Tuesday, July 26 2011: Dancing Continents
"Sixty million years ago, not long after an asteroid slammed into the Earth to end the rule of the dinosaurs, India began to sense the presence of Asia. The bulk of what is now the Indian subcontinute had been drifting, footloose, ever since it broke away from Antarctica during the shattering of Pangea [225 Mya]. Now it was moving steadily northward at the rate of a few inches per year, and Asia was in its way. There was only one possible outcome: a continental pileup. When ocean basins collide, one or other of the crusts tends t obe forced downward, back into the Earth's interior. But continents are not nearly dense enough to sink. When two continents crash, the only way is up.
So India crashed into Asia, and the land began to rise. First the rust of Asia squeezed around the sides of the thrusting arriviste. Then, as India wedged itself like a chisel farther beneath Asia, the surface crust crumpled and folder into a range of mountains more than two thousand miles long. These were the beginnings of the Himalayas. And the land around the mounts was forced up into a vast plateau, the "roof of the world", whose average height is greater than the highest mountain in America. India is still pushing. The Himalayas grow by nearly half an inch a year, and Everest and its kin would be taller if their fresh young rocks weren't eroding away as they rose.
Meanwhile, partway around the world, Africa was aggressively reacquainting itself with its old Pangean neighbor, Europe. The first part to hit was a peninsula, sticking out from the northern part of the African plate and bearing what is now Italy and Greece and the countries of former Yugoslavia. This collision threw up the beginning of the Alps. Spain crammed into France, and henceforth there were Pyrenees. And though Africa and Europe may seem as if they are joined only at their Arabian hip, the Mediterranean is slowly closing. When Africa itself collides with the European continent a mighty new range of mountains will be born.
Arabia is now shoving into Iran. Europe and Asia have never parted since Pangea, and Australia is heading northward to join in. In a few tens of millions of years, Australia's left should will probably catch on the southernmost islands of Southeast Asia. It will twist and jerk upward, to slam into Borneo and the southern parts of China."
-- "Snowball Earth", Gabrielle Walker, pp 241-243
From the footnotes:
More can be found at the Paleomap Project web site: http://www.scotese.com/
So India crashed into Asia, and the land began to rise. First the rust of Asia squeezed around the sides of the thrusting arriviste. Then, as India wedged itself like a chisel farther beneath Asia, the surface crust crumpled and folder into a range of mountains more than two thousand miles long. These were the beginnings of the Himalayas. And the land around the mounts was forced up into a vast plateau, the "roof of the world", whose average height is greater than the highest mountain in America. India is still pushing. The Himalayas grow by nearly half an inch a year, and Everest and its kin would be taller if their fresh young rocks weren't eroding away as they rose.
Meanwhile, partway around the world, Africa was aggressively reacquainting itself with its old Pangean neighbor, Europe. The first part to hit was a peninsula, sticking out from the northern part of the African plate and bearing what is now Italy and Greece and the countries of former Yugoslavia. This collision threw up the beginning of the Alps. Spain crammed into France, and henceforth there were Pyrenees. And though Africa and Europe may seem as if they are joined only at their Arabian hip, the Mediterranean is slowly closing. When Africa itself collides with the European continent a mighty new range of mountains will be born.
Arabia is now shoving into Iran. Europe and Asia have never parted since Pangea, and Australia is heading northward to join in. In a few tens of millions of years, Australia's left should will probably catch on the southernmost islands of Southeast Asia. It will twist and jerk upward, to slam into Borneo and the southern parts of China."
-- "Snowball Earth", Gabrielle Walker, pp 241-243
From the footnotes:
More can be found at the Paleomap Project web site: http://www.scotese.com/
