Transcription: The theory of plate tectonics explains the movements of the Earth's outer shell or lithosphere on which the continents and the oceans rest. According to this theory, the lithosphere is divided into about a dozen major plates which move slowly over the upper mantle and interact with each other along their boundaries. The slow movement of the plates also changes the Earth's geography over time. Geologists believe that some 320 million years ago all the continents were joined together in one single continent called Pangaea. This supercontinent broke up and drifted apart over the millennia to give ...
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