Explanation:

The Himalayas consist of part of the Tethys Ocean. As the Indian Plate moved north it pushed through that now extinct ocean, and as it drove into South Asia, the frontal part of it which had been part of the Tethys, was squeezed against the Eurasian Plate. It folded and buckled as the continuous pressure of India’s drive northwards and grew into first hills, then mountains- the mountains we call the Himalayas.