Page:The origin of continents and oceans - Wegener, tr. Skerl - 1924.djvu/217

 former festoon, New Zealand. In North America the drift from the poles shows itself in the south-westerly displacement of Grinnell Land relatively to Greenland (or of Labrador relatively to South Greenland), also further in the incipient longitudinal compression of the separating coastal range of California, and in the earthquake fault of San Francisco, connected with it. Even the small block of Madagascar tends towards the equator, for it has moved north-eastwards from its position of rupture from the African continent. It is true it is possible that it has been passively carried along by a stream of sima. Africa and South America lie to-day on the equator, and undergo but slight meridional displacement. The great displacements which South America suffered in the Tertiary period, and which led to the uplifting of the South American Andes, were directed towards the north-west relatively to the position of the poles of that period, and likewise exhibits the drift from the poles. The same thing probably happened to Antarctica.

The compression of Lemuria from the Tertiary to the present day can be conceived in its earlier stages as a drift from the pole. It is true that it lies to-day 10° to 20° north of the equator, so that a drift from the pole could only diminish the folding. It is difficult to say how this movement is to be understood, for we can only determine the relative displacement. Perhaps India was pressed against the interior of Asia by a stream of sima flowing northwards; possibly also it is more correct to trace back a great part of the folding to the drift of Asia from the pole.

The other component, the westward drift of the continents, becomes still clearer by a study of the map of the world. The large blocks move