Why do we call the billion year old himalayas as young mountains?
If the himalayas were truly a billion years old they would not be considered young. In fact they are nowhere near that. The mountains formed as the result of a collision of India with Asia (India had broken off from Africa around 200 million years ago together with which it was part of the supercontinent known as pangaea). The force of the collision between the Indo-Australian Plate and the Eurasian Plate resulted in the creation of the Himalayan range. However, this event did not occur until relatively recently, indeed India only broke away from Africa about 200 million years ago, and hit Asia about 40-50 million years ago – which makes these mountains incredibly young (consider earth is about 100 times that old!). There’s a nice little animation of the last 200 million years of continental drift showing India breaking off from Pangaea and hitting Asia here: http://www.scotese.com/pangeanim.htm (you need to drag your cu
