Page:The origin of continents and oceans - Wegener, tr. Skerl - 1924.djvu/76

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52

THE ORIGIN OF CONTINENTS AND OCEANS

the Carboniferous. The great depth of the sea in the western portion of the North Atlantic also seems to indicate that the floor of the sea is more ancient in this region. The contrast of the Spanish peninsula with the opposite American coast has also the same bearing.^[1] The Azores, Canary Islands and Cape Verde Islands are to be conceived as fragments of the continental margin comparable to the pieces of calf-ice in front of a floating iceberg. Thus Gagel also came to the conclusion, in the case of the Canaries and Madeira, “that these islands are pieces broken off the European-African continent, from which they were first separated in comparatively recent time.”^[2]

Farther to the north we find in immediate succession three old zones of folding which extend from one side of the Atlantic to the other, and offer another very impressive confirmation for the assumption of a former immediate contact. The most striking to the eye are the Carboniferous folds, which E. Suess calls the Armorican mountains, and which make the coal deposits of North America appear as the direct continuation of the European. These strongly planed-

↑ This is held by many to be an objection to the displacement theory. The Devonian strata in particular on the North American coast require a greater land mass to the east than could be given by Spain, with its anomalous structure. On the other hand there is the continental shelf to be taken into account, which extends far in front of the American coast. But it is impossible to take up any strong view on this question so long as the size and the outline of the Spanish block in the Devonian period are not known. At present this is impossible, because the Carboniferous as well as the Tertiary folds which traverse the Iberian peninsula in thick swarms would have to be smoothed out. But as long as the displacement theory declares itself for these reasons unable to carry out the reconstruction of this region for the Devonian period, no one can tell whether the American Devonian will afford refutation or confirmation.
↑ C. Gagel, “Die mittelatlantischen Vulkaninseln,” Handb. d. regional. Geologie, vol. vii, Part 4. Heidelberg, 1910.

[1] This is held by many to be an objection to the displacement theory. The Devonian strata in particular on the North American coast require a greater land mass to the east than could be given by Spain, with its anomalous structure. On the other hand there is the continental shelf to be taken into account, which extends far in front of the American coast. But it is impossible to take up any strong view on this question so long as the size and the outline of the Spanish block in the Devonian period are not known. At present this is impossible, because the Carboniferous as well as the Tertiary folds which traverse the Iberian peninsula in thick swarms would have to be smoothed out. But as long as the displacement theory declares itself for these reasons unable to carry out the reconstruction of this region for the Devonian period, no one can tell whether the American Devonian will afford refutation or confirmation.

[2] C. Gagel, “Die mittelatlantischen Vulkaninseln,” Handb. d. regional. Geologie, vol. vii, Part 4. Heidelberg, 1910.

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