The Min Shan and central and southern parts of the Longmen Mountains form the middle segment of the north trending earthquake zone at the eastern edge of the Tibetan Plateau. The Min Shan Mountains are a Cenozoic to Quaternary uplift zone that has undergone south directed block movements to produce the 1933 Diexi earthquake (M=7.5) on the Min Jiang Fault and the 1976 Songpan earthquake swarm (M=7.2, 6.7, 7.2) on the Huya Fault. The Min Jiang Fault on the western boundary of the uplift zone is dominated by reverse movement with a right-lateral component. The Huya Fault on the eastern margin of the Min Shan Uplift Zone is also dominated by reverse movement but is associated with a left-lateral component. The uplift and block movement of the Min Shan Mountains are probably related to the compression at the eastern end of the Kunlun Fault which is a major northwest trending strike-slip fault within the Tibetan Plateau. Quaternary deformation in the Longmen Mountains is characterized by relatively continuous thrusting on major faults and Himalayan folding events in foreland basin deposits, and no earthquakes of M≥7 have been recorded there. ¿ American Geophysical Union 1994