Combining Numerical Simulation and Seismology to Unravel the Exhumation Mechanism and Pathways of the Yardoi Dome, Eastern Himalayas

Abstract The mechanisms of rapid exhumation of North Himalayan gneiss domes remain debated. We integrate phase equilibrium modeling, teleseismic tomography, and geodynamic simulation to reconstruct episodic exhumation paths and elucidate the underlying mechanisms. Our results confirm the previously inferred P‐T‐t evolution for the mid‐upper crust Greater Himalayan Sequence (GHS), featuring rapid near‐isothermal decompression during retrograde metamorphism followed by near‐isobaric cooling. Geodynamic modeling demonstrates that sustained intra‐crustal high temperatures trigger pervasive partial melting and pronounced rheological weakening within the middle‐lower level of upper crust. Consequently, extensive crustal melting and associated weakening are prerequisites for enabling exhumation. Sustained convergence and resistance from the Lhasa terrane induce prolonged shortening and thickening of the weakened crust. This culminates in rapid exhumation, driving upper‐crustal extension. Modeling reveals two primary exhumation pathways: (a) direct emplacement near the suture zone, forming the Yardoi dome, and (b) lateral migration facilitated by upper‐crustal shear zones along low‐viscosity channels, transporting material to the GHS and beyond. We conclude that crustal weakening induced by partial melting, in conjunction with the ongoing convergence of the Indian Plate, constitutes the primary control on multi‐stage exhumation events in the Himalayan orogen. The occurrence of multiple exhumation episodes requires successive thermal perturbations to regenerate these low‐viscosity zones.