Metamorphic constraints on the thermal evolution of the central Himalayan orogen

Recent studies that integrate conventional thermobarometry of pelitic mineral assemblages with thermodynamic modeling of garnet zoning reveal complex Tertiary P -T paths for the Greater Himalayan metamorphic sequence in the central Himalaya. Viewed in light of our current understanding of the structural evolution of the Himalaya, these data provide insights into the relations between tectonic and thermal processes during orogenesis. In this paper, we present an interpretive model for tectonothermal evolution of the Greater Himalaya in the central part of the range. This model involves: (1) middle Eocene—early Oligocene burial to depths of more than 30 km during the early stages of collision between India and Asia; (2) early—late Oligocene uplift and cooling; (3) late Oligocene heating and renewed burial synchronous with the early stages of anatectic melting and leucogranite plutonism; (4) latest Oligocene-middle Miocene rapid uplift and continued leucogranite production associated with ramping on the structurally lower Main Central Thrust and tectonic denudation on structurally higher low-angle detachment systems; and (5) middle Miocene—Recent rapid cooling during the final stages of uplift to the surface