In a later paper he proposed that this occurred by their being dragged towards the equator by tidal forces during the hypothesized capture of the moon in the Cretaceous, resulting in "general crustal creep" toward the equator. Ĭontinental drift without expansion was proposed by Frank Bursley Taylor, who suggested in 1908 (published in 1910) that the continents were moved into their present positions by a process of "continental creep". This led Mantovani to propose an Expanding Earth theory which has since been shown to be incorrect. In Mantovani's conjecture, this continent broke due to volcanic activity caused by thermal expansion, and the new continents drifted away from each other because of further expansion of the rip-zones, where the oceans now lie. įor example: the similarity of southern continent geological formations had led Roberto Mantovani to conjecture in 18 that all the continents had once been joined into a supercontinent Wegener noted the similarity of Mantovani's and his own maps of the former positions of the southern continents. In addition, Eduard Suess had proposed a supercontinent Gondwana in 1885 and the Tethys Ocean in 1893, assuming a land-bridge between the present continents submerged in the form of a geosyncline, and John Perry had written an 1895 paper proposing that the earth's interior was fluid, and disagreeing with Lord Kelvin on the age of the earth. Īlthough Wegener's theory was formed independently and was more complete than those of his predecessors, Wegener later credited a number of past authors with similar ideas: įranklin Coxworthy (between 18), Roberto Mantovani (between 18), William Henry Pickering (1907) and Frank Bursley Taylor (1908). Wegener and his predecessors File:Alfred Wegener 1910.jpgĪpart from the earlier speculations mentioned in the previous section, the idea that the American continents had once formed a single landmass together with Europe and Asia before assuming their present shapes and positions was speculated by several scientists before Alfred Wegener's 1912 paper. This suggested that the oceans were a permanent feature of the Earth's surface, and did not change places Template:Clarify with the continents. This appeared to be confirmed by the exploration of the deep sea beds conducted by the Challenger expedition, 1872-6, which showed that contrary to expectation, land debris brought down by rivers to the ocean is deposited comparatively close to the shore on what is now known as the continental shelf. Dana was enormously influential in America – his Manual of Mineralogy is still in print in revised form – and the theory became known as Permanence theory. … and this will probably prove to the case in Primordial time with the other continents also". This has been proved with respect to North America from the position and distribution of the first beds of the Silurian – those of the Potsdam epoch. In his Manual of Geology (1863), Dana wrote, "The continents and oceans had their general outline or form defined in earliest time. In 1889, Alfred Russel Wallace remarked, "It was formerly a very general belief, even amongst geologists, that the great features of the earth's surface, no less than the smaller ones, were subject to continual mutations, and that during the course of known geological time the continents and great oceans had again and again changed places with each other." He quotes Charles Lyell as saying, "Continents, therefore, although permanent for whole geological epochs, shift their positions entirely in the course of ages." and claims that the first to throw doubt on this was James Dwight Dana in 1849. Kious described Ortelius' thoughts in this way: 1.3 Rejection of Wegener's theory, 1910s–1950sĪbraham Ortelius Template:Harv, Theodor Christoph Lilienthal (1756), Alexander von Humboldt (18), Antonio Snider-Pellegrini Template:Harv, and others had noted earlier that the shapes of continents on opposite sides of the Atlantic Ocean (most notably, Africa and South America) seem to fit together.
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