Where did Mount Everest come from?

By Michael Brown

A good analogy of our planet is a pot of soup that has been left on the stove at a slow boil for too long. On the top there is a crust of overcooked parts and lighter materials that pile up away from the hottest boiling areas. Our earth doesn't exactly boil but there are huge currents of molten material that 'convect' inside the mantle.

Instead of being in a confined pot our earth is a slowly churning sphere held together by its own gravity. The surface has thick flat blobs of crust made up of the lightest materials, the continental plates floating on a heavier oceanic material. Normally the blobs of continental crust move away from the most active 'boiling', mid ocean ridges and rift zones. About 100,000,000 years ago a piece of the floating crust, the Indian crustal plate escaped from a larger continent and moved north colliding with the Asian plate. The result of this unusual continental collision was spectacular with the impact zone being pushed up by massive forces to form the mountain chain we call the Himalaya.

Mount Everest may very well be the highest mountain that planet earth has even known and it is still growing. The growth is slow, though fast by geologic time scales. This growth is partially offset by huge glaciers and tumbling rivers carrying sediments away.

The rocks that make up the Himalaya are made up of a mix of many different kinds of rock from granite and metamorphic layers below to sedimentary at the highest levels. There is a striking band of yellow coloured sedimentary rock, that shows prominently on the upper slopes of Mount Everest. As our team traverses from Camp III (7,000m) to Camp IV (8,000m) they will meet a steeper obstacle of crumbly rock called the Yellow Band. If one looks closely one might even find fossils of sea creatures that have been lifted seven and a half kilometres above the sea.