Paleomagnetic Constraint on the Age of the Shyok Suture Zone

The India-Eurasia collision is a key case study for understanding the influence of plate tectonic processes on Earth's crust, atmosphere, hydrosphere, and biosphere. However, the timing of the final India-Eurasia continental collision is debated due to significant uncertainty in the age of the collision between the Kohistan-Ladakh arc (KLA) and Eurasia along the Shyok suture zone. Here we present paleomagnetic results that constrain the Karakoram terrane in northwest India to a paleolatitude of 19.9 +/- 8.9(degrees)N between 93 and 75 million years ago (Ma). Our results show that the Karakoram terrane was situated on the southern margin of Eurasia in the Late-Cretaceous. Our results indicate that the KLA and Eurasian continent had a not converged until <61.6 Ma, placing a Paleocene older limit on the age of final closure of the Shyok suture zone. This suggests that the India-Eurasia collision in northwestern India likely occurred after the closure of the oceanic basin between the KLA and Eurasia. The Paleocene collision event affecting India that has been widely interpreted to represent final India-Eurasia collision instead records the arc-continent collision between the KLA and the northern edge of India prior to final India-Eurasia collision. Final India-Eurasia collision in northwest India most likely occurred after the closure of the oceanic basin between the KLA and Eurasia.

Automated summary

The India-Eurasia collision is an important case study for understanding the impact of plate tectonic processes on Earth. However, the timing of this collision is still debated. This study presents paleomagnetic results that provide insights into the position of the Karakoram terrane in northwest India during the Late-Cretaceous. The results suggest that the final India-Eurasia collision likely occurred after the closure of the oceanic basin between the Karakoram terrane and Eurasia.