《Global Plates (PaleoMAP Project by CR Scotese)》.ppt

* Pangea Ultima will form 250 million years in the Future The next Pangea, Pangea Ultima will form as a result of the subduction of the ocean floor of the North and South Atlantic beneath eastern North America and South America.? This supercontinent will have a small ocean basin trapped at its center. The Atlantic Ocean begins to Close New subduction zones along the eastern coasts of North America and South America will begin to consume the ocean floor separating North America from Africa.? About 100 million years from now the present-day Mid-Atlantic Ridge will be subducted and the continents will come closer together. This is the way the World may look like 50 million years from now! If we continue present-day plate motions the Atlantic will widen, Africa will collide with Europe closingthe Mediterranean, Australia will collide with S.E. Asia, and California will slide northward up the coast to Alaska. The Present-day world has well defined climatic zones. We are entering a new phase of continental collision that will ultimately result in the formation of a new Pangea supercontinent in the future.? Global climate is warming because we are leaving an Ice Age and because we are adding greenhouse gases to the atmosphere. The Earth has been in an Ice House Climate for the last 30 million years When the Earth is in its Ice House climate mode, there is ice at the poles.? The polar ice sheet expands and contacts because of variations in the Earths orbit (Milankovitch cycles).? The last expansion of the polar ice sheets took place about 18,000 years ago.? The World Assumes a Modern Configuration 20 million years ago, Antarctica was covered by ice and the northern continents were cooling rapidly.? The world has taken on a modern look, but notice that Florida and parts of Asia were flooded by the sea. During the Early Cenozoic India began to Collide with Asia. 50 - 55 million? years ago India began to collide with Asia forming the Tibetan plateau and Himalayas.? Austral