Paleomagnetism of Late Triassic Volcanic Rocks From the South Qiangtang Block, Tibet:Constrains on the Closure of the Paleo-Tethys Ocean

The Paleo-Tethys Ocean was a major eastward-widening ocean that separated eastern Gondwana and eastern Laurasia during Carboniferous-Permian time. The eventual disappearance of this ocean coincided with the amalgamation of the terranes comprising the modern Qinghai-Tibet Plateau. However, the plate kinematic history that led up to this ocean closure/terrane amalgamation remains poorly constrained. In particular, the South Qiangtang block, which is thought to have formed the southern margin of the system, is a key area in need of additional constraints. In this work, we present new paleomagnetic results which indicate that the South Qiangtang block drifted rapidly northward between the middle Permian and Late Triassic to arrive to a paleolatitude of 30°N by 222 Ma. Such a position suggests that the Paleo-Tethys Ocean may have closed by this time.