Page:The origin of continents and oceans - Wegener, tr. Skerl - 1924.djvu/168

142 crescent-shaped Seychelles shelf, which bears the individual islands formed of granite, does not fit into either Madagascar or India, the straight outlines of which denote rather an earlier immediate connection.

Therefore the explanation suggests itself that we have a molten mass of sial which has risen from the underside of the block, was then carried off by the flow of the sima and has travelled a large part of the way in the direction of India. This stream of sima, which Madagascar itself is also following, runs exactly in the track of India, and was perhaps produced through its displacement, or possibly, on the contrary, the current caused the displacement of India, as indicated by the breaking-away of Ceylon. Movements in liquids, including viscous ones, are only rarely of so simple a kind that cause and effect can be clearly separated. Our knowledge of these matters is still all too defective. It is, therefore, absurd to demand of the displacement theory that it should link up and explain every relative movement that is observed. We consider these matters only for the explanation of the flow phenomena in the sima, and these show, by the recurved ends of