The Main Central Thrust is one of the fundamental fault systems of the Himalaya, a broad ductile shear zone that carried the ancient high-grade rocks of the Greater Himalaya southward over younger rocks of the Lesser Himalaya. It extends for more than 2,000 kilometres along the range and helped raise the highest peaks on Earth.
Active mainly during the earlier phases of the India-Asia collision tens of millions of years ago, the Main Central Thrust is a ramp on the Main Himalayan Thrust system at depth. Its trace is marked by a zone of intense deformation and metamorphism, and some segments continue to accommodate crustal shortening today.
Although less prone to producing surface-rupturing earthquakes than the frontal thrusts, the Main Central Thrust zone hosts a belt of concentrated microseismicity where the underthrusting Indian crust bends downward. This makes it central to understanding where and how strain accumulates before the great Himalayan earthquakes.