Continental Drift

[raman22feb1988]

Continental Drift (750 million years ago to 250 million years in the future)

Late Proterozoic (750 million years ago to 540 million years ago)

750 million years ago the supercontinent of Rodinia broke apart. Half of the sundered supercontinent (the half that included North America) went south and crossed the South Pole. The other half drifted northward towards the North Pole. Because so much land was near the poles, the Late Precambrian was an Ice House World - much of the Earth was covered by ice. Eventually the two halves collided with the Congo continent (Central Africa) and a new supercontinent was born - Pannotia. Pannotia began to break apart at the very end of the Precambrian. The Paleozoic began (540 mya) with 4 new continents: Gondwana (the core of Pannotia), Laurentia (North America), Baltica (Northern Europe), and Siberia.

The blue areas are deep ocean basins. The light blue areas are flooded continental shelves and oceanic plateaus. The tan areas are land, and the red areas are mountains. Watch North America (Laurentia) head towards the South Pole . Also note the volcanic island chains and extensive mountain belt that was formed by Late Precambrian collisions (Pan-African orogeny).

Paleozoic (540 million years ago to 240 million years ago) -- The assembly of Pangea

Watch North America (Laurentia) collide with Northern Europe (Baltica) to form the "Old Red Sandstone" continent. Also note that Pangea began to assemble in the Devonian but was not completely assembled until the early Permian. In the Early Permian, Cimmeria rifts away from the Indo-Australian margin of Gondwana and begins to cross the wide, v-shaped Tethys Ocean.

Mesozoic and Cenozoic (240 million years ago to Today) -- The Breakup of Pangea

Watch the Caribbean evolve, especially the northernmost part of South America. Watch India move forward inexorably towards Asia, leaving behind the 90E Ridge hot spot track.

Today to 250 million years into the future -- The assembly of Pangea Ultima

This animation was made by projecting present-day plate motions into the future, and trying to take into account unpredictable events, such as the formation of new subduction zones. By extending present-day plate motions into the future we can easily predict that Africa will collide with southern Europe closing the Mediterranean, that Australia will collide with S.E. Asia and China, and California will slide northward along the west coast.

Subduction is now beginning in the Central Indian Ocean, and it seems likely that new subduction zones will form off the east coast of the Americas. (Subduction has already begun in the Puerto Rican trench and Scotia arc.) If this happens, then Antarctica will be drawn northward towards India, and the Atlantic will close forming a new ring-shaped Pangea.

The dark blue areas are deep ocean basins. The light blue areas are flooded continental shelves and oceanic plateaus. The tan areas are land, and the yellow areas are mountains. The continents are covered by the sea when there is a lot of rifting going on, and they are emergent when the continents are in collision.

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