High Mg-A1 granulites and calc-silicate granulites provide evidence for ultra-high temperatures of metamorphism (ca. 1000ยฐC) at moderate pressures (9-10 kbar) in the Eastern Ghats Belt, India. Lack of proper geochronological data prevents the dating of this extreme metamorphism. High Mg-A1 granulites contain different subsets of mineral assemblages involving spinel, quartz, sapphirine, cordierite, orthopyroxene, garnet and sillimanite coexisting with either rutile-ilmenite or titanohaematite-ferrianilmenite. These high Mg-A1 rocks are poor in Zn and Cr, as reflected primarily in the composition of spinel. Evidence of ultra-high temperature metamorphism comes from (i) textural interpretation of the former coexistence of spinekordierite-quartz and sapphirine-quartz and stabilization of the assemblages orthopyroxene-sillimaniteecordierite and spinel4uartz-sapphirine-garnet and (ii) the high A1203 content of orthopyroxene coexisting with garnet and/or cordierite. Consideration of the sequence of deduced mineral reactions in petrogenetic grids in the system FMAS attests to an anticlockwise P-T path of evolution for the granulites. In calcsilicate granulites stabilization of nearly pure meionite and of the wollastonite-plagioclase-andradite-rich garnet, wollastonite-scapolite-grandite garnet-calcite association corroborate high temperatures of metamorphism. Conventional mineralogical geothermobarometry in all the rocks record lower temperatures (maximum 950ยฐC) at 9-1 0 kbar pressures, attributed to resetting of the mineral compositions during cooling. Following peak metamorphism, the rocks firstly experienced near-isobaric cooling followed by near-isothermal decompression. On the basis of the available evidence it appears that non-extensional lithospheric thinning and/or heat input from basic/enderbitic magma are the causes of such ultra-high temperature metamorphism on an anticlockwise path in the Eastern Ghats Belt. KEY WORDS ultrametamorphism; Eastern Ghats; India; Mg-A1 granulites; calc-silicate granulites 1. INTRODUCTION Ultra-high temperature ( > 9OOOC) regional metamorphism signifies anomalously high thermal input and, hence, is of fundamental importance in understanding the thermal structure and related petrological processes that shaped the continental crust through geological time. Experiments on biotite-bearing quartzo-feldspathic assemblages predict extensive melting even under vapour-absent conditions, leading to the formation and emplacement of voluminous granitic magma at shallow crustal depths, which leads to large-scale crustal differentiation. Along with some other regional granulite facies terrains of the world (Napier Complex,