What are some similarities between the theory of continental drift and plate tectonics?
Movement of continents is the biggest similarity. Continental drift postulated that the continents were independent “plates” or masses that drifted slowly through the oceanic crust. The mechanism was never clear, although the results were obvious. That is one reason that continental drift never became an accepted theory. One other similarity is the concept of Holmes (a supporter of Wegener) that developed as an explanation for continental drift of a “conveyor belt” or convection currents which were deep within the earth and moved the continents around. This concept is still alive as part of the theory of plate tectonics, such that deep asthenosphere may have movement of molten or semi-molten crust returning to the mid-ocean ridges from subduction zones where it is melted. However, it is no longer believed to be the single driving force, as Holmes suggested. Plate tectonics involves the same (similar) motion of the plates as continental drift proposed, but uses what are now known plate
