On these diagrams, pairs of parallel lines show boundaries where plates are spreading apart, lines with ticks show boundaries where plates are colliding, and simple lines show other types of boundary. These include places where plates are simply sliding past one another, places where motions are too complex to portray simply, and places where new plate boundaries may be forming.
Antarctica was part of eastern Gondwanaland along with Madagascar, India and Australia. Eastern Gondwanaland broke off of Africa about 120 million years ago, and not long afterward, India and Madagascar broke off. Finally, Australia and New Zealand broke off around 50 million years ago. As a result, Antarctica is almost entirely surrounded by divergent plate boundaries.
As North America, South America, and Antarctica spread away from Africa, they also pulled away from each other. The gaps were filled by oceanic crust that now forms the tongue-like Caribbean and Scotia Plates.
In addition to the large plates, significant small plates are labeled. Very small plates are not labeled.
Created 10 August 2009, Last Update 14 December 2009
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