echanical mechanism capable of moving landmasses as large as continents. The idea of huge bodies of rock plowing through the earth's crust was ridiculous. It wasn't until 1960 when Harry H. Hess hypothesized that cracks in the sea floor open along the crest of mid-ocean ridges where new sea floor forms and spreads out laterally on either side of the crest. Robert S. Dietz took Hess's ideas further, naming the process "sea floor spreading"(which occurs at &a
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