The Himalayas formed because the Indian craton moved exceptionally fast northward (all the way from Antarctica) and collided with Eurasia, one of the fastest sustained plate motions known in geological history.
The collision with Asia began around 50–55 Ma and is still ongoing, which is why the Himalayas are still rising today.
They're also mountain ranges formed from the collision of plates? Otherwise, nothing, the timelines of the formation of the Himalayas and the Appalachians are hundreds of millions of years apart.
