Sea Floor Spreading Activity Model now you can demonstrate to your class the forces behind continental drift: the creation of new lithosphere at mid-ocean ridges which serves to push the tectonic plates apart. When Alfred Wegener was astute enough to propose continental drift in the early 1900s. He was unable to explain what natural force could move entire continents. Recreate the oceanic expansion of the past 150 million years. You'll be able to retrace the process over the past 150 million years, providing visual 'snapshots' as the earth evolved through the Includes comprehensive teacher's guide.