Page "Continental drift" Paragraph 12

For example: the similarity of southern continent geological formations had led Roberto Mantovani to conjecture in 1889 and 1909 that all the continents had once been joined into a supercontinent ( now known as Pangaea ); Wegener noted the similarity of Mantovani's and his own maps of the former positions of the southern continents.

Through volcanic activity due to thermal expansion this continent broke 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.