What are three differences between Continental Drift and Sea-Floor Spreading?
Continental drift was the original theory of continental movement first proposed by Alfred Wegener about 1915 (others preceded him). It was based primarily on the observations that (a) the continents fit together like a puzzle; (b) glaciations had happened in currently warm areas like South Africa; and (c) many fossils over now widely separated areas were the same in earlier periods. It lacked deeper geophysical evidence and had several objections raised including (a) no mechanism to push the continents around was known (spreading wasn’t yet discovered); and (b) it would have required the continents to plow their way through the sea floors because Wegener never proposed “plates” or “subduction” The modern theory is supported by geophysical and oceanographic evidence discovered starting in the 1950’s, and so overcame the objections and became generally accepted.
