'Ultrahigh temperature (UHT)' regional crustal metamorphism: geological and petrological aspects, heat and water

Abstract

"Ultrahigh temperature(UHT)metamorphism" is defined as crustal metamorphism attaining >900°C at mid to deep crustal levels(Harley, 1998). Either of IBC or ITD P-T trajectories has been estimated for individual UHT terrane, and, furthermore, UHT conditions are attained regionally, or only locally in the highest grade portion of the terrane, or as contact aureole around plutonic body. The Napier Complex in Antarctica has experienced >1000°C UHT metamorphism in a regional scale. This talk gives the geological and petrological aspects of 'regional' UHT metamorphism in this terrane, and also discusses about the constraints for 'heat' source and more important 'dehydration' process.