RDS Monthly Lecture (May 2026) - by Dr. Arun Kumar Ojha

Title: Stop-and-go tectonics of the Karakoram Fault Abstract: The ~1000 km long Karakoram Fault, a prominent right-lateral strike-slip fault in the western sector of the Himalaya-Tibet orogen, is critical in the orogen's geodynamics. Recent observations suggest a kinematic readjustment of the Karakoram Fault, which raises questions about its role in the India/Asia collision and extrusion of Tibet. In this talk, I will show my results from the investigation of the impact of the Longmu Co Gozha Co fault system on the kinematics of the Karakoram Fault using a multi-proxy approach. The kinematic readjustment is found to be non-unique, as pulsating extension in the Pangong region and episodic cessation of the northern Karakoram Fault segment are observed. The initial kinematic readjustment began around 22-23 Ma, which exhumed the metamorphic core complex in the Pangong region. The last kinematic readjustment event has an estimated average age of ~500 ka, inferred from the crustal extension proxy, which is consistent with the earlier reported last activation age of the northern Karakoram Fault segment. About the Speaker: Dr Arun Kumar Ojha is a Scientist-D at CSIR-National Geophysical Research Institute (CSIR-NGRI), Hyderabad, specialising in structural geology, tectonics, and Himalayan geodynamics. His research focuses on the evolution of major fault and shear-zone systems, crustal deformation, fault kinematics, and the tectonic processes operating in the Himalaya–Tibet orogen. Through field-based structural studies and multi-proxy analytical approaches, Dr Ojha investigates the timing, mechanism, and geodynamic significance of deformation in active and ancient tectonic settings. In this lecture, he will discuss the “Stop-and-go tectonics of the Karakoram Fault”, highlighting its episodic activity and implications for the India-Asia collision and the tectonic evolution of the Tibetan region.