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More Information about the Eocene

The third, and final phase in the breakup of Pangea took place during the early Cenozoic. North America and Greenland split away from Europe, and Antarctica released Australia which like India 50 million years earlier, moved rapidly northward on a collision course with southeast Asia. The most recent rifting events, all taking place within the last 20 million years include: the rifting a Arabia away from Africa opening the Red Sea, the creation of the east African Rift System, the opening of the Sea of Japan as Japan moved eastward into the Pacific, and the northward motion of California and northern Mexico, opening of the Gulf of California.

Though several new oceans have opened during the Cenozoic, the last 66 million years of Earth history are better characterized as a time of intense continental collision. The most significant of these collisions has been the collision between India and Eurasia, which began about 50 million years ago. During the Late Cretaceous, India approached Eurasia at rates of 15 - 20 cm/yr - a plate tectonic speed record. After colliding with marginal island arcs in the Late Cretaceous, the northern part of India, Greater India, began to be subducted beneath Eurasia raising the Tibetan Plateau. Interesting, Asia, rather than India, has sustained most of the deformation associated with this collision. This is because India is a solid piece of continental lithosphere riding on a plate that is primarily made up of stronger oceanic lithosphere. Asia on the other hand, is a loosely knit collage of continental fragments. The collision zones, or sutures, between these fragments are still warm, and hence, can be easily reactivated. As India collided with Asia, these fragments were squeezed northwards and eastwards out of the way, along strike-slip faults that followed older sutures. Earthquakes along these faults continue to the present-day.

The collision of India with Asia is just one of a series of continental collisions that has all but closed the ocean great Tethys Ocean. From east to west these continent-continent collisions are: Spain with France forming the Pyrenees mountains, Italy with France and Switzerland forming the Alps, Greece and Turkey with the Balkan States forming the Hellenide and Dinaride mountains, Arabia with Iran forming the Zagros mountains, India with Asia, and finally the youngest collision, Australia with Indonesia.