Exhumation history of the Altun Shan with evidence for the timing of the subduction of the Tarim block beneath the Altyn Tagh system, North Tibet

The Altun Shan is a tectonic block to the south of the Tarim basin, North Tibet, bounded to the south by the Altyn Tagh fault. U/Pb crystallisation ages on zircons are 441 +/- 9 Ma. 40Ar/39Ar analysis on muscovite yields an age of 383 +/- 7 Ma. Both indicate a cooling rate of 7.3 +/- 0.6 degrees C.Ma(-1) from 441 to 383 Ma. Further cooling, probably due to exhumation, began at this time and continued at a rate of 0.8 +/- 0.3 degrees C.Ma(-1). From three apatite fission-track analyses, cooling rate increased to 8 +/- 2 degrees C.Ma(-1) at 10 Ma. ((C) 1999 Academie des sciences/Editions scientifiques et medicales Elsevier SAS.).