overprinted by a separate high-grade event at ~530 Ma. The new age data indicate that the UHT granulites of
the Rauer Group experienced a complex, multi-stage tectonothermal history, which cannot simply be explained via a
single Pan-African (~500 Ma) high-grade tectonic event. This is critical in understanding the role of the eastern Prydz
Bay region during the assembly of the east Gondwana supercontinent, and the newly recognized inherited Archaean
ages (~2.53 and ~2.65 Ga) suggest a close tectonic relationship between the Rauer Group and the adjacent Archaean of
the Vestfold Hills
Study Area
| Publication type | Report |
|---|---|
| Publication Subtype | USGS Numbered Series |
| Title | Zircon U-Pb Ages from an Ultra-High Temperature Metapelite, Rauer Group, East Antarctica: Implications for Overprints by Grenvillian and Pan-African Events |
| Series title | Open-File Report |
| Series number | 2007-1047-SRP-023 |
| DOI | 10.3133/ofr20071047SRP023 |
| Year Published | 2007 |
| Language | English |
| Publisher | U.S Geological Survey |
| Publisher location | Reston, VA |
| Description | 4 p. |
| Larger Work Type | Report |
| Larger Work Subtype | USGS Numbered Series |
| Larger Work Title | Antarctica: A Keystone in a Changing World--Online Proceedings for the Tenth International Symposium on Antarctic Earth Sciences. Santa Barbara, California, U.S.A.--August 26 to September 1, 2007 |
| Other Geospatial | Antarctica |
| Additional Online Files (Y/N) | N |
| Google Analytic Metrics | Metrics page |