The Floor of the Oceans

Abstract

The antipodal distribution of continental blocks and oceanic receptacles ranges among the most peculiar features of the earth. The deep-sea area of the North Pole is situated directly opposite the Antarctic Continent. The six non-polar continents are grouped in pairs, with a roughly meridional orientation, and form an elongated triangle with its apex pointing southwards. Conversely, the oceanic sectors extend in an opposite direction. The broad bases of the continents, arranged in a nearly continuous ring around the North Polar Basin, have their antitype in the broad, circum-Antarctic ring of water. The counterpart of the Indian Ocean is found in North-America and that of Australia in the Atlantic north of the equator, etc. Of course, there are exceptions to this antipodal distribution of land and water, but the fact remains that only 1 /20 of the whole land-surface is antipodal to land ¹). This exceptionally prominent feature of the globe, in which land masses are opposed to oceanic areas, reminds one of a tetrahedron, i.e. a crystallographic body in which a rib is always situated opposite a plane. It has given rise to a great deal of speculation, but it need hardly be said that this characteristic is such a remarkable one that any valid theory as regards the origin of continents and oceanic receptacles ought to be able to furnish an explanation of their tetrahedral arrangement ²). It is clear, however, that this question involves the whole intricate problem of the origin of continents and ocean-floors, and there are many conflicting views on this subject.

“....it appears that the higher continental masses and the depressed oceanic basins came into being very early in the history of the earth”

(Ch. Schuchert)