Abstract: The Grove Mountains, 400 km south of the Chinese Zhongshan Station, are an inland continuation of the Prydz Belt, East Antarctica. The basement terrane of the Grove Mountains consists of voluminous mafic-felsic intrusives of ca. 920-910 Ma and a small amount of Mesoproterozoic sedimentary rocks. This terrane experienced only a single Pan-African (ca. 570-500 Ma) tectonometamorphic cycle and therefore is a typical Pan-African metamorphic terrane in the Prydz Belt. The Pan-African high-grade metamorphism may have reached the peak P-T conditions of 770-840?C and 1.18-1.40 GPa, rather than low- to medium-pressure granulite facies as previously thought. This peak metamorphism was then followed by a near-isothermal decompression of ca. 0.6 GPa. Numerous A-type charnockites and granites intruded in the metamorphic terrane during syn- to post-orogenic episodes, which resulted in a late near-isobaric cooling of the terrane. These granitoids were probably generated by partial melting of the underplating materials (alkaline basaltic rocks) derived from a long-term enriched subcontinental lithospheric mantle. Coupled with the available data from other localities, we infer that the Prydz Belt developed on the Archean-Grenvillian basement terranes. Subsequently, these basement terranes and Neoproterozoic (?) cover sequences may have suffered from the same Pan-African orogenic event. The crust of the Prydz Belt was thickened to ca. 40-50 km, followed by ca. 20 km of exhumation during the Pan-African orogenesis. Accordingly, the Prydz Belt should represent a Pan-African collisional zone as a consequence of the East Gondwana assembly.

Key words: Neoproterozoic basement, single Pan-African tectonometamorphic cycle, syn- to post-orogenic magmatism, collisional zone, Grove Mountains, East Antarctica