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

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 similar to 1019 and similar to 970 Ma. Our data show that at least two tectono-metamorphic events at similar to 913 Ma and similar to 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.

Automated summary

Understanding the geological history of the Larsemann Hills and other exposures in Prydz Bay is crucial for reconstructing the formation and evolution of the East Gondwana continent. Based on the analysis of zircons, the metasedimentary rocks in the Larsemann Hills are mainly derived from Mesoproterozoic to early Neoproterozoic magmatic rocks, and have undergone at least two tectono-metamorphic events. Furthermore, Prydz Bay has existed as a whole entity before the Paleozoic era and was later reactivated by Pan-African tectonic events.