Figure 2.5 Models of Rodinia at 750 million years ago. (a) Classic reconstruction at 750 million years ago. (b) Alternative reconstruction. Sources-, (a) Adapted gt from Torsvik a al. (1996); (b) adapted from Hartz and Torsvik (2002). Sj upwards. Eventually, the single landmass will break apart, and fragments of the supercontinent will disperse. The heat that has built up under the supercontinent escapes through the new ocean basins created between the dispersing continental blocks. When eventually enough heat has escaped, the continental fragments come back together. Thus, the model depicts the surface of the Earth as a sort of coffee percolator: the input of heat is essentially continuous, but because of poor conduction through the continents, the heat escapes in relatively sudden bursts (Nance et al. 1988, 44).

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