According to the theory of plate tectonics, the plates have both oceanic and continental parts, so the Atlantic floor's spreading motion means North America is moving slowly away from Europe and South America from Africa.
(the plates; have; both oceanic and continental parts) (the Atlantic floor's spreading motion; means; North America is moving slowly away from Europe and South America from Africa) Context(the Atlantic floor 's spreading motion means,List([99, 142))):(North America; is moving; slowly away from Europe and South America from Africa)
the Atlantic floor 's spreading motion means,List([99, 142))
the plates the Atlantic floor's spreading motion North America
have means is moving
both oceanic and continental parts
North America is moving slowly away from Europe and South America from Africa
slowly away from Europe and South America from Africa