A novel theory about Earth's ancient history is presented. It is proposed that North America and Antarctica once lay side by side for perhaps as long as a billion years. The importance of these continental connections to geology and other disciplines is discussed. (KR)

Describes a computer simulation called "Supercontinent Aggregation and Dispersal" designed to model the interplay between the movement of the continents and the flow patterns of rock in the mantle. Discusses the strengths and weaknesses of the program in relation to the effects of continents on the mantle. (CW)