 Together with the intense compressional force and thrusting it experienced amidst collision, intense crustal thickening occurred, resulting in the major phase of uplift in South Tibet.As the collision proceed (26—13 Ma), the Northern Tibet continental block experienced compression, thrusting and shortening as well.This interpretation is supported by the thermochronological data of apatite fission tracks from the North Tibetan Plateau, which indicate phases of rapid exhumation and compression from 20 Ma onwards.