SIMULATION OF HIMALAYAN MAJOR THRUSTS BY FINITE ELEMENT METHOD

Abstract

The Himalayan mountain system developed from the powerful earth movements which occurred as the Indian plate pressed against the Eurasian continental plate. A series of elastic finite element models are presented to examine the development of major thrusts (MCT, MBT and MFT) in the central Himalaya. Balanced geologic profiles of the central Himalaya which are modified from Johnson's profiles (2002) are used for the purpose under plane strain condition. The convergent rate of India has changed 10 cm/a at 40 Ma, 5 cm/a at 20 Ma and 2 cm/a at 10 Ma. Results show that the horizontal compressive stress σ1 leads to the development of thrust faults in the Ththys Himalaya, Higher Himalaya, Lesser Himalaya, Sub-Himalaya and incipient zones of MCT, MBT and MFT. Especially, the thrust faults are highly concentrated within the whole area of the incipient zones, which influenced the formation of MCT, MBT and MFT at their early stage.