 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.This led Mantovani to propose an Expanding Earth theory which has since been shown to be incorrect.Continental 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".