A mechanism to move continents was proposed by Arthur Holmes, Scottish geologist in 
1928. He believed heat trapped in the Earth caused convection currents, areas where fluids
 beneath the Earth's crust rise, flow laterally, and then fall. The currents would rise beneath 
continents, spread laterally, then plunge beneath the oceans. (Geologists now know that 
solid rock, not fluids, convect in the mantle).