A review of paleomagnetic constraints on the India-Asia collision: Paradoxes and perspectives

Abstract

The timing, kinematics, and geodynamic evolution of the India-Asia continental collision are crucial to understanding the geological and geomorphological evolution of the Himalayan-Tibetan orogen. However, the debate over how and when the collision occurred persists due to disputes concerning the reliability of paleomagnetic data obtained on both sides of the suture zone. This paper presents a comprehensive analysis and evaluation of paleomagnetic studies to address this controversial issue. The study focuses on well-preserved Cretaceous-Paleocene rocks from the Lhasa and Tethyan Himalaya (TH) terranes over the past two decades. We conclude that: (1) the paleomagnetic data of the Linzizong Group of the Lhasa Terrane and the Zongpu Formation of the TH are in their primary origin and can be used for tectonic reconstruction; (2) the Tethys Himalaya Basin (THB) was generated due to the rifting of the TH from Greater India before the Late Cretaceous; (3) the southern margin of Asia was aligned in the NW-SE direction before the India-Asia collision. The study suggests a quasi-synchronous multi-stage collision where the TH collided with the Trans-Tethyan subduction system in Late Cretaceous-Early Paleocene times (∼65 Ma), followed by collision with Asia at 56–59 Ma. Finally, the India Craton collided with the TH, resulting in the synchronous closure of the THB at approximately 40 Ma.