Geodynamic modeling study reveals crustal melting and weakening drove plateau flattening in Tibet, suggesting crustal flow reshaped the high-elevation landscape.
Key Points
To identify the deep crust-mantle processes and mechanisms responsible for transforming Tibet from high-relief mountains into a high, flat plateau.
Conducted geochemical analyses of the Lhasa middle to lower crust spanning 30 to 15 Ma.
Applied thermodynamic and geodynamic modeling to simulate crustal weakening, melting behavior, and topographic evolution.
Geochemical evidence showed synchronous high-temperature dehydration melting and low-temperature water-fluxed melting in the Lhasa crust between 30 and 15 Ma, marking a transition from earlier cold-and-dry crust (45 to 30 Ma).
Geodynamic simulations confirmed that a hot, wet, and weakened crust facilitated crustal flow that flattened the plateau, with continued subduction of the Indian plate maintaining its elevated topography.