Tectono-thermal evolution of ultrahigh-temperature- (UHT-) metamorphic rocks in the Madurai Block of the Southern Granulite Terrane (southern India)

点击翻译按钮获取中文摘要

The metamorphic rocks of the Southern Indian Shield are considered as the best archive for geodynamic processes and serve as a valuable tool for the reconstruction of Precambrian crustal evolution in the Indian sub-continent. The Madurai Block constitutes part of the Southern Granulite Terrane in southern India and is made up of a variety of rock types, including mafic granulite, charnockite, sapphirine-bearing granulite, calc-granulite, quarzite, leptynite, gneisses, migmatite, etc. Of particular significance are sapphirine/kornerupine-bearing granulites because they preserve signatures of metamorphic crystallization along the prograde path through arrested textures and are thus potential tools for the derivation of the P-T trajectory of metamorphism. To date, the nature and cause of ultrahigh-temperature- (UHT-) metamorphism in the Madurai Block remain unresolved, with conflicting models of P-T paths presented in the literature. Detailed textural and petrological analyses of arrested reaction textures are planned, in combination with the modeling of pseudosections. Such an approach will yield distinct P-T segments for various evolutionary stages and will thus provide a far more complete description of the geodynamic evolution of this UHT metamorphic complex in particular and will contribute to a better understanding of UHT metamorphic complexes in general.