Whole-Rock Geochemistry, Zircon U-Pb geochronology and Lu-Hf isotopic constraints on metasedimentary rocks (Paragneisses) in Stornes Peninsula, Larsemann Hills，East Antarctica

ABSTRACT

Understanding the geological history of the Larsemann Hills and other exposures along the southeastern coast of Prydz Bay is essential for reconstructing the formation and evolution of the East Gondwana continent. This research involves analyses of the major elements, trace elements, REE, U-Pb and Lu-Hf isotopes of zircons from the metasedimentary rocks found in the Larsemann Hills. The results suggest that the provenance of the metasedimentary rocks within the Larsemann Hills is mainly Mesoproterozoic to early Neoproterozoic magmatic rocks. The age of the protolith of the metasedimentary rocks is between ~1019 and ~970 Ma. Our data show that at least two tectono-metamorphic events at ~913 Ma and ~552–555 Ma affected the metasedimentary rocks. Furthermore, Prydz Bay has been an integral whole since before the Palaeozoic era and was subsequently reactivated by Pan-African tectonic events. The thickened crust stretched and thinned, accompanied by partial melting of lithospheric mantle into the lower crust. The real Prydz Bay Pan-African collision orogenic belt should be located under the ice sheet east of the Grove Mountains and strikes close to north-northeast.

KEYWORDS:

• East Antarctica
• metasedimentary rocks
• Whole-Rock Geochemistry
• zircon dating
• tectonic evolution

Article Highlights

• The metasedimentary rocks in the Larsemann Hills experienced at least two high-grade tectono-metamorphic events at ~913Ma and ~552-555Ma.

• d during the late Neoproterozoic-Mesoproterozoic era (between ~1019 and ~970 Ma), Lu-hf zircon data of these para-metamorphic rocks indicate that they are of two distinct sources, mainly derived from Mesoproterozoic to Paleoproterozoic rocks.

• The Prydz Belt is most likely a subduction suture zone of the Rodinia continent.

• The Prydz Belt has been an integral whole since before the Paleozoic era and was subsequently reactivated by Pan-African tectonic events.

Acknowledgments

We acknowledge the leaders and members of the 34th Chinese National Antarctic Research Expedition (CHINARE) for the logistics support during the 2017–2018 Antarctic fieldwork. This research has been financially supported by the National Natural Science Foundation of China (Grant nos. 41941004,41472172), Open Fund of Key Laboratory of Coalbed Methane Resources and Reservoir Formation Process of the Ministry of Education (China University of Mining and Technology) (No. 2021-005), Carbon Neutralization Project of China National Administration of Coal Geology (ZMKJ-2021-ZX02).

Disclosure statement

No potential conflict of interest was reported by the author(s).

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Funding

This work was supported by the National Natural Science Foundation of China [41472172,41941004]; Open Fund of Key Laboratory of Coalbed Methane Resources and Reservoir Formation Process of the Ministry of Education (China University of Mining and Technology) [No. 2021-005]; Carbon Neutralization Project of China National Administration of Coal Geology [ZMKJ-2021-ZX02].