Denudation Process of Crystalline Nappes in a Continental Collision Zone Constrained by Inversion of Fission‐Track Data and Thermokinematic Forward Modeling: An Example From Eastern Nepalese Himalaya

Thermochronological methods were applied to the Higher Himalayan Crystalline (HHC) nappe and underlying Lesser Sequences (LHS) elucidate denudation process for middle- upper-crust of eastern Nepal over millions years. inverse modeling was undertaken new results fission-track (FT) age FT length data zircon apatite in order reconstruct time-temperature (t-T) paths temperature range 60–350°C. Eight t-T calculated along across-strike section show that cooling HHC this study area is characterized by following three aspects: (a) gradual followed rapid subsequent cooling, (b) northward-younging timing (c) <2 Myr frontmost part nappe. The observed ages then compared with those predicted forwarding thermokinematic modeling. “Flat-Ramp-Flat MHT model”, which LHS are denudated direct proportion uplift rocks transported Main Thrust (MHT), reproduced Nepal. This indicates reflect a driven movement flat-ramp-flat geometry rate its spatial distribution have roughly been constant since ca. 9 Ma.