We studied the formation of the Himalayan mountain range and the Tibetan Plateau by
investigating their lithospheric structure. Using an 800-kilometer-long, densely spaced
seismic array, we have constructed an image of the crust and upper mantle beneath
the Himalayas and the southern Tibetan Plateau. The image reveals in a continuous
fashion the Main Himalayan thrust fault as it extends from a shallow depth under Nepal
to the mid-crust under southern Tibet. Indian crust can be traced to 31 degrees N.
The crust/mantle interface beneath Tibet is anisotropic, indicating shearing during
its formation. The dipping mantle fabric suggests that the Indian mantle is subducting
in a diffuse fashion along several evolving subparallel structures.
