Page:The origin of continents and oceans - Wegener, tr. Skerl - 1924.djvu/169

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THE FLOOR OF THE OCEAN
143

the Seychelles shelf, that the movement of the stream of sima diminishes on both sides of the median line from Madagascar to India. We may also assert that the stream runs most strongly in the freshly exposed sima, whilst the older deep-sea floors north-westerly and south-easterly therefrom move more slowly. The second figure shows, in the Fiji Islands group, a form which is suggestive of a two-armed spiral nebula, and indicates a spiral movement of flow. Its formation seems to me to be connected with the alteration of movement which Australia underwent when it ruptured its last connection with Antarctica and began its still recognizable movement towards the north-west and left the New Zealand festoon behind. Before this rolling together, the Fiji Islands probably formed a parallel chain near the Tonga ridge, and both together comprised an outer festoon of the Australia-New Guinea block, and, as in the case of all festoons of Eastern Asia, adhered on the outside to the old deep-sea floor, and therefore became detached on their inner margin from the continental block, the inner chain being swept together by the separation of the block. The New Hebrides and the Solomon Islands may be two further echeloned island festoons left stationary on the way.[1] Of the Bismarck Archipelago, New Britain (Neu-Pommern) has, as already mentioned, remained adherent to New Guinea, and been dragged round, whilst on the other side of the great Australian block the spiral curvature of both of the most southerly chains of the Sunda Islands indicates a whirling flow in the sima, similar to that of the Fiji Islands.

No positive picture can yet be obtained, on the basis of the observations made up to the present day, as

  1. Hedley also arrives at the same result on biological grounds, namely, that New Guinea with New Caledonia, the New Hebrides and the Solomon Islands form a unit.