In the 19th and early 20th centuries, several scientists suggested that the continental masses had the ability to move across the Earth's surface. Paleoclimatic evidence indicates that now tropical regions on some continents had polar climates in the past. This may indicate that these regions were located at different latitudes.
Some continents seem to fit together like a jigsaw puzzle.
Some geologic deposits of rocks on the East coast of North and South America are similar to deposits found on the West coast of Africa and Europe. During the first 30 years of this century the theory of continental drift was actively debated among geo-scientists. However, during the following 30 year period, debate on this theory waned because of the inability of scientists to propose a mechanism to cause the movement of the continental masses. In the 1960s, the theory was resurrected with the discovery of alternating patterns of rock magnetism in surface sea-floor rocks. Scientists had previously discovered that the magnetic orientation of certain crystals in rocks varies from normal to reversed polarity depending on the date that the rock was formed and solidified.