Geodesy and Gravity/Tectonophysics
Evidence for Mesozoic shear along the western Kunlun and Altyn-Tagh fault, northern Tibet (China)
Article first published online: 29 JAN 2003
Copyright 2003 by the American Geophysical Union.
Journal of Geophysical Research: Solid Earth (1978–2012)
Volume 108, Issue B1, January 2003
How to Cite
2003), Evidence for Mesozoic shear along the western Kunlun and Altyn-Tagh fault, northern Tibet (China), J. Geophys. Res., 108, 2053, doi:10.1029/2001JB000904, B1., , , , , , and (
- Issue published online: 29 JAN 2003
- Article first published online: 29 JAN 2003
- Manuscript Accepted: 4 NOV 2002
- Manuscript Revised: 13 MAY 2002
- Manuscript Received: 1 AUG 2001
- strike-slip faults;
 The strike-slip faults of north Tibet accommodate part of the Cenozoic convergence between India and Asia. Along the Karakax valley south of Yecheng and near the Xidatan trough south of Golmud, the active traces of the Altyn-Tagh and Kunlun faults follow narrow belts of metamorphic rocks. The deformation recorded in those mylonites is sinistral strike-slip. Rb/Sr and 40Ar/39Ar ages of deformation from syntectonic fabrics formed at 350–400°C 120 Ma. Argon loss suggests that deformation was associated to a 250–300°C thermal pulse that lasted 5–20 Ma after the onset of movement. Unroofing occurred much later, around 25 Ma when sudden cooling suggests a component of thrusting or more likely normal faulting. The Cretaceous shear may be related to collision between the Qiantang and the Lhasa blocks. The Karakax and Xidatan shear zones may have formed a unique, continuous boundary in the Cretaceous, which was later reused by the Tertiary strike-slip faults, leading to potentially calculable offsets along the Altyn-Tagh fault.